Dmin Dmax for scanning

[Jonathan Lee]

Lately, I've been scanning some of my older 4x5 BW negatives with an Epson 1160 faltbed scanner. While this won't be news for most of you, I have noticed that compared to a silver print of the same negative, I can discern more shadow detail in the sacnned negative, but the highlights blow out earlier. Since I'd like to switch over to digital, I would like to use densitometry to optimize future negative processing for flatbed scanning. If shadow detail is better, the calculation of film speed that I have been using (0.15 above b+f) might be too slow. Maybe I should also the Zone VIII density (currently ~1.2) as well. Just for fun, I thought about about trying speed at 0.05 above b+f and trying to put Zone VIII at 1.1 for N. Has anyone been down this road before?

[j.e.simmons]

I have the same difficulty with my old negatives. I've wondered if the proper approach would be to expose the negative as one would a slide by metering for the highlights. j

[Brian Ellis]

In general it's best to scan for a flatter print (i.e. lower contrast) than you exepect to actually print and then increase the contrast in Photoshop. That might help with your shadow detail. What inks are you using? The MIS inks with the curves that you can download from their web site might help, or possibly the Cone inks and software. At one time the people in the Yahoo digital black and white printing group seemed to agree that the best combination was MIS inks with the Cone softwre but Cone is in the process of changing everything around and I'm not sure they still sell the software.

[Jonathan Lee]

Brian,

I use the Cone software and inks. It produces a beautiful image that I really like for my 35mm and medium format work. However, as far as my digital ability now stands, it does not do justice to large format work and I find that I prefer a silver print from 4x5 negatives. The new Cone product will replace their Photoshop plug-in with a printer driver. The only advantage to the changeover is that the new product is OSX compatible for Mac people like myself.

[JohnnyV]

Jonathan,

You should have no problem scanning B+W on the Epson as B+W film does not have the density as say Chrome film.

Could be your scanner software settings.

What software are you using and settings? I'm thinking the software settings are clipping the highlights.

Have you tried Vuescan? www.hamrick.com

Here's an excellent tutorial:

http://homepage.mac.com/onelucent/VS/vsm.html

[Steve J Murray]

I have been getting good results scanning 4x5 B&W negs with my Epson 2450. Using Vuescan really helps. I typically adjust the "white point" and "black point" to zero at first. With white point at zero, you capture as much of the highlight detail as you can. Black point can be increased as you see fit. You can adjust overall contrast once the scan is in Photoshop. I've gotten some amazing contol this way. I actually got the disk of the sun to show up in one sunrise image, which I couldn't do in the darkroom. Looks like I was using Pyro instead of D-76! I'm just printing on a cheap Epson 820.

[Bruce Watson]

Jonathan,

I think you are headed down the road I went down quite a while ago. I think it's a good road, but YMMV of course. Thinner negatives scan better due to the collier effect. This is especially true of drum scanners. For that matter, it's also true of darkroom enlargers, within reason ;-) Also, since one of the things that effects grain size is development time, reducing development time to get thinner, less contrasty negatives can have the side effect of better grain (of course, depends on your film, developer, agitation, etc...).

I've been developing my 4x5 Tri-X negatives similarly to what you allude to, doing my own drum scanning, and printing with Piezotone inks for a while now. I find the resulting prints to be considerably better than my darkroom prints, especially in shadow *and* highlight detail. I don't get blown out highlights at all.

If you are 1) having highlights blow out in your scans, and 2) think the Piezotone inks don't do justice to large format work, I immediately suspect your scanner. To find out, consider sending a favorite negative off for scanning by someone else. A high end flat bed or a drum scan to compare against a scan of the same negative from your existing scanner might prove interesting for you. At least it will help you evaluate your scanner's health.

Just so you'll know what's possible, I've got negatives I intended for scanning (not for darkroom printing!) that go out to Zone XII (density over 2.0) that scan and print just fine without a trace of blown out highlights. With scanning, my days of N-x development are over.

BTW, the new Cone product does NOT "replace their Photoshop plug-in with a printer driver." It replaces the plug-in with an ICC profile; Cone will no longer supply printer drivers at all. For more details:

http://www.inkjetmall.com/store/piezographyBW.html

[Jonathan Lee]

Thanks for your input. Maybe it is the scanner or scanner software. I have an Epson 1600 that is probably getting long in the tooth and I haven't done any serious playing around with VueScan. If you can print the sun or up to 2.0, I must be doing something wrong. I'd better get cracking at the keyboard! There is a local photo store that does Imacon scans so maybe I can send them one of mine to scan.

[David A. Goldfarb]

If it's an option, also be sure you're scanning in 16-bit mode to use the maximum density range of the scanner.

[Richard_3152]

16 bit mode and Dmin/Dmax are separate things. Some scanner software may indirectly associate them by always using the widest dynamic range for 16bit mode for example. But in general setting Dmin and Dmax is done independently of whether you capture in 16bit or 8bit.

[Richard_3152]

Another thing to play with if you are not aware of this yet : When scanning B&W negs, perform the scans as RGB and then perform the conversion to monochrome in Photoshop (or your editing software) via the various ways you can find on the 'net. In general adjusting the relative contribution of each of the R,G and B channels allows you to tailor the final contrast and highlight/shadow detail. These operations should probably be performed in 16bit mode!

[JohnnyV]

Correct...scan in RGB then Invert in Photoshop. Try to do all corrections in RGB 16 Bit. There probably will be a slight color cast...but the cast can be fixed with Hue and Saturation. If you don't need a Grayscale file proper try to stay in RGB as the file will be more versatile...like mostly all filters will work in RGB and not Grayscale.

[Ken Lee]

Before you spend money on an Imacon scan, you might consider downloading a trial version of VueScan. If it supports your scanner, you can use it to make complete scans, except that it embeds some $ characters in the image (prompting you to pay the modest license fee).



You can configure VueScan to "do nothing" to your image, other than present the widest possible contrast range.



Lock Exposure Option, RGB Exposure = 1
Exposure Clipping = 0%
Color Balance = Manual
Black Point = 0
White Point = 0
Brightness = 1... or however much/little to print the film edge as black
B/W Vendor = GENERIC
B/W Brand = COLOR
B/W Type = NEGATIVE