Films For Astrophotography

Latest PJM Multispeed 640 film tests

By Chris Schur

I have several pros and cons for this film worth mentioning. First, the film is certainly hard to get. We just recently got it at a supersized professional photo store in Phoenix, but they said the photographers loved it so much that they would carry it from now on.


1. The film is very red sensitive, about the same as hypered Pro 400ppf

2. The grain is HALF that of the Pro400, I was shocked by this.

3. The grain is not clumpy like Pro 400, and smooth and even.


1. The film is VERY low contrast. This means you must really pump the negaive up in the darkroom.

2. Pumping the negative results in a very obvious vignette that is not even visible with the same appearance with Pro 400 and brings out all negative defects and scanner defects.

3. The film is very slow, more like 200 asa when unhypered

4. According to Jerry Lodriguss, the hypering time always is different, roll to roll, and results in inconsistent results.

Final Analysis.

It took me over 2 hours of digital darkroom work to make these images look decent. With the Pro 400 even including the tedeous sandwiching operation, takes half an hour or so. Most of the time was spent trying to remove the vignette from the images, which was very time consuming. This is something I never have to do with my Pro 400 shots, since the films hi contrast doesnt need to be pumped much at all to get a great image with my 12" f/5.

My opinion at this point is if you have a system with a flat, no vignetted field, such as a wide field lens or refractor stopped down to f6 or slower, this may be a good choice. but be prepared to boost the contrast to new heights to make them look good. I will be doing more tests with schmidt cameras with this film so stay tuned...

Select one of the following for a larger view:

IC1795 in Cassiopeia - Two 45 minute exposures on unhypered film with a 12.5" f/5 and coma corrector that were sanwhiched in Photoshop for a combined 90 minute equivelent exposure. The films good red sensitivity made the difference on this object, the field filled with very faint nebulosity.

NGC6946 in Cygnus - Same equipment and exposures as above. The red nebulosities in the spiral arms are unreal! This certainly adds a new aspect to galalxy photography.

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