Re: [ATM] photo supplies

[George Anderson <georgea@cam.org>]

Hi David

There is only one B&W sheet film that is suitable for astrophotography
and that is hydrogen gas hypered Tech-Pan. The largest available size is
in 4 by 5 sheets and Kodak will be dropping the film over the next six
months.
Only a few people in the world shoot 4 by 5 tech pan for AP work, you
would need to buy the regular film and then have it hypered. There are
some developing issues with that film as well when you get to that size,
Wallis and Provin found the answer but IIRC they never published the
"secret".
Non of the currently available IR films are worth a hoot in AP work, the
reciprocity failure on them is so high that even with an f/1.4 lens the
captured image is minimal after one hour.
For colour films the choice is very limited, you would have to check Don
Westergren's site for what colour films are good, and then check the
manufacturers site to see if it is available in large format. I know the
choices are tough in medium format so large format will be even tougher.
Have a visit to the following sites for some info on doing AP.
http://www.astropix.com
http://www.robertreeves.com
Also you may want to have a look at the following books
"Astrophotography For The Amateur" by Michael Covington
"Wide Field Astrophotography" by Robert Reeves
Both are available through Willman Bell.
On the second hand market you may be able to find a copy of "A Manual
For Advanced Celestial Photography" by Wallace and Provin.

George Anderson
Montreal Canada

Clear skies and good health

David Williams wrote:
> 
> Hello list
> 
> I was just wondering since I have a darkroom and take pictures and sometimes use it to take astro pictures I need supplies of chemicals and paper and film just like any one else.  Someone earlier had a good website about a good supplier of chemicals, but I'm looking for film and specifically 8X10 film and besides that black and white, infra-red sensitive.  All I need are one or two sheets to start with not a bulk amount, and then maybe a large variety including 25 speed, ortho litho, color 200 speed,  black and white 800 speed.  I've already check out Freestyle but they make you buy at least 10 sheets.  That's not what I need;  I need just one or two of each of those that I just listed.  So does any one know where I can find these films?  Thanks
> 
> David
> _______________________________________________
> ATM mailing list http://www.atmlist.net/
_______________________________________________
ATM mailing list http://www.atmlist.net/