View Full Version : How does digital handle highlights and shadows?


K. Forman
August 3rd, 2003, 04:33 AM
My question would be, do the digi stills have the same problem as digi video when it comes to subtle differences in light and shadow? Film has little problem gradually stepping from bright to dark, where digital usually has blocky artifacts.

Jeff Donald
August 3rd, 2003, 05:42 AM
There are several variables in your question, Keith. One, would be the number of pixels in your camera, the size of the chip (CCD, CMOS) and of course exposure technique. However, the short answer is, the new DSLR's have about the same exposure latitude as slide film. They can provide detail within a 5 to 6 stop range.

The smaller (physically and number of pixels) digicams do not usually have that latitude. This may not be readily apparent to many users. The type of printer, inks, paper, size print etc. all factor in to hide or exacerbate the weakness of the smaller cameras. Of course film cameras have their limitations too.

Digital has very little noise in most cases. Film users may be plagued by grain due to their choice of film ISO/ASA. The lack of noise benefits the digital user because it provides greater apparent sharpness.

Rob Belics
August 3rd, 2003, 06:24 AM
As regards to negative film, digital cameras are not in the same league. Highlights still bloom, shadows are still gone, so they have none of the latitude.

Robert Knecht Schmidt
August 3rd, 2003, 06:50 AM
For still photos in which there is no movement in the frame, there is a method for obtaining high dynamic range (HDR) radiance maps that are of far greater latitude than any conventional film stock using a good digital still camera. See http://www.debevec.org. An LDR image that in large part retains the highlight/shadow detail of the HDR image can then be recovered using a gradient domain method, e.g., http://www.cs.huji.ac.il/%7Edanix/hdr/

Boyd Ostroff
August 3rd, 2003, 07:04 AM
My experience with consumer-level Nikon digtal cameras is that you do not have the lattitude of film. However there are a number of other factors which made me put away my film camera about 4 years ago. I recently upgraded to a Nikon 5700 which I believe has a 2/3" CCD. The images I'm getting from this camera have a much more film-like quality to them, with 5 megapixels.

You still have to be very careful not to burn in the highlights, so I always try to err on the side of underexposure. Photographing stage shows is still difficult due to the very high contrast of stage lighting where one part of a scene can be blinding bright while the corners are dark. It just isn't possible to capture this sort of dynamic range digitally, and film can't really do it either.

But fortunately still cameras don't suffer from the severe compression that DV applies to its images, and you get 5 million pixels to play with instead of about 350,000 for DV.

Rob Belics
August 3rd, 2003, 09:44 AM
I haven't looked at Paul's HDR site for quite a while but this method was only for digital creation, not capture. It allowed the compression of the dynamic range of light into the minimal presentation abilities of, specifically, computer monitors and video projectors and printers. It does not extend the range of digital cameras and the method is software acting on already captured data.

Jeff Donald
August 3rd, 2003, 01:31 PM
Keith, plain and simple, for many, many users digital has replaced film. However, depending on your application, film or medium format may be a better choice.

Kodak recently announced the layoff of some 6,000 workers. Why? Simple, even Kodak said it, a drop in film sales. For the vast majority of people, digital is replacing film. Digital meets their quality and durability requirements. Is digital for everyone? No. But neither is film.

If you would like I can provide a link to some images that show extremes in exposure values. This may be the easiest way to determine if digital is right for your application.

Vladimir Koifman
August 3rd, 2003, 02:10 PM
Well, there are attempts to enhance digitals contrast range. See, for example, this:

http://www.smalcamera.com/technology.html

or this:

http://www.fillfactory.com/htm/technology/htm/dual-slope.htm

or this:

http://www.pixim.com/technology/technology.phtml

or this:

http://www.dpreview.com/news/0301/03012202fujisuperccdsr.asp

You can see that industry is realizing the problem and working toward solution in one form or another.

The first reference is actually implemented in a consumer camera that is available right now in stores under different brand names.

Boyd Ostroff
August 3rd, 2003, 04:02 PM
<<<-- Originally posted by Jeff Donald : Kodak recently announced the layoff of some 6,000 workers. Why? Simple, even Kodak said it, a drop in film sales. -->>>

Actually, according to a report I heard on Bloomberg, another big factor in Kodak's sales drop was due to the growing popularity of Fuji film. Funny, a reported said he did an informal poll of film photographers who were COVERING THE KODAK ANNUAL MEETING, and all of them were shooting Fuji!

Gints Klimanis
August 4th, 2003, 03:32 PM
Boyd , I just looked up the specs on the Nikon 5700 to verify that it has a 2/3" CCD. Nice !

http://www.steves-digicams.com/2002_reviews/nikon5700.html