Differences between Tmax 400 and Tri-x characteristic curves?

[Lachlan Young]

From what I'm reading, all it takes is a few decades displayed. No mention in the link below of any torture test being applied. When you write "the he worst you are going to likely do is bleach out the brightener", that's significant. From what I'm reading, those brighteners add a lot to the viewing quality of the print. As I mentioned, one poster commented that an Amsel Adams print was changed in such a way that it wouldn't be sale-able. I find that disconcerting.

https://www.aardenburg-imaging.com/optical-brighteners-obas/

That's a single data point presented by someone who has a commercial interest in drumming up cash to promote their idea of 'archival' to a sociologically specific marketplace. And I recall that the original claimant that story came from tried to claim it was only 'indirect' daylight they were exposed to - and they didn't consider any other environmental aspects of chemical exposure etc. Pre-1970's most photo paper manufacturers weren't interested in the concerns of the 'fine-art' marketplace to any great extent - and the warmer toned papers used for portraiture etc (ie the prints average people were perceived to want to be long lasting) generally had nil to low brightener & often had a toning step that sulphided the paper. You have to decide what is perceptually important to you & whether you are going to be exposing your prints to intense UV containing light for hours per day, 365 days of the year for multiple decades. An awful lot of papers (be they printmaking or photographic), no matter their additives or not, will change in that sort of environment. And the nature of environmental reaction with the OBA's cannot be discounted - dyes can have bad reactions with 'archival' buffering in mount materials, just as siderotypes can. Whether or not storage/ display materials pass the Photographic Activity Test is a more likely indicator of future problems than someone making claims on the basis of baking prints for a few weeks.

The other thing is that top layer of photo paper coating packages nowadays generally includes some degree of UV filtration - and the Ilford paper(s) with washable brightener is Multigrade Warmtone FB and (I think) Art 300 which may have either the same system, or less brightener. Foma's warmtone papers may or may not have some, but they also have dyes to adjust their base colour - their cooler papers are likely to contain them.

 

[Lachlan Young]

It's you insisting you alone are correct, what I say is that both ways are totally correct:

> taking a linear capture and compressing what necessary to fit the excessive range in the negative into the 2.1D range of the paper

> refining the exposure-processing to get a negative that will print easily like we want, and making those compressions with the help of toe/shoulder,

Many artists have exploited and exploit the second way with perfect results, as perfect than those from first way. In fact the entire Zone System it's based in explaining what zones are compressed or not in the toe or shoulder, depending on exposure/processing. No need to follow the ZS, and linear films are less suitable for the ZS recipe, but they way we use is a personal choice.

What you don't seem to want to understand is that the curve behaviour of TMax films is a feature, not a bug. Highlight compression via shouldering of the negative is intended to make it easier for those with poor process and exposure controls to not get accidentally far too dense highlights for printing, at the expense of poorer highlight separation when those highlights are burnt in. At ISO contrast & exposure of a 7-stop subject printed on G2 paper, even a film with a shoulder should have the subject highlights located on the straight line part of the curve in order to interact correctly with the toe of a G2 paper. Control of negative contrast via lowering curve gradient is largely intended to reduce/ push up the curve/ eliminate shouldering such that your highlights will be compressed only by the paper curve - at a cost that your midtones may become flattened to the point that they are difficult to print well.

 

[138S]

Lachlan, bye, bye...

 

[138S]

No silver paper from Ilford or Foma has OBA's? Do you have a source for that? I really have my doubts about that, as the poster I read seemed to know what he was talking about, and said few, if any wet printing silver papers have no OBA's.

It would be a crime Somebody would set fire to their manufacturing plant


In FB paper you don't see the paper itself, you see a layer of gelatin with Baryte. In RC paper you also don't see paper but a layer of while polyethylene.

The baryted layer is a serious solution for serious work. FB photopaper is a very serius museum grade medium. I cannot even imagine what it would happen if somebody discovers dirty chem in an ilford photopaper... these are noble materials to work with.

Today's RC photopaper may have at least a century long permanence, but ilford recommends FB for high LE:

https://www.ilfordphoto.com/faqs/photographic-paper-faqs/

 

[RalphLambrecht]

So I exposed a roll of Tmax 400 and developed in Rodinal. This film is amazing, but I'm not sure it's what I'm looking for. The images are ultrasharp, with a very fine grain, only really visible if you view the 24MP RAW files at 100%. Even then, it's still quite fine. At a more reasonable 70%, the grain is almost invisible, and the details I could cut with a knife. This is all too digital looking for me....too perfect. I might try Ilford HP5 in HC-110. Its curve looks straight, somewhat like Tmax's, I am sure i can get more grain.

I also believe that Rodinal is finer-grained than its reputation.

 

[Acticus]

What do you think of this idea? Instead of making silver prints by projection from an enlarger, suppose I print a large negative from an inkjet from my digitized 35mm negative, and then contact print on silver paper? It would be one generation down, so, theoretically worse quality than projection, but on the other hand, a whole lot can be done in photoshop to fix that file up before printing.

 

[MattKing]

What do you think of this idea? Instead of making silver prints by projection from an enlarger, suppose I print a large negative from an inkjet from my digitized 35mm negative, and then contact print on silver paper? It would be one generation down, so, theoretically worse quality than projection, but on the other hand, a whole lot can be done in photoshop to fix that file up before printing.

Not a bad way to start out with your experiments, but there are some things to be aware of.
Most digital printers offer less resolution than an optical enlargement can achieve.
That can be partially offset by making the digital negatives larger, which permits larger contact prints, which lead to greater viewing distances.
That is why a lot of people who are using digital negatives - whether with the traditional processes or with silver gelatin - try to make them larger than 8x10 - 11x14 and 13x9 being popular choices.

 

[Acticus]

Not a bad way to start out with your experiments, but there are some things to be aware of.
Most digital printers offer less resolution than an optical enlargement can achieve.
That can be partially offset by making the digital negatives larger, which permits larger contact prints, which lead to greater viewing distances.
That is why a lot of people who are using digital negatives - whether with the traditional processes or with silver gelatin - try to make them larger than 8x10 - 11x14 and 13x9 being popular choices.

Well, there's not too much to resolve in my negs....mostly portraits. I don't want to resolve pores.

 

[MattKing]

Well, there's not too much to resolve in my negs....mostly portraits. I don't want to resolve pores.

The real question is whether you like how the digitized image looks when produced this way - particularly in comparison with the more random distribution of film stored information printed optically.

 

[138S]

What do you think of this idea? Instead of making silver prints by projection from an enlarger, suppose I print a large negative from an inkjet from my digitized 35mm negative, and then contact print on silver paper? It would be one generation down, so, theoretically worse quality than projection, but on the other hand, a whole lot can be done in photoshop to fix that file up before printing.

Yes, you can do that. Quoting:


"FOTOSPEED Digital Contact Film A4

If you're in the unfortunate situation of having a great picture that you've only shot digitally, it's tough to make it into a negative so that you can print it on proper photo paper.

Not everyone has a Lambda or Lightjet printer in the garage, even though you can now buy them used for less than the price of the garage itself.

In this case, this Inkjet film comes to the rescue. It's an 80 micron thick PET film, which is coated on one side to accept ink from an inkjet printer. You can create a large-format negative from your digital files, then make a contact print from it in the darkroom.

Ideal for creating contact-negatives for alternative processes."



But you can order a lightjet of lambda light print on silver photopaper...

Many times they only print on RC paper, but some selected printers also print on FB with the Lambda printer.


Anyway, a genuine optic silver print, enlarged in the darkroom, with not digital manipulation may have an extra emotional (or economic) value, it is a hand crafted art object, you see the artist's hand in the craft. A sound optical print comes from a photographer mastering his tools.

High level Collectors usually buy only optical prints, but this is a difficult market, and YMMV.

 

[miha]

No silver paper from Ilford or Foma has OBA's? Do you have a source for that? I really have my doubts about that, as the poster I read seemed to know what he was talking about, and said few, if any wet printing silver papers have no OBA's.

All modern papers are loaded with OBA's.

 

[Lachlan Young]

I also believe that Rodinal is finer-grained than its reputation.

Very much so - I think the 'problem' granularity seems to be an issue mainly on low MTF performance scanners, where the slightly more prevalent granularity & lesser edge sharpness at low cyc/mm of Rodinal contribute to creating issues with aliasing on cheaper scanners. In the darkroom & on competently used high-end scanning kit, it's a non-problem.

All modern papers are loaded with OBA's.

Up to point - Ilford has essentially stated that Classic, Cooltone, Galerie all have heavily ballasted brighteners that resist wash-out, but when Warmtone had to go to white rather than toned base, the brighteners are not ballasted, so they will wash-out. I don't think any of the 'archival permanence' people have ever tested a piece of pure linen rag paper to see if it changes under their test conditions - linen being the best way to make a very pure white paper without pigments, bleaches or brighteners.

What do you think of this idea? Instead of making silver prints by projection from an enlarger, suppose I print a large negative from an inkjet from my digitized 35mm negative, and then contact print on silver paper? It would be one generation down, so, theoretically worse quality than projection, but on the other hand, a whole lot can be done in photoshop to fix that file up before printing.

It works, is relatively painless to do - the ink density requirement is lower than with some alt processes. Main irritating thing is dealing with the dither pattern of the printer driver - it can produce a highly identifiable and distinctive gritty granularity in areas of tone that should be smooth. Generational loss isn't much of an issue, if your scan is first-class. Main challenges are getting good contact between neg and paper, depending on your output size - any any image produced from a scan will look different to a fully optical wet darkroom print - if done well, not better or worse, but somewhat different - if you saw them side-by-side you'd see the differences more than if seen in isolation. As you gain experience, you'll discover that PS isn't always the magical tool it seems & you can end up doing multiple operations to do what happens automatically in the darkroom. It mainly makes complex retouching and compositing easier. I wouldn't worry as much about collectors tastes until you find yourself in a position of selling work - and even then, the exact means by which a print was exposed isn't as massively fetishised as some in this thread seem to want you to believe.

 

[RalphLambrecht]

What do you think of this idea? Instead of making silver prints by projection from an enlarger, suppose I print a large negative from an inkjet from my digitized 35mm negative, and then contact print on silver paper? It would be one generation down, so, theoretically worse quality than projection, but on the other hand, a whole lot can be done in photoshop to fix that file up before printing.

a valid hybrid method with reasonable quality up to 8x10.

 

[Acticus]

Ok folks, a followup. First, thanks to all who replied. I learned a lot. Now the question is about pushing. Keeping in minds the characteristic curves, what's happening when I push, and why is it necessary? For instance, if I am simply scanning and not wet printing, why can't I simply underexpose, and just do standard development? I'm thinking that if I simply underexpose, I lose shadow detail. (one, two or whatever in the way of stops,) and I am left with what's left on the upper, right side of the curve. If I am scanning, why would I need to extend development? And with wet printing, why?

 

[Alan Edward Klein]

Ok folks, a followup. First, thanks to all who replied. I learned a lot. Now the question is about pushing. Keeping in minds the characteristic curves, what's happening when I push, and why is it necessary? For instance, if I am simply scanning and not wet printing, why can't I simply underexpose, and just do standard development? I'm thinking that if I simply underexpose, I lose shadow detail. (one, two or whatever in the way of stops,) and I am left with what's left on the upper, right side of the curve. If I am scanning, why would I need to extend development? And with wet printing, why?

I don't use the zone system. I don't develop my own film. My labs process normally with no pushing or pulling. I've notice that the best scans for me are on negatives that cover the full range from black to white. I then have the most latitude to do what I want in post processing.

 

[Lachlan Young]

Ok folks, a followup. First, thanks to all who replied. I learned a lot. Now the question is about pushing. Keeping in minds the characteristic curves, what's happening when I push, and why is it necessary? For instance, if I am simply scanning and not wet printing, why can't I simply underexpose, and just do standard development? I'm thinking that if I simply underexpose, I lose shadow detail. (one, two or whatever in the way of stops,) and I am left with what's left on the upper, right side of the curve. If I am scanning, why would I need to extend development? And with wet printing, why?

Extended processing and underexposure will affect your midtone scale and highlight behaviour in a different and more complex way than you think. The point is to steepen midtone gradient & boost highlight contrast so that the effect of shoving your neg down the scale via underexposure doesn't leave you with flat highlights and bland midtones, which can add up to a neg that needs a lot of work at a high contrast grade to get a good print. T-Max 400 is designed to have some degree of latitude for underexposure (1 stop), so you'll mostly just lose some shadow detail.

 

[Acticus]

Extended processing and underexposure will affect your midtone scale and highlight behaviour in a different and more complex way than you think. The point is to steepen midtone gradient & boost highlight contrast so that the effect of shoving your neg down the scale via underexposure which can add up to a neg that needs a lot of work at a high contrast grade to get a good print. T-Max 400 is designed to have some degree of latitude for underexposure (1 stop), so you'll mostly just lose some shadow detail.

Extended processing and underexposure will affect your midtone scale and highlight behaviour in a different and more complex way than you think. The point is to steepen midtone gradient & boost highlight contrast so that the effect of shoving your neg down the scale via underexposure doesn't leave you with flat highlights and bland midtones, which can add up to a neg that needs a lot of work at a high contrast grade to get a good print. T-Max 400 is designed to have some degree of latitude for underexposure (1 stop), so you'll mostly just lose some shadow detail.

"the effect of shoving your neg down the scale via underexposure doesn't leave you with flat highlights and bland midtones"

Would that be the same for scanning as well? Same issue?

 

[MattKing]

"the effect of shoving your neg down the scale via underexposure doesn't leave you with flat highlights and bland midtones"

Would that be the same for scanning as well? Same issue?

Yes.
Push processing improves the rendition of under-exposed mid-tones and, to a certain extent, near shadows.
Your highlight rendition will not be as good though.

 

[Acticus]

Yes.
Push processing improves the rendition of under-exposed mid-tones and, to a certain extent, near shadows.
Your highlight rendition will not be as good though.

Why is that? What's actually happening to the negative that causes that?

 

[M-88]

Why is that? What's actually happening to the negative that causes that?

What happens is that during "push process" you overdevelop your film and therefore increase contrast/detail/brightness. However, if not being careful, it will wash away whatever the highlights you have on the negative, due to prolonged submersion in chemicals. Same submersion which "brightens up" the dark parts of our negative, will "brighten" our highlights too...

 

[Anon Ymous]

Why is that? What's actually happening to the negative that causes that?

In order to get a better understanding of what happens, one should have a look at a set of characteristic curves for the same film and developer, for different development times:

This is taken from the Tri-X datasheet and you can see the curves for 400TX in D76. One unit in the X axis is equal to 3,33 stops. The left part of the curves is where the shadows are. You will notice that the beginning of the curves shows that the curves are flat lines (horizontal). In this region there's no contrast and information isn't recorded at all. Once the line becomes more upswept, there's some information being recorded. So, if you were to underexpose your film by 2 stops (EI 1600 instead of 400), you would definitely have shadows that suffer. If you increase development time, then you gain better shadow detail and you'll likely need a medium contrast grade filter (or paper) to get a reasonably good print, without too much of a hassle. You can't expect miracles, but it definitely helps. Now, you might be wondering, if I'm just scanning, why not use the standard development time? Well, it might be easier to pull something usable out of an underexposed negative with digital methods, but IME the result looks quite ugly. Shadows will look very grainy/noisy and will still lack detail. Go ahead and underexpose a shot on purpose by at least 2 stops, especially of a scene with a wide subject brightness range. While you are at it, bracket your shots and see what the effects are. If you were to increase development time, the effects of underexposure would be mitigated, but not eliminated. Considering the highlights, they may suffer in push processing because of shouldering and increased granularity, although IME underexposure will lessen this effect considerably. If you were to expose normally and push process, then it would become more obvious.

 

[MattKing]

Speaking colloquially, when you push process (increase development) you can end up crowding the highlights into the top part of the curve. When they are crowded in there, they don't look as good in the print.
With all due respect to M-88, it has nothing to due with chemical submersion.
Humans are really sensitive to how high midtones and highlights appear. Our sensitivity to the appearance of shadows is much less. It is for that reason that Kodak recommends against increasing development for T-Max 400 that is under-exposed by one stop (shot at an EI of 800). Under their criteria, the improvement that may be gained in the shadows and low midtones by increasing development is more than offset by the deleterious effect on the highlights. It is a balancing act that is influenced as well by the choice of film and developer, and the nature of the scene and the character of the scene illumination.
The decision to push process or not is also greatly influenced by the preferences of the photographer.
I rarely push film. Others I know do so regularly.

 

[Acticus]

Just an observation.....After all that I've learned in this thread, all the technical details, now when I read the dozens of "Tmax vs...." comparisons, or "HP-5 vs...", on photography blogs, I now understand them as mostly full of....uh, something. : )

 

[radiant]

Just an observation.....After all that I've learned in this thread, all the technical details, now when I read the dozens of "Tmax vs...." comparisons, or "HP-5 vs...", on photography blogs, I now understand them as mostly full of....uh, something. : )

What you should learn is that this is pixel peeping of film world and has nothing to do with photography Tmax, HP5 .. are all just great films and all very suitable for using as a medium in film photography. None of the films mentioned here make you bad photographer. None of the manufacturers guarantee better photographs when using their film

 

[Acticus]

What you should learn is that this is pixel peeping of film world and has nothing to do with photography Tmax, HP5 .. are all just great films and all very suitable for using as a medium in film photography. None of the films mentioned here make you bad photographer. None of the manufacturers guarantee better photographs when using their film

I like pixel peeping and understanding what's happening in that emulsion, and thanks to the posters in this thread, I know a lot more now. What I meant in my post is you see all these comparisons on photo blogs by people purporting to be "testing" films. Thing is, they all come to different conclusions. I've read ton of blogs trying to learn about film. It was pointless. I learned what I need to know right here.