Lenses and Optics
Optical Quality Assurance
*Pinhole images from new, but optically decentered lens. Olaf Optical Testing, 2016* After we published a number of posts about copy-to-copy variation, people were quick to say that this company or that needs to ‘just’ improve quality control. I totally agree but realize most people don’t have a…
LensRentals Staff to Participate in Reddit Ask Me Anything on Monday at 3pm ET
We’re excited to announce that Roger Cicala and Aaron Closz will be participating in an Ask Me Anything (AMA) session of reddit’s /r/photography forum on Monday at 3 pm ET. Over the last few years, /r/photography has been a huge supporter of our blog, so we wanted to give back by inviting the users…
What Actually Happens When You Stop Down a Lens
I got an email the other day that got me thinking. A guy simply asked “How far do I have to stop down a lens to get maximum performance. I’ve heard two stops from wide open. I’ve heard down to f/8. Which is correct?” I asked him which lens he was referring to, and was he talking about the center…
How to Use AF Microadjustment on Your Camera
The most common questions and complaints I hear almost always have to do with AF accuracy, in one way or another, even if they don’t seem like it at first. “I’m trying to focus on this person’s eyes, but the ears are in focus instead,” or, “This lens is front focusing like crazy,” or, “This fast…
Sigma 35mm f/1.4 DG HSM Art Lens Teardown
Last week we did a tear down of the Canon 35mm f/1.4 Mk II, an expensive, large, weather-resistant lens. Then we did a tear down of the Sony FE 35mm f/1.4 ZA lens, and expensive, weather-resistant lens with very different technology. Today we’re going to tear down the Sigma 35mm f/1.4 DG HSM A1…
Canon 35mm f/1.4 Mk II Teardown
As soon as we optically tested the Canon 35mm f/1.4 Mk II lens we couldn’t wait to tear into one for a couple of reasons. One was that Canon has been making a lot of interesting advances in lens mechanics lately, so we’re always excited to look inside their new lenses. Another was that Canon…
Tamron f/1.8 VC Prime Lenses Sharpness MTF Curves
OK, for the first time I can remember, I’ve been browbeaten into doing a test I didn’t plan to do. When Tamron released their neat little Tamron 35mm f/1.8 SP Di VC and Tamron 45mm f/1.8 SP Di VC lenses, I thought, well that’s interesting, and the price point is reasonable and didn’t think about…
Nikon 24-70mm f/2.8 ED AF-S VR Sharpness & Optical Bench Testing
Like a lot of people, we were pretty excited to get our hands on the new Nikon 24-70mm f/2.8E ED AF-S VR lens. Compared to the other brand’s 24-70mm zooms, the original Nikon 24-70mm f/2.8 ED AF-S wasn’t quite as good at the outer part of the frame, and just wasn’t as good at 70mm. I expected the…
Sony E Mount Lens Optical Bench Tests
It has taken a long time, the sacrifice of a couple of cameras and lenses, and a lot of soldering, but we have finally managed to rig up a powered Sony mount to our optical bench so that we can test the new full-frame Sony and Sony-Zeiss E-mount lenses. For those of you who haven’t understood why…
Lenses I Love: The Canon 200mm f/2L IS
As a photographer who has used nearly every lens in Canon’s repertoire, it’s rare to find one that truly impresses me beyond the ones I own and love. For the longest time, I’ve grown content with my current lineup (which is an overwhelming collection of prime glass), and haven’t had much gear lust…
Sigma 24-35mm f/2 DG HSM Art MTF Curves and Sample Variation
For years now, I’ve been telling people to always take the results of tests done on one copy of a lens with a serious grain of salt. Not matter how carefully it was tested, it’s still just one copy. Others will be worse. Others will be better. Because I’m so aware of copy variation, I (in theory at…
Canon 100-400 IS II MTF and Variation Tests
When the Canon 100-400 f/4-5.6 IS L Mk II lens was first released we immediately did some testing. First we took one apart and were extremely impressed with the build quality. Then we compared it using Imatest to the original Canon 100-400 IS L and the new Canon 400mm DO L IS Mk II lenses at 400mm.…