Expose for the shadows, develop for the ... scanner?

[Koen Van Crombrugghe]

Film, like paper, has its limits. A scene can have far more dynamic range than a film can handle but careful manipulation can bring compress that range to fit that of the film. (ever heard or pushing or pulling?)
All film base has optical density. The chemistry used to process the film increases this density with no exposure to the film. This is called Film Base + fog.
Any scanner regardless of software used and any editing software has a histogram. The base line of the histogram is film base plus fog labeled fb+f. A histogram is a graphical representation of the information contained in the scanned material.
View attachment 253613
0 on the histogram is pure black and at base line is no detail or in wet printing is paper black; 255 is pure white and at base line is no detail or in wet printing paper white. The dynamic range of the film or paper in use is irrelevant to these two points. Information contained on the scanned medium is registered above the base line. A perfectly exposed and developed negative with scene detail that fills the range of the film will have the blacks starting at 0 with the whites ending at 255.
View attachment 253614
A over exposed but correctly developed negative will have information above the base line at 0 which cannot be retrieved in either scanning or wet printing.
View attachment 253615
A over exposed over developed negative will have information above the base line at both 0 and 255 which is detail lost and not retrievable by any means.
View attachment 253616

Another way to state this is the exposure is set so that the deepest blacks are just above the start of the toe of the film and the development is such that the highlights end just before the shoulder of the film. Exposure that extends the scene dynamic range into the toe of the film is lost detail from the scene and development that puts the highlights into the shoulder of the film is also lost information. I have yet to see a negative whose detail put the peak of the information between the toe, histogram 0, and the shoulder, histogram 255, beyond the height of the histogram but one may exist and that peak of information will likely not be loss of detail.

Repeating, any negative whose deepest blacks are just above the toe of the film and whose highlights are just before the shoulder of the film will wet print well (not perfect) at paper black and will scan well on any scanner or scanning software.

I fully agree that completely filling the histogram with scene detail is the optimal result.
We just need to be careful that the scanning software is not tricking us and showing a histogram after some internal shifting and scaling which will impact the actual number of levels we are capturing.
For this reason I like to use Vuescan as the 'graph raw' histogram function will show the histogram directly as the data comes out of the sensor, without any adjustments applied.

I'm not so sure about your last statement; the location of the shoulder in film density depends heavily on the development.
If you look at this graph which I posted above you'll see that none of the three proposed curves show any real shoulder at all within the displayed range (well maybe a bit on the 6'):

But the density of the 11' curve goes well above 3, even when subtracting the fb+fog, so well above what my scanner (and I believe most paper) is able to handle.

 

[Koen Van Crombrugghe]

@Koen Van Crombrugghe Wow, just the other day I was thinking that I should do some sort of calibration on my Coolscan 5000. So I have some questions about how you accomplished your scan.

1. Which model (or size) Stouffer wedge did you use?
   
2. If you could do this scan all over would you get a different size wedge?
   
3. How did you feed the wedge into the scanner so that all the 21 steps got scanned?
4. Which scanning software did you use?

Phil Burton

1. I used a Stouffer t2115 (0-3 density in 21 steps, 1/2"x5") as it was the cheapest one I could find.

2. I would love to have a Stouffer tp35-21, but the only one I can find in my area is about €140+shipment, way to expensive for me

3. At first I scanned it with the FH-3 film holder so the step wedge spanned multiple frames. It kept shifting around which I hated so I decided to cut it into 3 strips and mount those side by side in a slide mount.
As they still kept shifting around I decided to put small dots of CA glue around the edges to fix the strips in position. This worked fine while scanning that same day. Overnight the CA glue reacted with the materials creating spots of fog. The density hasn't really changed but it looks really unprofessional now
I also have some IT 8.7 slide film targets from http://www.targets.coloraid.de/ which I will try to test with. The manufacturer states "Important calibration patches like neutral dmin/dmax (A16/L16) and dmin/dmax (GS0/GS 23) are reaching the limits of normal E6 film processing. This makes sure no highlight/shadow details are lost with scanner profiling software." but my first impression is that the Stouffer t2115 is a lot denser, which is odd as the slide film used in the IT 8.7 targets is able to reach more than 3 Dmax.

4. I have used both Nikon Scan and Vuescan. For this kind of testing I prefer Vuescan as it offers more low-level controls and allows me to save a raw image file directly from the scanner sensor without any adjustments made by the software. I used this method to do this test.

 

[Koen Van Crombrugghe]

Agreed! Instead of wasting time on misplaced ramblings on photography 101 here, a fun project is to take your favorite film and break it into, say, 3 short rolls and shoot the same controlled, hopefully tone-rich and high-dynamic range scene on each roll with under/over exposure. -2, -1, 0, +1, +2. Then you develop each roll gradually increasing development time. Then you scan them all and it becomes very clear what the limits of your film and scanner are. No need to trust the specs. You'll see that density is generally your friend, both from the dynamic range perspective, but you get nicer grain too.

This is indeed what I intend to do. So far I have developed one roll to a density of 1.8 using default development time, and one roll to 3.0 by increasing the development time by 30%.
Based on the scanner tests I will target a density of about 2.6 (2.4+fb+fog) in my next development.
This brings me in about the same density range as a standard developed C41 color negative.

 

[shutterfinger]

@shutterfinger, saying "if it prints well it scans well" is absurd. You have not communicated anything that everybody here doesn't already know. I can contribute! One must make sure there's enough available flat surface under the enlarger or the paper may not fit, so if there's a bowl of fish eyes in the way, care must be taken. Also, your house must have electricity to engage in wet printing. Should I continue "arguing"?

So is your reinvented wheel circular, elliptical, or new to the world geometric shape?

Scanner raw is the only true identifier of the negatives tonal range. Auto exposure has a tendency to clip shadows and highlights to make a good picture and is why I prefer to edit in post not scan software.

For this reason I like to use Vuescan as the 'graph raw' histogram function will show the histogram directly as the data comes out of the sensor, without any adjustments applied.

I have EpsonScan, Silverfast Ai6, Silverfast SE8, and Vuescan. I like Vuescan the least and only use it with scanners (Plustek) that do not run on Windows 10.
A negative that is exposed and developed so that its deepest blacks and brightest highlights are in the central 2/3 of the film's range do not scan or print well.

I'm not so sure about your last statement; the location of the shoulder in film density depends heavily on the development.

Development can and will increase density to the point to where light from a scanner or enlarger will not penetrate the density.
I have a sheet of film, 100 ISO, that has been exposed to light for days and when put in front of a lens and looking at the sun on a clear day the sun is a round spot, a double layer of the film blocks the sun completely. I bet if I processed it normally I would get the same results. How dense do you need you negatives to be to get your ideal scan?

Now, are Washing State Apples better than Georgia Peaches, Florida Oranges, and California Alvarados or are they all equally good. (hint: it depends on their ripeness)

 

[shutterfinger]

have developed one roll to a density of 1.8 using default development time, and one roll to 3.0 by increasing the development time by 30%.

A 25% increase in development time is a 1 stop push.

 

[Koen Van Crombrugghe]

A 25% increase in development time is a 1 stop push.

I think that's oversimplifying things a bit. It depends a lot on the developer used and the process temperature.
I got the 1.3 factor from the following chart in the T-Max 400 datasheet:

Maybe I'm trying a bit too hard to make this an exact science, that's the engineer in me I guess

 

[MattKing]

Let's see how you'll do



Ok. Should I copy-paste a random banal truism from a photography book in response? Of course it's true and nobody was arguing. But what is also true, is that a scanner is capable of pulling even more information out of the negative. Paper doesn't translate anything, it simply "throws away" data it can't capture. Scanning is a higher bar.



Why are you saying it? It sounds like a copy-paste from a random photography book.



No. Not the same. Much more. You didn't really talked about this very point I was making, instead just repeating random truisms.

No truisms, just experience.
A negative that is well exposed and well developed will be easy to print optically and scan effectively.
Some types of poorly exposed or poorly developed negatives may scan better than they will print optically.
Some types of poorly exposed or poorly developed negatives may print optically better than they will scan.
And you can optimize your negatives for the output you are seeking: whether you print optically on silver gelatin paper, or make contact prints using traditional or historic processes, or make digital negatives designed for those same processes or scan for eventual digital display.
When Zone System practitioners expose and develop their film in a manner that permits them to contact print their negatives on to fixed grade paper, they are doing that sort of optimization. It just so happens that the resulting negatives will also enlarge well on to variable contrast paper, or scan well too.
If you do any of those optimizations, you will find that there is a range for which each is effective, and that those ranges overlap.
The central sweet spot of most of those ranges is the optimization for which the film was designed - an optical print on photographic paper.
The outliers are those traditional processes which were designed for different materials.
If you are attempting to use a scanning system that doesn't work well with a traditionally exposed and developed (for optical printing) negative, your scanning system isn't suited to the job. If you distort the film's response to try to fit it to your scanning system, you will cause it to perform at a less than optimum level.
Scanning science and scanners are quite advanced. Good equipment in the hands of experienced and skilled operators has tremendous capabilities - just look at the digitized results from the decades of fine work done by Fred Herzog (to pick an example). All of his Kodachrome (mostly) slides were taken long before scanning existed. They were designed to be projected and, in some cases, printed using Cibachrome materials. If you see any of the fine recent prints made from scans, you will understand that film that has been well exposed for projection or printing is perfectly suited to scanning as well.

 

[radiant]

What I have found out is that unprintable negatives can mostly be saved with scanner. Under-developed negatives can be have so low contrast that it is impossible to drag the contrast to any usable range with multigrade filters but scanner can do it. I have also "saved" many underexposed negatives digitally. I'm not saying that everything could be saved with scanner but I'm pretty sure many negatives can be.

I have banged my head to enlarger so many times because of trying to print bad negatives which looked good after scanning. I now can easily see good negatives by just watching against available llight.

I haven't yet found a negative that is printable but un-scannable. I even don't know the characteristics of those.

 

[MattKing]

I haven't yet found a negative that is printable but un-scannable. I even don't know the characteristics of those.

I'm better at printing severely over-developed negatives than I am at scanning them. That may be related to the scanners I've had available to me.

 

[radiant]

I'm better at printing severely over-developed negatives than I am at scanning them. That may be related to the scanners I've had available to me.

Over-developing usually increases the contrast because highlights become more dense while shadows gain density slower. Aren't dense negatives just "slower" (if the contrast is acceptable) - is there some other differences when printing?

 

[MattKing]

When I speak of contrast, I tend to be referring to the transitions between similar tones - so called micro-contrast.
I think you may be referring to macro-contrast - the difference between the darkest blacks and brightest highlights.
If you go to far, over-development can result in highlights being so blocked up (so far into the shoulder) that it is difficult to differentiate the details within them. The highlight micro-contrast disappears.
It is that sort of negative that I am better at dealing with using an enlarger than a scanner.

 

[radiant]

When I speak of contrast, I tend to be referring to the transitions between similar tones - so called micro-contrast.
I think you may be referring to macro-contrast - the difference between the darkest blacks and brightest highlights.
If you go to far, over-development can result in highlights being so blocked up (so far into the shoulder) that it is difficult to differentiate the details within them. The highlight micro-contrast disappears.
It is that sort of negative that I am better at dealing with using an enlarger than a scanner.

Yes, I meant macro-contrast. How does micro-contrast work? This is probably unknown to me. I mean, isn't film "linear" in sense that the tones "map" no matter what kind of macro contrast you have?

And yeah, on over-development one has limits too to not make highlights too dense (and the micro contrast too low).

My point also was that scanners have limitations on the density which darkroom doesn't have. Scanners have maximum density those can peneratre while in darkroom that just means more light or more time (again, expecting that the macro contrast is within printable limits).

 

[Bormental]

What I have found out is that unprintable negatives can mostly be saved with scanner...

I haven't yet found a negative that is printable but un-scannable. I even don't know the characteristics of those.

Exactly. Scanning+post-processing is about stretching all of the available DR on a negative, while printing is shrinking. "What prints well scans well" is absurd because printing is just a subset of what's possible with scanning, it's like saying "if this car can go 100mph it can go 200mph".

I have no idea why Matt and others keep walking around the basic science by (what feels like quoting) tangentially related obvious truisms about perfectly exposed negatives. So many interesting conversations on photrio get stalled by walls of texts about photography 101, IIRC I saw someone above explaining (to whom? did anyone ask?) what a histogram is. I guess too many of us have the urge to teach! Gotta suppress that every once in a while and focus on what's being discussed. Otherwise, I swear to god, I will find an electronic version of a book on DSP and will start copy-pasting chapters from it here. Eye for eye!

 

[radiant]

I have no idea why Matt and others keep walking around the basic science by

Chill down, man. There is no need to attack anyone here. If you think someones postings are too basic, just skip them. Sometimes (I don't mean Matt here) people just haven't got right words for things and not all of us are great writers either. My native language isn't english and I'm constantly using wrong photography terms but still people are friendly and try to help. Matt is a great guy and he doesn't try to harm you, I promise

 

[Bormental]

Matt is the best!

 

[PhilBurton]

Exactly. Scanning+post-processing is about stretching all of the available DR on a negative, while printing is shrinking. "What prints well scans well" is absurd because printing is just a subset of what's possible with scanning, it's like saying "if this car can go 100mph it can go 200mph".

I have no idea why Matt and others keep walking around the basic science by (what feels like quoting) tangentially related obvious truisms about perfectly exposed negatives. So many interesting conversations on photrio get stalled by walls of texts about photography 101, IIRC I saw someone above explaining (to whom? did anyone ask?) what a histogram is. I guess too many of us have the urge to teach! Gotta suppress that every once in a while and focus on what's being discussed. Otherwise, I swear to god, I will find an electronic version of a book on DSP and will start copy-pasting chapters from it here. Eye for eye!

What he said.

 

[MattKing]

Exactly. Scanning+post-processing is about stretching all of the available DR on a negative, while printing is shrinking. "What prints well scans well" is absurd because printing is just a subset of what's possible with scanning, it's like saying "if this car can go 100mph it can go 200mph".

Have you ever made a good quality optical print from a negative that you were unable to obtain a good quality scan from?
Have you ever exposed and viewed a well projected and well exposed slide that you were unable to obtain a good quality scan from?
And with respect to the scans you have, what do you do with them?
I have a feeling you don't target much of what you do to reflection media - prints.
In my experience, the most demanding use of a scan (or a digital camera file) is to make a print from them.
Poor scans often look okay on a screen but look wretched in a print.
The dynamic range of the presentation media is usually of relatively little importance. And it is relatively easy to match good quality source material - whether negative, slide or digital file - to the dynamic range capabilities of the presentation media.
It is the image detail and contrast and colour and tonal relationships within the presentation (not storage) media's inherent capacity for dynamic range that determines the quality of the final image. And a well exposed and developed (for optical printing purposes) negative is easy to scan for the purposes of creating a digital file that can then be used for making a good quality reflection print, or a good quality higher dynamic range transmission print, or a good quality image on a relatively low resolution but high dynamic range monitor.
In my experience a negative that prints poorly in the darkroom is less likely to yield a good quality scan.

 

[Alan Edward Klein]

No truisms, just experience.
A negative that is well exposed and well developed will be easy to print optically and scan effectively.
Some types of poorly exposed or poorly developed negatives may scan better than they will print optically.
... If you see any of the fine recent prints made from scans, you will understand that film that has been well exposed for projection or printing is perfectly suited to scanning as well.

That's what I;ve found. I have a lab process my film normally. No pushing or pulling. When I bracket my shots, +1, 0, and -1, both with Velvia 50 and Tmax 100, the one that looks exposed best consistently scans the best.

 

[Bormental]

Matt, the question was not about what someone has experienced in their lives. It was much simpler: "do I need to optimize development to extract maximum dynamic range from a negative in a scan?".

Replying to that that "dynamic range is of little importance" and sharing personal experiences with printing is kind of off-topic. I think we all agree here that quality of the image is mostly about subject, light, photographer's skill and even personal preferences of a viewer!

Yet, the question was not about what we think a quality image is, it was about the dynamic range, which is a much simpler and concrete concept deserving a simple and obvious answer. Scanning is a superset of printing, so yes, to get the maximum DR one needs to develop very, very precisely to get the maximum out of film.

I think of scanning as an archival activity. A well-made scan allows me to throw the negative away. I can see why the OP wants this to be done right. "When it prints well..." is inappropriate in this context.

 

[PhilBurton]

So is your reinvented wheel circular, elliptical, or new to the world geometric shape?

I have EpsonScan, Silverfast Ai6, Silverfast SE8, and Vuescan. I like Vuescan the least and only use it with scanners (Plustek) that do not run on Windows 10.
A negative that is exposed and developed so that its deepest blacks and brightest highlights are in the central 2/3 of the film's range do not scan or print well.

@shutterfinger

I tried to start a conversation with you, but the system blocked me when I tried to send it. Would you mind starting a conversation with me so I can reply. Thanks.

 

[MattKing]

Here is the question asked by the OP:
"As I scan all my negatives and have no intention (now and in the foreseeable future) of doing any dark room printing I would like to optimize my negative development to obtain the best possible results from scanning (I'm using a Nikon Coolscan 4000)."
The rest of the OP's response discusses dynamic range.
In summary, I am saying that best possible results don't come from changing the dynamic range from the range inherent in a well exposed and well developed (for optical printing) negative.

 

[MattKing]

A well-made scan allows me to throw the negative away.

Unwise in the extreme.

 

[PhilBurton]

Unwise in the extreme.

Could not agree more. Same for scanned slides. I only throw away negative strips that are just bad photos, or discard the "culls" from my slides.

 

[Alan Edward Klein]

I made digital slide show when my projector broke. I then threw away the slides. I didn't see ever going back a second time to scan them again and make another digital slide show. I do admit that was a mistake for the first bunch as I was not that good with scanning. But I still doubt I would have gone back to rescan all of those slides again. You have to be a gluten for punishment. The finished product of a slide show was given to family and kept for myself as well. I'm done. It's kind of like old photo albums. When the prints came back from the lab, you put together an album of the trip or party. Of course I kept the negatives for years. But never once except of a rare occasion did I ever go back to do anything with the film. They stayed in a shoe box in the closet and never looked at again. An in between solution would be to keep just the few slides that are really keepers.

 

[Bormental]

Unwise in the extreme.

Fair enough. It should be noted, that this can be done (in my circumstances) only with 35mm B/W negatives. I get 100% of information out of them in terms of resolution and dynamic range, no need for a lecture here (trying to be preemptive), my B&W 35mm scanning is superb. Plus, I have the comfort of doing data management professionally (RAID, checksums, four append-only backups in four separate locations).

I am nowhere close to achieving this with medium format or color, so perhaps I should have added some disclaimers.