Ideal Developer for Film to be Scanned

[Jay DeFehr]

Since VC papers have become the predominate printing paper for most photographers who still print in the darkroom, many of the traditional demands on the photographer have faded into obscurity, or, at the very least, have assumed secondary importance. When graded printing papers dominated darkroom shelves, photographers had to learn to scale their negatives to their printing papers, and to adjust print contrast for between-grades, by the manipulation of exposure and print developers. A practical knowledge of sensitometry and basic chemistry was indispensable to serious photographers, and a wide range of testing and calibration procedures evolved to aid the photographer and darkroom worker. With the advent of VC papers, it was no longer necessary to precisely scale the negative to the printing paper, and processing for a roughly middle grade was more than adequate, since the paper could be very precisely scaled to the negative. I'm often surprised at the testing and calibration gymnastics performed by photographers who use roll film and print on VC paper, and can only assume these photographers are laboring under one or more misconceptions about the level of precision required by their materials, and how best to exploit the advantages they confer.
Hybrid film/digital workflows represent a similar shift in the demands on the processing film to be scanned for either digital printing, or making digital negatives for contact printing, and suggests new criteria for film developers. A film developer for film to be scanned should be optimized for producing the kinds of negatives that scanners are optimized to scan, or in other words, for maximum compatibility.

What kind of negatives do scanners like best?

Grainless
low contrast/ low-moderate density range
high resolution

And, while scanners don't care, photographers almost always prefer high film speed, long shelf life, economy, ease of use, and low toxicity, all other things being equal.

While there are developers commercially available that possess some of the characteristics listed above, none are optimized for the entire description, and other desirable characteristics could be added, such as: long tray life, compatibility with rotary processing, commonly available ingredients, etc.

I think we have within our membership the experience and expertise to narrow the many options to a few, high probability approaches to distilling something like an optimized developer for film to be scanned. I have a few ideas of my own, and more questions. I hope there is enough interest to generate some positive discussion and debate on the most likely approaches. I'll try to start the ball rolling by suggesting Pat Gainer's PC TEA, which I think satisfies most of the criteria, with the exception of the "grainless" one. It might be possible to use some variation of PC TEA as a two- part developer by diluting the concentrate with a sulfite solution. An even less toxic version might use glycol in the concentrate, and add a less toxic alkali to the B solution. In any case, I favor a simple, ascorbate/ phenidone concentrate made up in TEA or glycol, but I welcome alternative opinions, and I hope for many.

[Ron Marshall]

Xtol!

[Jay DeFehr]

Ron,

Xtol does indeed meet many of the criteria I outlined, but not all of them. Xtol's shelf life and economy leave something to be desired, not to mention its formula is proprietary, which rules it out for me. On the other hand, the fact that Xtol is commercially available might be in its favor for some users. My point, and the point of this thread, is that there are improvements to be made, and I think we can find ways to make them. I think Xtol represents an excellent benchmark against which to compare alternatives.

[Keith Tapscott.]

When graded printing papers dominated darkroom shelves, photographers had to learn to scale their negatives to their printing papers, and to adjust print contrast for between-grades, by the manipulation of exposure and print developers. A practical knowledge of sensitometry and basic chemistry was indispensable to serious photographers, and a wide range of testing and calibration procedures evolved to aid the photographer and darkroom worker.

Hybrid film/digital workflows represent a similar shift in the demands on the processing film to be scanned for either digital printing, or making digital negatives for contact printing, and suggests new criteria for film developers.

A film developer for film to be scanned should be optimized for producing the kinds of negatives that scanners are optimized to scan, or in other words, for maximum compatibility.

What kind of negatives do scanners like best?

Grainless
low contrast/ low-moderate density range
high resolution

And, while scanners don't care, photographers almost always prefer high film speed, long shelf life, economy, ease of use, and low toxicity, all other things being equal.

While there are developers commercially available that possess some of the characteristics listed above, none are optimized for the entire description, and other desirable characteristics could be added, such as: long tray life, compatibility with rotary processing, commonly available ingredients, etc.

I think we have within our membership the experience and expertise to narrow the many options to a few, high probability approaches to distilling something like an optimized developer for film to be scanned. I have a few ideas of my own, and more questions. I hope there is enough interest to generate some positive discussion and debate on the most likely approaches. I'll try to start the ball rolling by suggesting Pat Gainer's PC TEA, which I think satisfies most of the criteria, with the exception of the "grainless" one. It might be possible to use some variation of PC TEA as a two- part developer by diluting the concentrate with a sulfite solution. An even less toxic version might use glycol in the concentrate, and add a less toxic alkali to the B solution. In any case, I favor a simple, ascorbate/ phenidone concentrate made up in TEA or glycol, but I welcome alternative opinions, and I hope for many.

The only developer I know of which has been specifically formulated for films to be scanned is Speedibrews Celer-Mono designed by Michael Maunders.

[sanking]

I agree that a hybrid work flow in which we develop film to scan, rather than print directly on silver papers or with some alternative process, obviates the need for the exposure and development controls used with the Zone and BTZS systems.

For scanning the best negatives are those that are developed to a fairly low contrast because most scanners, especially consumer flatbeds, have the least trouble with negatives of this type. And it turns out that developing film to a low CI also minimizes grain and optimizes detail, or resolution.

Do we need to be concerned with micro-contrast, which results from acutance or adjacency effects, when developing negatives for scanning? That depends on the scanning equipment. Adjacency effect lines are very small and capturing them requires a scanner with very high real resolution (at least 3600 spi or higher). Consumer flatbeds, even top ones like the Epsons V700/750 and the Microtek M1, don’t have enough real resolution to capture edge effects. So if you are scanning with this type of scanner there is no need IMO to develop for edge effects. However, if you are scanning at effective resolution of over 4000 spi it is possible to actually record the edge effect lines, and this can add a great deal of apparent sharpness to the print, which becomes even more enhanced with magnification. You can of course simulate the look with unsharp mask in Photoshop but the look of sharpness produced by real edge effects captured in a scan is different from the look produced by edge effects created in Photoshop. I suspect that the extra sharpness that can be seen in high resolution scans made with professional quality CCD and durm scanners is due to the capture of adjacency lines because over-sampling sometimes gives more sharpness than can be explained by the detail in the negative itself in terms of pure resolution.


You can develop to a low contrast with any normal B&W developer simply by reducing development time, but if you expose your film over a wide range of subject brightness range you will still need to take notes. For this reason I have come to the conclusion that the best developer for scanning is one that allows two-bath development. With two-bath development you just make sure to give enough exposure for the deepest shadows where detail is desired and the mechanics of development pretty much assures that the film will not be overdeveloped. There are plenty of two-bath developers out there but most I have tried, divided D23, divided D76, and Diafine, don’t produce edge effects. Not important, however, with consumer scanners because you cannot capture them anyway with this type of equipment.

Sandy King

[Ken Lee]

This may sound silly, but... Some have found that consumer grade scanners deliver their best results out of the green sensor.

If we are considering an ideal film/developer combination for scanning, then perhaps a green image would be best.

[jnantz]

hey jay!

according to some ( myself included )... caffenol C

http://caffenol.blogspot.com/

[Ron Marshall]

This may sound silly, but... Some have found that consumer grade scanners deliver their best results out of the green sensor.

If we are considering an ideal film/developer combination for scanning, then perhaps a green image would be best.

XTOL is one of the "Greenest" developers.

[Mike Anderson]

hey jay!

according to some ( myself included )... caffenol C

http://caffenol.blogspot.com/

Interesting. Do you use caffenol C for most of your development?

...Mike

[jnantz]

i use caffenol C for pretty much everything ... 2+ years now ...
if i stand-develop i add about 100cc ansco 130 /1000cc caf C

the film scans ez and prints on paper ez too

- john