Long Scale films

greenspun.com : LUSENET : B&W Photo - Film & Processing : One Thread

I'm not exactly sure what is meant by "long scale," but I think it has something to do with the variation in light intensitys which a film can capture, and still show good shadow detail but without blocking up the high values. Ilford XP films have always seemed to me to be excellent at this. I've always heard that Verichrome Pan has the longest scale of the conventional films. But what good is a long scale film, if the range of densities exceeds the ability of printing paper to translate it? Could I have some discussion of this, and hopefully examples. This is not a troll. TIA, Bill

-- Bill (bmitch@comcast.net), May 13, 2002


The best is to avoid those vaguely defined terms that are often used connotation ridden. If you consider prints to be final product, you should think about matching with paper.

Films that can record wide range of optical energy exposure can still be scanned and presented on CRT's that have much wider dynamic range compared to reflective prints.

Also, even if the d-range of paper is narrower, you can burn in and dodge out to make use of wider d-range of film.

-- Ryuji Suzuki (rsuzuki@rs.cncdsl.com), May 14, 2002.

Or develop a bit longer and contact print on Pt/Pd. I have seen some lovely 6x6 contact prints on Pt/Pd. Exquisite, long tonal range miniature jewels. The fact that some are mine has, of course, nothing to do with it.


-- RICHARD ILOMAKI (richardjx@hotmail.com), May 14, 2002.

Or develop a bit longer and contact print on Pt/Pd. I have seen some lovely 6x6 contact prints on Pt/Pd. Exquisite, long tonal range miniature jewels. The fact that some are mine has, of course, nothing to do with it.

PS!! Portaits of children on 6x6 Pt/Pd make beautiful gifts for cameos and small bedside frames. Imagine selling a 6x6 print in a pewter frame for $100.

ars gratia pecunia Cheers

-- RICHARD ILOMAKI (richardjx@hotmail.com), May 14, 2002.

>Or develop a bit longer and contact print on Pt/Pd. I have seen >some lovely 6x6 contact prints on Pt/Pd. Exquisite, long tonal >range miniature jewels. The fact that some are mine has, of >course, nothing to do with it.

Any pointer to information on the PT/PD process?

-- Rob (rob@robertgruber.com), May 14, 2002.

I'd define long scale to mean that a greater subject brightness range can be recorded by film A compared to film B, a short-scale film. A comparison could be TMX 100 vs Tech Pan.

TMX can record an SBR of at least 15 stops (that's as far as I measure) with a fairly straight-line response or iow the density increase stays proportionate to the exposure increase. There's no shouldering of any significance within this range. Although the DR may be unprintable in a straight print, if you burn highlights you can still print highlight detail/contrast.

TP otoh can record only about seven stops before abruptly shouldering to D-max. More exposure doesn't result in any more density, therefore there's no highlight detail/contrast and no highlight detail can be printed by burning in. It'll just make a very light detailless grey a darker detailless grey.

So I consider TMX to be a long-scale film and TP to be a short-scale film.

IMHO the ideal film has a rather broad shoulder rather than a straight line or a abrupt shoulder; this would allow a subject with a higher SBR to be recorded and printed in a straight print but would still have sufficient highlight contrast that highlight detail would be visible.

A couple of examples of this are Delta 3200 and Delta 400.

-- John Hicks (jhicks31@bellsouth.net), May 14, 2002.

IMHO, John hit the nail on the head. You want some shoulder and some toe, since you're usually trying to compress the brightness range of the scene into the limited range of the paper *AND* maintain the midtone contrast at a reasonable level. If the midtone contrast is too low, the print will be muddy. Thus my intense dislike of TMX. Even though you can "save it in the darkroom", it's too much work on almost every negative. Processing TMX in dilute XTOL works better, but limits the Dmax. That gives something easier to print with an early shoulder, but also takes away any exposure latitude. Call me a luddite, but I'll take a good old fashioned film with a toe and shoulder any day of the week.

-- Conrad Hoffman (choffman@rpa.net), May 14, 2002.

Thanks to John and Conrad for their very informative comments!

Given those comments, it would seem that the ideal film (for me, at least) would have a very steep incline in the middle of the curve (for sharp definition within the mid-tones), but very gradual shoulders at the high and low ends so as to avoid blocking up the highlights or the shadows. My question is, which mid-speed film and developer combination most closely fits that description?


-- Ben Crabtree (bcrabtree@mn.rr.com), May 15, 2002.

Ben, FP4 would be a good choice. DDX or Xtol would be appropriate developers. If you need more speed try HP5 Plus. For really wide range scenes try some 2 part compensating developers.

-- Henry Ambrose (henry@henryambrose.com), May 15, 2002.

I don't think FP4 Plus has a usable shoulder; neither does HP5 Plus. Plus-X or Delta 400 would be a better choice. Verichrome Pan can also be very good. D-76 1+1 for Plus-X. If you want a shoulder, you have to go to very slow films like APX25 or other old films like Plus-X. Delta 400 and 3200 are exceptions, and some of us here put them in the "old films" category.

I don't find "compensating" formulae work as they are supposed to with films I tried on the market today. Pyrocatechin *might* work better because of its hardening effect. High definition formulae on the other hand seem to work pretty well for what they are supposed to do without compensating effect.

-- Ryuji Suzuki (rsuzuki@rs.cncdsl.com), May 15, 2002.

Ryuji wrote above: "I don't think FP4 Plus has a usable shoulder; neither does HP5 Plus."

Huh? Ilford's published information shows a nice shoulder on both films. My experience indicates this as well. Are we talking about different things?

Try Diaxctol on either film for compensating effect.

-- Henry Ambrose (henry@henryambrose.com), May 16, 2002.

Ilford data I have at hand show nearly straight line at slight bend at midtone depending on how you see it. I do not know if Ilford has made a change in the film recently (because my stock is in bricks I bought many months ago that are frozen). However, I don't know how much I trust Ilford's published data because they tend to oversimplified. Either way, compared to XP2, Delta 3200 and Delta 400, HP5+'s shoulder is almost nonexistent.

If you can make a big shoulder, I would like to know how. One of my ultimate purpose of messing with chemical is to make one film produce straight line and a big shoulder depending on processing (with little hope... I don't know a trick at this moment).

-- Ryuji Suzuki (rsuzuki@rs.cncdsl.com), May 16, 2002.

OK, I take it back about HP5. It does continue straight. It is easy to tame - try Diaxctol. FP4 does shoulder off quite well. As for XP2, its kinda all shoulder! Which is why it does what it does but I've never found anything that matches it. I love XP2. But anyway I was answering Ben's question about a mid speed, long scale film and I think in terms of getting a lot of scene range on the negative FP4 is a good choice.

-- Henry Ambrose (henry@henryambrose.com), May 16, 2002.

Moderation questions? read the FAQ