Imacon Flextight: banding & lines in scans

Rishi Sanyal , Oct 28, 2008; 12:13 a.m.

Imacon Flextight: banding & lines in scans

Particularly: noise in shadows

I've had some consistent problems with an Imacon Flextight 848 scanner I use at the University.

I am scanning 35mm E-6 Velvia, preferably at full resolution (8000 ppi). Sometimes, I get perfect scans. But more often than not, I get scans with thin greenish lines, of pixel width 1 to 3, across scans. These are most noticeable in deep shadows, and sometimes not even visible in anything BUT deep dark shadows. And sometimes, the scan just goes all haywire, like this:

Take a closer look at this 1:1 crop from the above image:

This particular scan is completely jacked up; most scans still look fine but upon close inspection, I'll find those same thin green lines across just the dark shadows of the image. Sometimes parts of the image will get re-arranged like this, or some colors inverted... just completely messed up!

What I'm more worried about, though, are those thin green lines in shadows. Where could these be coming from? I can hardly ever just get a clean scan free of problems; sometimes I think the scan is perfect, but upon close inspection of some black part of the image, I'll see those same thin green lines.

I've tried loading the software on a different computer to see if it was the computer. Nope.

I haven't tried swapping out the Firewire cable... could that be an issue?

A photographer friend mentioned this may be dust on the CCD; however, if portions of the image getting inverted/rearranged, as you see above, is also due to the same reason as the thin green lines, clearly it cannot be dust. But I guess it IS, though unlikely, possible that these two problems are unrelated (the thin green lines vs. parts of the image getting rearranged).

I tried, just for the heck of it, to scan at various resolutions. I tried 4000 ppi and suddenly the horizontal green lines became diagonal green lines! At some ppi's the lines disappeared, but only temporarily, to come back in a subsequent scan.

I'm completely confused & scratching my head over this one. Has anyone seen anything like this before? Any idea where to even start looking for the source of the problem?

By the way, the lines are certainly not on the film (though that's probably self-evident at this point!) because the same frame scanned on a Nikon LS-9000 looks perfect (& much better) in the shadows!

Many thanks in advance,
Rishi

Responses

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T Feltus , Oct 28, 2008; 04:52 a.m.

the finer lines, the ones that look like scratches, are probably either dust (bulb or ccd), or just the Imacon trying to dig out detail from dense areas. I have this problem a lot with my cross processed film, that highlights may end up with odd magenta streaks like that.

The green band is something i experienced with a machine at college also. It could be any variety of problems, but the main thing is that it is not you, and the technician should understand that he isn't doing his job, and the Imacon needs fixing. The techs at my college were a bunch of jackasses and cared as much about the Imacon as they did about me. Due to the width of the band, it could also be a problem with the gearbox.

Anyway, your best bet for resolving the fine streaking is through balancing the exposure of the scan, so scan a full res 3F file, and work on it from there (which you can do on any machine that you install Flexcolor on).

Patrick Lavoie , Oct 28, 2008; 10:14 a.m.

could it be a bad connection? a loose wire? happend to me once ..just carefully double check both connection and>or change the wire between the scanner and the mac. a scsi wire could be defective. if you plug it using a firewire i would suggest to try a scssi instead, i use to get those when in firewire with the stupid little black box supplied to connect it.

Patrick Lavoie , Oct 28, 2008; 10:15 a.m.

also, you could try resting the imacon to its default setting and run a calibration using the supplied target.

T Feltus , Oct 28, 2008; 10:23 a.m.

I would point out that these are all issues that the lab technician should deal with, and not you, and simply because you shouldn't have to deal with the hassle of a service provided which is not maintained correctly. If you owned it, the situation would be different. Fundamentally, you are not doing anything wrong.

Rishi Sanyal , Oct 28, 2008; 01:55 p.m.

Patrick: there is no black box with the Imacon 848... it just has a Firewire 400 port on the back of the machine. I'll see if I can get the technician to try a different cable.

T Feltus: you're right, but I just find that I have limited bargaining power here, as the lab is pretty much providing this service to us for free. That being said, I do agree that if you own a piece of equipment that is worth thousands of dollars, you may as well spend a little time & money to upkeep it.

Question though: you're saying you sometimes see these green or magenta lines in your own scans? Is that also with an Imacon? Because I've never in my life seen these artifacts with either a Nikon LS-4000, LS-5000, or LS-9000. So it can't be a limitation of the technology... right?

Thanks, Rishi

Patrick Lavoie , Oct 28, 2008; 02:01 p.m.

oups..sorry didtn get the 848 model..just read Imacon : )

as for the green line, i dont know for T, but i only saw this problem personnaly when the cable or the connection was bad. It not normal when a 10k scanner (maybe less with the 848 im sure but still) does *problem* like that.

T Feltus , Oct 28, 2008; 02:01 p.m.

yes, though mine are usually magenta. they seem to occur when the light is not powerful enough to get through the dark parts of the neg or tranny. and yes, mine is with my Precision II, a bit older, but not much difference in the hardware. they generally are on one channel, so i have spotted some out with the spotting brush in PS. or you balance exposure to eliminate them. those areas are probably meant to be black, as mine are meant to be white.

the service may be free, but remember, they are paid to do that, and you aren't paid to use it, so they ought to do their job. talk to their boss.

Patrick Lavoie , Oct 28, 2008; 02:02 p.m.

Oh, also..free or not a lab should take care of there equipment..theres no reason to have a bad scanner other than telling you loud and clear that you should move to digital and stop bothering them..is that what they want to tell you? maybe?!

Rishi Sanyal , Oct 28, 2008; 02:31 p.m.

Haha, Patrick, that's actually what I want to tell myself. Yet somehow I still found myself shooting 12 rolls of Velvia these past 2 weekends which cost me $200 in film + developing. If I do the math, my use of film over just the past year, I'm sure, probably already exceeds the cost of a 5D. Cognitive dissonance, I guess, allows me to still shoot film.

But either way that doesn't take care of the problem of what to do with my hundreds (thousands?) of exposures on film lying around!

T Feltus: you say that 'those areas are probably meant to be black'... but if you look at the 100% crop, the green lines still run across regions that are certainly not meant to be black; i.e., the shinier portions of the rock. Also, if you're scanning negs and you get magenta lines, that makes sense, since magenta is opposite green on the color wheel & you're speaking of neg film which gets inverted. But note also that I have some magenta bands, especially in the lower center portion of the 100% crop.

I may forward this thread on to the supervisor of the lab.

Thanks guys, Rishi

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