scan lines(artifacts) in Under exposed negatives

[Macpod]

I've noticed that my scanner produces scan artifacts in the form of purple or light magenta lines in most if not all under exposed images, but the same scanner produces perfect line free images when the negative is exposed right.

Is this just the way it is or is something with my scanner? epson V300

This only shows up in badly lit indoor shots. and its always on the top or bottom of the frame, but the exact position is always shifting.

the lines are present in both color and B/w negatives. I have not seen it in slides mainly because i rarely shoot them and they are nearly always well exposed.

 

[Macpod]

 

[Roger Hicks]

I have had much the same with a Nikon Coolscan, and the same on a much reduced scale from a Konica Minolta 5400, so I don't think it's your scanner!

Cheers,

R.

 

[Macpod]

I see. I was going to get a coolscan thinking it would solve the issues. Im otherwise happy with the scans so i think ill get a lens instead!

 

[Keith]

I'm curious here ... are you scanning lab processed C41 or do you develop your own film?

 

[sevo]

Known issue with all scanners on marginal source material - many high end to professional slide or flatbed scanners have one or more special modes that reduce those inconsistencies. On the Coolscan 9000 that would for example be multi-sample and ultra-fine (i.e. single scan line) scan.

 

[Keith]

The reason I asked about the OP's film choice is because I noticed this happening on some of my negatives when I was using C41 processed at the local Kodak one hour. Those auto feed C41 machines are notrious for leaving this type of damage on film if they're not kept totally clean internaly. When the scanner is scanning an underexposed negative it's trying to pull as much information from the negative as it can and will consequently pick up these faint lines left from indifferent processing!

That's my theory anyway!

 

[bagdadchild]

This is banding, a common problem with any kind of scanner. It can have a range of causes, the most common ones as far as I know is dust/dirt, faulty or dirty calibration strip and failing or even dirty lamps.

Try clean your lamp housing and calibration strip if possible, but be careful and use proper cleaning equipment and avoid unknown chemicals. Do not touch the mirrors unless you know exactly what you are doing. Many people have tried to clean mirrors and instead damaged them. A simple 'rocket blower' or camel brush is ok if used carefully.

 

[bagdadchild]

I've noticed that my scanner produces scan artifacts in the form of purple or light magenta lines in most if not all under exposed images, but the same scanner produces perfect line free images when the negative is exposed right.

Often the bands are there but you will not see them. If you pull down the exposure slider in post processing you may see the bands appear in not only under-exposed negs. With slides you can try to increase the exposure until the image becomes almost white and you may see the bands appear.

 

[Pherdinand]

i also see them with my epson v700 when scanning very dark slides. Which is kind of the opposite case to yours.
Simply put, a bad exposure can not be unlimitedly corrected for no matter what scanner you use.

 

[sevo]

i also see them with my epson v700 when scanning very dark slides. Which is kind of the opposite case to yours.
Simply put, a bad exposure can not be unlimitedly corrected for no matter what scanner you use.

Yep. The worse the signal, the higher the relative noise level (which is a mixture of grain, dirt and scratches on film and holder, electric sensor and line noise).

 

[Matus]

As I am having a similar problem with my Microtek right now, I would advice you to make a color positive scan of a BW negative and than have a look at each color channel separately. It this is dust somewhere in the optical path, that you should see the bands in all 3 channels (not necessarily with the same intensity). However if you see the band in one channel only (what I suspect) that it may a problem in the light source or something.

I have taken all the covers off the scanner and used canned air to blow the possible dust away, but the line remained. You can try that too.

Also - any single pass scan will show band-like structure if you push too much, but this will be banding structure in the noise - showing simply the direction in which the scanning head moves (usually along the scan bed). Strong single lines signal a problem.

You will find a few examples of my banding problem here:
hybrid photo forum

 

[Macpod]

i see it in all kinds of film, c41 color and self developed. the only common denominator seems to be underexposure.

The lines changes position constantly although it is always consistent with one piece of film. this makes me think it might be the film? but if one frame is exposed correctly and the other not, the line would only show up on the underexposed one........although i will have to try what you guys suggestd and increase compensationt to see if it is in the correctly exposed shots too. i suspect it might

at this point i think i will do more hard then good in trying to clean anything.

Thanks for the information though. It would have been a hassle contacting epson aftersales and i dont think it would have solved anything aftering hearing from you guys.

 

[lorenzo1910]

I have got this kind of issue with a flatbed scanner (while scanning prints...but the bands were always in the same place)
No problem at all with my (old) Minolta Dimage Scan Dual (SCSI)
Maybe it's a calibration and/or dust issue

 

[kaider]

Hey everyone! I bought myself an Epson V600 a month back. Since then I have been scanning 35mm without any problems (no visual artifacts).
Today for the first time i tried scanning my medium format film. Near the center of the image, you'll notice a split of tone between the left and right side. Almost all of them came out like that except for some overexposed shots.
I hope someone here has came across a similar problem and could help me out. Thanks!!!

 

[kaider]

Here is a clearer image of what i mean. I am really frustrated with this issue. :bang: I've never came across it with my 35mm film, be it spot on exposure, underexposure or overexposure.

 

[sevo]

If it is not on the film (some lab errors can have the same effect), the most likely suspect is dirt or a foreign object on the scanner calibration zone.

 

[kaider]

I've only had the scanner for a month. Might be a defective scanner. I will be taking my film to scan in the lab just to make sure its not the film.

 

[kaider]

So check this out...i scanned it in positive mode and inverted it back in Photoshop and there is no more split tone in the center! This **** is bizarre!!