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Re: [APML] More SS4000 scanning questions
Hey Carlos,
--- "Carlos Milovic F." <cmilovic@yahoo.es> wrote:
> You should avoid color management with your raw scans
> becouse that will change the values of the pixel when
> it will be readed by PS or another IP (image
> processing) software. Of course that color management
> can be exploided just for displaying purposes, but i
> think that the raw data is so precious that we must
> preserve it as much as we can (save it directly to a
> cd or dvd, for example). Anyway, if you don't color
> manage the file, it will be assumed that it is in the
> sRGB color model.
sRGB is the usual defalt then?
> The SS4000 scans your films with a 12bits accuracy in
> the tonal range, so that's the true final amount of
> gray levels (for each channel) that you will see.
> Becouse TIFF archieves supports only 8, 16 or 32 bits
> per channel, the scanning softare fills the other
> 4bits with zeros. You can easily see that in
> PixInsight. Open the image's histogram, and view it at
> 12bits precition. The histogram function will look
> nice, but if you change to 14 or 16bits, you will see
> a lot of gasps in there.
Don't have PixInsight so I'll take your word on that.
> If you are doing raw scans, the results are just the
> same. The data is saved as the CCD reads it. That is
> exactly what I do with my scans, and it works very
> well, and saves a lot of time. BTW, you can speed
> things a bit more by doing the scanning with the
> thumbnails interfase intead of the preview/scan one.
> You can scan the whole set of slides/negatives with
> just one operation.
I was trying to figure that out last time I scanned and made no
progress. Looks like I'll try it again.
> Yes. Scan always at the maximun optical resolution of
> your scanner. It is always better to do that, becouse
> you can push the digital processing much more. The
> noise introduced by the scanner will be much smaller
> than the real features, so it will be easy to delete.
> You can perform deconvolutions, multiresolution
> analysis and much more more easyly... and finally, the
> data will "tolerate" much more the processes applied
> without introducing artifacts.
Most of what you descibe is a little over my head, but even so, I have
noticed the data gets whacked because I can tend to really stretch
things out just working with levels, curves and the other basic image
adjustments.
What you and Jerry have said has convinced me to start scanning at the
full resolution. I just got back some more real nice M33 shots that
look great and I want to pull everything I can out of them.
Thanks,
Alan
=====
SCT Astrophotography: http://www.pbase.com/avoetsch/astrophotography
FS-102 G-11/Gemini: http://www.pbase.com/avoetsch12952/tak_fs102
& http://www.pbase.com/avoetsch12952/fs102
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