Scanning skies

[Gary Holliday]

I've recently stumbled upon this forum and it looks like a great place! I'm sick of all these idiots telling me to ditch my hasselblad for a D1X Mark 43.6 whatever...get a grip??

Anyway, my first post is a digital one unfortunately.

I left in a 6x6 trannie for printing in a so-called pro lab and they handed me a print with terrible scan lines across the plain sky. In short I told them to do an interneg and a real print. Well they've shut down their darkroom and I'm left without a pro lab in my area.

My question is, do film scanners suffer this problem often when scanning large areas of a solid tone such as a clear blue sky?

The only scan tests I see are for detailed areas of negs, so i'm not sure if this is a common problem or if it's just a dirty scanner.

[kswatapug]

Older equipment and operator error contribute to those type of results, as does poor image processing techniques. As scanner technology has improved and bitdepth increased it should happen less and less. Surely not from a professional lab, regardless.

[Bob Carnie]

Large areas of open sky or neutral tone are the hardest to reproduce whether traditionally or digitally.
We have noticed the digital effect in these areas when printing on our Lambda Unit. Sometimes it is due to sharpening function in PS and or on the Printing Device.
As we try to use sharpening with each image we produce , sometimes it is a balancing act to do so.
Highlights seem to be the giveaway area for some of these problems. We just produced a series of mural prints from holga negatives and at the magnification not only did we see the sharp grain pattern but also a grid like area in neutral upper midtone areas. By turning off the sharpening we erased the problem.
This would be very hard to manage at your end if your lab is not even seeing the problem in the first place.
Scan lines should be not part of the process you are paying for.