Category: Lenses and Optics
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Setting Up an Optical Testing Station
There are a lot of right ways to do optical testing. The gold standard is to put the lens on a $150,000 optical bench or run it through a well-equipped Imatest lab. But unless you have an optical bench or Imatest lab handy, that’s not practical. We have to optically test around 400 lenses a day,…
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Why You Can’t Optically Test Your Lens with Autofocus
By far the most common email and PM I get basically says, “I think my lens is optically out of sorts. What do you think?” The second most common is, “So what’s the best way to optically test my lens without a ton of equipment.” Years ago I wrote an overly long post about testing lenses, but it was…
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Tamron 150-600 Telezoom Shootout
There’s been a lot of interest in the newly released Tamron 150-600mm f/5-6.3 SP Di VC USD lens. (For those wondering what the initials mean, VC means vibration compensation, the others all read ‘marketing drivel’.) But meaningless initials or not, with a price under $1,100, a superior range, and…
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A Bit of A7R Sanity
A while back I wrote a post I humbly called Roger’s Law of New Product Introduction, complete with the graph shown below. The release of the Sony A7R has demonstrated the accuracy of that post as few other releases have. A few weeks after the A7R release we seem to be following the path quite…
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Otus is Scharf
I’m probably setting myself up for a replay of the Exo Tria Arxidia scene, but my friend Bernhard introduced me to the German term _scharf_ the other day. It can mean both sharp and hot (as in spicy, or as in, you know, hot). After testing our first copies of the Zeiss 55mm f/1.4 Otus lens I felt…
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Inspecting an ‘In Spec’ Lens
I’m going to open a can of worms today. I’ve been getting more and more emails from people telling me the same story that goes like this: > I’ve got this lens. It’s awful. I’ve sent it in for adjustment and the service center tells me it’s ‘in spec’ and nothing is wrong with it. Am I crazy? Second…
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Nikon 58mm f/1.4 is (hopefully) Not About the Numbers
## The Silence We have a routine when a new lens comes out at Lensrentals: the first new copies get sent to me for optical testing. I have about 4 or 5 hours with them because they’ll have to be packed up and shipped out to the customers that have been waiting for them and expect them tomorrow. So…
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There Is No Perfect Lens Test, Either
In my last article, I wrote about the fact that every copy of a given lens has some bit of sample variation. This affects lens reviews, whether lab-based or photography-based, because the copy they tested will be just a bit different from the copy you buy. I suggested, that if you want to get a…
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There Is No Free Lunch, Episode 763: Lens Adapters
Lens adapters can be useful things sometimes, letting you mount one brand of lens on another brand of camera. One thing that has always bothered me, though, is the idea of doubling the number of lens-mount interfaces. When you look at the thick metal pieces on the front of the camera and the back…
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There is No Perfect Lens
## The Three Questions I get asked a couple of questions every time I publish a graph showing Imatest results for multiple copies of lenses like the one below. Most people understand that some copy-to-copy variation is inevitable in the manufacturing process. Most are surprised, though, at how…
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Canon 200-400mm f/4 IS: Quick Comparison
Yeah, it costs almost $12,000. You could buy a Canon 400mm f/2.8 IS II and a 2X teleconverter for that. You could buy 10 copies of the Canon 100-400mm f/4.5-5.6L IS for that. I don’t know what you’d do with them, but you could. I sure can’t tell you if a lens is worth $12,000 by running a few…
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Zeiss ZE 135mm f/2 vs. Canon 135mm f/2L
We had a chance a few days ago to look at the first copy of the Zeiss 135mm APO-Sonnar CP.2 lens, but today received several copies of the 135mm APO-Sonnar in ZE (Canon) mount. I’ve been wanting to play with it personally, of course, but more to the point wanted the chance to test multiple copies,…