I'm Roger and I am the founder of Lensrentals.com. Hailed as one of the optic nerds here, I enjoy shooting collimated light through 30X microscope objectives in my spare time. When I do take real pictures I like using something different: a Medium format, or Pentax K1, or a Sony RX1R.
Equipment
OK, in the last post we did something useful, but rather boring: we looked at how MTF changes when lenses are stopped down. Today we’re going to use a more powerful optical bench tool, the MTF vs. Field vs. Focus. Unless you work in a metrology lab (and probably not even then, very few are performing […]
Geek Articles
For quite a while now we’ve been publishing our MTF curves. They’ve always been the same thing; at least ten copies of each lens, in 4 rotations, and measured at the widest aperture. The reasons for that are (to us) very straightforward. Our purpose in doing the tests is to establish reasonable expectations, learn what type […]
Equipment
People think that because I expect the worst and try to prepare for it, that I’m negative. That’s not it at all. I’m not a negative person; I’m cheerfully cynical. If I expect the worst and it doesn’t happen, I’m happy because things went better than I expected. If I expect the worst and it does […]
Equipment
I posted an article about circular polarizing filters recently, letting you see some data I obtained for Lensrentals when they were reviewing which of the polarizing filters were among the best. I concluded that they all polarized light really well. I also said that none of the CPs I tested seemed to cause optical problems at […]
Equipment
I’ve been slow to test the Batis lenses for several reasons. We can never get enough copies when they’re first released and by the time we do have enough copies I’ve got six other things to do. That said, I did give an overview of the Batis 25mm and 85mm a while back and even did […]
