Opteka?

[Cat]

Opteka 650-1300mm High Definition Telephoto Zoom Lens http://opteka.com/6501300.aspx
Opteka 500mm f/6.3 High Definition Telephoto
http://opteka.com/50063.aspx
Opteka 800mm f/8 High Definition Telephoto
http://opteka.com/800mm.aspx
Looking at these lenses due to their price... just curious if anyone has tried them and their opinion if the have.

Thanks in advance!

[Cat]

has no one actually tried one of these?

[Yousef I]

I did some reading on the 500mm f/6.3 and they seem to be negative
http://www.alphamountworld.com/reviews/pro-optic-500mm-f63-mirror-lens-review?page=0%2C0

I can't believe how cheap they are. I have not heard of them before your post. Maybe you can take the plunge and let us know! hehe