There is another program like CoCa called Argyll CMS GUI. In contrast to CoCa it enables most, if not all Argyll options.
No good for me. It requires OSX 10.5 running on an Intel Mac. I'm still on OSX 10.4.
I feel that editing can make them equivalent. Which is the better starting point for editing? Which is easier to edit?
After several days of comparing editing techniques, I'm coming to the conclusion that the overall problem of getting the best result from a scanned slide lies not with the selection of the best profiling technique, but in the editing itself. Most of my reference scans require serious editing, even given perfect profiling, and I'm finding that sometimes I cannot obtain similarly good results if I select a different scan gamma to start with, or if I change the colour space. i.e. if after editing I choose a particular image as the optimum (to be used as a reference), most of the time I cannot reach that optimum with a different scan technique or in a different colour space.
Like I mentioned before, I think the >1 gammas can be noisier. Is the extra red noise visible?
I've seen lots of noise if I try and bring the shadow detail out, and I'll take your results as definite – that Gamma 1.0 has the least noise, as would be expected. Although, I have found that extra noise in the darkest shadows, as long as it is not obviously coloured, improves the image because the noise appears to be detail within the black. i.e. solid blacks are not desirable in most images. If they are broken up with noise, it can give the impression of detail, even though it is false detail.
It seems that the deep shadows can be made very neutral, which would make them easier to edit, compared to the standard-preparation profiles that almost all go red in the dark tones.
I have a technique that easily removes the colour cast in deep shadows, but it would be easier to edit if it wasn't there.
I found that even better is to adjust each R,G,B channel individually with its own value. Adjusting the R,G,Bs individually allows you to control the tint in the dark tones to achieve neutrality.
Do you think that will work for a variety of slide images? The shadows on my slides show a range of colour casts because of the lighting conditions: red (sunsets or bright red shirts), green (forest), blue (sky). They have to edited away for a more natural look, and such editing may swamp the small improvements available by adjusting the profile. It's good to have the most accurate profile, so I'll give your new plugin a go to see the effect.
When the profile with this built-in flare compensation is used on an image with less flare, the darker tones can be clipped, making ugly artifacts.
I'm seeing some of this clipping, I think. It is difficult to edit away, and if the original slide had a lot of shadow detail, it makes for an unsatisfactory image. I am still finding that editing gamma 1.8 scans sometimes gives the best end-result. Not all the time. Gamma 1.0 comes out on top here and there, and so does sRGB. Which is rather annoying. I was hoping for a single method to give optimum results for all slides.Clever Kodak?
What are the chances that Kodak purposely designed those flaws into GS18-23 so that when profiled, such a target gave the most pleasing shadow result? Monitors, for example, only have 256 levels. If the end result is to be displayed on a digital screen (in my case, eventually, BluRay via a monitor or projector), there must come a point when you have to say: for the best image when viewed, those extra 16-bit levels have to be compressed in a certain way for optimal results on an 8-bit display. I need convincing that all my attempts at better profiling have not resulted in a degraded 8-bit image when viewed – because blacks on the digital image are now closer to the slide-blacks. Deeper blacks are difficult to reproduce digitally (obtaining rich blacks is the Holy Grail of all digital projectors), and having an excess of them, as does Kodachrome, can only cause problems.
Given a perfect profile applied to a perfect scan of a Kodachrome slide, you will still end up with a very poor digital image because Kodachrome has been optimised for projection, not digitising. Kodachrome scans will always require significant editing because of the way they are, and I'm hoping that such editing doesn't render profiling unnecessary. It's been a good learning experience, but I hope it hasn't all been wasted.
What's happening in my testing (a couple of hours a day for six months), is that I'm moving away from the "science" of scanning Kodachrome, and into the "art" aspect. And that may pose more serious difficulties than any of the science.
P.S. Thanks for the emailed profiles. Will test and get back to you.