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View Full Version : T Max 400 Technical Discussion by Sandy King



Michael Kadillak
3-Feb-2006, 17:09
Sandy King was kind enough to provide us with a technical discussion of T Max 400 film and we wanted to provide the link to the J&C web site where this information can be obtained.

http://www.jandcphoto.com/index.asp?PageAction=Custom&ID=26

Enjoy!

Ken Lee
3-Feb-2006, 19:13
Concise, articulate, factual, no hyperbole, nothing vauge... super !

Oren Grad
3-Feb-2006, 19:58
Live link, for your E-Z clicking pleasure:

www.jandcphoto.com/index.asp?PageAction=Custom&ID=26 (http://www.jandcphoto.com/index.asp?PageAction=Custom&ID=26)

Larry Gebhardt
4-Feb-2006, 04:52
Do the times for Grade 2 and 3 Azo look switched to anyone else? Maybe it is too early in the morning.

Amund BLix Aaeng
4-Feb-2006, 07:05
Larry, get a good strong cup of coffee, and look again :-)

Michael Kadillak
4-Feb-2006, 07:39
Larry is correct as unintentionally the times for Azo 2 and 3 need to be modified. Sandy is making the correction and it will be corrected shortly at the J&C web site.

Thanks

sanking
4-Feb-2006, 08:23
Yes, the times were revcrsed, but they have been corrected.

There was also a wrong graph in the article that has been replaced. It was the fourth or last one one so if you downloaded the article earlier you might want to make the substitution.

Thanks for your comments, and hope the information is useful.

Andrew O'Neill
4-Feb-2006, 08:52
Hey Sandy, I use HP5+ and there is not pronounced shoulder in my curves, therefore no muddy high values when I develop it in pyrocat-HD, so your statement is not accurate. My high value curves bend slightly upward.
Tmax 400 in my experience is indeed a unique film. You can really manipulate it's curves in a big way...I just didn't like the look of it.
Really good article, on the other hand!

Michael Mutmansky
4-Feb-2006, 10:14
There is something not quite correct with your curves. The times listed in the response curves above do not match those listed in the N value curves below. I suggest you provide comparable curves to be consistant with your data.

I dispute your characterization that TMY is a better film at 'expansion and contraction' than TXT. While I agree that it is a better film for expansion in that it can obtain a higher gradient before reaching gamma infinity, I don't believe your tests can make any conclusion for contraction conditions, because it provides no information on how contraction is dealt with in a manner that makes it better than any other film available. Most films can handle contraction fairly well, because those conditions are much less demanding of the film gamma-infinity characteristics.

This is especially true in conditions of high contrast. A film like HP5 can be a very effective film in these conditions because the slight shoulder helps tame the severe highlights that can occur otherwise. This lower contrast in the highlights can result in a more satisfying image, because the shadow and midtones are at greater expansion compared to the highlights, which will result in greater microcontrast in the resultant image. Ultimately, the shoulder acts to increase the range of shadow and midtone density at the expense of highlight range. With some alt processes, this is a meaningful difference. For a reference document, refer to 'Whispered Prayers' by Stephen Harrison as an example of HP5 work that utilizes this characteristis to good effect.

The comparison charts you provide also indicate that TXT has an upswept curve characteristic shape, and the TMY has a much straighter line characteristic. These differences may be somewhat dependant on the film/develper combination, but that is another consideration in how the film renders that you have not discussed. In particular, a film with increasing gradient as the TXT has shown may be a more suitable film for conditions where a bit more contrast is desired in the highlight region. This can be of particular importance for pt/pd printers who intend to shoot and develop aiming for a low contrast mix, because the highlight region has especially low contrast. Where a straight-line curve may lose the snap of the specular highlights, an upswept curve may hold them better.

TMY is not the silver bullet of all films, but it is a good film under certain conditions, so let's not get carried away with praise for TMY as the 'one film to bind them together'. It is a worthwhile film to have in the stable, but I don't think it is the answer for all occasions. For alt process shooters, especially with the possibly limited availability of film in the future, I don't think I would be standardizing on this film exclusively, as the keeping properties (and transporting-keeping properties) of this film may cause difficulty in a few years as the B+F increases to a point where it becomes difficult to print without solarization problems becoming apparent. While in this respect, it is no better than TXT, a film like FP4+ is better in this regard, and this consideration should not be overlooked for anyone who is planning to stock a freezer full for future years of shooting.

---Michael

sanking
4-Feb-2006, 10:41
Michael,

I accept your disagreement about contraction. Most films do not have any problem with contraction so my main point here was on expansion.

Regarding HP5+, yes, any film can perform well in some lighting conditions. In fact, there are some conditions where I would prefer a film like BPF that has great latitude but virtually no expansion potential. HP5+ would also do well in contrasty light because of the tendency to shoulder (when developed to a high CI).

And yes, the incresing gradient, or flaring curve of TXT (Efke PL100 also has this) can be a great characteristic for printing with Pt./Pd. bcecause it compensates for the print shoulder in the highlights.

But how much would you want me to say in a short review of less than four pages of text? When you consider the range oif proceses folks are using and the many developers the range of possibilities for a "very best" combination is virtually infinite.

Also, I did not say tht TMY was a silver bullet. However, in my opinion a film with a very straight line curve and tremendous expansion potential is a superior film for most subject, and espeically for alternative processes, and if I could only have one film it would be TMY. But that is my opinion, and note that the title of the review indicated that there would be fact and opinion.

Oren Grad
4-Feb-2006, 10:58
My own interest is not in alt-process, but simply in using standard developers such as D-76 to make negatives that yield "full information" prints in silver with a minimum of printing hassle. For that application, I've found HP5 Plus to be vastly superior to TMY. And I've never gotten a "pronounced shoulder" and "muddy highlight detail" from HP5 Plus, whereas I've found it very difficult to make TMY negatives that have adequate shadow information for my taste without also having excessively dense highlights.

I don't mean to dump on TMY. I think that it is indeed an excellent film for certain uses, I'm in awe of Michael's and John's initiative and hard work in pulling off the TMY ULF order and I'm happy that he has succeeded in preserving a valuable additional option for us. But yeah, even if it wasn't intended that way, the piece did come across as a bit over the top, especially for those of us who aren't committed to alt-process and who don't want anything to do with pyro.

Michael Mutmansky
4-Feb-2006, 11:44
Oren,

The characterization of 'muddy highlights' is purely from the context of alt process printing, as I don't believe HP5 will produce a meaningful shoulder within the range of useful silver densities.

Despite the fact that I am an alt process shooter, I found the article to be a bit in excess as well. What people decide to use for themselves is their decison, and I won't get involved in any advocacy of a particular product, because each photographer will have their own set of requirements for how the film needs to perform. Making a decision on film based on the writings of another photographer is injudicious at best, because without the effort to use and analyze the film, an truly informed decision cannot be made.

All of the film options available out there can be made to work under many different circumstances, and a film that may not seem to be 'ideal' in one aspect can prove to be the preferred film for a photographer in other ways.

I ordered some TMY for my purposes when I absolutely had to have the highest shutter speed possible (which isn't too often at all) and when I am shooting well into reciprocity failure conditions (which does happen sometimes when shooting dark interiors). In both of these cases, I felt that the TMY may be the best solution for my needs. Beyond that, I would not consider TMY as a film to add to my freezer, and if it were to remain unavailable in ULF sizes, I would not be lamenting it's unavailability.

---Michael

Michael Kadillak
4-Feb-2006, 12:04
We requested that Sandy contribute some TMY test data simply because Sandy has an extensive background in sensitometric testing, working with alternative processes and pyro developer research. Cognizant of the fact that there are a number of people that have not worked with TMY in ULF sizes we wanted to get a jump start on assisting people that have ordered this film (or who might consider doing so in the future) with providing some base knowledge of this film in the hands of the consumers or the interested photographer. J&C is comitted to supporting the LF and ULF markets with best products available. Providing some fundamental technical support is a very natural extension of this commitment.

Sandy stated that it was his opinion that TMY would be the best choice for his LF and ULF photography. ULF photographers that have been using what sheet films have been available up to this point and have mastered these materials we are not trying invalidate any comfortability or experience you have gained with these products.

The simple facts are that another viable alternative in sheet film - TMY can now be considered. I do not feel that anyone could disagree with the fact that in a market where many are regularly expressing fear for the future of film, the more options we all have to consider the better. Whatever film you are comfortable with by all means consume it. The most important thing here is to continue to make images and purchase film - any film. That is how we as photographers will insure the future of the art form we so dearly enjoy.

Cheers!

John Z.
4-Feb-2006, 12:30
Beyond just looking at the curves and data, I can say that TMY will be a big help in the field, particularly in two situations, which currently can make photographing very difficult. One is when there is any wind, and a shorter shutter time is needed (it gets windy in Death Valley!), and secondly any instance where reciprocity is encountered.

With Efke film currently, it is not unusual to encounter very very long exposures. One photo I took last week took over an hour at f90, whereas the same photo with TMY would have been a few minutes!

sanking
4-Feb-2006, 12:50
Hi fellows, you don't like TMY, don't use it.

But from my perspective, which is that of an alternative photographer who uses ULF, TMY is my favorite film. I have used and tested a lot of other films, for processes such as AZO, carbon, kallitype and Pt./Pd., but TMY is my favorite, primarily because of its high ASA, great expansion potential and straight line curve. I am definitely an advocate of it, especially for processes that require negatives of high average gradient. And I say that, not totally ignorant of the characteristics of the other films I have used and tested. I would certainly recognize and acknowledge that there are circumstances where another film might be the better choice. And for that very reason I use on a regular basis a number of other films in LF and ULF, including FP4+, Efke PL 100 and HP5+.

But no one is forcing you to agree with me, and indeed if you do you will be in good company. Dick Arentz is probably the foremost Pt./Pd. printer in the world and he prefers TRI-X 320, and I am sure not going to argue with the quality of his work.

sanking
4-Feb-2006, 13:46
John,

Your experience closely parallels mine, and is one of the reasons high effective film speed, all other things being at least equal, is such an important consideration in ULF work. I tend to shoot a lot in low lighting conditions and almost inevitably get into reciprocity failure situations with ASA 100 films such as FP4+ and Efke PL 100, which are otherwise really nice films for alternative work as they have a great deal of expansion potential.

Most people won't remember Royal Pan, but when I first started working with ULF cameras someone sold me a few boxes of it. It was, as I recall ASA 800, and the speed was a great advantage in the field, and for contact printing grain was fine. I would sure like to have some of that stuff again.

Michael Mutmansky
4-Feb-2006, 15:28
One photo I took last week took over an hour at f90, whereas the same photo with TMY would have been a few minutes!

John, that's one of the two situations where I find this film useful. However, under normal shooting, the speed difference isn't going to get an exposure from 1/2 or one second up to the point where you can disregard wind, so it is of little utility except when the shooting becomes very long, or in a narrow illuminaince range where the two stops will benefit the shooter by permitting them to disregard the wind. Beyond that, I believe the speed diffferences are greatly overstated.

The speed and reciprocity is a double-edged sword, as it makes it harder to have a long exposure when you desire one, and inherent to the reciprocity characteristic is the greater propensity for the film to fog with time, heat, and rediation. This means the film won't keep as well, and travel with it will be somewhat more perilous. Flying across the ocean will often introduce one or two x-ray doses, plus the 6 or 8 hours of high altitude exposure, which can be quite considerable if there is any solar activity at the time. Then, you have to get the film back...

As I said, I am not advocating any specific film, and I never said I didn't like TMY, but I don't believe that it is the answer to all ULF photographer's prayers. With people talking of stocking up freezers, I think it is in their best interests to understand what this film may be like in 5 or so years. I'm not planning to have mine in the freezer that long, but if I do, I've begun to change my process a bit to mitigate the problems that probably will arise with using long-stored film (of any brand)

---Michael

John Z.
4-Feb-2006, 15:41
Good points to remember, thanks. Howard Bond did a lot of his church interior portfolios in England with TMY, and has talked about the benefits of the low reciprocity. I plan to freeze the film I don't use, but also probably rotate my stock every 2-3 years.

sanking
4-Feb-2006, 16:09
A couple of comments.

1. On reciprocity. I agree with Howard Bond. Low reciprocity failure is a very big advantage of TMY in my work, which is quite often in low lighting conditions. Just consider this example. With a traditional film such as TRI-X 320 or JandC 400 the adjusted exposure for a calculated exposure of 10 seconds would be +2 stops or an adjusted time of 50 seconds. For TMY the adjusted exposure for a calculated exposure of 10 seconds would be 1/2 stop or an adjusted time of 15 seconds. That is a big time difference to me.

2. On storage. Concern for fogging from long-term storage is certainly a major consideration if we plan to buy in quantity and store the film for many years. However, Clay Harmon reported results on the JandC website of B+F testing of outdated TMY. As I recall, he developed in Pyrocat-HD and the B+F levels were about .10 or .11 for Visual and Blue reading, and .35 for UV reading. Folks, this is not a lot different that what you will get out of the box for fresh TMY film, and the film Clay tested was dated to expire in 2003. So when was it manufactured? I figure at least three or four years prior to 2003, though someone may want to correct me on this if they have better information. In any event, I purchased several hundred sheets of this film from Clay, same emulsion batch I assume, and its B+F now is only slightly higher than some fresh TRI-X 320 I purchased only six months ago. I am not sure what Kodak has to say about this, but in my experience the T-grain emulsion films do not develop nearly as much B+F for equivalent periods of storage as traditional films of the same ASA.

Michael Kadillak
4-Feb-2006, 16:45
You are correct Sandy in your assessment that T Max 400 is superior to Tri X as it relates to long term storage and increases in fog. I spoke to Kodak about this when Clay shared his results with us on his B+F assessment that you are making reference to. Of course reasonable consideration must be given to proper storage with frozen storage the preferable method.

One variable that must not be overlooked is understanding exactly when a master roll of film has been produced and cut. Sometimes the period between these events can be quite long and the box date does not always convey the full story.

We were assured that by acquiring an entire master roll of TMY we will be allocated the most recent manufactured product and since it will all be cut within the confines of one purchase order any uncertainty of optimal film life can be put to rest. I believe that one should reasonable expect a minimum of five years of risk free usefull film life for the TMY film purchase and quite possibly it could be even longer.

Great discussion.

Ken Lee
4-Feb-2006, 18:33
"over the top"

"a bit in excess"



Some of you are trained scientists and tenured professors - so your discrimination is no doubt quite keen, when it comes to this sort of thing, namely "Some Facts and a Few Opinions".



So with all due respect, where did you find the article to be excessive or "over the top" ? I welcome and appreciate your insights !

sanking
5-Feb-2006, 16:45
There were a couple of comments made yesterday that I meant to address but apparently my reply went astray.

First, Michael commented, “There is something not quite correct with your curves. The times listed in the response curves above do not match those listed in the N value curves below. I suggest you provide comparable curves to be consistent with your data.”

Michael, the curves are quite correct. The first set of graphs, i.e. the families of curves, are there to show the contrast in curve shape of TXP and TMY. The second set, the N charts, is there to show the difference in expansion potential between the two films. There was never any intent on my part to suggest that the data was comparable, indeed I state very clearly that Set 1 was based on the 1:1:100 dilution of Pyrocat-HD and Blue mode analysis, while Set 2 was based on the 2:2:100 dilution and UV analysis. A more specific or extensive review of the film would call for comparable data, but in this case I did not consider it important.

Oren wrote, “And I've never gotten a "pronounced shoulder" and "muddy highlight detail" from HP5 Plus, whereas I've found it very difficult to make TMY negatives that have adequate shadow information for my taste without also having excessively dense highlights.”

Oren, although you may have not been able to obtain the type of tonal scale you like that does not mean it is impossible to do so. The major difference between TMY and traditional films such as HP5+ and TXP is that TMY has very little latitude in development. It is a film capable of developing a very high average gradient, and it does this fairly rapidly even in developers of moderate energy. This obviously places a lot of emphasis on getting the time and temperature of your developer just right for the process because a couple of minute’s difference in time of development will result in a large difference in average gradient. By contrast, the latitude of HP5+ and TXP allows us to be less precise with our development procedures because the difference in time will not have nearly as much impact on average gradient.

Sandy

Oren Grad
5-Feb-2006, 18:04
Sandy -

The responsiveness of TMY to development changes and its ability to achieve extreme highlight densities is a feature for you - understandably so, given that you often need a much higher average gradient than I do - but for my purposes I consider it a bug.

That said, all my sheet film is developed in Jobo Expert drums with good control over temperature and agitation; any slop is on the order of fractions of a degree and a few seconds in timing in pouring chemicals in and out. D-76 is my standard film developer - I've tried many others in the past but never found any advantage in them, and at this point I rarely use anything else. Within this context, my experience has been that TMY is a very unfriendly film. For the kind of shadow information I want it's probably a stop slower than HP5 Plus (though it would gain that back in very long exposures because of its reciprocity characteristics). More importantly, the negatives look and behave in printing as though TMY has an upswept curve like TXP. Bearing in mind that I tend to pull my developing times a bit relative to manufacturers' recommendations, this is in fact consistent with Kodak's published curves for TMY in D-76.

In case it's not already clear from my comments, a characteristic curve that's concave upward throughout its density range is absolute poison for silver printing so far as I'm concerned, even if the overall density range is within bounds for silver. Where HP5 Plus negatives made under virtually any lighting conditions with an exposure remotely in the ballpark print easily on readily available papers and deliver a tonal scale I like, printing TMY negatives to my taste is a never-ending headache; and it's all too easy to make a negative that won't print at all to a scale I like, or won't do so without heroic measures. You may be right that it's "not impossible" to get what I want out of TMY, though based on my experience with the product I remain to be convinced. But even granting that point, why would I use TMY when I can get what I want so much more easily and reliably with HP5 Plus?

Your article has lots of good information in it. But much of the enthusiasm for TMY is based on sensitometric characteristics that are almost entirely at variance with what I believe makes for good prints in silver, a medium that even in this day and age can hardly be considered exotic - in fact, it's still the way most traditional photographers print. Those of us who know you and your work will recognize why you wrote the article the way you did, and why the product is of such great value to you, and that's fine. But given that it's posted as reference material on a dealer's website rather than as commentary on a personal blog, and is labeled "an analysis of TMY" rather than "why a well-known alt-process photographer loves TMY", I would be happier if it had even a brief sentence or two at the top to make your frame of reference clearer for those readers who really are new to your writing and to the film, and whose purposes may be different from yours.

Anyway, I'm happy to agree with Michael Kadillak:

Whatever film you are comfortable with by all means consume it. The most important thing here is to continue to make images and purchase film - any film. That is how we as photographers will insure the future of the art form we so dearly enjoy.

Right about now I'm thinking we're all pretty lucky. I'm going to focus my energies on going out as often as I can to make more pictures, and I'm eagerly looking forward to having a good time making lots of new negatives in my favorite odd formats.

Cheers...

sanking
5-Feb-2006, 19:36
Oren,

We all have our opinions, and I feel that the title of the short review, "Some Facts and a Few Opinion" made it very clear that some of what was going to be said would be opinion.

I know a lot of photographers who share your opinion of TMAX films and prefer traditional films like TXP and HP5+. But to be perfetly fair, it is also important to recognize that there are quite a number of very well-know silver photographers who use almost exclusively TMAX films. For that reason I certainly do not agree with you that the sensitometric characteristics of TMY are poison for silver printing, though for some reason that may be true in your work, for whatever reason.

In any event I know we can all agree that ULF photographers are fortunate to still have so many choices availble to us at this point in time when many films are being dropped from the market. In fact, as of early 2006 there are actually far more choices of ULF film than when I became involved in this type of photography in the late 80s or early 90s.

Oren Grad
5-Feb-2006, 20:12
prefer traditional films like TXP and HP5+

Although they're both "traditional", in terms of their curve shape TXP and HP5 Plus are different as night and day. For my purposes TXP shares the most important vices of TMY and is every bit as hard to work with - even more so when the light fades, because the reciprocity issues are compounded by the unforgiving curve shape.

Anyway, as Michael K would say: Onward!

sanking
5-Feb-2006, 20:46
The flaring curve of TXP is probably the main reason why so many people who print on VC silver papers prefer to develop it in pyro staining developers. The stain functions as a continually increasing yellow filter, compressing the flaring curve, and making it almost impossible to blow out the highlights. But that, as they say, is another cup of tea.

Sandy

Ken Lee
5-Feb-2006, 22:14
Do the curves of Silver paper and paper developers play a role in this ? Has there been much study of these curves ?

It seems reasonable that a given film/developer combination might match (or mis-match) the curve of a given paper/developer combination... or are paper/developer curves rather linear, and therefore not an issue ?

Oren Grad
5-Feb-2006, 22:26
Do the curves of Silver paper and paper developers play a role in this ? Has there been much study of these curves ?

Yes, and yes. That's what BTZS is all about - controlling and matching film and paper curves to get the tonal scale you want.

It seems reasonable that a given film/developer combination might match (or mis-match) the curve of a given paper/developer combination...

That is exactly right. When you have a good match, printing is a joy, as your negatives fall effortlessly on to the paper. When you don't, the consequence is tedious manipulation as you fight the paper's natural behavior to try to salvage the picture from an inappropriate tonal scale.

William Mortensen
5-Feb-2006, 23:06
"Most people won't remember Royal Pan, but when I first started working with ULF cameras someone sold me a few boxes of it. It was, as I recall ASA 800, and the speed was a great advantage in the field, and for contact printing grain was fine. I would sure like to have some of that stuff again." --Sandy King

Sandy- I think the Royal Pan was rated at 400, but the Royal Pan X was rated 1250, and had a grain structure not too much coarser than Tri-X. If it came out today, it would be heralded as a technological breakthrough; yep, I'd love to have some again too!

I suspect most all of today's films are quite nice if one just takes the time and effort to learn to use them.

Kerik Kouklis
5-Feb-2006, 23:15
Sandy,

Thanks for posting the results of your experience with TMY. It will be a big help in getting dialed in with this film when it arrives. I respect your opinions and it was clear that you presented them as such. But, as often as not in these forums, no good deed goes unpunished...

Ken Lee
6-Feb-2006, 05:06
Thanks Oren -



Where might we find some data on the various Silver papers, their curves, etc ? The few articles that I have read, deal with films, and their suitability to the Pt/Pd process.



I imagine it gets fairly complex, when dealing with multigrade papers, but it strikes me as being more important than the study of film, since it's the final link in the chain, where the rubber meets the road (if you'll pardon the mixed metaphor and cliches).



I recently compared some Selectol-soft to Dektol. At first, I thought that the "softening" effect was merely equivalent to a change from a #2 to a #1 filter - until I made an image with the same paper, using Dektol, and a #1 filter. It is not the same: the distribution of tones is different, not just elongated. The Selectol curve, for that paper if I were to discover it, was a curve, not a straight line, and the aesthetic effect was quite different.



If others have already made some investigation, I for one, would love not having to repeat it !

robert_4927
6-Feb-2006, 07:01
Sandy, Thanks for your efforts in the research and testing of various films and developers. You have narrowed the learning curve in many instances for many of us. But like Kerik said " no good dead goes unpunished". So please don't allow that to be a deterrent to your efforts. Keep up the good work.

Oren Grad
6-Feb-2006, 08:04
Ken -

Although many paper manufacturers publish characteristic curves, I don't know of any published or posted data systematically showing the effect of paper developers on curve shape. I think there's hardly any, actually - certainly far less than the already limited information on films. So if you want to study this variable and control it precisely, you're probably best off getting your own step tablet and densitometer. The upside is that it's even less hassle to do the paper tests than it is to do the film tests.

As for the rest, no "punishment" of Sandy intended. He's a big boy and can defend his own point of view admirably in a debate, as demonstrated once again here. I think that between the various comments and his responses, the TMY "story" is clearer. I appreciate Sandy's taking the trouble to respond substantively, and I'm happy with the exchange.

sanking
6-Feb-2006, 09:04
Ken,

The only accumulated data of this kind I could point you to would be the paper curve files on Phil Davis' Winplotter program. There are lots and lots of papers covered in the data, but a fairly limited number of developers. However, given the many variables of light sources and VC filters, and how these interact with the exact spectral sensitivity of VC papers, any information you find published will likely deviate to some extent from your own conditions, so Oren's advice to do your own paper curve testings is sound.

There is is an interesting article somewhere on the AZO forum that compares different developers, and dilutions, on the curve of AZO papers. This includes Dektol, Neutol, Amidol and Ansco 130. If you can find the article you will see that there are some very significant differences in the way these various developers change the curve. I would include the page but in a brief search a few minutes ago I was not able to navigate to the article. Perhaps that section of the AZO forum has been eliminated or is temporarily unavailable?

Sal Santamaura
6-Feb-2006, 09:17
"Perhaps that section of the AZO forum has been eliminated or is temporarily unavailable?"

It's on the site, but not in the forum. See DJ's article here (http://www.michaelandpaula.com/mp/DJ_curves_article.htm).

As an aside, there are many flavors of Neutol. The one typically used with Azo is Neutol WA.

Oren Grad
6-Feb-2006, 09:19
How about these?

unblinkingeye.com/Articles/Azo/azo.html (http://unblinkingeye.com/Articles/Azo/azo.html)

unblinkingeye.com/Articles/Azo/azo1.html (http://unblinkingeye.com/Articles/Azo/azo1.html)

Rick Moore
6-Feb-2006, 16:38
Sandy,

I thought I was the only one who remembered Royal Pan. It was ASA 400, and was similar to TMY in its ability to produce negatives with high density ranges suitable for salted paper, albumen and POP printing. It produced very clean, low fog negatives in HC-110. My last frozen stocks of it ran out in the late 90's and I still miss it.

For my uses, negatives with a DR of 2.2 or higher are necessary. TMY is without equal in this ability today. BPF and TXP are fine films, but simply cannot produce the needed range. I realize that silver gelatin printers probably wont' appreciate this capability, but it's absolutely necessary for my work.

TMY's excellent reciprocity failure characteristics are an added bonus.

Ken Lee
6-Feb-2006, 17:24
Thanks so much for the info and the references. I am encouraged to test the next formula on my list: Formula 130. I'm not ready to do any rigorous tests yet, but it's encouraging to know that it is among the most linear of the formulas.

You guys really are top-shelf. Many thanks !

Jimmy Peguet
7-Feb-2006, 06:08
Michael wrote above "...and inherent to the reciprocity characteristic is the greater propensity for the film to fog with time, heat, and rediation." I wonder about the relationship between reciprocity and film storage : Michael, if you are still here, please could you tell more ?

I asked the same question on the french forum galerie-photo www.galerie-photo.info/forum/read.php?f=1&i=590&t=466 (http://www.galerie-photo.info/forum/read.php?f=1&i=590&t=466) and got some answers with a list of books. If you read french, are we talking about the same thing ?

Jimmy