Tech Pan 8x10 in a Jobo - Looking for Info

I just acquired 75 sheets of supposedly cold stored Tech Pan in 8x10. My normal mix for my Jobo ATL3 is XTol Replenished. I've never used TP before however, but I've read that POTA is required...you can't get Technodol AFAIK. Photo Formulary sells some, just wondering if I should go that route? Or did people process it with normal developers to get the excessive contrast that can occur...

As an aside...would processing Ilford Direct Positive in POTA result in lower contrast w/o the preflash perhaps?

Thanks!
-Mark

(I also got a 100 sheet box of the old version of TMax 400 in 5x7...100 sheets, what glory days those were!)

Pota is not required....the big thing is contrast and film speed, as TP tends to be very high contrast and low film speed. I used to use TD-3 from the formulary, but also using c41 color film developer, just the developer, also worked fine. Any of the developers for document films should work fine, but many will call for less vigorous agitation than your jobo gives.

General TP principles:

TP can be processed for high (100-200) film speed and high contrast -OR- slow (12-25) film speed and normal contrast. In either case, TP is a continuous tone film and not a document/microfilm.

Technidol, only available on ebay, worked the best for developing. I was never able to get POTA to work well.

The next best developer choice will be Photographer's Formulary TD3. As Peter points out, regular color negative developer also works well. And agitation will be a problem, you may find you get better results in a tray.

Some people claim they like the results with HC-110 and even Rodinal. I found the results execrable but my standard is a 4x5 look from a 35mm negative - no grain and creamy tones. It all depends on the results you are aiming at.

8x10 Tech Pan should be good for rather grainless 6x7.5 foot enlargements (~18x (= 16x24" from 35mm)). If you like looking at murals with a jewelers' loupe then this is the film for you.

I found 4x5 Tech Pan to be rather disturbing. 20x24 enlargements had no grain and thus looked like they were out of focus - grain, even very fine grain, gives the eye something to lock on to and say "that's sharp, I can see something with very fine detail even though it is only the grain."

Done well, 35mm Tech Pan enlargements to 6x9" are hard to tell from LF contact prints.

It's sorta con-tone. Don't expect deep shadows or specular highlights to reproduce well. They won't. It was designed for high contrast development, though it can be reasonably tamed if needed. Formulary has an appropriate developer. And HC-110 1:15 from STOCK (not concentrate) might be acceptable. But it's the high RPM of Jobo development that would worry me - just too much oxidation.

I disagree completely with nolindan about TechPan prints resembling contact prints. Sure, a ton of detail can be packed in using a lens equal to the job. But what particularly graces a contact print is sheer tonal gradation; and Tech Pan prints fail badly in that respect. If you aren't careful, you'll get more of that annoying "soot and chalk" effect that AA so criticized in his handbooks. And believe me, I've seen a LOT of Tech Pan prints from very high-end MF lenses. I've personally worked with it in everything from 35mm to 8x10, but mainly for forensic or technical applications, just like its brand name implies. But it can indeed be fun to experiment with for pictorial purposes, particularly if you stick with scenes of moderate contrast needing a bit of contrast boost, rather than the other way around. Just be aware of its extended red sensitivity too. Start out around ASA 25, or do a bracket test.

I also just acquired some 8x10 Tech Pan so this is quite timely. I use a Jobo but with PC-TEA so my plan was to use a very dilute solution. I’m curious what constitutes high contrast for Tech Pan as I plan to use the negatives for Palladium prints so that may work well.

You can get long expired technidol of ebay, but the prices are outrageous. I imagine the Adotech developer for CMS20 should work well.

No, don't think in terms of the high-contrast potential of Tech Pan. It was designed to behave just like an all-or-nothing ortho litho graphics film, except with extended red pan sensitivity. It was in fact often used for title slides in 35mm format. For realistic Palladium printing you'll still need to tame the contrast down quite a bit. And be aware it's a relatively thin slick film. I advise using Anti-Newton glass in your contact printing frame.

When I was shooting 8x10 TechPan many years ago I processed it in Rodinal 1:100. I agree with Drew that getting the "soot and chalk" effect was annoying. Too many times I got this effect and eventually just went back to shooting FP-4. For some reason the images that I shot on 35mm TechPan film and enlarged never exhibited that "soot and chalk" effect. FYI: Back then my 35mm enlarger had a condenser head. For me using TechPan for photomicrography was an ideal matchup.

Quote:

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Originally Posted by Drew Wiley

I disagree completely with [Nicholas Lindan] about TechPan prints resembling contact prints. ... It was designed to behave just like an all-or-nothing ortho litho graphics film ...

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It seems Drew Wiley and myself have no common ground.

Here is a 6x8" print as an example of gradation. High contrast subject, inside of skylit shopping mall, Nikon FM2, 16mm fisheye, f2.8 @ 1/8, hand held, so not the sharpest. LF Forum doesn't seem to like high res. in-line images so it's a 75dpi scan and should show up somewhat lifesize on a 72 dpi monitor.

Attachment 221785

A center enlargement, 4x - or 24x32" print:

Attachment 221786

Looks like smooth gradation, good shadow detail and nary a sign of soot nor chalk.

Technical Pan seems to have some of its roots in Solar Flare patrol film, hence the extended red sensitivity. It was heavily promoted for microscopy, electron microscopy, and photographing electrophoretic gells (DNA evidence), applications where the subject contrast is low but continuous tone.

The Technical Pan data sheet opens with:

Kodak Professional Technical Pan Film is Kodak's slowest and finest-grained black and white film for pictorial photography (when developed in Kodak Technidol liquid developer). It is a variable contrast panchromatic film with extended red sensitivity; because of it's extended red sensitivity, it yields prints with a gray-tone rendering slightly different from that produced by other panchromatic films. (This is most noticeable in portraits, in which it suppresses blemishes.)

Use this film for pictorial, scientific, technical, and reversal-processing applications. It is an excellent choice for making big enlargements or murals.

The data sheet does say it can be used in microfilm applications when developed in Dektol (!), HC-110 or Versamat (don't know why anyone would want to - TP is much more expensive than any microfilm).

Its variable hig gamma potential is nice for boosting the contrast of color neg film when making interpositives, prior to making internegatives on ordinary pan film like TMX or FP4 in turn form those, resulting is richer scale black and white prints from insufficiently contrasty color neg film. In other words, a superior alternative to panchromatic b&W printing paper, and doable in any size, but a lot of preliminary work.

You can also use it like a near-infrared film using a deep red 29 filter. I once sleuthed art fraud cases by detecting suspicious underpainting using Tech Pan and infrared copystand lamps. But unlike the ghostly flare look of true infrared films, you can get extreme detail. Lots of fun applications.

nolindan - thanks for posting those; but that sure doesn't look like a high contrast setting to me, so those don't disprove anything I stated. Now get out in high altitude where shimmering ice and deep deep shadows under open sun exist in the same scene, like me and a climber buddy of mine addicted to Tech Pan do, and it's unavoidable when comparing our respective prints that my own TMX or ACROS choice captures the full tonal range, while my friend's TP shots exhibit only about a Zone 3 to 7 range, and everything outside of that soon turns into either soot or chalk.

I also happen to have a certain amount of inside knowledge of how Kodak began marketing TechPan for pictorial purposes outside its primary range of technical applications, having had in-person conversations with certain people who wrote some of those sheets. Some wishful thinking involved. One significant problem with 35mm shots is that there are a fair amount of tiny little spots or zits of missing emulsion, evident in areas of continuous tone like skies. I've seen it hundreds of times over. It's a little less evident in 120 roll film due to a lesser degree of magnification, and relatively hard to detect in large format work.

I don't know its specific astro applications. At the time it came out, Kodak was making astro glass plates using original TMax 100 emulsion, far more suited to that particular application. But I'd love to cut down some of my remaining 8X10 stock to 4x5 microscopy size - itself wishful thinking at this point. I'd still haven't purchased a Zeiss trinocular microscope analogous to what I used back in my Microbiology college courses. Otherwise, I might turn the full sheets into highly detailed photogram contact negatives of big interesting leaves and so forth, and just enlarge those normally in one of my 8X10 enlargers. Too many bucket list projects, too little time.