Familiarizing myself with the Celestron CPC-925 GPS XLT. I downloaded the manual today from Celestron's website. This is a GPS enabled, fork mounted, go to, 9.25" SCT. Here is an excerpt from the section on astrophotography. It appears to have been lifted from an orange tube era Celestron Pacific manual from the 1970's. I wonder how much confusion this may be causing younger purchasers. Hard to believe this is in the manual - but worse, it's indicative of a disconnect between some at Celestron and how their products may be used. Thought some in PAS may care to take a trip back in time. Enjoy.
"When getting started, use fast films to record as much detail in the shortest possible time. Here are proven recommendations:
Ektar 1000 (color print)
Konica 3200 (color print)
Fujichrome 1600D (color slide)
3M 1000 (color slide)
Scotchchrome 400
T-Max 3200 (black and white print)
T-Max 400 (black and white print)
As you perfect your technique, try specialized films, that is films that are designed or specially treated for celestial photography.
Here are some popular choices:
Ektar 125 (color print)
Fujichrome 100D (color slide)
Tech Pan, gas hypered (black and white print)
T-Max 400 (black and white print)
There is no exposure determination table to help you get started. The best way to determine exposure length is look at previously
published photos to see what film/exposure combinations were used. Or take unguided sample photos of various parts of the sky
while the drive is running. Always take exposures of various lengths to determine the best exposure time."