|
Terry nothing built with 'ordinary glass' even ED at F2.8 can come close to perfect lack of CA and astigmatism. Why they get away with it at short focal lengths is because you or the camera can't see it.
The lens I lent to Scott was the first of really well corrected telephoto lenses. In fact if you have seen the start of 'Tootsie' where Dustin Hoffman walks down the street in the general crowd taken from way back was taken with the lens Scott has got in his possesion (or one exactly like it) and it was wide open at F2.8 to differentiate him from the crowd.
I could not resist owning it even though I did not need it. It pleases me that Scott is making good use of it.
The Canon 300mm F2.8L I think is better than the IS version for astrophotography. You have seen the images it can produce.
At least for the price you paid you have a quite usable lens. Most telephotos have very noticeable purple fringes.
Bert
|