Joanna Carter wrote:It's a bit like the end quote I see on messages from a contributor on one of my software development groups: "I want to live in Theory, everything works there"
I like that! But then I'm slightly idealistic and stubborn, I keep hitting it till it does work
Joanna Carter wrote:Well, I have no reason to doubt the effort behind Wolf Faust's targets, and they are hand-measured for the particular colour dyes
They're just targets, each one individually measured. They're not formulated for individual dyes or anything, at best they may be created with an output profile, which would help to get the values on the emulsion as close to the intended value as the film will allow, but they're just standard IT8 produced on different films. What's
on the target is not so relevant, the value is that they're accurately measured.
Don't get me wrong, I'm not having a dig at Wolf Faust, I think his targets are very good ( I have one! ) and he's not doing anything different from Kodak or Fuji with their targets, and he's a good deal cheaper than they are! I would buy his targets in preference to all others except Don Hutcheson's. If Wolf were to dig a little deeper and maybe design a new target specifically for profiling scanners, he could be sitting on a gold-mine, he has all the equipment to do it.
Joanna Carter wrote:which, according to Tim and others, is relevant to how the light is transmitted through the film
Tim talks of Metamerism, which is the phenomenon where a colour can appear different under differing light sources, however, we're not dealing with differing light sources ( unless you're planning on changing the scanner bulb after every scan! ), we're dealing with one light source, one scanner. Interestingly, in Tim's two profiles of his V and N targets, the white point is absolutely identical, the bases of those two films are the same.
Joanna Carter wrote:Don't forget, in profiling, I don't want to eliminate the differences in tonality and saturation between, say, Astia and Velvia, I want to scan colours that are true to the way a particular emulsion renders them, not simply "true" to the "colour numbers"
I think we may have hit upon the problem. If I'm reading that right, you're under the impression that the ICC profiling of your scanner is intended to
change the colours or perhaps in some way
homogenise the colours or casts in the source material? or perhaps munge them down into some common denominator of "true" colour? That's really not how it works. Remember, we're profiling the
scanner, once we've worked out the casts and range of the scanner, it can see whatever is in front of it. Your scanner doesn't suddenly develop a magenta cast when you put Velvia over it, or a cyan cast when you put Astia over it, it doesn't know or care what you put in front of it. Think of it as simply removing the tinted spectacles of your scanner so it can see clearly.
Your scanner ICC profile really contains no information from your target, it's used to generate a map of the capabilities of the
scanner and then discarded. It never had the information of what emulsion is used, it never had the original target colour values either, it has two pieces of information, what the scanner sees, and the spectrophotometer reading.
A good scanner profile will see what's in front of it,
whatever is in front of it. If you put Velvia in front of it, it will see Velvia, Astia and it will see Astia, and all the subtle differences between them. Scanner ICC profiles will remove the casts and neutralise the
scanner, not the source material.
Joanna Carter wrote:I use Wolf Faust's targets, not because they are scientifically correct but because they give me superbly good scans that are true to the "feel" of the film I am scanning.
Try not to think of targets as "correct",
none of them are
correct, they just are what they are, but as long as we have accurate measurements of them we can use them to profile. The quality of that profile may be affected by how well that particular target tests the gamut of the device, i.e. a very limited film may make a limited profile, but I believe that would manifest in clipping or posterisation, not an colour cast. This is why it's better to pick one that has as wide a gamut as you can.
Joanna Carter wrote:What's more, there's a slight price difference between them an the Hutch targets; like $75 instead of $480; that's a lot of film!
Can't argue with that! the prices of these things are horrendous.
Joanna Carter wrote:DJ, you'll have to get together with one of us and see what a difference the Faust targets make; take off your scientific eyes and simply accept that they work
Oh I don't doubt that they work, I have used them myself, I just don't believe that you need a separate profile for each emulsion, a good profile will allow you to see all emulsions.
DJ wrote:So, what software are you using?
I use ProfileMaker Pro 5 for all my profiling, in the colour management market it's the equivalent of Adobe Photoshop. I've tried many different packages over the years, from ColorVision PrintFix (dreadful and thankfully discontinued), freeware solutions, Gretag Eye One Photo / i1Match (good), Monaco EZ-Color. Some were awful, some good. The main reason I didn't like Monaco EZ Color was because it used proprietary encoded data formats rather than the standard open format ones, which meant the target could only be used with their software.
Joanna Carter wrote:As with the Faust targets, for the level of sales that I am generating from my pictures, cost has to be a consideration; and the ColorVision kit does a very acceptable job for an acceptable price. Most people viewing my prints would not have a clue if I had spent pennies or pounds on profiling; they simply want a picture that looks right, at the right price. What I want is a means of easily giving me the results that people want to buy.
Oh I'm not advocating everybody goes out and spends thousands on colour management equipment! Mostly this type of kit is the sort you use rarely to set something up, and then don't touch it again, it's a heavy investment. Compared with using nothing at all, the Colorvision thing will do a bloody marvelous job! I also believe it's the best product they've come up with to date, and probably makes pretty good profiles, I just wouldn't choose it myself.