How suitable are camera telephoto lenses for imaging?

[25585]

As some camera telephoto lenses have smallish f ratio & length, how suitable are they optically for imaging. 

I am thinking more of fixed fl than zooms. 

Cameras with spot metering would be ideal theoretically for brighter objects. 

[alan potts]

I tried it about 5years ago with my 300mm F2.8 and it worked fine, I just mounted it on the mount and had it driven. I got a decent picture though what it was escapes me now. Should work with any fixed lens, I stopped back to F4 and used 800ISO for 2 mins  if I recall but cannot remember why, maybe I read something.

Alan

[jarbi]

Hi,

I use a Tokina 300mm AF pro f/2.8 lens on my modded Canon 1200D, works like a charm on the Star Adventurer. I can take up to 50s frames without guiding when it is balanced properly.

You can see one example here: https://www.astrobin.com/297983/?image_list_page=2&nc=&nce=

Clear skies,

Janos

 

 

[SteveNickolls]

Here is a link to an informative site-http://www.astropix.com/html/i_astrop/lenses.html 

And this site carries a number of valuable lens reviews-https://www.lenstip.com/lenses_reviews.html

Cheers,
Steve

[wxsatuser]

Some are some aren't.

Out of all the lenses in my collection the Samyang 135mm f/2 is by far the best optically wide open.
Next would be the Canon 200mm f/2.8 but not perfect wide open, very good @ f/4.

[tooth_dr]

I'm not sure if 105mm would be classified as telephoto, but my sigma does a pretty awesome job wide open at F2.8.

 

[russp]

Or even a 200-500 f5.6 zoom can produce a decent image - total integration time around 17minutes.

[Alien 13]

No telescope apart from a Tak Epsilon gets even close to a good camera lens... for speed vs cost.

Alan