Which 4x5 B&W films capable of N+/-2 or greater?greenspun.com : LUSENET : Large format photography : One Thread
Tapping the collective wisdom of the large format world....
Ansel Adams comments several times in The Negative that contemporary, thin emulsion films lend themselves easily neither to heavy expansion/contraction, nor to contrast control processes that rely on developer absorbtion into a thick emulsion (e.g., water bath, two soln. development). So, what currently available film and developer combinations can you vouch for going to true N+\-2, 3, or 4 (as opposed to a situation where the change in slope isn't pronounced, and you're essentially pushing the whole characteristic curve up/left)? Is it common to vary developer concentration, holding time constant, to get there? Call it impatience, but I don't particularly look forward to standing in a pitch black room for 20+ minutes(!)
I've heard many good and bad things about T-MAX, depending on whether you call its behavior "sensitive to zone system controls," to paraphrase Kodak's technical literature, or simply erratic and difficult to make consistent, as others have regarding its development time/temp/technique sensitivity. I'd be particularly interested in responses from past or current users of TMX and TMY. Any opionions on Tri-X Pan Professional? And out of curiosity, is the TXT that's currently available even the same formulation that Ansel used?
Thanks for your help,
-- Rick Koo (firstname.lastname@example.org), July 27, 1999
It is my understanding that the TMax films were tested during the development stage by processing in rotary processors, such as the JOBO line. They are very consistant when processed this way, using time and temperature controlled just as you would when processing color films. If you do so, TMax 400 can be developed to Plus and Minus and controlled all the way. It is a good film with a lot of capability for manipulation. But, process it using sloppy technique, be off a touch on temperature or not consistent in your agitation, and it will give you headaches as it just won't produce repeatable results. Use it and process in a JOBO or similar system and you will get the results you can depend on.
-- Dan Smith (email@example.com), July 27, 1999.
In my experience, changing the development time always does change the slope rather than merely shifting the curve. It changes the contrast, with little effect on toe speed.
I have now standardised on Delta 100 or 400 for 5x4, with Paterson FX39 developer (not available in the USA?), giving contrast indexes of about 0.46 to 0.71. For various reasons, I don't use Adams's N+x descriptions, but I suppose this translates to about N-1 to N+2. I haven't experimented sufficiently to find the maximum contrast.
I might be strange, but I enjoy spending 20 minutes in the dark rocking dishes, and vary the time rather than temperature or dilution. I have a Jobo, but I don't use it.
I've never used T-Max in LF, but I have shot a few hundred rolls in 35mm. Even with hand-development, I had no problems with consistency. Consistent development gave me consistent negatives. However, I now prefer the tonality of Delta.
-- Alan Gibson (Alan.Gibson@technologist.com), July 27, 1999.
HP5+ will go +/-2N in PMK. Tech Pan will go -2N in dilute Technidol, and + as much as you want in D76/HC110/Dektol. High Speed Infrared has a strong S-shaped curve, so you can vary contrast with exposure fairly easily (and it responds well to changes in developer for different levels of contrast as well).
-- John Lehman (firstname.lastname@example.org), July 27, 1999.
I think if you have always been picky and exact with your development techniques, then you will have no problems with a film like tmax. I have had no problems getting N+2 out of tmx100 and I don't think it would be a problem getting even more.
Remember, you can always selenium intensify the negative (yes the negative) to get even more contrast.
-- mark lindsey (email@example.com), July 27, 1999.
As others have said, T Max films work well as long as everything remains constant (time, temp, agitation, etc.) Since you talk about standing for 20 minutes in the dark, I assume that you are developing in trays. I've never tried trays but in my darkroom it would be difficult to keep temperatures constant for 20 minutes session after session. With roll film in tanks I found that unless I keep the tank in a water bath at around 64 degrees, the temperature of the developer in the tank increases from 68 degrees to 72 - 75 degrees in the course of eleven minutes. With 4x5 film I use the BTZS tubes in the BTZS water tray and this keeps the developer temperature constant and has the side benefit of permitting the processing to be done in room light.
-- Brian Ellis (firstname.lastname@example.org), July 27, 1999.
For trays I place them on wire platforms (usually used for cooling pie plates or pans etc. --just don't tell my wife where they are!) Then these are placed into print trays with water of the proper temp running through them, this seems to work nicely.
-- mark lindsey (email@example.com), July 28, 1999.
I have found T-Max emulsions quite soft and scratch easily if great care is not taken when processed in a tray. I also don't see as much of a value shift as I would like at N+1 and N+2 with the T-Max. I have long had a favorite film for black and white work, Kodak Super XX, which while still available, is quite hard to find, except through the mail. When processed in HC-110 (Dilution B)this film gives wonderfully consistent results with a very long tonal scale. It responds well to both expansion and contraction developing.
-- Britt Leckman (firstname.lastname@example.org), July 28, 1999.