Do you expose and develop film in the same way for scanning as for printing?

[maponline]

This question is really for those who master both activities.

In analog photography one is encouraged to expose for the shadows and develop for highlights, whereas in digital photography, it is usually best to expose for the highlights and process for the shadows. So what do you do when you shoot film with the aim to end up with a digital file?

Most of the advice out there re how to capture and develop an image on film seems to be based on the assumption that you are going to print it optically. But does the process of digitalization mean that you might want to work differently when you know you are going to be scanning (and probably further digital-processing) the negative?

There is a corollary question to that: in my first scan tests and in tutorials I saw online, bumping exposure of the digital file seemed necessary even with negatives apparently properly exposed (and I'm talking about a dramatic +1 to +2). Is that normal? If everybody gets that, where should you bump up the exposure in the scanning process of your negative, in order to keep maximal image quality? I've seen people do it in the last stage (Lightroom), which does not sound right to me (when shooting digitally, bumping exposure up in Lightroom is the best way to add noise to the shadows). Other options are at scanning time (within Vuescan, SilverFast, etc.) or at the moment you convert the negative into a positive (ColorPerfect in my case, with the "Black" slider). I've started running some tests but I'd love to hear any thoughts on that, ideally with examples of pictures if you have them so everyone is clear what we are talking about.

Many thanks for your help!

 

[hsandler]

It's a good question, and I am not sure of the answer. I only scan. for b&w, what I have found is thatvery dense (overexposed or overdeveloped) negatives scan very grainy, but even my cheap Epson v500 can see quite deep into the dense highlights so they don't clip, as do digital exposures. (Not so for seep shadows in slide film though.) In general, negatives exposed and developed to spread the density widely from very thin to reasonably dense seem to scan with least apparent grain. I usually expose at box speed and develop according to the massive develment chart. I have tried pulling one stop which works well with delta 100, but does not seem necessary with acros.

I don't think leaving some extra space between the white point and the start of the white information in the histogram on the scanner hurts. yes, you have to adjust the white point later in photoshop, but you don't run the danger of clipping, qnd the noise in the scanner is fairly negligible. I think the low end scanners are only doing digital manipulation with those sliders anyway, not really changing the gain for the scan. I scan at 16 bits, so losing less than one bit is not going to hurt.

 

[Alan Klein]

I agree that the scanners are only applying software edits to the white and black points. The results come out very similarly if I compare the scanner software adjustment results to scanning flat and adjusting white and black points in post. The gain is constant regardless of the selected auto control settings and would be optimized to the highest gain without distortion by the manufacturer to get the highest Dmax to "see" through the dense parts of the film - whether negative or positive. Reducing gain would only make it worse.

An interesting experiment you can do is scan in Preview mode. Then go to the Auto Color selection and switch it off. You see a "raw" image scan from the scanner eited image. Or do it the opposite way. Scan "raw" and then after the scan click the box that says Auto Color. The "raw" image is color corrected. Now of course there was only one scan. So the application of "raw" or "auto" had to be applied to a single scan result = the raw data which came from the scan. That same data would be sent to your computer for application of post processing edits. It's sort of like getting a raw or jpeg from a digital camera. It both cases neither the scanner's sensor and gain nor the camera's sensor and gain changes, just the software edits being done in camera or in computer or scanner.

 

[L Gebhardt]

Yes, I develop them the same. I've found that a negative that prints well on grade 2 or 3 paper will scan well. If it's thinner (needing grade 4 or 5) the scan is more likely to show posterization when worked on (due to a low tonal range). If it's a denser negative (needing low grade of paper) you increase the appearance of grain in the film. Also depending on the quality of the scanner you will also get more noise in the dense parts of the negative. Being a negative this noise will be in the highlights in the final image, where it's much more visible than if you scanned a transparency. So I find it best to target my film development for a gamma of about .5 to .6 for scanning. I like the lower end of the range for darkroom work on VC paper, so I aim for .52.

 

[lenny]

This is a topic that gets religious... I have a drum scanner, and I develop my negatives to about 1.5 or 1.6. That's a bit denser than you would for silver, more like .9-1.1.

My answer, is that yes I do, I develop differently for scanning.

Lenny

 

[maponline]

This is a topic that gets religious... I have a drum scanner, and I develop my negatives to about 1.5 or 1.6. That's a bit denser than you would for silver, more like .9-1.1.

My answer, is that yes I do, I develop differently for scanning.

Lenny

Thanks for this. Sorry to be ignorant, but how do you decide to develop "to 1.5 or 1.6" or any other number? Many thanks.

 

[L Gebhardt]

Thanks for this. Sorry to be ignorant, but how do you decide to develop "to 1.5 or 1.6" or any other number? Many thanks.

There are a lot of ways to express film development with numbers. I think Lenny is giving you the max density for a zone 10 exposure, but that may not be right. When I mention a gamma of .52 this is the slope of the film curve.

To determine either number you ideally will have a densitometer, which is a device which measures film density. Then you can expose the film through a step wedge, which is a piece of film with a range of known densities. By plotting the exposure (from the step wedge) against the resulting film density you can get the slope, or gamma, as well as the density. Most step wedges have a range of about 10 stops broken down by 2 or 3 steps per stop. Sensitometry - Wikipedia, the free encyclopedia and negative density should get you started.

 

[Richard Boutwell]

The majority of my negatives over the years have been developed for contact printing on Azo or making platinum/palladium prints so they are almost always on the denser side. Most of my roll film was usually been developed about 20% or more longer than "recommended" and the last few years I've been doing the Shawn Dougherty semi-stand diluted Rodinal process. I tend to do a mix of rodinal or pyrocat, depending on what is around the darkroom and how much time I have. Pyrocat is usually continuous or near continuous agitation for whatever the standard recommended time is (depending on what/where I photographed), and the Rodinal is 40-min agitating a min every 10 mi—i can't remember the dilution off the top of my head. 1:100 to 1:150 maybe?.

I am of the mindset that it is better to have well exposed (but not over-exposed) shadows to be able to capture all the detail possible without introducing too much noise/artifacts when scanning and then trying to bring out detail in the darker areas—it is easier to push down detail with a curves adjustment that try to bring out what it doesn't exist in the negative. Then I kick up the midtone separation up a bit by slightly overdeveloping (for gelatin silver enlargements). The worst thing about digital prints for me is flat empty shadows and mid-tones with "lots of contrast" but no fine mid-tone separation. I think the slight additional exposure and development tends to alleviate some of those issues.

I remember Sandy King mentioning that a divided pyrocat was a good idea to get a long flat negative that you could increase contrast digitally. I figured it was worth exploring and tried that with about 5-10 rolls. Those scans needed a whole lot more work in photoshop than usual, but some were totally unusable. I went back to my standby and never looked back.

Richard Boutwell

 

[maponline]

I am of the mindset that it is better to have well exposed (but not over-exposed) shadows to be able to capture all the detail possible without introducing too much noise/artifacts when scanning and then trying to bring out detail in the darker areas—it is easier to push down detail with a curves adjustment that try to bring out what it doesn't exist in the negative. Then I kick up the midtone separation up a bit by slightly overdeveloping (for gelatin silver enlargements). The worst thing about digital prints for me is flat empty shadows and mid-tones with "lots of contrast" but no fine mid-tone separation. I think the slight additional exposure and development tends to alleviate some of those issues. Richard Boutwell

Thanks a lot Richard, what you say makes sense to me. Do you have maybe links to examples for the various scenarios you mention (especially ""lots of contrast" but no fine mid-tone separation" vs. "kick up the midtone separation up a bit by slightly overdeveloping"?). That way we'll be able to visualize what you advocate. Many thanks!

 

[maponline]

There are a lot of ways to express film development with numbers. I think Lenny is giving you the max density for a zone 10 exposure, but that may not be right. When I mention a gamma of .52 this is the slope of the film curve.

To determine either number you ideally will have a densitometer, which is a device which measures film density. Then you can expose the film through a step wedge, which is a piece of film with a range of known densities. By plotting the exposure (from the step wedge) against the resulting film density you can get the slope, or gamma, as well as the density. Most step wedges have a range of about 10 stops broken down by 2 or 3 steps per stop. Sensitometry - Wikipedia, the free encyclopedia and negative density should get you started.

Thanks! This is helpful.

 

[Alan Klein]

My scanner has densitometry readings and test points. How would you use that to improve scans?

 

[lenny]

I spent plenty of time plotting things all over the place. Some numbers made a lot of sense, and some didn't. A few years ago I decided to tacked a different tack. I chose to test in real life. I did a series of images until one negative was so good that it damn near "printed itself". That became the new "perfect negative". Then I measured that, and that be became the standard for how dense the neg should be for scanning. I'm lucky to have a wonderful scanner and it can handle that range easily. Maybe not so with the consumer level ones.

However, none of the numbers matter. That's the real truth. What matters is that you can make a print that is exactly what you want, within the contrast range you want, with all the shadow detail, highlight detail, midtown separation and everything else. I have a print that I made here where you can tell it's winter light vs summer light. That takes quite a bit of sensitivity and a perfect range.

With all due respect to the engineers among us, all those tests do is help you develop the discipline to reproduce your results. It's the print you can make that matters.

I can't tell you how many people (my scanning clients) have used a hyperlocal distance calculator of some sort, some f16 stop and asked me why they didn't have the range of focus they expected. People need to do the printing test - does diffraction matter, and most of them will conclude, as I did, that diffraction is too small a factor to be concerned with for large format lenses, or at least mine... everyone should do their own test. If they want to use filters, and they wonder how much sharpness they will lose going thru a plastic filter - test it.

However, doing a test where you take a picture of the air force test target will get you nowhere, all modern lenses are pretty good. Do a test of what you're photographing.

We can all bracket, both in exposure and development easily enough. One of them will yield the results we need. If we record what we did, we should be able to do it again, or get very close. I have a development time chart in my bathroom. Every time I develop I use those times. If the neg is slightly dense, I'll knock a bit off the time. After a few years, you get it spot on.

The hardest part of the printing process is knowing what you want. One has to look at prints, decide what area of photography you feel the best in, decide the contrast range you like, and then go after it. I like looking at Stieglitz, Paul Strand, Paul Caponigro, Frederick Evans, Weston, and many others. I have been looking at a lot of images from the photo-secession lately. They may be a little soft (I'm not much for soft focus) but the lighting and delicacy of the prints is exquisite. If you study these results, you will see where these photographers were reading the light, how they developed a sense of atmosphere in their images. It takes studying this, then considering your own work, and how it should fit... do you want to be a little more contrasty, but not as much as this one, etc. We have a very rich history...

I've been working a lot with papers that are translucent these days. The light bounces off the mat and the images are somewhat luminescent. It takes a lot to get it right but when it does its delicious. You know you have things right when you use words usually reserved for food to describe things... let that be your measure.

Lenny

 

[removed account4]

i process my film the same whether it is for digital enjoyment or for printing on paper or glass.
i tend to make my film a little dense .. and split process between 2 developers .. caffenol c (made with sumatra beans )
and i used to use ansco 130 .. but now have settled in on dektol.