View Full Version : Question: Scala as negative and more...
I know some of you here develop Agfa Scala as negative. By doing so, do you get film that has overall grey tone or it becomes like Scala as B&W slide but with inverted black/white?
I want to start developing B&W slide film myself with TMAX 100 and Kodak Direct Positive Film Developer. However, from what I understand, I will never get pure transparent film to create true white when projected, that is very bright highlights remain greyish.
Anyone has actually try this TMAX 100 with Kodak Direct Positive Film Developer? Google search didn't give me any sample photos made this way.
In case you are wondering why I'm willing to take this complicated route, Agfa Scala here in Australia costs AU$90 for 5-roll pack. Development mailer is $13.50 + $3.80 postage per roll. Turn around time is 7-10 days. :(
I tried to develop TMAX 100 in Kodak's kit but I found it difficult. I didn't have the equipment or the patients for the accuracy the kit calls for when developing. Plus, you were kind of limited to the film and speed you could shot at. If I recall, TM100 had to be shot at 50. It probably doesn't help you much, but have you checked out http://www.dr5.com ? They can turn just about any B&W film into a slide.
Also, just curious why you'd want to limit yourself to slides. I use Diafine to develope just about all my B&W and love the stuff because it's so cheap and easy to use. Plus, you get a push on your film speed (Tri-X 400 is now 1600). It's really hard to mess up developing with Diafine.
Hope this helps you some with your issue.
Originally posted by KirkT
Also, just curious why you'd want to limit yourself to slides. I use Diafine to develope just about all my B&W and love the stuff because it's so cheap and easy to use.
It's just because I like seeing photos projected more than any other ways.
Also it is easier with slides to spot which shot is a keeper, worth mounted on double glass mounts and scanned at high resolution, and which ones destined for trash can. I don't make prints/contact sheet out of my negatives so looking at positive films speeds up selection process very significantly.
As far as having to use TMAX at ISO50, it is not a problem for me. I shoot quite a lot of FP4 at ISO64 and I tend to use large aperture even in broad daylight.
The 'overall greyness' is a feature of the film base, so it isn't affected by processing. If Scala were to be developed to a negative, it would also look clear.
Most negative films have a grey or coloured base (Maco Cube has a distinct blue base). The grey base helps to stop light from 'piping' along the film. Some films look coloured because they have sensitising dyes that should be washed out during processing - but these are in the emulsion (coating) not the base.
Strangely enough, slides made from grey-based films do not look grey when you look at them on a lighbox, or project them.
(have to dash off, I'll write more later)
(quickly) Some negative films, like Technical Pan and some of the Maco films, have comparatively clear bases.
I have developed Scala as a negative with great results. The result is a negative not a positive image. The negs look really good and can be pushed ( I have pushed to 400, and pulled to 100). I developed them in Rodinal, you can find the dev. times here: http://digitaltruth.com/devchart.html (great site). Good luck.
The dev chart covers only ISO 200 for Scalai Rodinal, 8 minutes at 18C. What temp/times did you use for push and pull processing?
Scala has a very clear base. The reason I developed as a negative was for the monetary and time of processing reasons you suggest. I've been pleased with home developed Scala negatives because one can get the "Scala" look and tonality with careful scans. If you are projecting, that's another matter. Good luck and please keep us informed how it works out.
Helen, that's very useful information. Thanks a lot. You said Kodak Tech Pan has relatively clear base. I haven't used Tech Pan before and probably never will because it is too slow. How about TMAX 100 compared to Tech Pan? From what I can see, TMAX base is indeed thinner than FP4 so I should get pretty bright and clear highlights if I use TMAX?
Todd and Mike, what's the advantage of Scala (developed into negs) over other B&W negatives? I've used Scala at ISO200 and 400 but they were processed to create slides. Apart from being a slide film, I don't see much difference in tonality compared to FP4 (warning: a newbie here with untrained eyes).
I wrote the speel below before I read your latest post. TMX does have a clearer base than many other neg films - no surprise that Kodak chose it for a dedicated reversal kit.
FP4+ reverses well, and gets a speed increase. Look at the dr5 site mentioned by KirkT for inspiration on which films can be reversed, then try some yourself. dr5 themselves are a bit expensive and very slow. As I mentioned before, the grey base isn't all that noticeable, unless of course you are viewing side-by-side with clear film. The brightest thing you can see becomes your reference for 'white', so if you can't see anything brighter than the projected grey film base it looks white.
Maco PO100c: Maco call this 'orthopanchromatic' because it isn't particularly sensitive to red light. It does reverse quite well though.
Maco ORT25: a slow ortho film. Completely insensitive to red light.
Maco list other clear-based films. Cube 400c (the 'c' is the giveaway) has a blue base, so wouldn't reverse well. The infrared films have a clear base, but are hardly ideal for general photography - nor are they cheap. I've never seen the TP64c available - Maco say that it is panchromatic, and ideal for reversing.
Maco have instructions (http://www.mahn.net/OrtPoP.htm) for reversing on their website. The first developer is a paper developer with potassium rhodanide added as a silver solvent. 'Rhodanide' is the same as 'thiocyanate'. Their method is worth looking at for other films because it would save you from making up developer from scratch. You might try Kodak Polymax T instead of LP-BROM 4. By the way Silverprint (http://www.silverprint.co.uk/) in the UK supply the Speedibrews (http://www.speedibrews.free-online.co.uk/) 'Celer-Reverser' reversal kit, and ship worldwide. Speedibrews claim EI 80 as the usable speed of Tech Pan processed in the kit. Trying that combo has been on my 'to do' list for years.
The potassium bichromate reversing bath Maco suggest is a bit unfriendly to the environment (chromium), and could be replaced by Kodak R-10, which is a permanganate bleach. Later edit (19 Sept): my original statement may be misleading because first developers that include thiocyanate should not be followed by permanganate reversal baths.
If you want lots of info, Kodak publication H-24, module 15 (http://www.kodak.com/US/plugins/acrobat/en/motion/support/processing/h2415/h2415.pdf) is the motherlode. The formulae start on page 25, and include R-10. A permanganate reversal bath was used for the Dufaycolor process back in the thirties - Dufaycolor was a B&W film with a colour mosaic overlay.
A Yahoo search on 'reversal processing' will turn up much other useful information.
Helen thanks heaps. That's very useful info. I just checked my lab website and they do have Maco stuff and PO 100c is also listed.
I need to do some more readings about processing chemicals though and ask the lab people too next time I visit them.
There's a lot of interesting stuff hidden away in Kodak H-24. One thing is T-19 fogging developer. This is a sulphide solution for redeveloping when you can't do the reversal exposure. You end up with sepia slides. The dr5 'Developer 2' may be a variant on this - I don't know, but the similarities are striking. The opportunities for experimentation are enormous. Good luck with it.
Good to hear that you can get PO100c - well worth a try.
My observation over the last year on this forum is that many, if not most, of us are "newbies," at least in some area of photography. And we want to improve our knowledge and skills by reading, observing, experimenting, and sharing new things with others. Apparently those who already know everything have (thankfully) moved over to photo.net. As far as Scala is concerned, I've been through only 5 rolls, 3 of which I've developed myself as negatives in Rodinal. I've also only recently tried FP4+, and I like it too. I don't have any real scientific experiments to show you, but I've posted some Scala images in my gallery if you want to check.
It seems to me that Scala renders the lower tones darker than FP4. On similar subjects, I got this effect from FP4 by adjusting the gray level arrow in PS to the right, until the middle "input level" reads around .65. But I don't think that's the whole story. Scala seems to have a nice way of rendering the subtle differences among the darker grays. The effect is difficult to describe, but there seems to be a "richness" (there's probably a better word, but I don't know it) in the tones that is very appealing. It's difficult to judge web images, so I'd recommend you try some prints. And please keep us all posted on your findings.
Thanks everyone for the reply, especially Helen. In three or four weeks time, I will very likely be asking tons of more questions.
First, I'm going to have to visit some labs to see if they have reversal developing chemicals available. This MACO film is confirmed available but I cannot locate reversal developer yet.
Helen, on MACO website for reversal processing, there is "second exposure" with 100W lamp from c.a. 1m away. What is this second exposure? My guess is this step valid only for paper processing?
What I can gather so far these are the steps I need to do for reversal processing
1. First development with LP-BROM 4 + Potassium Rhodanite or Kodak Polymax T (do I need Potassium Rhodanite added to Polymax T?)
3. Reversal bath with Kodak R-10
5. Clearing bath with Sodium Sulphite
7. Second development
9. Fix (any alternative chemicals to LP-FIX Supra suggested there?)
11. Protection bath (hardener?)
Sorry if the question sounds ridiculous. I've never developed my own film. :D
The second exposure is required for film - though it can be replaced by chemical fogging, or a fogging developer.
Here's how it works (using your step numbers):
1. First developer reduces the exposed grains of silver halide to metallic silver, leaving the unexposed grains as silver halide. This developer needs to be more energetic than normal film developers. My suggestion of Polymax T was just because it is in the same ball-park as LP-BROM 4. Other developers can be used, but I was trying to guess at the most readily available close alternative. Yes, you would have to add the rhodanide/thiocyanate or whatever it is called locally.
But here's something I should have mentioned before: don't use rhodanide/thiocyanate in the first developer if you are going to use a permanganate bleach. See my note on the Ilford instructions below.
3. Reversal bath oxidises all metallic silver to a soluble salt, so that all the metallic silver is removed from film. All the silver halide grains that were exposed have now been removed from the film. All that is left is the grains that received no exposure. There's an alternative to Kodak R-10 here (http://users.frii.com/jkbl/reversal/pf.html) - it doesn't require sulphuric acid.
4. The clearing bath removes all traces of the reversal bath. It's probably a good idea to stick to known reversal bath/clearing bath pairs.
You are now left with unexposed silver halide in the areas that got no exposure when the picture was taken. These get exposed in the second exposure - which just exposes all remaining silver halide grains.
7. The second developer then reduces all these silver halide grains to metallic silver, to leave a positive image.
9. The fix just removes any silver halides that may be left. Any rapid fix should do. There shouldn't be much silver halide left after the second developer.
The alternative to the second exposure and second developer is a fogging developer. This is a reducer that does not discriminate between exposed and unexposed grains of silver halide - it just reduces all the grains.
The first developer needs to develop more of the silver halides than a normal negative developer would - all the silver halide in the brightest highlight must be developed to finality, otherwise it will not be as bright as it could be in hte final slide. This doesn't have to happen with negatives. It does, of course happen with paper developers.
Ilford's instructions (http://www.ilford.com/html/us_english/pdf/reversal_web.pdf) may be better for you, with more readily available chemicals. You may have to adjust the first developer times, but as both Maco and Ilford times are all 'about 12 minutes' that seems like a good starting point.
If you've never developed your own film I wonder if it would be a good idea to start with the simpler negative process just to get the hang of it.
Ilford instruction is indeed much better. I think I've got the overall process of developing the film into slide. Still a bit scared by the "seemed very complex" chemicals though.
Now one last question, for now, fogging chemicals are readily available so I do not have to mix various substances to make one, right?
I'll need to follow Ilford's instruction and substitute the second exposure using light bulb with pouring fogging chemicals into the tank followed by wash?
I will give it a try as soon as I can find a good deal on darkroom equipment. If the first try turns out to be a complete failure, I guess I have to do some revisions and retry.
Warning: Now I'm going beyond my direct experience...
Kodak recommend that the second exposure is an exposure to light in preference to a fogging developer. Remember that fogging developers will fog all undeveloped film, so keep them well away from films that you don't want to be fogged!
Here are some Kodak formulae. I'm assuming that you know how to handle hazardous chemicals.
Kodak fogging developer FD-70a
EASTMAN Sodium Dithionite (90% minimum sodium hydrosulphite)
(Cat. No. P533): 6.0 grams (a flammable solid)
Water: 900 ml
KODAK 'Kodalk' Balanced Alkali or sodium metaborate tetrahydrate: 15.0 grams
EASTMAN 2-Thiobarbituric Acid (Cat. No. 660)*: 0.5 gram (you might not be allowed to buy this)
Add water to make 1.0 litre
Dissolve 6 grams of Part A in 1 litre of Part B just before use - it only has a life of 2 hours after mixing. Discard after one use. If using smaller quantities, proportion accordingly: 3 grams/half litre.
Kodak fogging developer FD-72
Part - A
EASTMAN Sodium Dithionite: 5.0 grams
Part - B
Water: 900 ml
KODAK 'Kodalk' Balanced Alkali or sodium metaborate tetrahydrate: 10.0 grams
EASTMAN L-(+)Cysteine Hydrochloride: 0.3 gram
Add water to make 1 litre
Use: Dissolve 5 grams of Part A in 1 litre of Part B just before use - it only has a life of about 2 hours after mixing. Otherwise, use as FD-70a.
Kodak fogging developer T-19 (also used for sepia toning prints, hence the 'T' designation. It smells of rotten eggs.)
Water: 750 ml
Sodium Sulphide (anhydrous): 20.0 grams
Add water to make 1 litre
Propionic acid 15 ml
Stannous chloride 2 grams
Sodium hydroxide 5 grams (care!)
Water to make 1 litre
T-19 is clearly much easier to make than the other three (just note that it is sulphide not sulphite). T-19 yields a sepia-toned image that is said to be sharp and of low graininess.
Times for all of them are probably about 6 mins at 20°C. You can do this stage in room light, so you can check the progress.
A guy called Ryuji Suzuki has suggested that the readily available Kodak Rapid Selenium Toner could be used as an effective fogging redeveloper - perhaps more effective than T-19, with less sepia tone. I have only read of this as an idea, not as a successful application.
Best of luck with your experiments. I'm sure that the results will be interesting.
If you are using a fogging developer for the second developer (your stage 7) your original sequence looks correct.
I used to do this in my darkroom, years ago, so please excuse me if my memory is a bit faulty, but I think I remember the procedure correctly.
The technique is to use "Litho" film, which you can get in 4x5 cut sheets, make a contact print of a 35mm b/w negative, using the white light from your enlarger, exposure determined by trial and error. Litho film is relatively cheap when compared to common camera films.
The Litho film is then developed in a dilute standard paper developer, such as Dektol, but any continuous tone paper developer should work equally. Since Litho film is not sensitive to red light, you can develop by inspection under a bright red safelight.
Then rinse in a weak acetic acid stop bath, and fix in standard Kodak Rapid Fix, or similar product, wash for five minutes, photoflo and dry. Litho film has such a thin emulsion, that extended washing is not needed.
The result can be beautiful full tonal range b/w slides. (you have to trim the film down to the individual frames to fit in slide mounts with scissors). While Ortho/Litho film normally only has the two tones black and white when processed in Litho developer, it can be made to have continuous tones, if processed in common print paper developer. Ortho/Litho film has a brilliantly clear transparent base, so on properly exposed images, the highlights should be crystal clear.
You can also expose the "Litho" positive by enlargement of your negative, thus resulting in a cropped final slide. Again exposure by trial and error. Remember, you can work under a bright red safelight, so you can see what you are doing, and cut strips of film from a sheet for economical use.
Kodak also used to make a product called "Fine Grain Release Positive" which was a 35mm film designed to make b/w positive images from negatives. It was (or is) the product used to make the prints for b/w cinema films that are projected in theatres.
I believe one could buy this in 100 ft bulk rolls. Again, this is cheaper than camera films. This is another alternative if still available. Again, the film is not sensitive to red light, and can be easily handled and manipulated in the darkroom with a red safelight. Exposure by contact printing from the 35mm negative. Developing similar to the Litho film above.
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