I recently bought a used Soligor Teleobjective lens on eBay for about $40 (!) and tried it out for Wide field astrophotography with my Canon Digital Rebel XTi (unmodified camera).
The Soligor is a 200mm F/D 3.5 Lens for 35mm SLR cameras. The Teleobjetive is lightweight – but gives impression of being very solid.
To use it with a Canon EOS Digital Camera you need an adapter that includes a lens.
Using an FD to EOS adapter usually extends the focal – in my case by 25% from 200mm to 250mm.
I took the following pictures at Joshua Tree, CA – under quite a dark sky on the 25th of October 2009.
The Lens was stopped at F/D 4. The Camera and Teleobjective were mounted on an Orion Onyx 72ED and an Orion Atlas M0unt.
Coma is still visible at the edge of the field. However, I am quite happy with the result given the cost of the lens, especially comparing it to the cost of a brand new Canon teleobjective …
Processing: MaxIm DL 5, Photoshop CS4, and Neat Image.
M31 – on 10/25/2009 – Soligor 200mm at F/D 4 – Digital rebel: 9 exposures of 104 sec.
M42 – 10 exposures of 104 sec – Soligor 200mm
Pleiades – 8 exposures of 104 sec – Soligor 200mm and Digital Rebel XTi
Jupiter and a Joshua Tree after Sunset – 18/50mm Zoom – Canon XTi
Astrophotography in Urban Environment 
#1 by Cat on December 14, 2009 - 6:20 am
Coucou TocToc,
Je viens de découvrir les très joulies images que tu as faites dans le désert !
Rien qu’en regardant les images on voit qu’il caille ! Ca fait rien pour réchauffer en ce moment chez nous il fait à peu près la même température qu’ à Joshua Tree quand on y était.
En tout cas elles sont très chouettes !
Bisous !
Cat et lapin