View Single Post
  #26  
Old 07-07-2013, 10:07 PM
alocky's Avatar
alocky (Andrew lockwood)
PI popular people's front

alocky is offline
 
Join Date: Aug 2010
Location: perth australia
Posts: 1,291
Yep - that's a superb Antares shot. I think the 14-24 does an amazing job, but, as you say, it's a pretty extreme bit of glass. The 8300 chip is pretty close to a crop sensor size-wise, I wonder if the lens correction in photoshop would be close enough if you told it you'd used a d200 or similar? It certainly improves things with the full frame.


Quote:
Originally Posted by DavidTrap View Post
Thanks Andrew,

The 8300 chip is significantly smaller, so it should be better than the FF chip. I'll have to do some test shots on my D800 and see how it compares for myself - might be whinging about nothing!

Link - this is a shot taken with an 85mm prime lens mounted on the CCD (before I'd made the bracket though). The stars are much tighter in the corners.

I was presuming that the focusing mechanism would move lenses inside relative to one another. Given that I was focusing on an object at infinity when the focus distance scale was reading 0.3m would mean that the optics wouldn't be where they should be to produce sharp focus across the field of view. I guess the prime lenses might suffer the same fate, but I hadn't seen it with the 85mm lens. I wonder if the 14-24mm lens is such an extreme case that it is more sensitive to a slight change in backfocus. I had the lens stopped down to ~f4 - an imprecise science given the lack of an aperture ring.
Reply With Quote