"Gestion CEF" wrote in message
My typical workflows is; old Nikon camera, film scanner, Photoshop and Epson1280 printer. I want to produce black and white print with MIS quadtone ink. My question is:
Is there an advantage of using a B&W film, ex. Portra 400BW, versus a color film, ex. Portra 400UC converted to B&W in PhotoShop? Paul
Color film for B&W digital output does have some advantages. First, scanning a B&W negative will give you an image with less data than a scan of a color image (no real color data, even though it may be a color/RGB scan of the negative). Scanning a color image (negative or positive) will give you three channels of color information. This is closer to the original scene than the scan of a B&W negative, meaning that when you start to manipulate it digitally you are starting with more (real/usable) data. Because many image manipulations loose data, you’re better off starting with more.
Second, channel mixing a color image is the equivalent of using a color filter on the taking lens when using B&W film. But using a filter on the lens creates an image-wide shift of the tonal values. For instance, a red filter will darken blue sky, but it will also affect every other element that makes up the image, sometimes leading to tonal shifts in some elements that are not desirable. The use of a color filter on the lens in B&W photography can be an exercise in compromise, unless you are lucky enough to be photographing a scene that is not otherwise unfavorably affected by your choice of filter. But when starting with a color image in Photoshop, channel mixing can be applied selectively to different parts of the image by using masks, giving you MUCH more control than slapping a filter on the lens and affecting the entire image. By using masks each image element can be given the channel mix that best produces the image effect the artist/photographer desires, rather than being stuck with the compromise imposed by the use of a color filter and B&W film.
Third, because you started with a color image, you can make both color and B&W prints from it. Yes, you can easily color a B&W image in Photoshop, but it just isn’t the same thing! (It will look like a hand-colored B&W image rather than a real color image.)
Fourth, because we are talking about digitizing and using Photoshop on the image, tonal range is not matter of concern. Whether shooting B&W or color, you can bracket your exposures and then put them together in Photoshop (either manually or using a plug-in for the purpose), building a single image with greater tonal range than can be captured by either type of film. Because most pros bracket (35mm film is very inexpensive per frame) this does not make for extra steps at the time of making the photographs, but actually can put to good use frames that might otherwise be deemed improperly exposed. Yes, there is an extra step involved in putting the images together in Photoshop, but you would do this to improve the tonal range in the image if necessary. Remember that desktop scanners don’t always get every last bit of tonal range from an image, so to wring that data out of your film and into digital form you should already be building tonal range from multiple images (aren’t you?). (Try this–make two or more scans of a contrasty image. Make separate scans for the highlights, the midtones and the shadows. [Make the best scan you can for each, don’t allow the image to become full of artifacts by pushing it too far.] Then put them together in a single image of greater tonal range than any single scan. Don’t have a plug-in that does it for you? It can be done manually. But that’s beyond the scope of this thread! LOL)
FYI, when I do scan a B&W image (neg. or pos.) I make an RGB scan. Why? Most noise ends up in the B channel and can be disposed. Also, the 24 bit RGB image has more image data than an 8 bit greyscale image, giving me more data to start with and greater control over the finished image. But with B&W digital output being the objective, given a choice between starting with B&W or color film, I’d pick color because it starts me out with more data, giving me more options and greater control over the final results.
My web site is currently down, but you can see the a few of my B&W images at the following links. All began as color transparencies, scanned in RGB, and had channel mixes selectively applied to them. I hope that they speak to the quality of image that can be attained when starting with color and working towards B&W.
http://www.dgrenier.com/alvord.jpg http://www.dgrenier.com/christ.jpg http://www.dgrenier.com/door.jpg http://www.dgrenier.com/squall.jpg Dave Grenier
Olympia, WA
