It depends. It's not an equation. There are instances where the real speed of the film is much slower than the rated one...
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Black and white reversal processing?
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Given that the Foma reversal kit is good for 8 rolls and it lasts almost 4 years after being opened the first time, you could give it a try.
Proof that the Foma kit lasts for almost 4 years is in this video
Can you please elaborate on what all of this is based on?
That Foma reversal kit is sometimes hard to find in the USA, but right now Freestyle has a kit in stock, but is flagged for low inventory. The Fomapan R they have is reduced in price due to short exp. date. Would it be realistic to assume I can use Fomapan R for a few months or a year past it's expiration date?
If I wanted to try the Foma reversal processing on a second film, in addition to Fomapan R, what would you recommend in either 135 or 120? Do the instructions for the Foma kit give times for any other films besides Fomapan R?
I'd like to send off an order today,
Thank you
The Foma R 100 film is perfectly usable also after years pas the exp date, see the video I linked...
Another film you can use is Fomapan 100 (the plain version, not the R), with the same times used in the R version (except for a shorter 5min bleach).
When you'll able, get the Adox kit: it's as good as the Foma's but at half the cost. Use it with the Scala-50 and life's good!
Seems like everytime I look for Adox products, my normal US suppliers never have any. Right now, Freestyle is showing "out of stock" for the Adox reversal kit, and the Scala 50 film, and the CHS 100 II. B&H has some Adox Scala 50 film, but no Adox reversal chemistry.
Normally, I prefer to shoot films which I can expose at EI 100 (or preferably higher). I might be willing to try some Scala 50 if I can get good results metering at ISO 50. However, if it needs more exposure than box speed, I probably won't have enough patience to shoot it.
No time to watch the video today -- I have too much stuff to do in real life right now. So I will have to wait another day to do more research. Thanks for your advice.
When I lived in the US, I ordered from Fotoimpex in Berlin all the time. It comes fast and is more affordable than you might think if you buy enough to offset the shipping.
two quick points: (I know I am always making points )
the film for making slides from B&W negatives is actually made for making B&W movie prints from B&W Movie Negatives. ORWO PF-2 or PF3 https://www.orwo.shop/products/orwo-pf2-35mm
or kodak 2302/3302 https://www.kodak.com/en/motion/product/post/print-films/black-and-white-2302-3302/
Both are Blue sensitive very slow speed films with No anti halo dyes. Untrafile Online somethins has the Older 5302 on an Acetate base. the curent films are on Polyester.
second point is that film schools often have students shoot Movies on B&W reversal as the Camera stock can be edited and projected. I suspect that they was one of the uses that Kodak expected for the ektachrome Movie film.
the film for making slides from B&W negatives is actually made for making B&W movie prints from B&W Movie Negatives. ORWO PF-2 or PF3 https://www.orwo.shop/products/orwo-pf2-35mm
or kodak 2302/3302 https://www.kodak.com/en/motion/product/post/print-films/black-and-white-2302-3302/
Both are Blue sensitive very slow speed films with No anti halo dyes. Untrafile Online somethins has the Older 5302 on an Acetate base. the curent films are on Polyester.
second point is that film schools often have students shoot Movies on B&W reversal as the Camera stock can be edited and projected. I suspect that they was one of the uses that Kodak expected for the ektachrome Movie film.
When I was a Photo 2 student in the early 1970's, we were given an assignment to create a black & white slide show. The idea was that the slides would stay on the screen for just a second or two. I happened to be going to New York City over spring break and I shot in two locations -- the viewing platform on the Empire State Building and kids riding their bicycles on what looked like a skateboard area in Washington Square Park. I ran across them about a month ago and was pretty blown away by the tonality. So I decided to give reversal processing another go. If you're interested in trying it, have a look at the post I'm about to create called "Reversal Processing Ilford Pan F Plus."
Yes, go for it! (I do stereo; Realist, ViewMaster and Medium Format). I would suggest Scala 50 film in the Adox Scala kit, as the film is tailored for reversal (i.e. clear base, high silver content, resistant to bleach-induced softening of the emulsion).
Yup, Adox HR-50 and Scala 50 is the same film and both are the very best for reversal!
It has very good resolving power, decent contrast, good tonality and holds up large projection sizes with no problems.
The extended red sensitivity cuts through haze like a charm, keeping distant details in landscapes + enables Infrared fun up to 750nm!
It has very good resolving power, decent contrast, good tonality and holds up large projection sizes with no problems.
The extended red sensitivity cuts through haze like a charm, keeping distant details in landscapes + enables Infrared fun up to 750nm!
Yes, of course. As I said, if you take Fomapan R for example, its coating is a mixture of two emulsions. The panchromatic one is about five times more sensitive than the non-sensitised. After a negative image has been developed we bleach it to make it soluble, then dissolve it out of the film. In that instant everything shifts to the heavily underexposed to non exposed fine-grain silver salts. As the complementary to the dissolved negative, exposed to (incandescent) light and developed through a positive image forms.
When you chart densities against amounts of light you will see that about ten times the sensitivity of the crude ISO-10 emulsion is attained, ISO 100.
The goal of such a material is to yield an overall contrast of (gamma log) 1.55 at maximum density of log 2.5 or more. Linearity is less than with print stocks that develop to log 3 easily. Not little of the speed gain relies on clear highlights and shadows that block projection light enough. A muddy image can’t make the lift.
Some people prefer to develop the negative rather contrasty because they lack discipline with the following steps. The bleach bath must be active and oxidation must be whole. The film has a creamy or milky yellowish white aspect after bleaching. A water bath is indicated now to dilute the bleaching agent. Clearing must also be done without compromise, long enough.
The last kick comes from the fixing bath.
Maybe I've got this wrong but afaik clearing bath must be composed of metabisulfite (after a permanganate bleach) and not simple water. That's for a specific reason: not only to eliminate the pink color of the bleach but also to restore the lost sensitivity of the film during the bleach phase.
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Please read slowly enough. I wrote of a water bath after bleaching to thin the bleach and wash some of it from the film before the clearing bath. I use sodium sulfite to clear.
For the second exposure the film is kept under water, clean water.
For the second exposure the film is kept under water, clean water.
I'll elaborate: I propose that two different sensitivity layers don't make a BW film a "true" BW Reversal film. Clear base is far, far more important factor for perceived image quality.
Where can I find info that R100 has two layers? Official datasheet doesn't mention it.
I've heard that FP4+ too has 2 sensitivity layers and it is a very good film for reversal - except the gray Triacetate base in 135 that darkens the image a bit (not a biggie)... Medium format comes on clear triacetate though, making it IDEAL for reversal. Sheet films come on clear PET base and again - superb choice for BW Reversal. If it came on clear base in 135 - it could easily be in my top 3 list of films!
Adox CHS 100II 135 however mentions it - it sports two sensitivity layers and comes on a clear base and has water-soluble AH layer which - unlike R100 - doesn't require bleach stage for AH layer to be removed. And datasheet even recommends it for reversal, and I've tried it, and was impressed!
In my personal experience CHS 100II blows R100 away when it comes to latitude and resolving power, but it has quite pronounced grain. I however welcome that too as grain is a species that some might be missing in a projected slideshow. One must reverse Delta 3200 to have some grain softcore porn. Or shoot some CHS100II
What's the difference what emulsion layer ends up contributing more to the image?
Clear-base single-layer films work just as well if not better, and in case of R100 - much better, because Foma ISO 100 films are quite soft and susceptible to fatal amounts of bleach damage. My main gripe with R100 is its fragile nature, quite frequent coating problems and low resolving power that produces a mushy presentation. Easily seen when projected next to Scala 50, Delta 100, FP4+, CHS100II slides and so on...
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In 35 mm size, slide frames are still made, and they are quite readily available, at least in Europe. For any other format, it is hard to find anything.
Why does everybody read so hastily, superficially?
I wrote Fomapan R for example, its coating is a mixture of two emulsions.
Two preparations get blended. One layer coated.
Maybe it's because your usage of language is/seems weird to me and requires decent mental gymnastics - with all due respect.
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I interpret this as a statement that R100 is the "true" BW reversal film, because 2 different sensitivity layers and some magical speed doubling is going on according to you! Which sounds just plain weird/speculative to me, again - with all due respect.
Soo, are tou saying that R100 has two grain sizes put into a single emulsion/coating or something?
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I'm sorry, but the phrase you quoted is clear enough to me. The only part I disagree with is the "unsensitized" part, which is technically not the right choice of words, given that the silver halides are evidently inherently light-sensitive, although without applying such tricks as dye adsorption, this sensitivity drops off at the blue part of the visible spectrum. Setting a bit of pedantry aside, I understand @Europan's 'unsensitized' to refer to a silver halide that's not treated to expand its inherent blue-sensitivity into longer wavelengths. The notion that these different silver halide components have dramatically different absolute sensitivities is a given; this is how a decently long-scale film is made in the first place. If you work with a single-speed emulsion, the response curve will be very dramatic and virtually unusable for continuous tone recording. How many silver halide components a given emulsion may contain, is a different matter, as is the question which components are coated in which image layer(s). These are product-specific factors.
Valid point, English is not my mothertongue. Still, it takes two to write and read.
We have that expression unsensibilisiert in the German language. It is so understood as that no effort has been undertaken to make a plate or a film (more) sensitive towards longer wavelengths. Sensitive to light we know it is since the discovery by Dr. Johann Heinrich Schulze published in 1719.
Indeed. Also I won't deny that I might've read it hastily, so apologies if hard feelings were encountered
The fact is there's no official technical document by Foma to prove that. Unless you are a Foma engineer I trust only what the manufacturer says and states. All other speculations until proven with verifiable manufacturer datas are useless to me. Sorry.
For the record, it's obvious that any modern B&W film will be a combination of different silver halide configurations that vary in speed and spectral sensitivity. Whether it's very useful to distinguish two, specifically, I couldn't say.
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