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.
Lenses and Optics
The King is Not Dead The Canon 85mm f/1.2 II lens, the king of creamy bokeh, is basically a 40-year old optical design first released in 1976 (in FD mount) and released as an EF mount lens after some slight optical modification in 1989. The “II” version, released in 2006, was an electrical/mechanical change only, the optics remained the […]
Equipment
You have been patient, my friends. You have made it through the first article, where we looked at how MTFs improve stopped down and saw it was a bit different for every lens. You enjoyed the second article, where we looked at the Best Individual Focus MTF (BIF MTF) which showed how good the MTF […]
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 […]
