Fine grain developers

[Tom Stanworth]

On the subject of Xtol (which I have only used briefly a long time back) I was under the impression that this gives excellent speed (like DDX), fine grain (10% finer than D76 according to Kodak) but that it a rather low acutance developer? Can anyone shed authoritative light on this. Metol, Pyrogallol, Pyrocatechin are acutance agents, but vit C? I have heard plenty of people say such contradictory things regarding Xtol acutance. I realise that dilution willl increase acutance, but what is Xtols general position re acutance?

 

[Tom Hoskinson]

Kodak lists Xtol as an acutance developer in their product literature. By comparison, Kodak does not list D-76 or Microdol-X as acutance developers.

 

[kaiyen]

As you dilute solvent developers, the sulfite goes down and acutance goes up. The FDC lists straight D76 as a solvent developer, but diluted D76 as a non-solvent one. You should get edge effects with diluted D76, in that case, which is why sharpness goes up.

I'm a little unclear myself at what point D76 "makes the change." Certainly by 1+3 the sulfite level is very, very low.

allan

 

[Tom Stanworth]

JDEF,

Have you come up with a Hypercat that does not use sodium hydroxide? I will not use the stuff as a darkroom product, but as I have the chems for Pyrocat, would otherwise be easily able to make up hypercat activator if is is a carbonate. Is there a reason why it has to be NaOH for B? I know this is your preference, but for many it would be a show stopper.

 

[srs5694]

On the subject of Xtol (which I have only used briefly a long time back) I was under the impression that this gives excellent speed (like DDX), fine grain (10% finer than D76 according to Kodak) but that it a rather low acutance developer? Can anyone shed authoritative light on this. Metol, Pyrogallol, Pyrocatechin are acutance agents, but vit C?

I can't really speak to your main question, but you might want to remember that XTOL doesn't use vitamin C as its sole developing agent; rather, it's phenidone (or actually a phenidone variant -- I believe it's Dimezone S) in combination with vitamin C. This is much like D-76 using metol with hydroquinone; the two developers are superadditive and have effects in combination that aren't apparent when they're used alone. Likewise, they interact with other agents in the developer, such as sodium sulfite.

I don't know of an exact published formula for XTOL, but you could check its MSDS sheet. (Freestyle has them available. I'm sure you can find them on Kodak's site, too, but I don't happen to have a URL handy.) I've also seen one attempt at a reverse-engineered XTOL, called XP: http://www.udmercy.edu/crna/agm/phenvitc.htm; see Table 3. I've never used this developer, though.

FWIW, as my first foray into self-created developers, I did a sort of cross between PC-TEA and Rodinal that I call PAC-TEA: 4.5g of para-aminophenol hydrochloride and 9g of ascorbic acid in enough hot (121C) triethanolamine to make 100ml of solution. Dilute ~1:50 for use and develop for a fairly long time -- Rodinal 1:50 times or greater seem to be in order. The result produces noticeably better acutance than XTOL with (to my eye) similar graininess. I haven't yet done any direct comparisons to Rodinal. Note that I don't claim to be a photographic chemist; I was basically just playing around, but I rather like the results. No doubt somebody who knows what s/he's doing could improve this.

 

[gnashings]

What kind of paper surface? Was the negative properly focused and the lens a good one at optimum aperture?

Mediocre lens at f8 (Meopta), focused using grain magnifier onto pearl Ilford multigrade warmtone RC through AGFA #3 contrast filter, and also onto glossy AGFA multigrade RC regular-tone paper. Grain practically invisible to the naked eye. Oh, developed in Dektol 1:1, fixed with Kodafix. I don't recall the exposure times.