Ferrania P30: curve shape and (un)coated lenses

[Henning Serger]

Hello Henning,

Thank you for your answer. I`m aware that i lack knowledge of film characteristics etc. - but i`m not in shape to work into this now. Which also is a reason i came here to the experts (no sarcasm intended).

Harry, maybe you can or should think about it this way: In the time you have spent here in this thread arguing with others you could have read already half of the excellent book that I've recommended to you . Or looked at hundreds of the sample pictures in the links given to you......

Nevertheless this effect does help to increase shadow density and to make shadow detail better visible, or even visible at all - as there is a threshold. A minimum of light needs to hit the silver grain for the grain to develop at all. If the amount of light hitting the film in the shadows is too small, additional light by flare, pre- or post-flashing can help to lift shadow detail above this threshold - and make detail visible which otherwise was lost.

Maybe we have here your general misunderstanding:
Do you think that lens flare is a kind of "automatic, in-built pre-exposure / pre-flashing"?
Well, at first sight it looks like flare could work that way, but in reality and daily photographic work things are much more tricky, complicated and we must differentiate. Member Film-Niko has already explained correctly the problems of that approach "flare as pre-exposure". But maybe I can explain it a bit more precise, and you will understand better:
In general the threshold effect is correct: A minimum of light is needed for the silver-halide crystals to develop. With the technique of diffuse pre-exposure / pre-flashing you try to get to that point. And you try to get most precisely to that point, because being below that point means no visible effect, and getting too much above the point results are getting worse and quality is diminished.
Problem: This threshold differs a bit from film type to film type. Therefore you have to do tests to find the "sweet spot". As a rule-of-thumb you should start with an additional density of 0.05 to 0.1 logD for the tests. That means an additional amount of light on top of the normally measured exposure for Zone V by an additional diffuse exposure of -4 to -4.5 stops.
Precision is key here.

And that is the big problem with lens flare: No efficient control possible! With the pre-exposure technique you can adjust / regulate the needed amount of additional light very precisely. With lens flare you can't. And in most cases lens flare will be much too strong (the needed light for reaching the threshold is very low), and decrease the picture quality significantly.
I think this picture can illustrate that problem very well: Please scroll down to the bottom with the landscape shot with lens flare:

Nikkor AF 180mm f/2.8 D ED (FX) - Review / Test Report - Analysis

Nikkor AF 180mm f/2.8 D ED Review (FX)

www.opticallimits.com

I do have that lens myself and it is generally really excellent, but with this one weakness of being prone to flare in backlight situations.
But this sample picture demonstrate very well the big problem with flare: When flare occurs, it is almost always much too strong for being useful as a kind of "pre-exposure". For optimal use of the pre-exposure technique relatively little additional light is needed.
And because of its strong and dominant appearance / effect flare is clearly diminishing picture quality. Details are vanishing by "Schleier" / fog / haze / veil and "Überstrahlung" / blooming / flare.

Next problem:
With the pre-exposure technique (if done right) the wanted effect is only visible in the shadows. But lens flare very often occurs not evenly, but in one strong primarily direction. Example:

Mitakon Speedmaster 50 mm f/0.95 review - Ghosting and flares - LensTip.com

Best digital cameras and lens reviews. If you are looking for the information about digital cameras and lenses you are in a right place. We have many professional tests of digital photography equipment.

www.lenstip.com

Further problem:
Supposed we have the absolutely theoretical perfect case / situation that the lens flare is even and has exactly the needed amount of light you want: With the TTL metering that light would also be metered / included and the reading would show the value for Zone V. But that would result in too dark shadows - darker than wanted.
Because the trick with the pre-exposure technique is that the additional diffuse exposure is really additional light measured by an additional metering. It's a first (or second, post-flashing is also possible) additional exposure perfectly matching the main exposure.

More problems: (Non)Availability of uncoated lenses:
As our member flavio81 has absolutely correctly explained single-coating already is very effective. For example when I compare my older single-coated Nikon Series E 1.8/50mm lens to my modern state-of-the-art multi-coated 50mm Nikkor lenses, the differences in lens flare are mostly not visible, and if, they are very small or negligible. You cannot get your wanted result of much more flare-influence with the single-coated Series E lens.

You will need at least uncoated lenses to get a more visible effect. But from what source?
P30 is only available in 35mm (at least so far). So we are talking about lenses for 35mm film. But: The 35mm format had its breakthrough as mass volume photo format after the second world war, it became the by far most used format.
And single-coating was introduced to the market during the 30ies. After WWII coated lenses became standard very quickly. Therefore about (almost) all lenses for 35mm format we have available today are coated.
The Nikon F mount is the oldest ("active") lens mount for 35mm on the market, introduced in 1959. Honestly, I don't know of any uncoated lens I could use with my Nikon cameras.
Therefore simply a lack of lenses is another big problem concerning your idea.

Summary:
If we combine all these factors it is very obvious that your approach / idea is not working as intended in the real photography world / your daily photography. At least not in 99.99% of the cases / shooting situations.

So what about pre- or -post-flashing it? Still i`m aware that this won`t turn a problematic film into a convenient any-light-situation-film, but shouldn`t it help a bit at least? And as pre- or post-flashing apparently is defined a "speed increase", wouldn`t this help to preserve at least some of its box speed?
You`re saying yourself that the current version is very contrasty. Shouldn`t this at least help a bit to counteract contrast loss in the shadows, caused by pre- or post-flashing?

Yes, if properly tested and used (see explanation above) diffuse pre-exposure / pre-flashing can help - a little bit.
You will have a little bit more shadow detail. But not enough at all to compensate the speed difference to the official box speed (which is definitely not correct and much, much too optimistic).
And the too steep curve shape will also not be changed by that, as the curve will only be sligthly parallel shifted (by the value of the additional exposure).
And important to not forget: Pre-exposure needs additional work, and for lots of photographers it might be too cumbersome.

And is the idea that film emulsions may have been matched to single- or uncoated lenses completely off?

Yes, I think so. At least I've never heard of it. It also would not make any economic sense.

I hope with this very detailed and long answer you see more clearly now.

Best regards,
Henning

 

[Harry Callahan]

No, it is not at all irrelevant! Because the curve shape is the main problem of P30. And the curve tells you many of the important characteristics of a film:
Real film speed, shadow detail, midtone detail, highlight detail, tonality.
So the curve shape is P30 main problem, and you have claimed that this main problem can be solved with uncoated or single coated lenses.
But it cannot, not in a proper and satisfying way.

And please remember that it was you (!), and not me who started this discussion (look on page 1): I just reported my test results of this film. Nothing more.
And then you joined in and claimed the old, inferior lens coating technology could solve this main P30 problem.
As you are so extremely convinced that you are right and know much better than all the experienced photographers who have done all these tests, then you at least should finally start going out to do your own test runs and deliver evidence of your claims.
I have used old lenses, and therefore I know that they won't help with this specific problem, in lots of shooting situations they make things even worse. There are good reasons why production of uncoated lenses had stopped decades ago.



Again, as I have already explained that in one of my postings above:
Pre-flashing is not easy, and it only works well and as intended when the amount of light used is extremely precise adjusted to the used materials and shooting conditions.
You have to pre-flash your film with a light intensity which must be measured very, very accurately. You have to do quite a lot of tests and have to use a densitometer. If you use not enough light, then you won't have an effect. If you use too much light, you will destroy the quality by overexposure.

And flare cannot effectively be controlled. In most cases it is so much that the details are destroyed (see the sample pictures in the links).
You cannot vary the intensitiy as with pre-flashing.
And with flare you most often have the problem that it is not evenly spread acros the whole frame, but varying in intensity and direction. And therefore unusable for a targeted shadow zones influence.



No, I did not deny effects in general, I tried to put them into a reasonable relation. Because that is extremely important for the final result.
Lens flare and pre-flashing are partly working in a similar direction, but they are not the same, and they have not end results on the same level and with the same impact. The differences in results are mostly very big. See explanation above.
And just look finally at the flare pictures on the links I have given you. Then you will see immediately.
But your posting behaviour cleary shows that you have not done that. There is clear evidence for my points in hundreds of sample pictures, and you simply ignore that. You don't want to see the facts.

Ok.
Where did i say that it would solve the main problem? Where did i say it would help in a proper and satisfying way? Where did i say it was a proper technical sollution? You could re-read and you would find that i never said so.
I called it a theory right from the start, to show that i DON`T consider myself smarter or better than anyone else.
It`s just an idea i wanted to discuss.

But YOU entirely misunderstood. As you`re again showing right now. You are claiming things i never said, never intended, making me look like a blowhard.

And as i tried again to show you how you reacted to me - you`re doing it AGAIN!!!

I think i now will stop talking to you - also to safe your precious time. This should be in interest of all parties concerned.

 

[Harry Callahan]

Harry, maybe you can or should think about it this way: In the time you have spent here in this thread arguing with others you could have read already half of the excellent book that I've recommended to you . Or looked at hundreds of the sample pictures in the links given to you......



Maybe we have here your general misunderstanding:
Do you think that lens flare is a kind of "automatic, in-built pre-exposure / pre-flashing"?
Well, at first sight it looks like flare could work that way, but in reality and daily photographic work things are much more tricky, complicated and we must differentiate. Member Film-Niko has already explained correctly the problems of that approach "flare as pre-exposure". But maybe I can explain it a bit more precise, and you will understand better:
In general the threshold effect is correct: A minimum of light is needed for the silver-halide crystals to develop. With the technique of diffuse pre-exposure / pre-flashing you try to get to that point. And you try to get most precisely to that point, because being below that point means no visible effect, and getting too much above the point results are getting worse and quality is diminished.
Problem: This threshold differs a bit from film type to film type. Therefore you have to do tests to find the "sweet spot". As a rule-of-thumb you should start with an additional density of 0.05 to 0.1 logD for the tests. That means an additional amount of light on top of the normally measured exposure for Zone V by an additional diffuse exposure of -4 to -4.5 stops.
Precision is key here.

And that is the big problem with lens flare: No efficient control possible! With the pre-exposure technique you can adjust / regulate the needed amount of additional light very precisely. With lens flare you can't. And in most cases lens flare will be much too strong (the needed light for reaching the threshold is very low), and decrease the picture quality significantly.
I think this picture can illustrate that problem very well: Please scroll down to the bottom with the landscape shot with lens flare:

Nikkor AF 180mm f/2.8 D ED (FX) - Review / Test Report - Analysis

Nikkor AF 180mm f/2.8 D ED Review (FX)

www.opticallimits.com

I do have that lens myself and it is generally really excellent, but with this one weakness of being prone to flare in backlight situations.
But this sample picture demonstrate very well the big problem with flare: When flare occurs, it is almost always much too strong for being useful as a kind of "pre-exposure". For optimal use of the pre-exposure technique relatively little additional light is needed.
And because of its strong and dominant appearance / effect flare is clearly diminishing picture quality. Details are vanishing by "Schleier" / fog / haze / veil and "Überstrahlung" / blooming / flare.

Next problem:
With the pre-exposure technique (if done right) the wanted effect is only visible in the shadows. But lens flare very often occurs not evenly, but in one strong primarily direction. Example:

Mitakon Speedmaster 50 mm f/0.95 review - Ghosting and flares - LensTip.com

Best digital cameras and lens reviews. If you are looking for the information about digital cameras and lenses you are in a right place. We have many professional tests of digital photography equipment.

www.lenstip.com

Further problem:
Supposed we have the absolutely theoretical perfect case / situation that the lens flare is even and has exactly the needed amount of light you want: With the TTL metering that light would also be metered / included and the reading would show the value for Zone V. But that would result in too dark shadows - darker than wanted.
Because the trick with the pre-exposure technique is that the additional diffuse exposure is really additional light measured by an additional metering. It's a first (or second, post-flashing is also possible) additional exposure perfectly matching the main exposure.

More problems: (Non)Availability of uncoated lenses:
As our member flavio81 has absolutely correctly explained single-coating already is very effective. For example when I compare my older single-coated Nikon Series E 1.8/50mm lens to my modern state-of-the-art multi-coated 50mm Nikkor lenses, the differences in lens flare are mostly not visible, and if, they are very small or negligible. You cannot get your wanted result of much more flare-influence with the single-coated Series E lens.

You will need at least uncoated lenses to get a more visible effect. But from what source?
P30 is only available in 35mm (at least so far). So we are talking about lenses for 35mm film. But: The 35mm format had its breakthrough as mass volume photo format after the second world war, it became the by far most used format.
And single-coating was introduced to the market during the 30ies. After WWII coated lenses became standard very quickly. Therefore about (almost) all lenses for 35mm format we have available today are coated.
The Nikon F mount is the oldest ("active") lens mount for 35mm on the market, introduced in 1959. Honestly, I don't know of any uncoated lens I could use with my Nikon cameras.
Therefore simply a lack of lenses is another big problem concerning your idea.

Summary:
If we combine all these factors it is very obvious that your approach / idea is not working as intended in the real photography world / your daily photography. At least not in 99.99% of the cases / shooting situations.




Yes, if properly tested and used (see explanation above) diffuse pre-exposure / pre-flashing can help - a little bit.
You will have a little bit more shadow detail. But not enough at all to compensate the speed difference to the official box speed (which is definitely not correct and much, much too optimistic).
And the too steep curve shape will also not be changed by that, as the curve will only be sligthly parallel shifted (by the value of the additional exposure).
And important to not forget: Pre-exposure needs additional work, and for lots of photographers it might be too cumbersome.




Yes, I think so. At least I've never heard of it. It also would not make any economic sense.

I hope with this very detailed and long answer you see more clearly now.

Best regards,
Henning

Thank you again for answering thorough.
My biggest problem is that i`m suffering health problems for quite a while now - so reading into a new topic is very hard at the moment, also doing my own test was very hard. I stated this before.
Years ago i worked into the topic of the zone system, curve, negative density etc. so i should be aware of the basics. I could explain in my own words what the curve is etc. if needed to prove that i know something about it - but for not taking too much time i skip that now, but i will if wished for.

As said before i`m aware that the curve of current P30 is problematic - no shadow detail etc. - but i also said that my theory was to let the curve the way it is and to try to match subject contrast to this troublesome curve.

Exactly as you concluded i assume lens flare to have similar effect as pre- or post-flashing - i just forgot about pre- or post-flashing, otherwise i had started my theory just with that.
And yes, with a lens producing a considerable amount of flare like a single-coated for example, i consider p-flashing to be automatically incorporated. I`m aware that amount of p-flashing needed does differ from film to film, but this could be measured for P30. I`m also aware that p-flashing is more precise than "auto-p-flashing" with lens flare, furthermore i`m aware that controlling lens-flare to achieve proper auto-p-flashing is problematic - but - i still claim there to be means of controlling lens flare to some extend. As there is the aperture and the possibility to attach (uncoated or single-coated) glass to the lens to increase flare production.
I took a look at the pictures you linked, but i also have some experience with multi- and single-coated lenses. Even with an uncoated lens i`ve found that flare doesn`t differ a lot if stopped down sufficiently - f16 or more of course. Therefore i am still convinced that at least some control on lens flare can be taken by the aperture.

I do see the point about inconsistent lens flare, but a f0.95 lens is a physical extreme. To my knowledge there aren`t any for 135 format, but only c-mount - which is the standard mount for 16mm cine-cameras for decades and was taken over for surveillance-video-cameras when these came up. As picture contrast and uneven flare does not matter too much for surveillance, as long as you still receive a recognizable picture on your TV-screen, i at least consider this example you did link as unusual for 135 still. Also you should be aware that most of these super-speed c-mount lenses are single coated only, though they desperately need the best multicoating you can get - though most are not.
Also i`m convinced that using a proper lens hood on this Speedmaster would have helped to reduce the problem of uneven flare a bit at least.
And because of such uneven flare i`d use a lens hood with a single-coated lens, though i want the lens to produce some flare - still i`d use it with a hood all the time to prevent just that effect of uneven flare.

I havn`t thought about TTL-metering so far. You`re right, this really was a problem, as a lot cameras meter aperture full open - when a single-coated lens is producing most flare. Even if the camera can meter aperture set, it still would meter the flare and count it to the metering result - i have to think about this, but you probably had to meter externally to get over this.
On the other hand, as my theory was that P30 might have been formulated for lenses of its time - a lot of cameras did not meter through the lens back then - and especially in cinematography they did not meter through the lens and still don`t today; if they still should shoot on film and not digital.
But you`re truly having a point there.

The availability-problem of uncoated lenses i don`t consider too big. I see your point, but if you should find your lens to produce too few flare, you just could put on (several) single- or even uncoated VU-filters. Some cheapo VU-filters on ebay, going for like 2$ each, only are single coated.
In fact you even could use your modern mc lens and put some single-coated UV-filters for a few bucks on the lens to increase flare-production - and then you had an additional control on flare, as you could reduce numbers of filters if you should have a light situation where too much flare was produced. You also could detach UV-filters for TTL metering and reattach for taking - not convenient of course but possible.
Also because of this i consider there to be quite some possibilities to control lens flare - though p-flashing was (way) more accurate.

I`m aware that even ideal p-flashing would not turn P30 into a convenient film - as i said i also am aware that the curve did not really change. If p-flashed the density in shadows would measure different but the actual behaviour of the film did not change at all - but as p-flashing was "automatic" with a flare-producing lens, it was very easy to achieve and no additional work had to be done. As i said before, p-flashing a 135 film would be pretty problematic; sheet was way easier.
...

I just was "smelling" a pattern there. A lot of older film-emulsions, like Foma for example, tend to have lower response in the shadows. Therefore i started to wonder whether this might have been formulated by intention, to somewhat match single- or uncoated lenses.

But as you made me aware the current version of P30 is not the same as the original P30 -
even if my theory of older films matched to fewer coated lenses was correct, it would not apply here.

Thank you again and best regards,

 

[tih]

This has all been very interesting (and a little bit frustrating when people seemed to think that Harry was making arrogant claims that he really wasn't), but I'm still wondering about the original thought Harry presented.

I don't read lens tests very often, but I have noticed that testers (and users) sometimes talk about how a given lens tends to increase or decrease contrast, so I assume that lens design, coating, etc, can make a difference.

How much, though? Compared to the inherent contrast differences of different films, how large are the contrast differences between lenses - including, to get back to Harry's original idea, old, uncoated lenses as compared to modern ones?

 

[relistan]

This has all been very interesting (and a little bit frustrating when people seemed to think that Harry was making arrogant claims that he really wasn't), but I'm still wondering about the original thought Harry presented.

I don't read lens tests very often, but I have noticed that testers (and users) sometimes talk about how a given lens tends to increase or decrease contrast, so I assume that lens design, coating, etc, can make a difference.

How much, though? Compared to the inherent contrast differences of different films, how large are the contrast differences between lenses - including, to get back to Harry's original idea, old, uncoated lenses as compared to modern ones?

The kind of contrast difference from lenses tends to be “microcontrast” differences and not overall contrast. You can definitely see the difference even between different modern lenses. (E.g. I have both a Summarit-M 2.5/35mm and a Color-Skopar 2.5/35mm and I can usually tell which lens I used). But I’m doubtful it will have any impact on on overall curve. With a film like P30, though, it may help prevent the lack of grayscale gradation for some subjects.

 

[Henning Serger]

Thank you again for answering thorough.

You're welcome, Harry.

As said before i`m aware that the curve of current P30 is problematic - no shadow detail etc. - but i also said that my theory was to let the curve the way it is and to try to match subject contrast to this troublesome curve.

Well, that will be a very different approach:
Then you change the subject contrast / scene contrast by reducing it, so that the contrast range of your scene will be significant lower (and more similar to the very limited contrast range / dynamic range of P30).
That can reduce the contrast problems with P30 to a certain extent.
Methods for reducing the subject / scene contrast are
- fill-in flash (one of the best and most powerful methods - especially with modern cameras and flashes - but unfortunately mostly ignored by film photographers)
- use of reflectors for fill-in light
- graduated ND filter (e.g. for landscapes)
- pol filter.

All that above will give you much, much better results as using an uncoated lens, by the way.

Exactly as you concluded i assume lens flare to have similar effect as pre- or post-flashing - i just forgot about pre- or post-flashing, otherwise i had started my theory just with that.

O.k., fine, then my assessment was right and my reply matches your idea correctly.

And yes, with a lens producing a considerable amount of flare like a single-coated for example, i consider p-flashing to be automatically incorporated.

Unfortunately (for you) it does not work strictly that way, see explanations in my posting.

I`m aware that amount of p-flashing needed does differ from film to film, but this could be measured for P30. I`m also aware that p-flashing is more precise than "auto-p-flashing" with lens flare, furthermore i`m aware that controlling lens-flare to achieve proper auto-p-flashing is problematic - but - i still claim there to be means of controlling lens flare to some extend.

I have my severe doubts concerning such lens flare control. But if you think it's possible, just try. Your curiosity will definitely be "feeded" and satiesfied by that. And that is in most cases a very good thing, because after that you will be more educated, and your mind can come to rest.

I took a look at the pictures you linked, but i also have some experience with multi- and single-coated lenses. Even with an uncoated lens i`ve found that flare doesn`t differ a lot if stopped down sufficiently - f16 or more of course. Therefore i am still convinced that at least some control on lens flare can be taken by the aperture.

Well, but then you will run into another set of severe problems:
- By stopping down to f16 or f22 you will have significantly reduced image sharpness and resolution because of diffraction. Because of that I personally never use f16 or f22 (with 35mm and rollfilm), because for my quality standards the quality loss is too much.
- Such small apertures with great depth of field affect the image aesthetics, and such a great DOF is often not wanted.
- With such small apertures in combination with a low-speed film like P30 you need quite long exposure times, and probably often a tripod. Your flexibility will be limited.

I do see the point about inconsistent lens flare, but a f0.95 lens is a physical extreme.

Well, that was just one example for quick demonstration. If you look at the lens test sources given above, you will find lots of samples also with lenses with max. apertures of 1.4, 1.8, 2.0, 2.8, 4.0 up to 5.6 / 6.3 (zoom lenses).
Uneven lens flare, with main direction determined by the position of the main light source, is a characteristic almost all lenses have. It's very typical.

The availability-problem of uncoated lenses i don`t consider too big. I see your point, but if you should find your lens to produce too few flare, you just could put on (several) single- or even uncoated VU-filters.

With the unwanted results of decreased sharpness and resolution.

I just was "smelling" a pattern there. A lot of older film-emulsions, like Foma for example, tend to have lower response in the shadows. Therefore i started to wonder whether this might have been formulated by intention, to somewhat match single- or uncoated lenses.

No, that has definitely other reasons: The Foma emulsions are quite "simple" single-layer emulsions. Not as sophisticated as Ilford or Kodak BW emulsions. And to achieve the real light sensitivity and shadow detail you want........it's not so easy, and it comes at a cost. Producing such a better emulsion will be more expensive.
There is a reason why the Foma films are significantly cheaper than the competition. You get what you pay for........

Best regards,
Henning

 

[Henning Serger]

I don't read lens tests very often, but I have noticed that testers (and users) sometimes talk about how a given lens tends to increase or decrease contrast, so I assume that lens design, coating, etc, can make a difference.

Well, we have to be precise and have to differentiate:
1. From a physical point of view, lenses cannot increase contrast (in relation to the original, photographed object). After the light has passed through the lens, the contrast on the picture will always be lower compared to the original.
But with an excellent lens this contrast loss is very low or minimal. That is what lens designers try to achieve in general.
With a worse or cheaper lens this contrast loss will be higher.
2. The contrast we are talking about is the so-called micro-contrast = the contrast difference between details of the subject.
And we have to differentiate / separate that from the overall scene contrast / subject contrast which is lighting contrast.

Unfortunately sometimes lens testers are not precise enough in their wording.
And users mix-up these factors very often, quite a lot of them don't know the physical laws behind it. And often very subjective and even esoteric statements are made (also often driven by marketing blah-blah as well).

How much, though? Compared to the inherent contrast differences of different films,

Concerning the "inherent contrast differences of different films":
We should remember that in most cases, with the vast majority of current BW films, the contrast is determined by development time, agitation, dilution of the developer and developer choice.
With any of these standard films I can get all wanted contrasts from very very low to very very high. Just as wanted or needed.

There are (were) some special films with a different inherent contrast behaviour like Foma Retropan 320 soft (low contrast), the aerial films with higher contrast and strong S-shaped HD curves, micro- and document films and of course our "special candidate" and 'Sorgenkind' P30 .

how large are the contrast differences between lenses - including, to get back to Harry's original idea, old, uncoated lenses as compared to modern ones?

The micro-contrast differences can be quite high, and are often easily visible in a direct comparison. I can identify my most modern lenses with excellent micro-contrast quite easily even if I only have the transparencies lying on the light table, and without using the loupe (!!). So I see the difference even at original size of 24x36mm, 4.5x6cm or 6x6cm.
Modern lens design is really amazing, and offers a lot of advantages to film photographers (they are benefitting even more from modern lenses than digital photographers!).

Best regards,
Henning

 

[Harry Callahan]

This has all been very interesting (and a little bit frustrating when people seemed to think that Harry was making arrogant claims that he really wasn't), but I'm still wondering about the original thought Harry presented.

I don't read lens tests very often, but I have noticed that testers (and users) sometimes talk about how a given lens tends to increase or decrease contrast, so I assume that lens design, coating, etc, can make a difference.

How much, though? Compared to the inherent contrast differences of different films, how large are the contrast differences between lenses - including, to get back to Harry's original idea, old, uncoated lenses as compared to modern ones?

Thank you for your appreciation, as i`m aware that this is a "flary" topic i chosen it`s even more difficult to discuss and think about it if someone, well is doing what he`s doing.

I also am no expert on the topic of different lens contrast, but i have found mc lenses to have biggest contrast usually, then come single-coated and then uncoated.
In theory it should be possible to determine differences in contrast between different lenses. I had to think about this first, but you should be able to use the zone system to check for differences in contrast between lenses - and how big these differences are.

 

[Harry Callahan]

You're welcome, Harry.



Well, that will be a very different approach:
Then you change the subject contrast / scene contrast by reducing it, so that the contrast range of your scene will be significant lower (and more similar to the very limited contrast range / dynamic range of P30).
That can reduce the contrast problems with P30 to a certain extent.
Methods for reducing the subject / scene contrast are
- fill-in flash (one of the best and most powerful methods - especially with modern cameras and flashes - but unfortunately mostly ignored by film photographers)
- use of reflectors for fill-in light
- graduated ND filter (e.g. for landscapes)
- pol filter.

All that above will give you much, much better results as using an uncoated lens, by the way.



O.k., fine, then my assessment was right and my reply matches your idea correctly.



Unfortunately (for you) it does not work strictly that way, see explanations in my posting.



I have my severe doubts concerning such lens flare control. But if you think it's possible, just try. Your curiosity will definitely be "feeded" and satiesfied by that. And that is in most cases a very good thing, because after that you will be more educated, and your mind can come to rest.



Well, but then you will run into another set of severe problems:
- By stopping down to f16 or f22 you will have significantly reduced image sharpness and resolution because of diffraction. Because of that I personally never use f16 or f22 (with 35mm and rollfilm), because for my quality standards the quality loss is too much.
- Such small apertures with great depth of field affect the image aesthetics, and such a great DOF is often not wanted.
- With such small apertures in combination with a low-speed film like P30 you need quite long exposure times, and probably often a tripod. Your flexibility will be limited.




Well, that was just one example for quick demonstration. If you look at the lens test sources given above, you will find lots of samples also with lenses with max. apertures of 1.4, 1.8, 2.0, 2.8, 4.0 up to 5.6 / 6.3 (zoom lenses).
Uneven lens flare, with main direction determined by the position of the main light source, is a characteristic almost all lenses have. It's very typical.



With the unwanted results of decreased sharpness and resolution.



No, that has definitely other reasons: The Foma emulsions are quite "simple" single-layer emulsions. Not as sophisticated as Ilford or Kodak BW emulsions. And to achieve the real light sensitivity and shadow detail you want........it's not so easy, and it comes at a cost. Producing such a better emulsion will be more expensive.
There is a reason why the Foma films are significantly cheaper than the competition. You get what you pay for........

Best regards,
Henning

Unfortunately i don`t see how to cut your posting into several parts, making more clear what part i`m answering to.

Yes, you can try to light the subject in a way the film does get along better with - but this i just meant as an example to explain that i don`t want to really change the curve. If you do what you described, fill-in-flash, reflectors etc. you`re not actually changing the shape of the curve. The neg will show more density in the shadows for example, but not because you did increase shadow-response of the film itself, but you did increase light in the shadows - and the same should happen with p-flash or lens flare.

All i wanted to say by that is that i don`t want to change the curve in the first place, while Film-Niko was implying me this again and again and again.

Stopping down to f16 or f22 of course does produce the results you describe, but again was just meant as explanation. All i wanted to point out is that the aperture of a lens can and does affect flare-production - and to such an extend that even an uncoated lens does produce very low flare, similar to a mc lens - if stopped down.

As you already pointed out, an uncoated lens would produce way too much flare for p-flashing and even a single-coated still was too much - i`ve already stepped away from this idea. If i was to try, i did with a mc lens and single-coated filters, as described above.
I havn`t thought about several UV-filters reducing sharpness. Is it that bad?

I see about Foma emulsions etc. .

As i never needed p-flashing a film and never done p-flashing i had a (hopefully) last question, in case you have experience with p-flashing:

How much does p-flashing help? Assuming a contrasty film having no detail in zone I and II, how much could p-flashing bring back? I assume two zones would be impossible and even one zone might be too much, but maybe half a zone?
Also, as p-flashing does reduce shadow contrast:
If you take a modern, normal contrast film, well there wouldn`t be a need to p-flash it - as it already has sufficient response in the shadows. But if you decided to p-flash it though, then you had to be careful to not p-flash too much - because then shadow contrast would be lost.
With a high contrast film on the other hand, could it be that p-flashing was less critical? Because the high contrast film will show greater tonal separation - so maybe a high contrast film does not loose shadow contrast that soon if p-flashed a little too much?
Maybe a high contrast film was more forgiving for too much p-flashing than a normal contrast film?

Best regards,

 

[Henning Serger]

The neg will show more density in the shadows for example, but not because you did increase shadow-response of the film itself, but you did increase light in the shadows - and the same should happen with p-flash or lens flare.

Yes, principally right, but nevertheless there is a big and significant quality difference: With pre-exposure / pre-flashing you add a diffuse light (and not reflected light from your object) to the film just to get to the threshold.
With fill-in flash e.g. you get additional light which is illuminating your object, and this reflected light is recorded on the film - light from the object.
The result of the fill-in flash will look much better. So far my experience with both methods.
Try it, see by yourself. I think that is the best way to understand the different "qualities of light" that does play a role here.

All i wanted to say by that is that i don`t want to change the curve in the first place, while Film-Niko was implying me this again and again and again.

I think he and you have just completely misunderstood each other, certainly an unwanted miscommunication.

I havn`t thought about several UV-filters reducing sharpness. Is it that bad?

Depends on the quality of the filter: I am using UV-filters mostly as a lens protection in critical environmental situations. I am using the best quality filters from German filter specialist B&W (= lens manufacturer Schneider-Kreuznach). With them there is no visible sharpness reduction (and I enlarge my pictures up to 1m x 1.5m in projection).

I see about Foma emulsions etc. .

As i never needed p-flashing a film and never done p-flashing i had a (hopefully) last question, in case you have experience with p-flashing:

Yes, I have a lot of experience with it.

How much does p-flashing help? Assuming a contrasty film having no detail in zone I and II, how much could p-flashing bring back? I assume two zones would be impossible and even one zone might be too much, but maybe half a zone?

It depends on the film, but half a Zone to one Zone is normally realistic. In best cases 1.5 Zones.
It also depends a bit on the object and scene you are photographing (from an esthetical point of view): If you try to get more than one Zone the increased diffuse pre-exposure can be visible as a kind of "fog" in the picture. And how much it is visible depends on the objects you are photographing.

Maybe a high contrast film was more forgiving for too much p-flashing than a normal contrast film?

In principal, yes. Because of the steeper curve shape. As already explained above: For a proper / useful effect with pre-flashing you have to adjust the intensity precisely to the specific film you are using. Tests to find that "sweet-spot" are necessary.

Best regards,
Henning

 

[tih]

Well, we have to be precise and have to differentiate: [...]

Thank you for taking the time to clarify for me - it all makes more sense now.

 

[Harry Callahan]

Yes, principally right, but nevertheless there is a big and significant quality difference: With pre-exposure / pre-flashing you add a diffuse light (and not reflected light from your object) to the film just to get to the threshold.
With fill-in flash e.g. you get additional light which is illuminating your object, and this reflected light is recorded on the film - light from the object.
The result of the fill-in flash will look much better. So far my experience with both methods.
Try it, see by yourself. I think that is the best way to understand the different "qualities of light" that does play a role here.




I think he and you have just completely misunderstood each other, certainly an unwanted miscommunication.



Depends on the quality of the filter: I am using UV-filters mostly as a lens protection in critical environmental situations. I am using the best quality filters from German filter specialist B&W (= lens manufacturer Schneider-Kreuznach). With them there is no visible sharpness reduction (and I enlarge my pictures up to 1m x 1.5m in projection).



Yes, I have a lot of experience with it.



It depends on the film, but half a Zone to one Zone is normally realistic. In best cases 1.5 Zones.
It also depends a bit on the object and scene you are photographing (from an esthetical point of view): If you try to get more than one Zone the increased diffuse pre-exposure can be visible as a kind of "fog" in the picture. And how much it is visible depends on the objects you are photographing.



In principal, yes. Because of the steeper curve shape. As already explained above: For a proper / useful effect with pre-flashing you have to adjust the intensity precisely to the specific film you are using. Tests to find that "sweet-spot" are necessary.

Best regards,
Henning

Yes, fill-in surely will be the better approach - i only tried once, but i`m aware that this is superior to p-flashing the film.
I also assume there to be a communication problem with Film-Niko, but i tried for days to make myself clear - several others did understand what i meant and reminded me of p-flashing. Anyway.

Even on zone is realistic, i hadn`t assumed this. So in theory, as current P30 is a high contrast film, p-flashing was an option and could bring one additional zone... do you know if anyone has tried so far?

Best regards,

 

[Henning Serger]

Thank you for taking the time to clarify for me - it all makes more sense now.

You're welcome.

Best regards,
Henning

 

[Henning Serger]

Yes, fill-in surely will be the better approach - i only tried once, but i`m aware that this is superior to p-flashing the film.

Fill-in light (especially modern state-of-the-art fill-in flash technology and fill-in reflector light) are extremely useful and powerful methods to manage even the most challenging light and contrast situations.
One reason why in my workshops these methods play an important role.
Unfortunately most film photographers don't know anything about these very important methods.

Even on zone is realistic, i hadn`t assumed this.

Well, up to one Zone, see above. It really depends on the film (and developer).

So in theory, as current P30 is a high contrast film, p-flashing was an option and could bring one additional zone... do you know if anyone has tried so far?

Yes, I have. But unfortunately P30 responds not so well to it. Got only about half of a Zone with it.

Best regards,
Henning

 

[Harry Callahan]

Fill-in light (especially modern state-of-the-art fill-in flash technology and fill-in reflector light) are extremely useful and powerful methods to manage even the most challenging light and contrast situations.
One reason why in my workshops these methods play an important role.
Unfortunately most film photographers don't know anything about these very important methods.




Well, up to one Zone, see above. It really depends on the film (and developer).



Yes, I have. But unfortunately P30 responds not so well to it. Got only about half of a Zone with it.

Best regards,
Henning

I`ve heard about 20 years ago about fill-in light. I cannot remember where, but the example pictures did show the interior of a church, where longer exposure time is needed anyway. The photographer used a handheld flash and a very long exposure time - several minutes i think - and walked around and flashed all the shadow areas.
The result was amazing, as you could see a lot more of the interior than without fill-in light - also the picture was color, so using different development to shape the curve was not a (real) option.
So far i`ve only tried once, it was a b&w film only having like 25ASA. Very fine grain, but also pretty long exposure time, so it was better suited for fill-in light. It was an interior subject, rather dark, but probably because of the film also being pretty contrasty, fill-in light didn`t work that well - it was too few fill-in light for the most.
Anyway i consider it a helpful and very interesting technique.

Too bad current P30 does not respond well to p-flashing. As p-flashing probably is a little out of fashion today, as modern films usually show sufficient response in the shadows, it may have been possible that nobody had considered this so far... but i was wrong on this. As you can only get about half a zone with P30, my theory ain`t completely wrong, but wouldn`t help a lot.

Best regards,

 

[Henning Serger]

I`ve heard about 20 years ago about fill-in light. I cannot remember where, but the example pictures did show the interior of a church, where longer exposure time is needed anyway. The photographer used a handheld flash and a very long exposure time - several minutes i think - and walked around and flashed all the shadow areas.
The result was amazing, as you could see a lot more of the interior than without fill-in light - also the picture was color, so using different development to shape the curve was not a (real) option.

Well, that technique is very well known for illuminating very big buildings or places. I've seen quite a lot of it.
But that is also a very special usage of fill-in light. And it is often more a kind of complete lighting than a fill-in light.

Just an example of a very popular usage of fill-in light: Wedding photographers: No matter whether film or digital, lots of wedding photographers are using on-camera fill-in flash for managing contrast. The flash is used in fill-in mode (which means that the flash power is automatically reduced by -2/3 to -1 stop), and the power of the flash is often further reduced manually by the photographer (so that you only have increased shadow detail, and no influence at all on the rest of the picture).
Its an excellent method in wedding photography as you have the general problem that the bride has the very light white dress, and the man has the very dark suit. Getting detail and texture on both is difficult. But not when using fill-in flash (with manually reduced power): You expose on the white dress and get enough detail on the dark suit by the fill-in flash.

At weddings you have (in summer) quite high contrasts outside as well. Can be easily managed by fill-in flash, too.
When I have photographed weddings on film I have used fill-in flash regularly (worked perfect with my F6 and SB-800 flash, also because of the HSS capability, which is also excellent for fill-in flash use).

Just a quick example for fill-in flash below:
Summer, and very high contrast because of mid-day sun. My "Mary Poppins" (the dress and set was a bit inspired by that novel) stood in dark shadow under trees. The green leaves also created a bit of a green colour cast by reflection.
The background was lit by full sun.
I wanted detail on the dress, face and hat, but I also wanted not too much of that and keep the "shadow character" of that scene. And of course I also wanted to remove any green colour cast from the model caused by reflection of the leaves (that is another big advantage of fill-in flash, removing of potential colour casts by white fill-in light).
So I just used fill-in flash with my F6 and SB-800 and reduced it further by about 2 stops (ISO 100/21° reversal film was used, Sensia 100 III).
That resulted in a very natural looking picture with detail from shadows to highlights despite huge scene contrast (the scan is not optimal, orginal is looking better, but I think it is clearly visible what I have described).

Best regards,
Henning

 

[Harry Callahan]

I see. I also once tried this, but as i have no adjustable flash, i increased exposure time so the flash got less obvious.
This also should help on P30 and was easier than p-flashing the film.

Best regards,

 

[Harry Callahan]

It `s been a while since i came up with my idea about uncoated lenses helping on higher contrast films like P30 - unfortunately i did forgot the proper terminology back then, leading to discussion and misunderstanding.

Today i`d like to add another idea, but this time i have the proper terminology right from the start - this should go a lot faster now.

My first idea was that an uncoated taking lens does produce flare, which does pre-flash the film somewhat, leading to brighter shadows on the print.
My next idea now is what would happen if you also did print with an uncoated lens.

An uncoated printing lens also would produce flare, which would pre-flash the photographic paper somewhat - resulting in darker highlights.

With a higher contrast film like P30 you not only can run into problems regarding shadows, no you also can run into problems regarding highlights. An uncoated taking lens should reduce problems in the shadows, while an uncoated printing lens should reduce problems in the highlights.
Therefore uncoated lenses should be beneficial in both aspects.

Now Mr. Serger reported that he already did properly pre-flash P30 and only got half a zone more tonal range. If you now did also pre-flash the photographic paper you also only may gain half a zone more tonal range, but in total it would be on zone more at least.
This of course wouldn`t solve every problem you can run into but it could reduce problems at least.

 

[Henning Serger]

My first idea was that an uncoated taking lens does produce flare, which does pre-flash the film somewhat, leading to brighter shadows on the print.

Harry, the participants here in this thread had explained to you in an extremely detailed way that that will not work as you think.
Uncoated lenses do not generally or automatically produce flare or veiling (from all photos I have ever made with my very old uncoated Agfa lens absolutally none is showing flare or veiling).
Only in certain conditions with a specific lighting / positioning of the light source in relation to the lens axis flare or veiling occurs.

My next idea now is what would happen if you also did print with an uncoated lens.

Even less change would occur because you don't have the conditions producing flare / veiling.

An uncoated printing lens also would produce flare,

No, see above.

With a higher contrast film like P30 you not only can run into problems regarding shadows, no you also can run into problems regarding highlights.

Correct.

An uncoated taking lens should reduce problems in the shadows,

No, just the opposite: Example: My best modern lenses from Nikon and Zeiss with the most advanced coating technology have a significant higher light transmission than for example my old uncoated Agfa lens. Therefore the modern multicoated lenses show better detail rendition in shadows compared to the old uncoated lens.

Now Mr. Serger reported that he already did properly pre-flash P30 and only got half a zone more tonal range. If you now did also pre-flash the photographic paper you also only may gain half a zone more tonal range, but in total it would be on zone more at least.

Besides the fact that all that would need additional work, efforts, time etc. (which could instead be spent on creativity and taking photographs), it also would not really solve the main problem of P30:
It's extremely steep characteristic curve. The additional one Zone you are hoping for is simply not enough at all to tame the very high contrast of this film.
If you want better shadow detail, a better CC and tonality, just use a different film. Period. No matter what you try to do in that regard with P30, the results will be worse / suboptimal compared to the alternatives (different films). Been there, done that.
Don't waste your precious time, that is my advice.

Best regards,
Henning

 

[JPD]

Uncoated lens, a Goerz Dogmar 6,3/135 from 1916, and it has four elements in four groups, so eight glass to air surfaces. Film is Agfa APX 100 in 6,5x9 developed in Rodinal 1+50.

Dark night and very bright lights, and I think the uncoated lens does pretty well. I don't think using it with P30 would change the results compared with a coated lens much.

https://live.staticflickr.com/4028/4704019765_ef55d2fce7_h.jpg

 

[Harry Callahan]

Maybe we have a misunderstanding about the term "flare" here. When i say "flare" i do not mean obvious artifacts around light sources as you can see on the right side of the picture posted by JPD.
When i say "flare" i mean an amount of light which is spread even on the entire negative not showing any obvious effects. I mean a kind of "fog" across the entire negative. I mean some kind of pre-flash on the negative.

And of course uncoated lenses produce more of that. Maybe you did not notice because you always shot at f64, but if you open the aperture wider you will notice drop of contrast on the negative - in comparison to a coated lens. 100 years ago lenses weren`t as fast as today, because lenses do produce more flare when the aperture is wider open. Back then small format lenses had a speed around f3.5, f4.5, because they would have produced too much flare at f2.8 for example. Today f1.8 is about standart because multicoating does reduce flare a lot, so it does make sense to produce faster lenses today.

With an enlarger you have a bright light source, being very close to the enlarging lens and directly hitting it. You cannot do a lot better to produce lens flare. Therefore an uncoated enlarging lens of course will produce more flare than a coated enlarging lens - and even the best coated enlarging lens will produce some flare as it is hit directly by a light source.

I am not talking about micro contrast here. A coated lens surely will produce better micro contrast, but i am in for Zones. An uncoated lens will produce flare which will increase density of the shadows on a negative - and an uncoated enlarging lens will produce flare which will increase density of the highlights on the print.
Uncoated lenses will expand the Zones a certain film has.

As i said before i don`t think that uncoated lenses will solve every problem you may have with P30. I think uncoated lenses could reduce some of the problems - and as uncoated lenses do produce more flare this compensation would be automatic. No additional work, just use uncoated lenses for taking and printing.

Best Regards,

 

[Harry Callahan]

Uncoated lens, a Goerz Dogmar 6,3/135 from 1916, and it has four elements in four groups, so eight glass to air surfaces. Film is Agfa APX 100 in 6,5x9 developed in Rodinal 1+50.

Dark night and very bright lights, and I think the uncoated lens does pretty well. I don't think using it with P30 would change the results compared with a coated lens much.

https://live.staticflickr.com/4028/4704019765_ef55d2fce7_h.jpg

I say that the picture has gotten that good because you did use an uncoated lens. There are bright lights and deep shadows and the uncoated lens did reduce this contrast - so the film could capture this high subject contrast better.
If you had used a coated lens shadows would have been darker and the structure of the roof may no longer be perceivable - while the uncoated lens did shed flare onto the entire film, by that brightening up the dark roof a bit.

P30 is a high contrast film so you better only expose low subject contrast onto it. An uncoated lens does reduce subject contrast, therefore it should be a better match to P30 than a modern mc-lens.

 

[Henning Serger]

Maybe we have a misunderstanding about the term "flare" here. When i say "flare" i do not mean obvious artifacts around light sources as you can see on the right side of the picture posted by JPD.
When i say "flare" i mean an amount of light which is spread even on the entire negative not showing any obvious effects. I mean a kind of "fog" across the entire negative. I mean some kind of pre-flash on the negative.

You are using the wrong technical term. Flare is a phenomenon which is well described in optics.
And as already explained in my posting above, uncoated lenses do not generally / automatically / in all situations produce a "fog" or "pre-flashing" on the negative.

And of course uncoated lenses produce more of that. Maybe you did not notice because you always shot at f64, but if you open the aperture wider you will notice drop of contrast on the negative - in comparison to a coated lens.

As already explained in numerous posts above, contrast is a different characteristic, quite different to flare / veiling.
And also as explained above: For P30 you need more details in the shadows. But your uncoated lenses have a lower light transmission, which is counterproductive for your target.

With an enlarger you have a bright light source, being very close to the enlarging lens and directly hitting it. You cannot do a lot better to produce lens flare.

Sorry, no, that is not how an enlarger works. In my unit e.g. I have a mix-box, and a double condensor. And absolutely no flare.

An uncoated lens will produce flare which will increase density of the shadows on a negative

No, it will not. See all the explanations above. You cannot fool physics.

As i said before i don`t think that uncoated lenses will solve every problem you may have with P30. I think uncoated lenses could reduce some of the problems - and as uncoated lenses do produce more flare this compensation would be automatic. No additional work, just use uncoated lenses for taking and printing.

As you are so totally convinced of your own created laws of physics, then just do it. Stop talking, stop writing, simply start making it.
From my numerous tests with P30 I can ensure you you will waste your time. Using a different film will bring much much better results in that regard with much less hassle.
But it is your time, you can do whatever you want with it.

Best regards,
Henning

 

[Henning Serger]

If you had used a coated lens shadows would have been darker

No, Henry. Modern multi-coatings increase light transmission. That is one main purpose they are designed for. Period.
You should compare a modern coated lens with an old uncoated lens, and then you will see that the modern lens offers better shadow detail.
If all the improved coating technologies of the last decades would have resulted in less shadow detail as you claim, lens designers would definitely not have used them.
And as already explained, I have lots of these different lens types with different coatings. I have the evidence in my work here.

Best regards,
Henning

 

[Harry Callahan]

I am thankful for the answers and i don`t want to waste your time, but what term am i meaning then if "flare" isn`t correct?
Also i am aware that an uncoated lens won`t produce the same amount of flare all the time. It also does depend on the aperture used (lens hood, yellow filter... but it will produce more flare than a coated lens).

You said that you need a light source in a specific position to the taking lens to produce flare. Even with a mc-lens you get flare when shooting direct into the sun for example. If the light source is in the picture you usually get flare.
The same situation does occur with an enlarger and the condenser only will produce more flare as it will produce reflections between film, lens and light source. People use glass-less negative carriers to improve contrast of the print, because a glass carrier also does produce flare.
You cant take a picture, shooting into the sun but through a window. Still you will get flare. It doesn`t matter if there is a window or a condenser between lens and light source, the lens will produce flare.

I already did take some pictures with an uncoated lens and it did increase density of the shadows on the negative. Shadows got brighter on the print, because the uncoated lens did shed flare onto the film during exposure.

Does this mean that a coated lens has higher light transmission on the shadows but not on the highlights?

My health condition does prevent me from testing myself. That's why i have time to have ideas and write about them. I am aware that other films will be (way) less problematic, but i am looking for a way to better get along with P30.

Best regards,