Originally posted by yusuf Originally posted by DSims Quote
Or it means that you don't mind how much overall IQ is lost using that widest stop.
Don't we expect that for any lens?
No, we don't, but it'll cost you.
The DA*55/1.4 is a perfect example of this. It has minimal loss of IQ at f/1.8 - even at f/1.6 much of the time. This is why it costs much more than the FA50/1.4.
The new $4000 Zeiss 1.4/50 is another example. Even though I haven't studied the lens carefully I believe the positive statements about it (that it comes as close to perfect as practicable in a 50) based on my brief experience with other outstanding (~$2000) Zeiss lenses.
Certainly you've noticed that your FA31 and FA77 outdo most other lenses in this regard. With them I can barely tell the difference (IQ-wise) between a shot taken at f/1.8 and one at f/2.2. In other words, shooting wide open doesn't degrade the IQ. These are the only two lenses I've used that I can say this of.
BTW, I can't help but notice your location. I taught a class there in early 2008. I have fond memories of visiting the butterfly park next to the game reserve, as well as taking a few photos of the silly monkeys that loved hanging around outside of it.