grain and sharpness

[Ole]

I'm only going to answer one of your questions here.

3) I have visibly grainy negatives, and prints made from them, from FP4+ developed in monobath developer. It seems the fixing action mobilises the silver, so the grains get "replated" faster than they are dissolved. I have since heard of a monobath developer that uses ammonium thiosulfate, which does not increase grain. The "classical" sodium thiosulfate developer does - in my experience.

 

[gma]

I know that Microdol "softens" the grain structure, but I cannot remember if the softening effect is more obvious with full strength or diluted 1:3.

I have used Microdol 1:3 with Tri-X rated at EI 250 and I like the look it produces.

 

[Jorge]

Jay, I dont know that you will ever see grain in a contact print. That was not my point when I was commenting about Tech Pan. In the shot you mention, I was able to tell so much by a scan because I vividly remember my first Tech Pan print and the disappointment it produced. I was sure I got an awsome negative, yet when I printed it, my first reaction was, well, that does not look that sharp! I went back and took the same pic with tmx and lo and behold the 100 tmx neg produced a far shaper print than TP. Of course, there was some grain, but I was perplexed that the grainier image was sharper.

Years later there was an article in photo techniques that explained why TP, although the finest grain film available, does not produce as sharp prints as any of the more regular films.

Now this is specific for TP, frankly in contact printing I dont think it matters what you use, I can't see any difference between 400 tmx and the PW ultrafine film! If you are not familiar with the peculiar tonality of tmx film I would dare anybody to choose a contact print and tell me which one was made from 400 tmx and which from the ultrafine film.

IMO for contact printing it is more important to look for the film that has a tonality that pleases us, since grain even on Tri X is not visible.

 

[Tom Duffy]

Jeff,
I have some experience with contact printing various films on either extreme. I've used Fuji Acros quite a bit in 8x10 (bought a lot from Badger when it first came out). To my suprise, I found that I liked Tri-x contact printed a lot better; it looked a lot sharper. Amazing when you consider that Acros is about as grainless and high resolving a film as you're likely to find, excepting TP.

That's when I decided that there was a difference between sharpness and apparent sharpness. Most of my Acros was developed in PMK or rollo pyro. Some of the sharpest contact prints I've ever seen were Michael A. Smith's whose film was developed in ABC pyro on Super XX film. The grain is almost visible to the naked eye.

Being a non technical a photographer, I lump it all together in the the word "accutance", which probably only relates to edge sharpness, but to me has elements of "local contrast".

Don't have time to write more today, I'm off to Vermont 'till Sunday with the kids. I look at your questions, and think you're on the right track. All other things considered, I think, in terms of apparent sharpness, a contact print benefits from using a course grained film with good local contrast with a pyro developer for edge effect. ABC pyro is probably the coursest grained developer you can use.

One closing thought, I can't cite a reference, but I read once that maximum sharpness is not obtained with a contact print but with a very slight enlargement, on the magnitude of 1.1 to 1.2 power. Light scatter in the contact vs. collimnated (sp?) light from the enlarging lens.
Take care,
Tom

 

[lee]

I know that Microdol "softens" the grain structure, but I cannot remember if the softening effect is more obvious with full strength or diluted 1:3

Using Microdol-x full strength creates the softer effect. 1:3 will sharpen the look of Microdol-x due to edge effects, I believe.

With largeformat it is not as much of a problem as it might seem with the smaller formats ie 35mm.


lee\c

 

[sanking]

I know that Microdol "softens" the grain structure, but I cannot remember if the softening effect is more obvious with full strength or diluted 1:3

Using Microdol-x full strength creates the softer effect. 1:3 will sharpen the look of Microdol-x due to edge effects, I believe.

With large format it is not as much of a problem as it might seem with the smaller formats ie 35mm.


lee\c

I agree that grain is not much of a problem with contact printing.

As for sharpness, it is a subjective quality that varies according to observer, but the two most important factors that enhance it are, 1) overall CI or negative contrast, and 2) micro-contrast, which results from the increased acutance of edge-effects. The former is determined primarily by overall time of development whereas the latter is determined by developer composition, dilution and method of agitation. The most fundamental mistake made by many photographers in comparing sharpness of developers is that they fail to develop the comparison negatives to the same contrast, in which case the one that is developed to the higher contrast will almost always have greater apparent sharpness.

In some cases, especially with 35mm and roll film formats large grain can also result in greater apparent sharpness. Rodinal, for example, is a developer known for huge grain and very high apparent sharpness. The opposite is true. Microdol-X which gives very minimal grain, gives images that look very soft, as Lee mentions, at least when used straight.


Sandy King

 

[c6h6o3]

In some cases, especially with 35mm and roll film formats large grain can also result in greater apparent sharpness.

Sandy King

An excellent example of this is the 35mm work of Sebastiao Salgado which, while displaying boulder sized grain, is razor sharp from edge to edge. Without the grain, his images would lose most of their impact, at least to my eyes. His prints are usually 11 x 14. I have no idea what the negatives are developed in.

 

[Foto Ludens]

An excellent example of this is the 35mm work of Sebastiao Salgado which, while displaying boulder sized grain, is razor sharp from edge to edge. Without the grain, his images would lose most of their impact, at least to my eyes. His prints are usually 11 x 14. I have no idea what the negatives are developed in.

I've heard rumors saying "rodinal", but since Kodak backs him financially (or at least with film), he cannot confirm nor deny this

Once again, these are rumors

 

[gma]

I have noticed that every Kodak sheet film intended for general photography has times included for Microdol-X straight. I do not know why anyone would want to use it for LF except for softer contrast. Does anyone in APUG use it for LF?

 

[sanking]

Sandy (professor King?),
thank you for the description of the factors that affect apparent sharpness and their mechanisms. Am I correct in understanding that you believe that invisible grain is not a player in the sharpness game?

Absolutely, and I believe everybody will agree on this. Invisible grain is not a player in the sharpness game!!

Sandy

 

[c6h6o3]

Jim,
you have a lot of experience with contact printing; how important do you believe that grain structure is in a negative for contact printing?

I don't know. My first inclination is to answer that it doesn't make any difference. But if it doesn't, how would we explain the apparent "meta-sharpness" obtained by our friends who are showing prints made from negatives developed using the minimal agitation technique? Are edge effects caused purely by different perceptions of micro contrast, or does the minimal agitation technique affect the grain structure differently than say, constant agitation?

Since grain is virtually invisible in my prints, I've focused on smoothness in the tones and not really paid much attention to the issue of grain, or even sharpness for that matter. The etched look is not really appropriate to the photogaphy I like to do anyway. That's why I haven't adopted the minimal agitation technique.

 

[Jorge]

Jay, I do think we apply different standards for contact printing and for enlarging. I was talking about enlarging TP, I dont know how it would look in a contact print, other that its weird tonality I suppose the sharpness we see in contact prints would still be there regardless of the mushiness of the grain.

For example there was some efforts by Durst to make a pt/pd enlarger and I think they did come out with an azo enlarger. Michael Smith is still involved in a azo enlarger. I dont know how successful these efforts will be, but on a personal note, I would not buy a pt/pd enlarger. I dont see the need for it nor do I think my photography would benefit from being able to enlarge in pt/pd. As I said in another thread, IMO the process is part of the final product, and the unique look of a contact print also plays a part in how we present our work.

 

[Jorge]

Jorge, I hope I didn't come across as contentious. You've been very inspirational to me, and I was just trying to answer some of my long standing questions for myself, and I couldn't pass up an opportunity to get your input on them. Thank you very much for your thoughtful consideration.

Jay

Not at all Jay, dont know what makes you think that....I was glad to give you my opinion, it is just that and hopefully it serves you in a small measure.

 

[Thilo Schmid]

The role of grain in accutance is fairly well known, and most printers recognize that prints with some apparent grain appear sharper than prints without apparent grain.

What is sharpness?
Let’s think of a dark grey object on a light grey background.

Sharpness is a physiological phenomenon that can be tracked down to Detail Contrast. There are several ways to enhance Detail Contrast and thus enhance Sharpness.

One is resolution. The higher the resolution, the more precise and harder can the borderline between the dark grey object and the light grey background been “modelled”.

The second one is print contrast. Everybody knows that prints on higher paper grades usually look sharper than the same print on a lower grade paper. A low contrast scene like a tree in the fog remains relatively unsharp, even if taken on TP and print on a grade 5. Paper grade affects the difference between the dark grey object and the light grey background so that the eye and the brain recognise the borderlines worse or better. In the extreme cases, the light grey background becomes white and the dark grey object becomes black or both are mapped onto nearly the same grey tone on the print. Color contrast can do the same thing on a color print. The borderline between red and green is always sharper than, e.g., blue and violet.

Acutance is a trick that increases the contrast directly at the borderline between the dark and light grey areas. Unsharp Masks and DIR-Couplers are other examples that work the same way. They aid the brain to better perceive the borderlines such that the image processor in our brain can calculate a clearer vision which makes us think that it look sharper. If you look at the MTF-Diagram in the Tech Specs of e.g. Kodachrome, you will see that at 5 lp/mm the output contrast is significantly higher than the input contrast, which means that this film is partially sharper than reality!

Third, there is a certain, not exactly determinable, physiological phenomenon that makes us think that a coarse structure is sharper than a smooth one. This adds some virtual sharpness to a grainy print which is objectively not there.

1) How does grain structure affect the appearance of an image if it is invisible?

It does not. Very small and invisible grain does increase resolution and thus provide a more precise way to separate things for the eye and brain. See above.

2) Would the apparent sharpness of a contact print be improved by visible grain?

See third point above

4) How does grain structure affect edge effects?

The sharper the edges of the grain the clearer are the borderlines between grain and no grain. Look at color film. Color film does not have grain. All the grain is removed in the bleach and fix. What is left are tiny dye clouds that have been developed together with the grain. On very high mag. ratios, these clouds look rather pointilisic with no edges at all.

 

[lee]

jdef asked, " Lee,
I understand that diffuse grain structure can degrade image sharpness compared to sharp visible grain. My question is; would the difference in grain between negatives made with Microdol X undiluted and Microdol X diluted 1:3 lead to sharper contact prints made from the 1:3 negative?"

I suppose that is true but I don't really know the answer, Sorry. I don't particulary worry too much about sharpness of grain. I use Microdol-X as a contrast control with sodium metaborate. This is described in Ansel's book, The Negative.

 

[fhovie]

I don't have too much to add - but I am so glad to be here ....

Actually there are grainy films and grainy developers. I am not a big fan of grain but am a big fan of sharpness. Leaving out the discussion of 8x10 contact prints which are in my mind the gold standard, I could use TRI X in microdol or Pan F 50 in PMK. After trying several combinations, I like TRI X in Microdol better. The film provides the edgy grain and the developer lets me use it in 35mm or 120 format. HP5 in Microdol is a good alternative although the grain in HP5 is not as defined and in Microdol looses some of its bite.

This really is a roll film discussion though - once you go 4x5 and up, grain and sharpness are fairly easy. I still am careful with TRI X in 4x5 - If I want to print big, PMK is a little coarse- PKHD seems better here.