scanning silver-based b&w film vs. chromogenic?

temujin

Member
Joined
Dec 7, 2006
Messages
49
Format
Medium Format
hi all, after working for years in traditional b&w analog photography, i am considering buying a film scanner to experiment w/ hybrid work. however, i have heard some people say that for scanning b&w negs, chromogenic film works much better. is this truly the case? if so, what advantages does chromogenic offer for scanning? i ask this because i am rather attached to certain traditional silver-based b&w films, and am hesitant to give them up. thanks...
 

Mike Richards

Member
Joined
Jan 30, 2005
Messages
115
Location
Preveza, Gre
Format
35mm RF
Scanner software usually features "ICE" dust and scratch removal, which works with chromogenic, but not silver-based films. Keep your silver negatives clean and scratch-free, and your manual clean up will be minimal. I have tried chromogenic films but much prefer to work with silver based films that I can develop myself and are much more versatile.
 

Thomas Bertilsson

Member
Joined
Jan 21, 2003
Messages
15,708
Location
Switzerland
Format
Multi Format
I'm by no means a scanning expert, but as I understand it you get better scans if you keep your negatives slightly thinner than what would be ideal for a silver print. Dense negatives are difficult to get separation in the highlights from digitally, while they might print well in b&w.
- Thomas
 

Katharine Thayer

Member
Joined
Oct 29, 2006
Messages
520
Format
4x5 Format
I hesitate to get into scanning discussions, since my scanning techniques are, well, let's say less than sophisticated, and I have no idea whether chromogenic films do or don't have some built in advantage for scanning.

But I do very often use color film (Provia, mostly) for monochrome images in gum, and I enjoy the extra flexibility offered by manipulating the channels. So to get a good monochrome negative from a color file, you can choose one of the channels and print that as a negative, if one of the channels has the contrast you're looking for, or you can use the channel mixer to mix the channels to your liking to make one negative. (I learned all this from Dan Burkholder, in the Before time). Then apply a curve if necessary to adapt the file to your printer's requirements.
 

sanking

Member
Joined
Mar 26, 2003
Messages
5,437
Location
Greenville,
Format
Large Format

B&W chromogenic films have finer grain than regular silver films of the same ASA. I did some testing recently and found that you could get finer grain with ASA 400 chromogenic films than with ASA 100 B&W films. In these films the silver image is bleached leaving just a dye image.

It is also possible to get finer grain by developing regular B&W films in staining developers. When you do this a high percentage of the total density is stain, or dye density.

However, as KT mentions, you can also shoot color negative film and use just one of the channels to make a B&W. I think you can get almost as fine grain with regular color negative film if you scan in RGB and drop the blue channel record which always has the most pronounced grain. I almost always shoot color negative film with MF because this gives one the opportunity to either make a color print or a B&W one. I also like color negative film for MF because there are quite a number of emulsions available in 220 size, which I much prefer to 120.

Sandy Kinig
 

lenny

Member
Joined
Oct 27, 2005
Messages
305
Location
Petaluma, CA
Format
4x5 Format
Chromogenic film is interesting in some ways, but it has a much lower tonal range than other types of film

Lenny
 

Les McLean

Subscriber
Joined
Oct 18, 2002
Messages
1,606
Location
Northern Eng
Format
Multi Format
Something that just crossed our lab, was a project where we were making very large mural fibres off scanned PMK processed film.
We found that scanning in greyscale and using a standard bw setting would give us increased noise in the shadows.
By scanning in rgb and putting a xp2 400Iso film setting which mimics the base density +fog gave us noise free murals. Basically we determined that less agressive movements were needed with Pyro film by doing this at the scanner stage.
 

Les McLean

Subscriber
Joined
Oct 18, 2002
Messages
1,606
Location
Northern Eng
Format
Multi Format
that last post and this one was/is by me Bob Carnie not Les, the silly bugger forgot to sign off my computer last week,
 

sanking

Member
Joined
Mar 26, 2003
Messages
5,437
Location
Greenville,
Format
Large Format

Les,

What scanner were you using? And when you made the scan in RGB did you use all three channels or did you discard one or more? As noted earlier, I don't normally see much difference in grain between the three channels when scanning in RGB, but there can be a big difference in contrast.

And BTW, what is the nature of the B+F of XP2 film? I assume it is not neutral tone?

Sandy
 

Bob Carnie

Subscriber
Joined
Apr 18, 2004
Messages
7,735
Location
toronto
Format
Med. Format RF
Hi Sandy

Bob here, the post was by me, Les was using my computer and did not log out.
The scanner in question was Imocan, we found that too hard of an adjustment was required using greyscale with a standard BW neg setting for pyro negative.
What was evident was major noise in the deepest of shadows.
By switching to RGB and using a profile for the XP2 which btw has a large BD&f it mimiced the pyro negative and at the scanning stage very little movements were required to get good looking image.
Once the image was sent to Lambda we printed rgb rather than convert to agreyscale .This worked quite well with no noise in the shadows.
XP2 film has a reddish cast as compared to the yellow green of the pyro neg, but the density start points are very close.


 
You must log in or register to reply here.
Menu
Log in
Register
Cookies are required to use this site. You must accept them to continue using the site. Learn more…