3 Questions from newbie

[falconeye]

I am a newbie but found it easy enough to use Silverfast.

First of all, let me say that the combination of "SilverFast SE 6.6 MultiExposure" / "Vista 32 Bit" / "Nikon Coolscan IV 40 ED" is working properly. The website lists this combination as unavailable... For Coolscan 4000 Ed it only offered Silverfast Ai, so I first felt I should just stick to Nikons software! Maybe, LSI may want to fix their wrong info as it directs customers away.

Still, I have the following question I cannot find answered anywhere:
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[*] Using HDR with Positive (Fuji Velvia), I notice that HDR does one normal scan, followed by one dark scan. Shouldn't HDR for positives use a normal and a bright (overexposed) scan to bring out the shadow regions? I am disappointed by the result as the dynamic range isn't enhanced, actually!
[*] My Velvia looks, well Velvia (dark shadows). Aren't there any built-in profiles to convert emulsions to AdobeRGB or alike? If not, why use Silverfast at all? If yes, where do I select the profile?
[*] My 48Bit Tiff looks darker than my 24Bit Tiff, w/o changing anything else. It's even reflected instantaneously in the preview window if I change the setting. I can't see why as one format just adds bit to the same RGB values. It shouldn't visually alter the image. The 48Bit result looks underexposed. I find this annoying. Nikon scan doesn't behave like this. Is this the intended behaviour?
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Sorry if all this has already been answered in the forum. Google couldn't find the answers, though. Thanks for listening.

[LSI_Luebker]

Dear falconeye,

I just copied your question into this post so it would be easier to read

[1] Using HDR with Positive (Fuji Velvia), I notice that HDR does one normal scan, followed by one dark scan. Shouldn't HDR for positives use a normal and a bright (overexposed) scan to bring out the shadow regions? I am disappointed by the result as the dynamic range isn't enhanced, actually!

are you talking about Multi-Exposure ? as Multi-Exposure should work excatly as you described but with increase dynamic range, could it be that you have savd the Scan as 48 BIT HDR file without embeding the propper Gamma value for HDR output? To enable the correct Gamma for HDR output you need to got to
Options->general-> and tick "the for HDR Output" box next to the Gamma setting.


2] My Velvia looks, well Velvia (dark shadows). Aren't there any built-in profiles to convert emulsions to AdobeRGB or alike? If not, why use Silverfast at all? If yes, where do I select the profile?

there are no profiles for positive film in SilverFast the dark apperance could be caused by the Gamma issue i described above



[2] My 48Bit Tiff looks darker than my 24Bit Tiff, w/o changing anything else. It's even reflected instantaneously in the preview window if I change the setting. I can't see why as one format just adds bit to the same RGB values. It shouldn't visually alter the image. The 48Bit result looks underexposed. I find this annoying. Nikon scan doesn't behave like this. Is this the intended behaviour?

this is also the problem of not setting the "Gamma for HDR" tickbox when saved as an 48Bit HDR Tiff


I hope this was usefull

kindest regards,

Thomas Lübker
-LSI- Software Support Specialist

[falconeye]

are you talking about Multi-Exposure ? as Multi-Exposure should work excatly as you described but with increase dynamic range, could it be that you have savd the Scan as 48 BIT HDR file without embeding the propper Gamma value for HDR output? To enable the correct Gamma for HDR output you need to got to
Options->general-> and tick "the for HDR Output" box next to the Gamma setting.

@ For the 48 Bit Gamma setting: Yes, it resolves the "too dark" issue. It is noted in the FAQ. Sorry for not having found it there.

However, there is a remaining problem: the resulting 48Bit Tiff files now have proper Gamma but they still have the scanner's .icc Silverfast color profile embedded. I don't even know if this is correct then, as a color profile includes a gamma value. If I already can specify Gamma for the resulting Tiff, a matching standardized color profile (sRGB, AdobeRGB) should have been used for the final result. As does the Nikon software (it outputs in "Nikon sRGB" which can be changed, to "Nikon AdobeRGB"). A final product from a scanner should not retain the scanner's color profile. It has a different white point and will cause trouble in post processing.


@ About dynamic range:

Yes, I talked about Multi-Exposure. Sorry for the confusion. I have now compared SilverFast Multi-Exposure with a manual HDR combination of two scans aquired at Nikon analog gains of -2EV and +2EV. The SilverFast Multi-Exposure has more dynamic range than a single exposure but seems to have somewhat less dynamic range than my manual HDR combination: Only in the latter can I see the film grain () in the darkest parts of the scan. Or is it the opposite and SilverFast treats the noise somehow?

The point is: While SilverFast does its Multi-Exposure, I see a normal and an underexposed image in the preview window when I would have expected to see, e.g., a normal and an overexposed image.

there are no profiles for positive film in SilverFast

Please add as a feature request. Thank You.