Anchell Darkroom Cookbook POTA dev. mod.

[Murray@uptowngallery]

I have an apparently older version of the Darkroom Cookbook as it's Anchell only and not Anchell & Troop.

It discusses a simple phenidone-based developer called POTA with an extremely wide range but low contrast.

I am curious if anyone has used it for other than it's original purpose (nuclear event captures), what the 'low contrast' means (good for high contrast film? correctable thru intensifying, film toning, anything else?)

There are plenty of other good recipes there and here that already work and don't need any help, but the extreme tonal range sounds like it's a good candidate to play with...maybe following Anchell's general suggestions for which chemicals to add/reduce to alter various characteristics.

The developer is so simple I am tempted to try it with ... nah, maybe I'll try it before I say what unspeakable concoction I have in mind.

Anyway, the previous questions still apply.

Thanks

 

[David A. Goldfarb]

People have used it for Tech Pan as an alternative to Technidol and similarly for normal pictorial results with high-contrast microfilms and also as a compensating developer for high contrast scenes with normal film (like say you wanted N-4, but not such an impossibly short development time as to produce uneven results).

 

[Tom Hoskinson]

Marilyn Levy's POTA

I have an apparently older version of the Darkroom Cookbook as it's Anchell only and not Anchell & Troop.

It discusses a simple phenidone-based developer called POTA with an extremely wide range but low contrast.

I am curious if anyone has used it for other than it's original purpose (nuclear event captures), what the 'low contrast' means (good for high contrast film? correctable thru intensifying, film toning, anything else?)

There are plenty of other good recipes there and here that already work and don't need any help, but the extreme tonal range sounds like it's a good candidate to play with...maybe following Anchell's general suggestions for which chemicals to add/reduce to alter various characteristics.

The developer is so simple I am tempted to try it with ... nah, maybe I'll try it before I say what unspeakable concoction I have in mind.

Anyway, the previous questions still apply.

Thanks

Marilyn Levy formulated POTA for developing Aerial Recon Films.

POTA is from the PHOTO OPTICAL TECHNICAL AREA at Fort Monmouth (where Marilyn Levy worked).

I used POTA in the late 1960s thru the 1970s to develop 70mm Kodak Tech Pan to pictorial contrast levels. However, POTA produces high fog levels.

I tried adding some Benzotriazole to the POTA - I found that the Benzotriazole reduced the fog levels - but it also raised the contrast - out of my desired range. I ended up by adding both Hydroquinone and Benzotriazole - plus some Sodium Carbonate - the resulting developer proved itself to be very fiddly.

Bill Troop has suggested modifying POTA with Glycin - sounds interesting - but I have not tried it - YET.

 

[srs5694]

I have an apparently older version of the Darkroom Cookbook as it's Anchell only and not Anchell & Troop.

Actually, there are two "cookbooks" by Anchell, one of which was co-authored with Troop, which people often confuse:

• The Darkroom Cookbook, 2nd Edition by Steve Anchell, ISBN 0240804236. (Of course, there's also a 1st Edition.)
• The Film Developing Cookbook by Steve Anchell and Bill Troop, ISBN 0240802772.

To the best of my knowledge, Troop was never a co-author of the first of these, even in the first edition; but he's always been a co-author of the second title.

 

[nick mulder]

I've used in 16mm cine developing with some hi-contrast stock '7374' normally used to shoot television screens ...

worked ... no complaints - easy and relatively cheap also

 

[Murray@uptowngallery]

Thanks.

OK, I guess you guys won't laugh too much...

I was thinking of adding coffee as a stain, probably normal (?subjective?) strength to start out (not like Caffenol) in place of water. Hey why not coffee & Vitamin C like Caffenol C? POTAcaffezole?

 

[Tom Hoskinson]

Thanks.

OK, I guess you guys won't laugh too much...

I was thinking of adding coffee as a stain, probably normal (?subjective?) strength to start out (not like Caffenol) in place of water. Hey why not coffee & Vitamin C like Caffenol C? POTAcaffezole?

Adding some Instant Coffee and Vitamin C to POTA makes sense to me. However, you should not see much - if any stain. See:

(there was a url link here which no longer exists)

BTW, the Fort Monmouth photographic chemist (Marilyn Levy) who invented POTA, formulated it for the development of Photo Reconnaissance Film - not for nuke photography.

 

[Gigabitfilm]

Pota is not stable, after few weeks you get loss in developing time, after a half year it will be a problem, the other is its fog. On the other side its simple, ideal for an experiend lab-user. As with D-76 and a wish for a diluted form, do not prepare from powder a direct diluted version, too high fog will occur. Allways prepare the concentrate, then dilute.

Experimenting with other substances could be interesting.

Gigabitfilm started in 1989, together with the ITC in Enschede,Netherland, with aerial photogrammetry films like High Definition Aerial and Panatomic-X-Aerial and other films for machine-developing in low gamma around G=1.0 and high speed in EAFS (effective aerial film speed) 25 or 150. You could say in historical manner, this was the enhanced version of Mrs Levy. To develop in a machine thinbased aerial films is not an amusement. But it was the first time to see a diffraction limited aerial negative, the perfect negative, with a low gamma for altitude of 1000 feet.

 

[Murray@uptowngallery]

Thanks, Tom.

I was quoting or paraphrasing the DRCB I have which claimed the nukevent source. Thanks for straightening that out.

 

[Murray@uptowngallery]

Giga, et al:

What is the benefit of low D in aerial film? More visible detail without 'too dark to see' areas?

Thanks

 

[AgX]

Murray, I guess you meant gamma, not density.

Well, in aero surveying gammas ranging from 0.8 to 1.8 are used, depending on the height above ground, the angle of view, which both relate to the grade of haze, etc.

Airplanes can vary from ultralight to twin jets. And 1000feet is quite low.

 

[Gigabitfilm]

One example: Perhaps you have heard from the famous "Schwebebahn" in Wuppertal-Germany - a metrotrain hanging in the air, built in 1900. To measure any detail for new renovation was to expensive, but with modern aerial mapping cameras (mostly 150mm apo-corrigated on 230x230mm, stop 1:5,6), motionless filmcassette and normal colour film for pictorial use/gamma you can be in the region of wanted exactness (2 centimeter?) in this altitude 1000 feet. I have seen this original in the stereoplotter. With high gamma this would be impossible.

With a high resolution film and with a no-edge effects chemistry you get 10-15% more resolution (and higher speed) in low contrast areas as with normal high gamma chemistry, this was measured in our flights.

Once I had have for a test flight in 1990 too good weather - this leeds to a desaster - without the filling up of the shadow parts thanks the dust in the air like a superbig diffuser, now all shadow parts were 2 up to 3 stops underexposed. Thuch weather is only on 2 or 3 days in the year in Germany - too late I heard how to measure the light quality before enter the plain. When you hold your map over your head and you see a brutal, sharp and deep shadow on the airport-surface, stay at ground or reduce your filmspeed.

 

[Murray@uptowngallery]

Thank you

 

[dancqu]

Adding some Instant Coffee ...

If a Sumatran coffee, using such will only
aggravate the salvaging of Sumatra's few
remaining Rhinos. Elephants there are
also endangered by the expansion
of Coffee plantations.

I suggest an Ethiopian or one from
South America. Aren't dark roasts
best for developing film? Dan

 

[Murray@uptowngallery]

I have nasty tasting 12-cup single-shot brew bags called 'Daily Grind'.

Second worst stuff I ever tasted.

From what I hear in separate email, sulfite opposes coffee's developing ability...all I want is stain cability, but now that I think about it, isn't sulfite one of the things unwanted with staining developer?

There is a POTA modified recipe at Photog. Formulary...someone #8, and Italian name, can't remember at the moment.

I'll avoid Sumatran...especially the weasel-fermented stuff.

 

[Tom Hoskinson]

I have nasty tasting 12-cup single-shot brew bags called 'Daily Grind'.

Second worst stuff I ever tasted.

From what I hear in separate email, sulfite opposes coffee's developing ability...all I want is stain capability, but now that I think about it, isn't sulfite one of the things unwanted with staining developer?

There is a POTA modified recipe at Photog. Formulary...someone #8, and Italian name, can't remember at the moment.

I'll avoid Sumatran...especially the weasel-fermented stuff.

Murray, you are probably referring to DELAGI-8. It is on Page 98 of the 1998 version of ANCHELL and TROOPS FILM DEVELOPING COOKBOOK.

Donald Qualls Reports no detectable stain with his Caffenol, Caffenol C and Caffenol LC+C developers. Donald uses Folgers coffee crystals in these developers (and no sodium sulfite).

If you want stain (and tanning), add some catechol to the recipe (one of Marilyn Levy's experiments) and keep the sodium sulfite level at or below 10 grams per liter - you may also need to add a bit of sodium carbonate.

 

[Murray@uptowngallery]

Thanks, Tom.

Can the stain disappear from fixing with fixer that has the common ingredients added to plain hypo?

I should probably use the Delagi 8 for starters.

 

[Tom Hoskinson]

Image stain and fixers

Thanks, Tom.

Can the stain disappear from fixing with fixer that has the common ingredients added to plain hypo?

I should probably use the Delagi 8 for starters.

Over-Fixing can degrade stain. Normal fixing should not degrade stain.

Murray, Instead of Delagi 8, Why not start with POTA or with Caffenol LC+C?

See: http://silent1.home.netcom.com/Photography/Dilutions and Times.html

Other alternative Developers would be T/O XDR-4 OR TDLC-103 (Page 98-99 of ANCHELL and TROOP'S FILM DEVELOPING HANDBOOK.

See the upper right corner of page 99 for Anchell and Troop's comments on LOW CONTRAST DEVELOPERS