RCicala

It really does sound like a decentered copy. While not 100% perfect, a Zeiss Star Chart provides a good decentering...

If there were no pictures we'd send him replacement gear. As long as there isn't water in the lens, it's covered.

If there were no pictures we'd send him replacement gear. As long as there isn't water in the lens, it's covered. Pictures of the event are a fun bonus, but have nothing to do with replacing the...

Lensrentals has no financial connections or arrangements with DPR.

The average is a weighted average: center = 25% 4 corners = 25% (6.25% each) 4 sides = 25% 4 mid 1/3 = 25% Unfortunately I just don't have blog space or time to put up the raw numbers....

I think it was just a sensor - lens mismatch thing. We usually test several different copies of a lens on at least two different bodies. Because D800s were in such short supply we had very limited...

We do have a couple of them, but when I mounted the first one to try to test, it turned out to have a bit of decentering and I found it had been dropped on it's last rental so I couldn't use it....

I did the tests and just want to absolutely second what slimandy wrote. The only purpose is to provide some info about which lenses give the maximum resolution because we're getting melted down...

It probably is: it's really hard to sell a stolen car or a stolen house. It takes about 15 minutes and a post on Craigslist to sell a stolen lens and camera.

No, I'm not. The guy behind CanonRumors.com owns LensrentalsCanada, which is a completely unrelated rental company serving Canada only. No affiliation with Lensrentals.com whatsoever. For the...

Hi, I'm Roger Cicala. I own Lensrentals and hang out here and on FM. I try not to jump in whenever our name gets mentioned because I come here to learn and don't want to seem I hang out pimping...

OK, let me condense this:
We are establishing a monopoly in order to serve you better.

Right.

My take on the Tammie is several years old, written when the vast majority of photogs were shooting crop bodies (as opposed to less of a vast majority today, I guess). It is weak in the corners but...

My take on the Tammie is several years old, written when the vast majority of photogs were shooting crop bodies (as opposed to less of a vast majority today, I guess). It is weak in the corners on...

I didn't mean to infer that slightly out of tolerance lenses get caught. Poor wording on my part. Rather I was suggesting that an occasionally awful lens does get by. Not often, but sometimes....

Hiram,

Trying to keep graphs in the allowed image size made the labels too small so I identified the axis in the text: Both axis are MTF50 in Line Pairs / Image height. The horizontal axis is...

You are absolutely correct - I typoed that. Roger

Leonard, for the example I use the same result occurs focusing on a star chart on a flat wall: there's nothing in front of or behind the target for the autofocus system to detect.

Roger

Actually I completely agree (and a great example of the same definition meaning different things to different people). But I consider theses one of the easily detectable "bad lenses". Optically...

The interesting thing is lens MFA wouldn't be hard: each lens contains electronic hook-ups inside that the manufacturer uses with proprietary software to adjust focus. It wouldn't fix a decentered...