Lenses and Optics
Cine Lens Teardown Comparison: Zeiss 85mm CP.2 T2.1 and Rokinon Xeen 85mm T1.5
I was pretty excited when I first heard about the Rokinon Xeen line of Cinema lenses. For several years now, Samyang / Rokinon photography lenses have given photographers with reasonable expectations some superb alternatives. They sell optically excellent lenses at amazingly low prices. There are…
MTF and Variation: An Example
We’ve spent most of the last month establishing a database of MTF curves and expected copy-to-copy variation for a number of lenses. Most people have a general idea about what we’re doing, can follow along the basics of MTF curves, etc. But many other people also have a very good question, “How…
70-200mm f/2.8 MTF and Variations
Finally, the last in our series of MTF and variation tests is here. We’ll be doing these going forward as new lenses are released but for now we’ve got a nice database of common lenses that we can measure others against. We’ve completed almost all of the common prime lenses, along with wide and…
Wide-Angle Zoom MTF and Variations
We recently published the MTF and variation curves of standard range lenses and now are going to tackle wide-angle zooms. As we’ve seen, zooms have more variation than primes and wide-angle primes have more variation than standard range primes. Also, the MTF curves of wide-angle primes are weaker…
Quick MTF of the Tokina 24-70 f/2.8 PRO Fx
* Courtesy Tokina, USA * Tokina is releasing a new competitor in the 24-70mm f/2.8 standard zoom lens group. It’s a reasonably sized lens, having an 82mm diameter front ring, measuring 4.25 inches long, and weighing 2.2 pounds. That’s just a bit smaller and lighter than the Tamron 24-70mm f/2.8 VC…
A Quick Look at the New Sigma 24-35 f/2 Art
* Image Courtesy Sigma USA * I generally do MTF testing on multiple copies of a given lens so that I can present the averages, look at sample variation, and stuff like that. I’m always aware that looking at any single copy of a lens, especially a zoom lens, gives only a limited prediction of how…
24-70 f/2.8 Zoom MTF and Variation
We’ve finished, mostly, our fairly long series of articles on SLR prime lens variation. We started with prime lenses for several reasons. They are much quicker (and quicker is a relative term here) to test than zooms. They are simpler lenses and we expected that meant they would have less…
Supertelephoto MTF Curves
Brandon has accomplished much during his summer with us, including several things I never thought we’d be able to do. One of those things was measuring the MTF of supertelephoto lenses on our optical bench. A vertical bench just isn’t designed to handle the mass of those big lenses and technically…
A Quick Guide to Teleconverters
Teleconverter use and compatibility can easily get confusing. I’d like to shed some light on the subject for those looking to get more length out of their lenses without the extra weight or cost. Teleconverters can add versatility to your camera bag by giving you extra length and a variety of looks…
Variation Measurements for Telephoto Lenses
We’re nearing the end of the Varation series for prime lenses. If you are joining in late, you may want to go back to the original article for an introduction into the methods used. Today will look at the short telephoto group, lenses ranging in focal length from 85mm to 150mm. We’ve also included…
Variation Measurements for Wide-Angle Lenses
When we started this series, we introduced our methods using 24mm lenses, then followed up with looks at the 50mm and 35mm groups. Today we’re going to go back to the wide-angle lenses; the ones we expect to have the most variation of all. We probably should call this post the Zeiss Invitational,…
Variance Measurement for 35mm SLR Lenses
Last week we posted optical bench MTF and copy-to-copy variation measurements for 50mm SLR lenses. We’re going to continue that series this week with the same measurements for the 35mm lenses. This set should fill out the wide-to-standard range lenses and gives us a lot of interesting data as we…