Halo on scans

Ste_S · Aug 2, 2018

I get my films dev and scanned at various labs, and I notice they always come back with a 'halo' where the sky meets the ground. This happens with various labs across C41 and B&W on Noritsu and Frontier scanners. If i try to work the scan in Lightroom, for example dropping highlights to compensate or blown over exposed skies, this makes the effect more visable.

This is 120 Tri-X shot on a Zeiss Ikon Netter, with the film unmodified after scan. Notice the halo in between the top of the trees and the sky

This is the file with the highlights dropped to -100 in Lightroom, just to make the halo more visible

Any ideas what's causing this ? Was pulled up on it at a Royal Photographic society distinctions advisory day

Doug Fisher · Aug 2, 2018

Those look like the classic halos that appear when someone over-sharpenes in Photoshop. The scanners you listed do a relatively significant amount of image processing by default. My guess is the scanner is set so that it is aggressively over-sharpening. Next time I would ask them to turn down the default sharpening level or not sharpen at all.

Doug

Ste_S · Aug 2, 2018

Thanks. I had wondered if it was sharpening related. These scans are mild in comparison to some others, one lab in particular sharpens much more aggressively by default.
I'll ask for no sharpening by default next time.

With the Noritsu and Frontier, is the sharpening done across the whole photo, or selectively ?

Doug Fisher · Aug 2, 2018

Applied to the whole photo.

Bob Carnie · Aug 2, 2018

You need to tell the lab to have the settings set to no sharpening please, as unfortunately most of these labs only make really small prints and never see the disastrous effect of sharpening when scanning.

Ste_S · Aug 3, 2018

Went in and spoke to the lab yesterday, and they say they only apply minimal sharpening on scans. They think it's a problem where contrasting areas meet ?

Dismayed · Aug 3, 2018

Ste_S said:
Went in and spoke to the lab yesterday, and they say they only apply minimal sharpening on scans. They think it's a problem where contrasting areas meet ?

Minimal sharpening appears to be too much sharpening.

Old-N-Feeble · Aug 3, 2018

It looks like sharpening with a huge radius. If the lab's sharpening settings are 'minimal' and radius is set appropriate for the image resolution then there's something else going on in their scanner software. At any rate, I don't want anyone doing anything to my images... not even 'minimal sharpening'. Just get everything on the scan with no clipping.

Lachlan Young · Aug 3, 2018

Minilab machines all sharpen quite drastically - & the files they output are designed to be 'final' - ie straight to print with no further work. Further interventions are often a quick route to hitting the hard limits of the file.

Probably worth getting the neg scanned as a 16-bit .tiff on a high end CCD or drum scanner & seeing what is really there.

Wallendo · Aug 3, 2018

Ste_S said:
Went in and spoke to the lab yesterday, and they say they only apply minimal sharpening on scans. They think it's a problem where contrasting areas meet ?

In many cases, the scanner sharpens without really warning the user. If this is minimal sharpening, I would hate to see full-on sharpening.

Prof_Pixel · Aug 3, 2018

Sorry, I don't believe it's a scanner sharpening issue - the edges of the trees aren't 'crisp' enough (nor are other edges in the image over crisp). I suspect it's a developer concentration edge effect.

calebarchie · Aug 3, 2018

It does not look like a typical over-sharpening artefact, almost like stand development halos at contrast edges.

Lachlan Young said:
Minilab machines all sharpen quite drastically - & the files they output are designed to be 'final' - ie straight to print with no further work. Further interventions are often a quick route to hitting the hard limits of the file.

Probably worth getting the neg scanned as a 16-bit .tiff on a high end CCD or drum scanner & seeing what is really there.

Really not necessary - loupe and light-box

Ste_S · Aug 3, 2018

The good news anyway is that the lab is happy to work with me to try to identify what's causing this. Hopefully not a development problem as that then leaves me not trusting the three labs I use in the UK...

Lachlan Young · Aug 3, 2018

calebarchie said:
It does not look like a typical over-sharpening artefact, almost like stand development halos at contrast edges.

Really not necessary - loupe and light-box

To be fair, I'd tend to agree with you - though I've most often seen similar effects from poor layer masking in PS or bad dodge & burn in the darkroom.

Lachlan Young · Aug 3, 2018

Ste_S said:
The good news anyway is that the lab is happy to work with me to try to identify what's causing this. Hopefully not a development problem as that then leaves me not trusting the three labs I use in the UK...

Have you looked at the neg under a loupe - is the effect visible? And just to be clear, are you processing the film, or are the labs handling it?

Ste_S · Aug 3, 2018

Lachlan Young said:
Have you looked at the neg under a loupe - is the effect visible? And just to be clear, are you processing the film, or are the labs handling it?

No, not looked at the neg under a loupe yet. Labs are handling the processing, this one in particular does dip and dunk for what it's worth

Lachlan Young · Aug 3, 2018

Ste_S said:
No, not looked at the neg under a loupe yet. Labs are handling the processing, this one in particular does dip and dunk for what it's worth

That would tend to rule out severe edge effects then, given that it's more than likely replenished XTOL - I strongly suspect something in the scanner's software. Nevertheless, an image of the negative would be incredibly useful.

If someone has the documentation/ operator's manual of the Frontier & Noritsu software it might give some clues as to what's happening.

Ste_S · Aug 3, 2018

For what it's worth, here's some more shots from the same roll of Tri-X.

First image is an unmodified scan, apart from the highlights dropped to -100 to make the halo more visible. A halo again at the tree line but not as obvious as the previous photo

The next two don't have a skyline and don't have halos, in fact I've worked on them both in Lightroom (including extra sharpening) and appear to be fine.

Lachlan Young · Aug 3, 2018

Found what might be a possible culprit: the Frontier software has something called 'hypertone' which automatically carries out local dodges & burns (like a masked curve adjustment layer?) & can be used to 'improve' shadows, highlights, backlighting etc. It's automatically on in 'full correction' mode.
I suspect that the Noritsu does something similar - either way, it's worth looking to see if somewhat imprecise masking in this part of the software is to blame.

Prof_Pixel · Aug 3, 2018

Lachlan Young said:
the Frontier software has something called 'hypertone' which automatically carries out local dodges & burns (like a masked curve adjustment layer?) & can be used to 'improve' shadows, highlights, backlighting etc. It's automatically on in 'full correction' mode.

Sounds more likely than a sharpening issue.

Ste_S · Aug 3, 2018

Lachlan Young said:
Found what might be a possible culprit: the Frontier software has something called 'hypertone' which automatically carries out local dodges & burns (like a masked curve adjustment layer?) & can be used to 'improve' shadows, highlights, backlighting etc. It's automatically on in 'full correction' mode.
I suspect that the Noritsu does something similar - either way, it's worth looking to see if somewhat imprecise masking in this part of the software is to blame.

Thanks, that's really helpful. I'll suggest it to the lab and see if their Noritsu has something similar and how they set it.

ced · Aug 5, 2018

It could be the development. The first image looks like it really is with near no USM in the image.

Lachlan Young · Aug 5, 2018

Ste_S said:
Thanks, that's really helpful. I'll suggest it to the lab and see if their Noritsu has something similar and how they set it.

It may be in the scene correction menu & have some degree of interaction with the digital mask - I fear it may be a bit tricky to deal with. If you can get a 16-bit scan (which the Noritsu can do) with minimal interventions otherwise, it might be easier all round.

Halo on scans

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