Automatic image optimisation problems

[imagefoundry]

Hello,

I find that results I'm getting when I use an Automatic Image Optimization function are seriously substandard.

This is not to say that I have a problem using Silverfast - I had it for about a year now and I have no issues achieving the colour I want by using manual controls. However, recently I had to use Scangear software bundled with my scanner (Canon 9950F has automatic dust removal feature, kinda like ICE) and I was startled to discover that 90% of the time its Autotone feature produced scans which were very good. This got me wanting to sort out whatever SF issues I'm having.

Problems I'm having with Silverfast's automatic adjustments are three-fold:

1. inability to remove even simple colors casts, particularily in negatives
2. malfunctioning tonal range optimization, both in negs and transparencies
3. unpredictable behavior from ACR (automatic color restoration?) - both in negs and trannies.


regarding p.1 - its possible that part of the problem lies with the fact that I often do not have appropriate negafix profiles for the film I scan. I also find that "Auto tolerance" slider never manages to get rid of the cast but starts to damage highlights when I move it past the middle of its range. My attempts to create custom negafix profiles were somewhat successful, but only for the same kind of images - i.e. portraits, besides it takes me far too long to optimize one.

regarding p.2 - oftentimes, even when uncorrected preview looks good in terms of tonal values, using Auto function damages the image severely - shadows get too open, unnatural compression in midtones, overly conservative highlights, etc.

regarding p.3 - by default my images scan very desaturated. Using ACR brings the color back, but in very "uneven" manner - ie. reds might still be not saturated enough, while greens are turning completely garish.


I do not seem to have any color-management related issues, - my previews match the final scans, and I have checked my settings against many help resorces on your site and forum as well as elsewhere on the net.

Conclusion:
If I were to venture a guess as to the nature of my problems, I'd say it seems that SilverFast's Auto-Image Optimization routine bases its decisions on a faulty preview data.

I'm submitting three scans of the same image, first one scanned with Scangear(Autotone), second one with Silverfast (Auto), third one adjusted by hand; as well as a screen shot of an "Auto" panel from my "Options" screen. These were left untouched from the time I installed SF.

www.imagefoundry.tzo.com/sg.jpg
www.imagefoundry.tzo.com/sf.jpg
www.imagefoundry.tzo.com/sfadj.jpg
www.imagefoundry.tzo.com/automenu.jpg

Your help with this matter will be greatly appreciated.

Thanks,
dimitri

[victor]

hi dimitri...
i saw the photos u have posted.
the first one is too saturated. the second one is dull indeed. the third i suppose is in your taste, although reds are too much in my opinion.
first of all - do use the color managment.
choose something that u will go consistently.
my options are:
gamma 2.2 and sRGB for web stuff and good for normal printing like "proof" prints or some other magazines that ask such things.
for serious prints - gamma 1.8 (of course with monitor profiled accordingly), and adobe rgb1998 profile.
everything is color sync of course. this gives the most consistant results with confidance.

about auto adjust. personally - i dont see auto adjust as "final result tool". it is good for basic and for start of optimization.
there are varius "image mode options" - "standard, etchnical, skin tones etc". use it and u will see slight differances.

also, when u press the auto adjust botton, u can also use "shift+click on auto" and u will have it with color cast removal. actually, it will fully level your data from the photo, while the normal click will level the "luminossity only".

for negatives - yes - the bes thing is to creat your own profiles - no other way. with practice, i can say that u will get about 3/4 of the job done. only then u can move the "auto tolatance slider to fine tune your profile.
by the way, make sure u have the negafix on auto reading. this way, negafix will read only the avalable data. also make sure that u have cropped your picture so that there is no borders of white and black. otherwise the reading will in not correct.

also, in general pannel - there is an option to "aouto-contrast". leave it unmarked and adjust the contrast your self with the gradation curve. it gives enormous control.

about acr... for saturation u have other control too.
also, if u see that one of the colros are too much off, u can control it menually - each color. it is very eassy with the "selective color correction".

hope this helps