Graphic Arts Film Question

[Shadowtracker]

Hi all,

I am not certain that I have this question in the correct area here.

I was given some Dupont, Graphic Arts Film with no data sheets for it. I says 738 Cronar, CCS-7, Commercial S Film, either .003 or .007 Thickness and it is 24" x 32" in size (that is correct; Inches).

I can do all kinds of things with it from cutting it down and using it in pinhole cameras, to making 4X5" sheet film out of it to enlarging negatives onto it and then developing the resulting "positive" that is on the film and then projecting that onto paper to make a 'negative' print.

However, having no data sheets, I have no idea what the ISO/sensitivity is or how to use it in terms of exposure times for any purpose. I do plan to take an 'alternative processes' class at some point but would like to get at least a feel for working with this film first.

I have searched the internet for this film type and found Cronar but nothing else and what I can find about it so far is zero, nada, zilch.

Now, I know some of you might want me to send it to you, but my mama didn't raise no fools, and my grandma, she raised me....

Any help is much appreciated.

 

[Rick A]

I dont remember ever using that brand of GA film, but we used to develope other brands (mostly Kodak) in Dektol. You can experiment with different dilutions to get desired results. Note, it will be contrasty. Try your normal film developer as well. We never checked chem temp, used at room temp, and developed by inspection under red safelight.
Try two part lith developer. I vaguely recollect doing some projects that involved that as well.

 

[Shadowtracker]

Thank you very much. That's at least a start for me.

 

[mike c]

I have been using lith film for Freestyle Arstia or something,it is about the speed of regular bromide paper in dektol at a 1:9 dilution.

 

[Shadowtracker]

Ok, that gives me a good idea of how I want to proceed now.

My brother has some glass plate positives from early 1900s and would like to see if I can make some prints from them. I figure I might be able to use this film to contact print from the positive, onto the film, develop film, put that into the enlarger and end up with another positive but on paper.

 

[mike c]

You can do that,would be a little contrasty,mybe try developing the lith in a really dilute solution of hc110 like 1:100 or 1:150 to see if you can get some lower contrast results.

 

[mike c]

Tim,check the package the film came in and see the type of safe light to use,the stuff I have is good with a regular red or oc safe lit so it makes easy to see while you work.

 

[2F/2F]

Here is a good continuous tone formula copped from David Soemarko, and which I first learned from the Christopher James alt. processes book:

Part A:

750 mL hot water
3 g metol
60 g sodium sulfite
3 g hydroquinone
water to make 1 L

Part B:

750 mL hot water
10 g sodium bisulfite
water to make 1 L

Part C:

plain water

I would start with a 1:1:3 ratio of parts A, B, and C, respectively.

Here is the part that makes this developer so good: It is a slow-acting, inherently-low-contrast, highly tweakable developer formula. You can increase the ratio of part A to the rest of the parts to increase contrast at a given development time. You can also increase the ratio of part B to the rest of the solution to lower contrast at a given development time. You can increase the amount of part A to control the developing time. On top of all of this, you can also highly control the contrast via development time.

The drawbacks are:

1. You have to mix it from scratch.
2. It requires constant attention and tweaking, so is not for the lazy.
3. To get the most control over it, you should use development times that are somewhat long compared to how fast this film develops in most developers. I would say based on experience that 5 minutes is a good starting minumum time, and ten minutes is not uncommon IME. As such, it can be slow going in the darkroom.
4. The emulsion is noticeably warm toned with this developer. Not a problem with most processes.

I suggest NOT cutting the film down. You can buy smaller sizes for dirt cheap brand new. Keep the large sizes intact IMHO.

The film keeps very well, so it is probably fine.

 

[Shadowtracker]

yes, it is red safe light safe. Also, I don't mind mixing my own, I'm not lazy. I have 50 sheets of this stuff... One sheet would give me a lot to work with - but I do see your point. Someone else gave me some old 4x5 sheet film that I can toy around with this same idea. Not having worked with anything other than 35mm and 6x6cm, I have a lot to learn so I will probably take your advice about not cutting it just yet.

Thanks for the combination's to try and the dilution ratios for development. This is going to be interesting.

 

[richard ide]

Dupont was my primary film supplier for 15 years. I do not recall that particular film but some things to be aware of are:

FYI It is an .007" base thickness.
It is probably a very high contrast film. Dmin to Dmax of 4+ over a 1 1/2 to 2 stop range or less.
Most likely a rapid access film which means a universal developer (read Dektol) would give you that density.
Whether you can extend the range or not, I do not know.
If the package says it is to be used with red safe light, try an ASA of 4 as a starting point.
A 21 step grey scale is ideal for testing as you can determine the range and exposure corrections from the scale reproduction.

 

[Shadowtracker]

Thank you Richard. That gives me much more specific information. The step scale to test with will be a first step. It may take me a while to get this done because I'm taking two classes at night this semester and a class during the summer as well - so I will have weekends at best to work on this. But the information will be useful for working with this.

 

[ricksplace]

I have shot quite a bit of this type of film in 4X5. I get excellent results shooting it at about iso 6 and developing in Rodinal 1+150 for about 7 min. I usually develop by inspection under a red safelight.