35mm slide noise reduction

[spacecadet]

6 minutes ago, Robbie Shaw said:

Alamy are saying 'noise', but I suppose it could be grain.  Though shots were taken on K64 which was good for lack of grain.

 

Robbie Shaw

It's a bit theoretical. Digital has noise, film has grain. If the film is grainy the scanner simply renders it as such. I haven't done it, but I wouldn't expect a hi-res scan to have any noise to speak of.

 

[Bill Brooks]

Any film scan of any film will show film grain where the luminance drops off to black. Film grain is not like digital noise that is finer, but more like lumpy noise.

 

A scanner has all the characteristics of a digital camera so it can create its own noise. Overexpose the scan in software to eliminate scanner noise, or have the scanner software run multiple scanning passes and then combine each pass into one to produce your final scan.

 

The best scanner today is a high rez digital camera with a macro lens.

http://www.filmtoaster.photography

[MDM]

2 hours ago, spacecadet said:

It's a bit theoretical. Digital has noise, film has grain. If the film is grainy the scanner simply renders it as such. I haven't done it, but I wouldn't expect a hi-res scan to have any noise to speak of.

 

 

That is not correct. Scanner noise (colour and luminance) is a real issue although it probaly picks up the film grain as well. I'm not an expert on this but I have practical experience and I have experienced some horrendous scanner noise in early Nikon slide scanners. The later prosumer Nikon slide scanners (LS4000 and stable mates) were much better than the early ones.

 

 

 

1 hour ago, Bill Brooks said:

 

 Overexpose the scan in software to eliminate scanner noise

 

 

I would say that it is not advisable to overexpose slide scans as that will likely completely wash out highlights. The dynamic range of slides is narrow enough in the first place without overexposing them in the scan. As far as I know ETTR really only applies to digital cameras where most of the detail is in the highlight regions but I would need to re-read what Bruce Fraser and Jeff Schewe have written in this regard.

 

 

[wiskerke]

There's grain; noise and pepper grain.

- article is from 2002.

 

wim

[MDM]

6 hours ago, wiskerke said:

There's grain; noise and pepper grain.

- article is from 2002.

 

wim

 

Thanks for that link Wim. I recall reading that now. I shot mostly Velvia 50 for my landscapes back then. I always used ICE on my LS4000 which apparently does a decent job in reducing the pepper grain. However, the film grain and digital noise are a different matter. However, I used to print them uop to A3+ and they looked fine at sensible viewing distance. 100% on screen is a different matter. My modern Nikons produce cleaner pics at ISO 3200 after some judicious noise reduction. Good ole days - they gotta be joking. 

[Inchiquin]

17 hours ago, Bill Brooks said:

have the scanner software run multiple scanning passes and then combine each pass into one to produce your final scan.

 

 

I can't recall whether it's the scanner or the the software, or a combination of both, that controls this, but using Vuescan with my Coolscan 5000 allows up to 16 passes. In theory this should pretty much eliminate scanner noise. This is another advantage of using high quality equipment.

 

Another thing that makes life easier if you're scanning Kodachrome is to get an IT8 target for Kodachrome. I think Lasersoft do them.

 

Alan

[MDM]

47 minutes ago, Inchiquin said:

 

I can't recall whether it's the scanner or the the software, or a combination of both, that controls this, but using Vuescan with my Coolscan 5000 allows up to 16 passes. In theory this should pretty much eliminate scanner noise. This is another advantage of using high quality equipment.

 

Another thing that makes life easier if you're scanning Kodachrome is to get an IT8 target for Kodachrome. I think Lasersoft do them.

 

Alan

 

It's the Vuescan software. Nikon Scan doesn't do multiple passes as far as I remember

[Robbie Shaw]

23 hours ago, spacecadet said:

It's a bit theoretical. Digital has noise, film has grain. If the film is grainy the scanner simply renders it as such. I haven't done it, but I wouldn't expect a hi-res scan to have any noise to speak of.

 

Appreciate all your help.  A couple of routes I am looking at going down now.

 

Many thanks.

 

Robbie Shaw

[Robbie Shaw]

22 hours ago, Bill Brooks said:

Any film scan of any film will show film grain where the luminance drops off to black. Film grain is not like digital noise that is finer, but more like lumpy noise.

 

A scanner has all the characteristics of a digital camera so it can create its own noise. Overexpose the scan in software to eliminate scanner noise, or have the scanner software run multiple scanning passes and then combine each pass into one to produce your final scan.

 

The best scanner today is a high rez digital camera with a macro lens.

http://www.filmtoaster.photography

Many thanks for all your help Bill.

 

Robbie Shaw

[Robbie Shaw]

4 hours ago, MDM said:

 

It's the Vuescan software. Nikon Scan doesn't do multiple passes as far as I remember

Many thanks for all your help, lots to think about.

 

Robbie Shaw

[Robbie Shaw]

12 hours ago, wiskerke said:

There's grain; noise and pepper grain.

- article is from 2002.

 

wim

Many thanks for all your help - have to admit I have never heard of it, but it certainly was an interesting read.

 

Robbie Shaw

[Chuck Nacke]

Just to add another note about finishing film scans.

 

I use Noise Ninja (old, I know) to clean up noise in the out of focus areas.  Works great.

[Robbie Shaw]

Thanks Chuck, will have a look.

 

Robbie Shaw