Category: Technical Discussions
-
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…
-
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…
-
Bad Times with Bad Filters
A long time ago I wrote a blog post called Good Times with Bad Filters about how cheap UV protective filters are different from good ones. It was mostly in fun. Today I’ve got a post about how cheap UV filters may hurt your lens. It’s not in fun. Here at Lensrentals we see lenses come back with…
-
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…
-
Good Vibrations: Designing a Better Stabilization Test (Part I)
_My name’s T.J. Donegan, I’m the Editor-in-Chief of DigitalCameraInfo.com and CamcorderInfo.com (Soon to just be Reviewed.com/Cameras). We recently wrote about designing our new image stabilization test for our Science and Testing blog. I showed it to Roger and he asked for the “nerd version.” He…
-
Silent Changes
Every so often I get an email asking me to jump in on some forum argument or other. I rarely do that because of the language barrier. Two of the common languages spoken on forums are CAKWAF (Complete, Absolute Knowledge Without Any Facts) and AFIDAWAB (Any Facts I Don’t Agree With Are Bullstuff).…
-
Sigma Optimization Pro and USB Dock
_“Commerce makes progress. Fortune passes everywhere.”_ – Frank Herbert A few years ago I was accused of being a Sigma hater. (For the record, I did hate their quality control and so-called repair service at that time, and I didn’t hesitate to say so in this blog.) For the third or fourth time in…
-
How to Ruin Your (or Our) Gear in 5 Minutes (Without Water)
If there hasn’t been a Color Run 5k or 10k race near you, there probably will be soon. And with all that color, you certainly want to take some pictures, right? Not with your camera you don’t (and not with ours either). I’m never one to worry much about lens dust. I’ve written about why you…
-
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,…
-
Roger Buys a Camera System: A 24-70mm System Comparison
Note: I’m going to bore people for a week or two while I decide on a new camera system for myself. To alert those who are going to be bored by posts about “Roger Buys a Camera System”; I’ll put that in the title for the rest of this series. I don’t own an SLR – I go check one out for ‘testing’ when…
-
Metabones Magic?
A few days ago I learned about the Metabones Speed Booster. For both of you who haven’t heard yet, this is an adapter containing optical elements and electronic controls that allows you to mount Canon EF lenses to Sony NEX cameras (other versions are planned for other lenses and cameras). The quick…
-
24-70mm f/2.8 Lens Teardown Comparison
Warning: This is strictly a Geek article. If you don’t like looking at lenses’ insides, there’s absolutely nothing of interest for you here. We’ve been doing a lot of teardowns lately and I’ve made comments like “well thought out” or “carefully engineered.” Several people have asked me to show them…