Matching Film Curves to Scanners and devices

[Ellen Stoune Duralia]

Ok... well maybe I was making things more complicated than necessary and thinking I was missing something. (I have a tendency to do that.) Anyway, Ron, that's what I've been doing as well.

Thank you for the clarification, Michael and Ron. Oh and Michael, I am really looking forward to reading the upcoming article.

[Kirk Gittings]

Michael,

I look forward to the article. You guys are making a great contribution. I am intereted on any information on scanner profiling with color and b&w negs. Silverfast and Monaco both do either transparencies or reflected art. Will you guys deal with that at all?

[Kirk Gittings]

About clipping when using the 4990 scanner and Silverfast AI 6 Studio.

I just went to scan something and was thinking about my workflow. For myself it doesn't make any sense to do the clipping in the scanner software because the preview is so poor. I reverse engineered a scan that I did last night-my normal way unclipped until I get it into PS. If I had clipped it in Silverfast with the low quality of the preview I would have clipped too much out of the highlights and shadows. By waiting until PS I could look carefully at the small highlights and deep shadows and make appropriate clipping decisions that I could not begin to even see in SF.

[Harley Goldman]

Kirk,

Are you then saying you leave the highlight and shadow sliders all the way to the outside for every scan? Is that what you mean by scanning unclipped? ( I am scanning on a 4870 using Silverfast Ai).

[Kirk Gittings]

Harley,

That is exactly what I mean, but I am very careful about framing so no extraneous stuff like the film holder or film edge in included in the prescan area or considered by the histogram to prevent the skewing of the histogram as Michael talks about above.

[Michael Mutmansky]

Kirk,

Profiling for negatives is complex, and can be a real problem for a few reasons. I don't think there will be room in the article to discuss profiling because it is really an article unto itself.

Profiling is generally an attempt to get a direct correlation between the source and the output in some logical manner (producing a linear response in the image file that relates to the changes in density of the original, for example). This can be done for B&W the same as for chromes (in fact, the profiling for chromes will help produce a good linear response for B&W, so it probably wouldn't need to be done in a special manner), but that doesn't necesarily result in a scan that looks good on the screen.

The article will explain (hopefully, in language that people can understand) why many people have difficulty with B&W negatives, and provide a little help to get over that hump and into quality scans from B&W negatives.

I haven't worked the entire issue of profiling for B&W in my head yet, and so I haven't tested my current hypothesis about profiling B&W. However, I have a feeling that profiling is unnecessary, and the unnecessary manipulation of the image file could result in more trouble with banding and loss of data later on. This applies only to B&W scanning, not to color.

---Michael

[tim atherton]

have any of you tried the NegPos plugin for photoshop, working from a raw file? (that is, an unadjusted scan, not a digital camera RAW file)

A bit of a learnign curve, but I find it excellent for colour and B&W (the maker just put out a new version that I'm not happy with - the orignal seems to work better for me)

extensive info on the site - small one man and his dog setup

http://www.c-f-systems.com/PhotoMathDocs.html

[Henry Ambrose]

There is the possbility of making a 16 bit unadjusted scan and working on it in Photoshop. At this point you are free from relying on the whims of the various scanner software. I know this sounds extreme but you can do this with great success and learning Photoshop well is a better use of your time in my opinion. This is especially the case if you have more than one scanner or when you buy a new machine. You still know Photoshop so ytou don't have to re-think your entire way of working.

I don't think that there is a possibility of a profile for color or B&W negs.

For color negs the orange mask is variable from run to run so you'd be profiling each day or even each set-up. Its still not reliable even then as slight changes in exposure will change the relationship of the color layers to the mask.

For B&W its not needed - there is no color to manage. Curves will take care of anything you need there. If you are using the "Photoshop and 16 bit scan" workflow you can save a curve in PS for your typical films/developer/scene type and apply that to your 16 bit scans. Or some scanning software lets you save curves to apply repeatedly.

Ellen it sounds like you are setting your black and white points correctly. I suggest that you leave a little room on each end to be sure you get all the info you can and as Kirk stated be sure to include in the scan only the image area and no extraneous out of the frame film.

To further answer the original question, keep in mind that you can do a lot of adjustments in Photoshop or in scanning but you still don't want all the info "balled up" in the middle of the histogram. (unless you want an image with pretty much the same tones throughout). So in thinking about how to expose and develop your film for scanning just go back to how you did it for darkroom paper. Have an intention of what you want the print to look like and apply that intention to getting info to your scanner and into your computer. There is lots of room to play in PS but its lots easier if you hit close to the mark in the beginning. At the same time a super high level of precision in manipulating your film exposure and development is not needed.

The advantage of color neg film like NPS is that it will put good usuable info on the film in a way that you can easily get it into your computer - and thats without any changes in development or screwing around.

The advantage for scanning B&W film is that you can use it to make conventional darkroom prints too - not just digital prints. And if its easier for you to process your film at home in simple processes/chemicals then B&W neg may be a better way to work for you.

[Jeffrey Sipress]

Thanks for the valuable input, Henry.