Digital Contact Sheet from PrintFile

[stevebarry]

This is my first post here, I got flamed over at apug for posting this question -

I tried making a digital contact sheet last night, by putting an old light box on top of my document scanner. I was pleasantly surprised with both the overall quality and speed I could do this.

There were a couple problems which I would like to work out.

There appears to be some sort of moire pattern? I dont know much about this. I reduced the contrast enough to pronounce the problem.

It almost looks like what happens when you take a photo of a computer screen....the banding. Is that from the monitor/light flicker? The pattern differs when I zoom/resize. Whatever it is, I think it is from the light source?

Someone on apug thought maybe it was the plastic from the PrintFile causing the pattern.

The light source is also not very well diffused, being much brighter in the center. So the edges of the contact sheet are lighter.

I could blur and size these down....but I would like to be able to see them at the size I have scanned....800dpi and tell if anything is out of focus.

Does anyone do this on the regular, and have any tips? Different light box, or light panel maybe? I know I could get a V750 or similar, overkill for contact sheets though. I might consider it so I could scan my 8x10 negatives though. But then again if I could work out these problems, I could use the solution to scan my 8x10 negatives this way too.


contact by steve_barry, on Flickr


contact-crop by steve_barry, on Flickr


contact-crop2 by steve_barry, on Flickr

 

[L Gebhardt]

Steve, that looks really pretty good. I think the lines are probably from the print file sheet. Why not just put the negatives on the glass and see if it goes away?

I may need to try this. I've been looking for a quick and dirty way to proof a whole sheet of negatives. If this works it's better than buying a new scanner. Thanks.

 

[OzJohn]

I think your results look terrific considering you're not using a light source specifically designed for film scanning. A simple but not obvious solution to the problem of making quick contact sheets. I was going to steer you towards another thread where the issue is being discussed and I notice that the member who started that thread has replied to you above. Here's the link anyway in case you have not found it:
http://www.dpug.org/forums/f6/scanner-8x10-larger-replace-contact-sheets-3347/

Welcome to DPUG. OzJohn

 

[stevebarry]

Thanks guys... I will try to scan just a neg strip with no plastic tonight...

Sent from my SCH-I535 using Tapatalk 2

 

[stevebarry]

The lines are still there when I scan a strip of film without the PrintFile.

The lines disappear when I use the "film" as the document type on scanner (instead of "reflective") and use the scanners light source on the lid.

So I think it is pretty safe to assume either the light box is causing the moire (if thats what it is), or the difference between "film" and "reflective document".

I downloaded a free trial of VueScan to try the scanner set to "film" for the entire platen.

If that does not work I will try putting my LCD monitor down on the scanner. If that does not work I would assume all LCD light will not work?

I have seen some DIY LED panels, I guess I could look that route.

 

[stevebarry]

Well. I cant get VueScan to scan as film over the entire platen of glass, no matter what I try.

My LCD monitor was no where near bright enough (to scan as a document) the scanners underneath lights far out powered it.

If I set the scanner to film, and use the lightbox, the result is all white film strips. So I guess my light box is much brighter than the light in the lid, which the scanner is expecting to be there.

I think the problem must be something to do with the light from the scanner (scanning as a document, light from underneath) interacting with the light box from above?

 

[stevebarry]

it would seem like I solved the problem by scanning at a higher than target resolution, and then sizing down to target. Lines disapear. Or at least they are reduced to invisible/blend on my monitor.

I noticed no matter what resolution I scanned at, the lines stayed the same size and spacing.

these need to be viewed at 100%

here is scanned at 2400 dpi and reduced to 800 dpi (lines/pattern gone):


F5-2013-07-22111 by steve_barry, on Flickr


here is scanned at 800dpi:


F5-2013-07-22112 by steve_barry, on Flickr

The problem with doing it this way, is the scan took 14 minutes and the file size was a GB. Since I reduced it right away, the only problem is the speed. And since I plan on doing one per night....I guess I can save myself the expense of the V750 and spend 15 minutes doing something else.

 

[stevebarry]

Full contact sheet hi res - click bar to see original


F5-2013-07-22111-2 by steve_barry, on Flickr

 

[L Gebhardt]

Thinking about it more, I bet it's flicker from the flourescent tube in the light box. So if you could get a light box with a different light source, like an LED or incandescent, I bet the lines would go away.