How to build a scanning curve?

[Henry Ambrose]

What if you scan B&W negs in RGB mode?

OK, go do this and come back and explain how it worked for you.
; >)

[Kirk Gittings]

I understand that, but those will not work with color negs right? At least my conversations with the engineers at Silverfast indicated that they wouldn't otherwise they would be offering them (there is a huge demand for them, as they do IT8 transparency targets and processing software in SF AI Studio and no other sw/scanner manudfacturer offers them either as far as I know). The SF engineers would not tell me however, how they did generate their color negative film profiles. Hence tweaking the existing profiles is all we can do.....In SF AI Studio there is a whole separate set of detailed information and tools in the Negafix Expert Dialoge for interpreting and modifying the scans and saving modified profiles.

[Henry Ambrose]

Its possible to make an internal profile of sorts for color negative but it will only apply precisely to the particular piece of film and particular conditions of exposure and processing. So if you try to use it for a bit different exposure or the lab just changed the chemistry its not accurate. There's a whole 'nother step involved in converting the negative color image into positive thats outside of normal ICC profile building. But at least they do give us internal film profiles that get us started down the right path. Internal meaning that its for use by the scanning software to convert the negative to some positive colors and not by the operating system color management.

You have a positive thing in your hand that is a particular color to refer to. The light blue (or whatever color) in your color transparency is the reference. That actual color is described mathmatically when it is digitized. Numbers and calculations are used to make sure that when your scanner says this is "light blue" (the number that represents light blue) your monitor understands exactly what "light blue" means after a calculation occurred that told it how the scanner renders the color and how that monitor should render the color. Same for your printer.

You do not have a positive reference in a color negative. How would you make a color profile for something that does not have a positive reference? A profile for something that's not there?

[Bruce Watson]

I am sure that Bruce & Kirk both know what they're about. But maybe it's easier stated in this most basic way: "you must get the scene information onto your film in a way that your scanner can see it".

That's the bottom line, yes.

Henry, if I were any good at writing/speaking I wouldn't need photography so much ;-)

[Kirk Gittings]

There is a LF photographer in the Midwest(I think), who does commercial drum scanning, who is known for his advocasy of scanning color negs. I can't for the life of me remember what his name is. I think his last name started with a B. Anyway I seem to remember some interesting info about scanning color negs on his website.

[Kirk Gittings]

That was Dan Burke, but my memory was wrong. Though he is a strong advocate of color negs, there is not in fact much info on his website.

[Chris_Brown]

OK, go do this and come back and explain how it worked for you.

Actually, there is a reason I mentioned scanning B&W negs in RGB mode, and it pertains to Imacon and PMT drum scanners. This may be moot to you, but others may find use for this info.

Both these scanners have independent capture elements for each color. The Imacon has a tri-linear CCD array, and PMT drum scanners have three photo multiplier tubes.

Since 2000, I've been using a Howtek drum scanner with Trident scanning software and it gives the option to scan in grayscale mode using one of the PMT channels. I tried it with each channel, but felt I was ignoring usuable data.

I don't print in grayscale mode on my printers (Epson, Canon) and usually apply a tint for content enhancement. To me, it makes sense to scan B&W negs in RGB mode.

As Caponigro says, "If you can see it, it's color."

[Henry Ambrose]

I didn't say you couldn't scan a B&W in RGB. For some older scanners this is a good way to get cleaner scans - its an old trick. But this has nothing to do with color profiles or the original question in this thread.

And I'm not putting down you or how you work - I was just trying to clear up the conversation and make the point that color profiles do not apply to B&W scanning.

I envy your scanner. That sounds like a great outfit. I bet you can make some great scans with it.

[Kirk Gittings]

It is even a good practice to scan in RGB with modern consumer scanners as one channel tends to be sharper and less noisy than the other two or a greyscale scan.

[Stephen Sample]

I started this question thread. There is a lot here to study and digest and it has been very helpful. I am getting pretty good 4 x 5 B&W negatives using the Steve Simmons Film Speed and Developing Time procedure. My contact print proofs are verifying this. I just received a refurbished Epson 4990 scanner and will be starting to scan those 4 x 5 B&W negatives using all of this advice. I also will make and use the input parameter controlled scene. Thank you for the seminar in scanning!

One more question about color positives. The scanner deal came with Silverfast SE, which Silverfast will update to the new version free of charge. This seems to be a quality outfit! I plan to learn the SE first. They will also give me an upgrade price on Ai and additional features. I do want to profile my scanner when I start scanning my 4 x 5 color Velvia 100F transparencies. How good and how good of a value is the Silverfast IT8 optional package? What are some other profiling packages that might do a good job and be cheaper?

Thanks again to everyone of you!