Scan focus issue only with positive film?

mr.datsun · May 16, 2013

It's been bugging me for ages. I'm scanning Super 8 film, reversal processed. Epson 4490. Nothing seemed to be sharp. Edges and sprockets not sharp, a hair not sharp, grain not evident, frame border soft. I tape the film emulsion down to the glass with masking tape.

I tested focus with the film strip stuck inside the slide holders to see if it needed to be off the glass, still no improvement. I tested with a stack of coins on the glass on reflective mode. Crisp right on the glass surface.

I tried another (better) Epson. Same problem. Same tests , same results.

I kept remembering (or dreaming) that my 35mm negs were sharp, so I tested a Super 8 negative processed strip. Same process. Much sharper all round.

So – negatives sharp, positives blurred. Is that even possible? Any ideas, please?

OzJohn · May 16, 2013

Might be a long shot but Kodachrome slides scanned with digital ICE switched on will sometimes produce a scan with scrambled elements in the picture and this can look like blurring. I've only seen it a few times as ICE does not work very well at all with Kodachrome and I've not ever scanned movie film but I'd think it a fair chance that your movies might be on Kodachrome. OzJohn

mr.datsun · May 16, 2013

OzJohn said:
Might be a long shot but Kodachrome slides scanned with digital ICE switched on will sometimes produce a scan with scrambled elements in the picture and this can look like blurring. I've only seen it a few times as ICE does not work very well at all with Kodachrome and I've not ever scanned movie film but I'd think it a fair chance that your movies might be on Kodachrome. OzJohn

OzJohn, thanks for comment but I always switch off all software enhancements and set the levels manually.

pellicle · May 17, 2013

Are you scanning both as positive?
Are you changing to films area guide?
Have you tried the stack of coins trick for checking focus?

mr.datsun · May 17, 2013

pellicle said:
Are you scanning both as positive?
Are you changing to films area guide?
Have you tried the stack of coins trick for checking focus?

pellicle,

1. yes both as positive.
2. not sure what you mean but the scanner has a strip down the middle for transparencies. I'm using that area.
3. yes, as mentioned the coin right on the glass is sharp.

Rudeofus · May 17, 2013

I have the V700 and discovered that this scanner sometimes tries to be smarter than it should be. If e.g. the film holder is shifted a bit, the scanner will switch to some other scan mode which essentially prevents me from getting useful results until I place the film holder perfectly.

So what could have happened is that your slides are somehow arranged in a way that makes your scanner think it should scan in a different mode. One way to verify if this is the case is cut a mask out of black cardboard such that all the area outside the image area is covered. If this suddenly gives you acceptable results, you have found the culprit.

mr.datsun · May 18, 2013

Rudeofus said:
I have the V700 and discovered that this scanner sometimes tries to be smarter than it should be. If e.g. the film holder is shifted a bit, the scanner will switch to some other scan mode which essentially prevents me from getting useful results until I place the film holder perfectly.

So what could have happened is that your slides are somehow arranged in a way that makes your scanner think it should scan in a different mode. One way to verify if this is the case is cut a mask out of black cardboard such that all the area outside the image area is covered. If this suddenly gives you acceptable results, you have found the culprit.

Rudeofus. Sounds like you are using it in the slide auto detect mode. This is where is detects the slides and cuts them out for you. I'm not. I'm using full manual mode. I stick the strip right on the glass. Then I select the area of the strip I'm going to scan after a preview. Then I adjust the levels by eye. Because I using full manual mode the software is not, to my knowledge, trying to be clever.

fwiw, I have tried to make a matt from black card and stick the strip inside it. This was to elevate the strip. It made things worse as the thin white edges of the black card cut-out caused havoc with the scanner operation. Once I confirmed that the surface of the glass is where focus is, I went back to sticking it on the glass.

I'll try and post scans and you can see what i mean.....

Les Sarile · May 18, 2013

Just to be sure since your target film is even tinier than 110 film format, have you optically verified that the film in question has the detail in it using something like a Carson MV-820 40X microscope?

mr.datsun · May 18, 2013

Les Sarile said:
Just to be sure since your target film is even tinier than 110 film format, have you optically verified that the film in question has the detail in it using something like a Carson MV-820 40X microscope?

No. I'm using a J&D Optecs Club Lupe. It's a good lens but at a measly 4x.

40x ! That's what I need! Can't find it yet in the UK, but I'm looking.

Les Sarile · May 18, 2013

Another alternative is a bellows setup. With the 50mm macro lens on my fully extended Pentax Bellows K is just a tad less magnification then the Carson MV-820 above.

pellicle · May 19, 2013

Hi

mr.datsun said:
2. not sure what you mean but the scanner has a strip down the middle for transparencies. I'm using that area.

Its one of the settings in the "professional mode" my 4870 doesn't have it but my 4990 does. Its one of the drop downs for film settings. I have noted that it changes the focal plane

Les Sarile · May 19, 2013

Chris, Can you elaborate on a setting used with the 4990 that changes the focal plane? It may be that I am misunderstanding your meaning but I was always under the impression that there are no Epson flatbed scanner todate that has the physical/optical ability to change the focal plane.

pellicle · May 19, 2013

Hi

Les Sarile said:
Chris, Can you elaborate

will do ... been busy with many other issues at the moment, will try to get some time to fire up the scanner (the work desk is filled with an LP player and stuff ... other projects ;-)

do you have an epson? You could give it a quick sprut yourself

Les Sarile · May 19, 2013

I am currently Epsonless since acquiring the Coolscan 9000. Now that I have an interest in old films - 4X5 and 8X10, it seems I will have to once again get an Epson V7XX.

No particular hurry and I will find out sooner or later but I would appreciate your insight on the matter.

mr.datsun · May 20, 2013

pellicle said:
Its one of the settings in the "professional mode" my 4870 doesn't have it but my 4990 does. Its one of the drop downs for film settings. I have noted that it changes the focal plane

pellicle, I'll take a look tomorrow. How could you tell that it changes the focal plane? Is it obvious from looking at the machine or that you could see from the scan results?

Also , does this mean that the coin test does not work - as I think you can only only do that in reflective mode.

pellicle · May 22, 2013

mr.datsun said:
r that you could see from the scan results?

See it in the test results

Also , does this mean that the coin test does not work - as I think you can only only do that in reflective mode.

Well my blog post was made with it in film scanning mode, so why you can't see it is a mystery to me

mr.datsun · May 22, 2013

pellicle said:
See it in the test results

Well my blog post was made with it in film scanning mode, so why you can't see it is a mystery to me

The coins are backlit and I thought were too dark to see when i tried. But now I see that your coins are mainly lit around the edges. Maybe I need to adjust the levels. I'll have another go.

pellicle · May 22, 2013

mr.datsun said:
The coins are backlit ...

Correct

I need to adjust the levels.

Bingo

I think I'd perhaps better put that in the post. I thought it was like saying "don't forget to tie your shoe laces", but you're the second person that has asked me about it, so clearly not.

mr.datsun · May 29, 2013

pellicle said:
Correct

Bingo

I think I'd perhaps better put that in the post. I thought it was like saying "don't forget to tie your shoe laces", but you're the second person that has asked me about it, so clearly not.

Well, I don't usually pride myself on being a dumbass and those coins have a got a lot of light on their under surfaces - especially for the one on the glass. It could have been construed that they had been scanned with the scanner on reflective mode at first glance .

This brings me to an observation. My positive scans also get a lot of light bouncing under them. This definitely contributes to them looking like they are out of focus.

pellicle · May 30, 2013

Hi

mr.datsun said:
This brings me to an observation. My positive scans also get a lot of light bouncing under them. This definitely contributes to them looking like they are out of focus.

interesting point, and one of the reasons I gave up using chromes for good

in my view ...: Provia v 160ProS

PS: also worth reading:
http://ajaxnetphoto.blogspot.co.uk/2006/11/digital-solutions-for-film-lovers-flat.html

Les Sarile · May 30, 2013

pellicle said:
interesting point, and one of the reasons I gave up using chromes for good

That would be simply unimaginable but the scanner would have to go!

pellicle · May 30, 2013

Les Sarile said:
That would be simply unimaginable but the scanner would have to go!

Les, I think you'll see the same effect with the Nikon scanners too ...

pellicle · May 30, 2013

mr.datsun said:
This brings me to an observation. My positive scans also get a lot of light bouncing under them. This definitely contributes to them looking like they are out of focus.

it is my view that the light bouncing around underneath leads to loss of contrast, the seemingly "lack of focus" on chromes is perhaps some other phenomenon.

Still I don't need to know causes what I see, that I see it and know that I can't change it is enough for me at this point. Empirical observation does not always need theory to support it as being true.

Les Sarile · May 30, 2013

pellicle said:
Les, I think you'll see the same effect with the Nikon scanners too ...

I have personally scanned close to 20,000 frames of every film types/brands of film with Coolscans (5000 & 9000) and thousands more with various flatbeds,r dedicated film scanners, mini labs, Imacons and DSLR scanners. Not being able to realize great results from chromes - or for that matter any film type, would be a real bummer . . . but fortunately that's not the case!

Rudeofus · Jun 3, 2013

Les Sarile said:
I have personally scanned close to 20,000 frames of every film types/brands of film with Coolscans (5000 & 9000) and thousands more with various flatbeds,r dedicated film scanners, mini labs, Imacons and DSLR scanners. Not being able to realize great results from chromes - or for that matter any film type, would be a real bummer . . . but fortunately that's not the case!

+1 to that. I ditched color negative film a few years ago because slide film was so much easier to scan. Only now with optical darkroom prints I have rediscovered negative film ...

mr.datsun's issues with slide film are very very odd and he should look at having his scanner checked by an Epson representative or service facility.

Scan focus issue only with positive film?

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