Archived posting to the Leica Users Group, 2007/07/26
[Author Prev] [Author Next] [Thread Prev] [Thread Next] [Author Index] [Topic Index] [Home] [Search]Yup, I've developed a few hundred rolls of Tri-X in Xtol 1:3. It works very well. Other films have a problem at this dilution, Tmax 100 in particular. I found this out the hard way <grin> Steve On 25/7/07 23:00, "pmcc" <pmcc_2000@yahoo.com> wrote: > Len, > > Thanks! I've been using the datasheets in the film > boxes or on the chemistry bags, which tend to be > limited to plain vanilla combos. This appropriately > named little chart seems to be just what I was looking > for. > > I'd like to know if anyone has had hands-on experience > with 1:3 Xtol and common films such as Tri-X. > > Now I'm in really deep. ;-) > > Hazmat Pete (cough), > SF, CA > > --- Leonard Taupier <len-1@comcast.net> wrote: > >> Peter, >> >> Try this. >> >> http://www.digitaltruth.com/devchart.html >> >> I find the information is this chart is very good. >> It pretty much >> covers every film with every developer made. >> >> Len >> >> >> >> >> >> On Jul 25, 2007, at 5:08 PM, pmcc wrote: >> >>> Many thanks Marty. Your posting was interesting >> and >>> helpful even to a non-chemical DIY'er such as >> myself. >>> You've inspired me to get out the hazmat gear, >> roll >>> down my sleeves and go to work. >>> >>> Next question: can you point to or have you >> derived >>> dev'pt times for Xtol at various dilutions -- 1:2 >> and >>> most particularly l:3 -- for various common films? >>> Higher dilutions don't appear on the product data >>> sheet. I've seen frequent discussions of the >> manifold >>> benefits of higher dilution, and it would be great >> to >>> have specifics for starting points. >>> >>> Peter. >>> SF, CA >>> >>> P.S. Hey, this is a non-digital thread -- feels >> like >>> Y2K. >>> >>> >>>> Since there is a bit of interest in chemical >>>> developers after the LuG being almost completely >>>> digital, I thought I'd post this. I wrote it for >> a >>>> newsletter a few of us here in Adelaide write and >>>> send around to each other. A lot of this is >> based >>>> on discussions I've had with LuGer John Black. >> The >>>> formula for JB9 is entirely his - and it's >> elegent >>>> and effective. My own experiments in pH were >>>> initiated after discussions with him and follow >> an >>>> approach I developed from our discussions. >>>> >>>> What follows is a long rant about Kodak Xtol. >>>> >>>> Xtol is probably the best commercially available >>>> developer for 35mm film. Why is it so good? It >> is >>>> an ascorbate developer. Ascorbates are effective >>>> developers of silver? with about the same >>>> efficacy at developing as hydroquinone, but the >>>> development by-products of ascorbates are acidic >> and >>>> act as development inhibitors. These by-products >>>> inhibit development proportionally to exposure >> (i.e. >>>> they inhibit more in dense areas of the negative >> and >>>> less in thinner areas). All ascorbate developers >>>> are, therefore, compensating developers with high >>>> acutance, dependant to some extent on the other >>>> components of the developer. This is good for >>>> tonality. ?Compensation? is claimed for >>>> many developers, but the ascorbate ones are among >>>> only a few where it has any real scientific basis >> or >>>> measureable effect. Kodak?s chemists were >>>> clever with Xtol in several ways beyond using an >>>> ascorbate as the primary developing agent. They >>>> added enough sulfite that the stock! >>>> solution can be used as a grain-reducing >> developer >>>> and as a replenishment developer where the only >>>> replenisher needed is more Xtol. This sulfite >>>> concentration, combined with high activity, >> allows >>>> the developer to be used at dilutions of up to >> 1+1, >>>> 1+3 or 1+5 depending on the film being developed. >>>> This results in enhanced edge effects; it >> maximises >>>> direct development and minimises solution or >>>> physical development (called ?solvent >>>> action?), increasing sharpness. They also >>>> used dimezone-S as the superadditive >> co-developer. >>>> Dimezone-S is a potent developer at low >>>> concentrations (it is, after all, similar to >>>> phenidone) but is easier to dissolve in water >> than >>>> phenidone and is less likely to oxidise once in >>>> solution. Properly mixed Xtol is actually quite >>>> stable ? not Rodinal or PMK Pyro stock stable, >>>> but very good. >>>> >>>> So it?s sharp and has great tonality. Super. >>>> Unfortunately, Xtol got a reputation early on for >>>> both failing catastrophically and leaving odd >>>> artefacts in negatives. So, what gives? Is it >>>> great or does it suck? >>>> >>>> As usual, the answer to both is yes. Xtol fails >> for >>>> two reasons. Ascorbates are strong antioxidants >> and >>>> will scavenge oxygen from solution. >> Unfortunately >>>> the oxidation products of ascorbates do not >> develop >>>> latent silver images and do not present a colour >>>> change in solution. This explains what we >> already >>>> know ? Xtol can die without warning. The other >>>> reason Xtol can fail is that the oxidation of >>>> ascorbates is catalysed by metal ions in water >>>> ? particularly divalent cations (they are the >>>> 2+ ones). These include calcium and iron, the >>>> former common in ?photo grade? chemicals >>>> and the latter common in tapwater. Odd >> donut-shaped >>>> dots on negatives developed in Xtol are seen >>>> sometimes even by people who are careful about >> air >>>> and mixing. I suspect this occurs when impure >>>> dilution water is used and a little particle of >> iron >>>> or some other substance ends up onthe film, >>>> oxidising the ascorbate (and therefore inhibiting >>>> development) forsome distance around. I! >>>> t?s not likely tobe in the original mix >>>> water, since impurities here would probably kill >> the >>>> developer, unless it was mixed and then used >> almost >>>> right away. >>>> >>>> ?Sudden Xtol death syndrome? can be >>>> fixed by keeping bottles completely full and in >> the >>>> dark; ?Xtol spots? can be avoided by >>>> always using distilled or deionised and filtered >>>> water to mix and dilute Xtol. Whether you think >>>> that is worth the bother is up to you. I think >> it >>>> is. >>>> >>>> Can you mix your own Xtol? Sort-of. Mark Rabiner >>>> sent aroundthe basic formula from the patent >>>> (that?s not an MSDS ? an MSDS is the >>>> ?material safety data sheet? and the one >>>> for Xtol can be accessed by going here: >>>> >>> http://www.kodak.com/eknec/PageQuerier.jhtml?pq- >>> >> > path=2879/4648&CID=go&idhbx=msds&pq-locale=en_US&_requestid=2627 >>>> and typing Xtol in the product name box) which >> comes >>>> from the patent. There are, however, indications >>>> from the physical behaviour of Xtol that what >> Kodak >>>> sells is somewhat different. Xtol stock >> solutions >>>> have a pH of 8.2 (what Kodak says); diluted to >> 1+3 >>>> the pH rises to 8.3-8.4. If you make the patent >>>> version, the startings olution is 8.35-8.4 and it >>>> stays fairly stable with dilution. Those pH >>>> differences might not seem like alot, but >>>> they?re important. The version from the >>>> patent is also about 30% less active. What does >> this >>>> tell us? The?weakly alkaline? >>>> (Kodak?s terminology) pH must come from a >>>> buffe! >>>> r, rather than just from metaborate and >>>> metabisulfite. I suspect a small amount of boric >>>> acid (i.e. a metaborate-boric acidbuffer) ? it >>>> makes the most sense chemically; I also have some >>>> supporting data frommass spectroscopy analysis of >>>> commercial Xtol. The EDTA is also probably not >>>> enough on its own to sequester the divalent >> cation >>>> concentrations that Xtol can handle ? I did >>>> this by adding known concentrations of dilute >> cation >>>> solutions to Xtol and self-made analogues and >>>> comparing them. >>>> >>>> So, what can you really do? Buy Xtol, of course. >>>> But if you really want to make a substitute, the >>>> following are options: >>>> >>>> Patrick Gainer?s PC-TEA >>>> 9 grams ascorbic acid >>>> .25 grams phenidone >>>> 100ml triethanolamine (TEA) >>>> Heat the TEA in a pyrex container in themicrowave >>>> for 30 sec.-1 minute, and add the ascorbic acid. >>>> When it isdissolved, add the phenidone. Be >> careful, >>>> because the TEA will get VERY hot. >>>> >>>> Dilute the concentrate 1:50 for use. >>>> >>>> PC-TEA is very good and if you have access to >> cheap >>>> TEA as those in the US do through >>>> www.chemistrystore.com it costs hardly anything. >>>> It?s grainier than Xtol, however, and >>>> doesn?t change its characteristics when >>>> diluted more. It works because it is very >> alkaline, >>>> which I think contributes to the grain >>>> characteristics of films developed in it. Many >>>> other ascorbate formulae have these flaws ? >>>> the absence of the weakly alkaline pH, low >> sulfite >>>> concentration (but withsome sulfite still >> present) >>>> and the increase in activity with dilution are >> what >>>> make Xtol extraordinary. >>>> >>>> John Black?s JB9 is functionally the same as >>>> Xtol, but you mix it yourself. >>>> >>>> The developer is made from 3 liquid concentrates >>>> that are stable for at least 6 months, perhaps a >>>> year (stability testing underway). Store the >>>> solutions in glass bottles, tightly capped. The >>>> solution A should be store in the dark (a closed >>>> cabinet is fine) or in an amber bottle. >>>> >>>> Solution A: (Phenidone, ascorbic acid) >>>> >>>> Phenidone 1.25 gm >>>> Ascorbicacid- 50.00 gm >>>> Ethyelene or >>>> propylene glycol >>>> or dry methanol- 600 ml >>>> >>>> Warm up solvent to hot tap water temp before >>>> dissolvingcomponents. They will dissolve at about >>>> 100-125F. Dissolve ascorbic acid first. >>>> >>>> Solution B: TBE (Tris-borate-EDTA) Sigma cat# >> T3913 >>>> One 1L dry pkg dissolved in 1L DI water >>>> Other buffer concentrates may be substituted if >> made >>>> up to about half molar at a pH of about 8.3. >> Boric >>>> acid-metaborate(BA/Kodalk) would be fine, you may >>>> have to fiddle a bit to get the right pH. >>>> >>>> Solution C: Saturated Na Sulfite solution >>>> Na Sulfite(anhydrous)- 180 gm >>>> Distilled water- 600 ml >>>> >>>> Stir vigorously for about 30 min. Temp will rise >> a >>>> bit and it will almost all go into solution. Let >>>> stand overnight to equilibrate (some will >>>> crystallize out). Use after that. >>>> >>>> JB9 developer: >>>> SolA: 10 ml >>>> SolB: 50 ml >>>> Sol C: 20 ml >>>> Distilled H2O Fill to 250 ml >>>> >>>> Add sol B and C to water first, mix and then A >>>> (protects phenidonefrom oxygen in water). This >> is >>>> enough todevelop 1 roll of 35mm film. Scale up >> as >>>> necessary. Works best as a 1 shot developer at >> 68F, >>>> with moderate agitation. I use 13 min for Tri-X. >>>> >>>> I?ve used the tris and metaborate/boric acid >>>> versions of JB9 and they are functionally >> identical >>>> to Xtol. You can modify the sulfite concentration >> as >>>> you like. One of the best things about JB9 from >> my >>>> perspective is that you can mix the developing >>>> agents to the same concentration as Xtol stock, >> but >>>> keep the same sulfite as Xtol 1+3 (or any other >>>> favoured dilution). This is great for films like >>>> TMX and Acros that run out of developer in Xtol >> 1+3, >>>> or for pushing TMZ. >>>> >>>> Of course the other option is to mix the patent >>>> formula Xtol and addboric acid until the pH of >> the >>>> stock is 8.2, but you may also run into problems >>>> with 'photo grade' chemicals. I really don't >> think >>>> the EDTA alone is enough to chelate ions out of >> the >>>> chemicals or water. >>>> >>>> Also look at US patents # s 3658527, 5376510, >>>> 5503965, 5738979, 6110655, 6489090, 6673528 and >>>> 6686135 in addition to the Xtol patent 5756271. >>>> >>>> I hope this explains a few things and is >>>> interesting. >>>> >>>> Marty >>>> >>>> >>>> -- >>>> We've Got Your Name at http://www.mail.com! >>>> Get a FREE E-mail Account Today - Choose From >> 100+ >>>> Domains >>>> >>>> >>>> >>>> _______________________________________________ >>>> Leica Users Group. >>>> See http://leica-users.org/mailman/listinfo/lug >> for >>>> more information >>>> >>> >>> >>> >>> >>> >> > ______________________________________________________________________ >> >>> ______________ >>> Pinpoint customers who are looking for what you >> sell. >>> http://searchmarketing.yahoo.com/ >>> >>> _______________________________________________ >>> Leica Users Group. >>> See http://leica-users.org/mailman/listinfo/lug >> for more information >> >> >> >> _______________________________________________ >> Leica Users Group. >> See http://leica-users.org/mailman/listinfo/lug for >> more information >> > > > > > ______________________________________________________________________________ > ______ > Sick sense of humor? 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