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PostPosted: Tue Nov 20, 2001 4:46 pm
by Joe Butts
I'm having output from the SS120 that looks like my negs have huge grain. I'm
scanning mostly Fuji NPH (400) at 4000dpi as suggested for best results. I'm
using the latest (I think) version of SilverFast which was giving me fits
until they kept firing new upgrades to me and finally got it to quick locking
up everything.
Anyway, the question is: What about this grain issue? What is anyone doing
about it?
I've used Filter/Noise/Dust & Scratches and brushed over a snapshot of the
image with the darken and lighten history brush to clean it up a lot, but
this takes a lot of extra time and, last night, locked up on me because I
hadn't saved recently enough. Now, I get to do it again. Need sympathy and Mo' RAM.
Thanks for any help you can give me.
Joe Butts

PostPosted: Fri Nov 23, 2001 11:35 am
by bear
Are you using the sharpening filter? If so turn it off and sharpen in Photoshop,I had the same problem and this worked for me.

PostPosted: Sat Nov 24, 2001 2:52 am
by Joe Butts
Are you using the sharpening filter?
No, this is even without the sharpening filter. A friend of mine has the Nikon 8000 and said he's not having any problems with NPH. Scans are smooth, clean and sharp. Could it be the scanner or could it be the software or both causing the grain issue?
Thanks

PostPosted: Sun Nov 25, 2001 7:50 am
by Guest
could ur film be under exposed?
most iso400 films only have iso320?
nikon and all 'led' scanners have smoother grain than polaroid scanner but does not mean polaroid gives worse results, i have sprintscan and gives excellant results.can u possibly tell more about ur settings?

PostPosted: Mon Nov 26, 2001 8:25 am
by Joe Butts
Negs are pretty well exposed. I generally rate my film (NPH) at about 250 depending on the situation I'm photographing under. Flat lighting requires more exposure and helps build contrast. I really try to avoid underexposing negs. If I'm under in a controlled situation, it's rarely more than 1/3 stop or so. OK, I do occasionally end up 1/2 stop or so off. Truth be known, it happens. But, no, these negs looks quite good.
Regarding my settings:
in Polaroid Insight: about the only settings that could have any effect would be that I'm set for Adobe RGB and for Autofocus on final scan.
in SilverFast AI:
Main Window:
General Tab: Normal, Negative, Save
Frame Tab: 36-24 Color, None, Save, Standard, Sizes are whatever will come up at maximum size at 4000dpi most times with the Q-Factor at 1.
Options-Defaults-General Tab: RGB, inch, 3 pixel, SilverFast Defaults, SilverFast Standard, 1X, my scratch disk is largest I available disk I have, Gamma Gradation 2.0 with HDR checked, Q-Factor 1.0 and RealTime Correction checked.
Auto Tab: 2,0,2,98,100,10, AutoPip Middlefactor -30,30 and Midpip 50.
CMS Tab: (I swear this has changed) None, Auto, RGB, None, AdobeRGB, None, Perceptual, Embed ICC Profile is checked, Profile to Embed is AdobeRGB. I had set the scanner profile as the Scanner profile under ICM. Oh, that gets switched back to Auto when scanning negs doesn't it?
The Special Tab is Green (never have understood that) with Prescan draft checked.
Do you need any more info?
Thanks for your help.
Joe

PostPosted: Mon Nov 26, 2001 7:39 pm
by ilyons
Joe,

Negatives tend to look grainy on most scanners and some films are more prone to produce it than others. The problem is grain aliasing and overcoming it is not easy.

The special tab showing green relates to the blind channel, i.e. it is the channel that Silverfast ignores when doing Monochrome scans. You can change it to blue or even red. Sometimes I find this helps with B&W negs - but colour negs are a different beast.

Your query about the colour tab - it reads None for when you're scanning negatives and should automatically return to the right settings for slides.

If your friend using the Nikon is getting smooth negative scans he/she is not telling you all. The Nikon uses GEM and ROC and if these are used it will help smooth the grainy effect.

You might want to read the following article on the topic of grain aliasing

http://www.photoscientia.co.uk/Grain.htm

You might wish to try scanning with the Descreen filter in place in Silverfast - I have found it works well on really bad cases of grain aliasing. Try setting the value to just uder the actual scan resolution. you might need to add some USM, but if so push the Threshold up to around 4.


Also do a search on google.com for the term "grain aliasing" - you should get a feel for how big the problem really is.





<font size=-1>[ This Message was edited by: ilyons on 2001-11-26 20:52 ]</font>

PostPosted: Tue Nov 27, 2001 1:04 am
by ilyons
Joe,

Although not yet complete the following tutorial might help with your grainy images.

http://www.rgbnet.co.uk/ilyons/sf5-nega ... uction.htm


Ian

PostPosted: Tue Nov 27, 2001 4:43 pm
by Joe Butts
Ian,
You always come up with the best and most thorough information on scanning. I've appeciated all that I've read of your works in the past. This time, you've given me more than I have time for. Thanks! I'm sure this will be of great help.
Yesterday, I visited with someone with an Imacon scanner. We scanned one of the negs I'm having such fits with. The Imacon gave me a beautiful, almost grainless (more like I'd expect from the film) scan. Then he showed me some of the tricks in Imacon's software to reduce it even further, to USM the image and still hold down the grain. These features seem to be missing in SilverFast AI. It was also explained that there is always some sharpening being done in the Polaroid scanner, that there is no way to turn it all off and that is increasing the grain.
Thanks again for your help. You're my scanning guru.

PostPosted: Tue Nov 27, 2001 5:07 pm
by ilyons
On 2001-11-27 16:43, Joe Butts wrote:

Yesterday, I visited with someone with an Imacon scanner. We scanned one of the negs I'm having such fits with. The Imacon gave me a beautiful, almost grainless (more like I'd expect from the film) scan. Then he showed me some of the tricks in Imacon's software to reduce it even further, to USM the image and still hold down the grain. These features seem to be missing in SilverFast AI.


The Imacon units are especially good at handling negatives. If you have the $ they are the way to go.

Ian