|Film & Developer Tests|
The results of the testing are presented in two pages.
This page explains the reasons for the testing, tells how it was done, shows the scene and locations of the two detail shots, and shows full-frame shots of the negatives for contrast comparison.
The second page, linked by hypertext at the bottom of this page, allows a side-by-side comparison of the films and developers. Your browser must support 'Frames' to view it.
|Since there is so much discussion and confusion about this
subject in the USENET newsgroup 'rec.photo.darkroom', I decided to do some experimentation
to find out for myself what happens when you use 'Developer A' with 'Film B'. The results
are posted here.
Kodak T-Max 100 is one of the most popular of the currently available films. I chose to use it because of its popularity, and because I use it for almost all my black and white work. I also chose to run three developer tests with Kodak Verichrome Pan. Someone recently posted that they like the 'tonality' of Verichrome, but I remember it as the 'standard' Brownie camera film that we always used on family vacations when I was a kid. I wanted to find out how its 'old-tech' emulsion compared to the current T-grain technology. The T-Max 100 was rated at E.I. 80 for these tests, the ISO 125 Verichrome Pan was rated at E.I. 100.
Kodak Tech Pan film is often mentioned as producing 'grainless' images when processed in the expensive Technidol developer Kodak produced to keep Tech Pan's contrast in check. I also used Kodak Xtol developer with Tech Pan. The Tech Pan was shot at its ISO 25 rating.
I had a few frames of Kodak Pro-100 (PRN) and some of the new Kodak Portra 160-VC left over from another shoot. I wanted to know how the new 160-VC stacked up against my favorite color negative film, PRN, in the grain department. Kodak purportedly booted the rated speed of the new film to 160, versus the PRN's 100 rating. Since PRN is discontinued and 160-VC will be the replacement, am I going to have issues with grainier negatives when using the new film? The ISO 100 PRN was shot at E.I. 80, the ISO 160 rated 160-VC film was shot at E.I. 125 and 80 to get an idea what its actual speed might be.
Another recent Kodak offering is T400CN film. It is a chromogenic film, meaning that it processes in standard C-41 color film chemistry, but it is used for making black and white prints. It also has very fine grain. Is it a true 400 speed film? I had to know! Frames were shot at E.I. 800, 400, 200, 100 and 50.
The testing was done as follows:
I shot the scene, shown below, during the Christmas, 1998, holidays. I had been waiting for some time for a nearly windless day, so the cactus wouldn't be moving. I put my Mamiya RB67 on a tripod, focused on the cactus, and operated the camera in mirror lockup mode, using a cable release. The aperture was set at f8, a nice, middle-of-the-range setting. I then only had to change shutter speeds to accommodate the different ISO film speed ratings as I exposed the various films.
The local Pro lab processed the chromogenic (color and T400CN) films. I processed the black and white films. All the B&W film/developer combinations were developed using manufacturer's recommendations for time appropriate to the developer temperature and dilution. Temperatures were not controlled to a specific value. They ranged between 72 and 75F. Times were adjusted to factory recommended values for these temperatures using the manufacturer's chart. The negs were then lain on my light box and a small portion of each was shot on T400CN 35mm, using a Nikon F2, PK13 extension tube, bellows and reverse-mounted 28mm Nikor lens to provide about 30X magnification. This is approximately equivalent to printing the 6x7 neg to about 60x80 inches. The 35mm T400CN negs were then printed to 8x10 paper. I'm not sure what that does to the final magnification ratio, but it's pretty damned big.
The scans were done at 600 DPI, then computer-reduced to 800 pixels wide. The bitmaps were then compressed to .JPG files that are indistinguishable from the bitmaps when viewed on my 19 inch monitor. These .JPG files run from about 70K to 120K in file size, depending on how many gray tones are included. One of the interesting things about the file sizes is that the grainer the image (more speckles=more gray tones), the larger the resultant file size.
Immediately below the main scene photo, I've posted the full-frame negatives so you can see the relative contrast and densities produced by the various film/exposure/developer combinations. The results can be varied by changing development times, but these are what I got from the developer manufacturer's time/temp recommendations.
While not entirely a scientific test, these comparisons have value in that they give a representative sample of what most users will experience when using these combinations for the first time in accordance with the manufacturer's development tables.
You will need to check your video settings to be sure that your display is set to 1024 x 768 and 16 bit color, minimum, to see the photos on the comparison page as close as possible to their actual appearance. Your browser must support Frames to view the comparison page, which is linked at the bottom of this page.
The scene shown below is of Arizona's Superstition Mountains (think Lost Dutchman's Gold). The grain/sharpness area that's outlined is a Cholla (pronounced CHOY-ah) cactus. The shadow detail area is a part of a Cholla skeleton (dead Cholla) that threw a very deep shadow on a lower branch.
The link to the comparison page is at the bottom of this page.
|T400CN EI 50||T400CN EI 100|
|T400CN EI 200||T400CN EI 400|
|T400CN EI 800||Verichrome Pan, Acufine 1:1|
|Verichrome Pan, D-76 1:1||Verichrome Pan, Xtol 1:1|
|Tech Pan, Technidol||Tech Pan, Xtol 1:1|
|TMX (T-Max 100), Acufine||TMX (T-Max 100), Acufine 1:1|
|TMX (T-Max 100), D-76||TMX (T-Max 100), D-76 1:1|
|TMX (T-Max 100), T-Max Developer 1:4||TMX (T-Max 100), T-Max Developer 1:7|
|TMX (T-Max 100), Xtol||TMX (T-Max 100), Xtol 1:1|
|TMX (T-Max 100), Alta Gamma Plus 1:20||TMX (T-Max 100), Microdol-X 1:3|
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