CD4-LC low contrast developer for scanning

[Alan Johnson]

I have found that use of high concentrations of CD-4 reduces the contrast of microfilms [pic] and the contrast is further reduced by minimal agitation every 3 min.
In combination with reduction of contrast in scanner software this enables some microfilms to be shot at box speed.
The CD-4 oxidation products [pic] probably partially block the silver grain surfaces, their composition is discussed by Weissberger:

https://www.jstor.org/stable/27829315?read-now=1&seq=1#page_scan_tab_contents

CD4-LC
Metol........................................1g
Sodium Sulfite anh...........30g
CD-4.......................................12g
Borax........................................4g
Water to...................................1L.....pH~8...............store in glass bottle under inert gas.

The developer is used with 5 inversions at start then 2 inversions every 3rd minute, adding 30% to the times given below, temperature correction according to the chart at Ilfordphoto.com.
Film 1 9m , 2 9.5 min, 3 9.9 min,4 10.5 min, 5 11 min,6 11.5 min, 7 12min, 812.7min, 9 13.2min, 10 14 min, all times for 20C. Reduce times if negatives too dense. Fix 2 min, wash 5min, Photoflo.

Examples:
Adox CMS20 II EI=20:



Spur Ultra R 800 EI=32:

 

[albada]

Alan, those photos are beautiful. Thanks for posting this formula. I have a few questions, if you don't mind:

1. What is the purpose of the Metol?
2. Could the sulfite be increased to improve longevity?
3. You mentioned scanning. Could such negatives be wet-printed with an enlarger?

Mark

 

[Alan Johnson]

Thanks Mark,
The evolution of this formula started from my observation that I could develop microfilm in Crawley's metol based FX-1 but the result was grainy and contrasty. I added a bit more sulfite to reduce the grain and from several sources got the information that p-phenylenediamine produced flat negatives. So I tried the ppd derivative CD-4 for reducing contrast as it is less liable to produce dermatitis than ppd and is easier to buy. It worked. On seeing that pictorial contrast could be obtained with the aid of scanner software I used this formula to develop 10 films in the first batch and am up to 4 in the second batch. That's all I have done.

The CD4-LC formula uses metol not phenidone as I have experienced streaking problems with microfilms and phenidone as discussed in the Film Developing Cookbook 2020 p129-138.
From what I have done I cannot give a definitive answer to your points 2 and 3. All I know is that many have experimented with dilute Xtol etc.
I would guess that with CMS 20 II and Spur Ultra R 800 at box speed a lot of dodging and burning in might be required. However they might be OK for wet printing when developed in CD4-LC shot at lower EI where they likely would give less contrasty negatives.

 

[Alan Johnson]

I tried using a P&S camera [manual setting to 25 ISO, 5 element lens] to shoot Spur Ultra R 800 at EI=25.
It looks like this type of [moderate] high resolution photography should be possible with suitable P&S cameras and fixed lens rangefinders.
The resolution of my scanner along with Flickr Pro is about 80 lppm.

 

[Alan Johnson]

This with Adox CMS 20 II Pro in my P&S camera at EI=25.
At EI =25 this fairly flat scene is satisfactorily captured.

 

[Murray Kelly]

There seems to be a large disparity between the 4g of CD-4, above and elsewhere nd the 12g above.
This is no critixusm - keep up the good work, please

 

[koraks]

There seems to be a large disparity between the 4g of CD-4, above and elsewhere nd the 12g above.

You mean in B&W CD4 developers? I'm not aware of any, although I once did some experiments a few years ago - unpublished, so doesn't really count. I did use something like 5g/liter like in C41 formulas, but development times were pretty long at that concentration.

 

[Murray Kelly]

OK Alan, I get it - one bath v 2 bathm Sorry

 

[Alan Johnson]

Here's what Bill Troop wrote in the Film Developing Cookbook 2020 p134:

"Low contrast developers based on PPD derivatives"
"Grant Haist has suggested that it should be possible to formulate low contrast developers valuable for both document films and tabular grain films by adapting techniques used for developing color negative films."

I managed to get CD4 to work in the 2 bath MeCD4 at 4g/L and subsequently in the single bath CD4-LC at 12g/L.
It is rather unlikely that these guessed amounts should be optimal so anyone who cares to do the work could likely improve on them. However, since I use scanner contrast gradation software to further bend the curves ,giving a satisfactory result, there is not much incentive to try to get more straightening of the curves by modifying the chemistry. There might be more incentive for someone who makes silver gelatin prints.

 

[Andrew O'Neill]

I'll have to give it a go with CSM 20. Thanks!

 

[Andrew O'Neill]

Alan, for CMS 20, what development time did you use? Thanks!

 

[Alan Johnson]

The developer is re-useable for at least 10 films and I have been increasing the time by 5% for each subsequent film starting at 9 min for the first, +30% for minimal agitation every 3 min =11.5 min 20C for the first roll, this to be corrected for temperature, I use the chart at Ilfordphoto.com. Subsequent film times, before correction for minimal agitation and temperature,are given in post 1 above.
Like all sulfite developers that are re-used, some silver is dissolved and precipitates out slowly, making it preferable to filter the developer through cotton wool to avoid spots from silver particles on the emulsion.
The above for CMS 20 II Pro at EI =20.
As usual development time can be varied for contrasty or flat scenes.
These are early days but I hope these times are a guide.
CD-4 appears generally the least likely of the CD series but it may cause an allergic reaction in some individuals.

 

[koraks]

CD-4 appears generally the least likely of the CD series but it may cause an allergic reaction in some individuals.

For what it's worth, I've always found CD4 to be far more irritating than CD3. CD3 I can handle in powder form without any apparent issues, but with CD4, I really need to buckle up. It's fine up to half an ounce or so, but beyond that point, it gets mildly annoying.
Given the way allergic reactions tend to creep up on people, I suppose it's best to limit exposure to especially the powder form of these compounds.

 

[Alan Johnson]

Here is PE on the toxicity:

Replace PPD by CD-3

When used alone PPD causes a severe loss of film speed and acutance. Because of this another developing agent was added to most formulas, metol, glycin, ... Of course this sort of negates the use of PPD in the first place because the grain is increased again. Kodak published a formula for a...

www.photrio.com

 

[Andrew O'Neill]

Thank you, Alan!

 

[destroya]

many thanks for all this work you have done Alan! I now have to dig out my few rolls of CMS 20 and my bulk roll of Tech pan and give them a go with your developer.

john

 

[Alan Johnson]

I tried Ferrania P30 EI=50 in CD4-LC [as per post 1] and in HC-110 1:60 12m 20C agitate only every 3min.

CD4-LC does not require much correction in scanner software:


HC-110 is more contrasty and requires more correction


Ferrania P30 does not resolve as much fine detail as microfilms. It has moderate high contrast and moderate fine grain.

 

[Andrew O'Neill]

Great results, I'd say!

 

[Alan Johnson]

Argenti Nanotomic-X B&W Film Review

Sroyon is here with another thorough film review, this time focusing on Argenti Nanotomic X, a respooled microfilm for 35mm cameras.

casualphotophile.com

Here is some history and philosophy about using microfilms for regular shooting.
Although it refers to Copex Rapid and I have used the slower, more contrasty, CMS 20 II and Spur Ultra R 800 the principle is the same. Specialist developers like CD4-LC should allow shooting at higher EI than using dilute "ordinary" developers, see posts 4 & 5.

 

[Alan Johnson]

The times given in post 1 for the re-use of CD4-LC were found to give rather thin negatives after 10 films and the following are proposed as better:
Film 1 =N min
Film 2 =N + 10% min, Film 3 = N+ 20% min, Film 4 = N +30% min, etc, the time increasing by 10% for each later film. Add 30% for minimal agitation every 3 min.

I tried developing Ilford Ortho 80 plus in CD4-LC with these times, the results were flat with low midtone contrast for this subject, not a good combination for this subject.
Unlike the other films so far tried, Ilford Ortho has only slightly more contrast than ,eg, Tri-X.

 

[Alan Johnson]

My CD4-LC is now 5 months old ,stored under inert gas, and this CMS20 II Pro is the 12th film developed in it ( [ 9m + 110%] x 1.3 = 24.6min 20C )
The negatives are now borderline too thin [more spotting]. This suggests that reuse of CD4-LC should be confined to 10 films.
I used a P&S camera for this which is not particularly sharp.

 

[GLS]

Interesting results, thanks for posting.

One nitpick though: as drawn, the quinone imine oxidation product in your scheme is missing a methyl group.

 

[Alan Johnson]

Interesting results, thanks for posting.

One nitpick though: as drawn, the quinone imine oxidation product in your scheme is missing a methyl group.

Yes, you are right, thanks.
My error was to copy Weissberger p659 not noting that his color developing agent was missing the methyl group present on CD4.

 

[Andrew O'Neill]

I tried CD4-LC with CMS 20, and the results look very promising. I used EI 12, though.

 

[Alan Edward Klein]

Alan, those are particular great scans as well. how big is the original film>? Very detailed scans. Can you describe your scanning process?