Artifacts in the sky

[paul_klingaman]

I'm scanning 35mm HP5+ with a dedicated minolta film scanner. I'm

using vuescan, scanning max resolution with auto exposure, white

balance, etc.

 

I'm getting ok scans, but it seems there is enhanced film grain, and

artifacts in my skies. Is these any way to smooth this out? When I

open the .tif in PS7, the image is huge at 100% and posterized. It

looks better downsampled to say 25%, but I see the troublesome

artifacts in skies. Is this due to the quality of the scanner, the

film grain (which isn't as apparent when printing in a 'wet'

darkroom), or can I overcome this problem via my scanning methods?

 

I don't have the same problem scanning 120 film with my epson 3200.

[jorn ake]

I think the answer is yes to film grain scanned vs. film grain printed. But I also think that developing a negative for scanning may require a slightly different negative than one developed for printing in a darkroom. Maybe less contrasty with more detail in the shadows. You can always up the contrast once you get the negative into Photoshop, but you can't do as much with posterization and blown out highlights.

 

A friend of mine from the world of photojournalism calls what you describe, a "bullet-proof" negative. They typically come from long developments in undiluted developer at elevated temperature (most easily gotten by having someone at a lab develop your negatives, given that most labs are set up for color processing by default.) I am just now starting to do my own film to figure out some dilution/time relationships that allow me to scan more effectively for this very reason.

 

I can't say why this seems to be a 35mm problem, but it could simply have to do with the relationship between negative size and scanning resolution. You are in short enlarging the 120 film less than the 35mm film to get a viewable size, which may help to hide negative attributes. If you are using a lab, they may also do a better job on 120 film than 35.

 

The way around this without developing at home is to shoot and scan color film, then Photoshop the image into black & white. Surprisingly this actually works pretty well. You can also switch to Ilford XP2, which I think scans nicely with great detail and a really even image. While XP2 has a reputation that it scratches easily, I don't think I have seen any more frequent scratches on XP2 than I have on any other similarly processed film. Color processed films are archivally less sound if that is a concern. And of course, they still are just similar to but not the same as true black & white negative film.

 

Obviously I have been wrestling with this one too. Hope some of my suggestions help.

[pvp]

Scanner noise in large smooth areas is often a problem. One way to clean up a clear sky is to select the sky area (in PS) and apply a 2 or 3 pixel gaussian blur to smooth it out.

[johann_fuller]

You have turned off the dust removal feature in vuescan? - sorry if this is stating the obvious. As the previous poster pointed out - dev and exposure have a big effect on grain. Having said that high res film scanners seem to acentuate grain - I have had good results with grain reduction programs - Neat Image and Grain Surgery. If you only use them lightly to reduce and not remove grain you don't get any artefacts and it actualy puts back a lot of the quaities you get with a traditional wet print. Don't give up - with the right technique it is possible to get very good results from conventional B&W neg.

[pdumais]

You will get Moiré patterns on the screen from the fine structure. It's a display artifact and should have a lesser bearing on the printed result (are you aiming for a print or a screen image ?).

 

Do you see artifacts when you look at it up close enough to see the grain ? Does your scanner resolve the grain ?

[jorn ake]

Geert Vanden Wijngaert's photos are a good example of shooting color to scan into black & white. He has the photograph of the week right now. If you look at his "journalisme" presentation, some of those images are shot on Reala - obviously a color film. Also 100ISO as well. Might be an option to consider.

[paul_klingaman]

Thank you all for your suggestions.

 

Developing my B&W negs differently is not an option. I'm processing the film in my own darkroom, and have spent a great deal of time and effort tweaking the process to get really great prints. Going digital was a color-only venture for me, but I need to scan and prepare some of my black and white work for a web site.

 

I think the main culprit in this is my scanner...I see some grain enhancement in the color 35mm film I've been scanning too. At any rate, I tried applying a gaussian blur and voila...much better. Still not 100% there, but it's a dramatic improvement without use of 3rd party software, or the other workarounds. Not sure what I'll do when I get to my portraits though :)

 

Thanks again for your thoughtful advice!

[bruce watson]

Good odds what you are seeing is "grain aliasing." See:

 

http://www.photoscientia.co.uk/Grain.htm

 

for more information.