Today we're going to take a look at Sony's E 50/1.8 lens, one of the newest additions to the Sony NEX lens lineup, and do a quick comparison to one of the best 50mm rangefinder lenses, Carl Zeiss Planar T* 50/2 ZM. The lenses are vastly different in optical construction, build quality, features, but ultimately, both are 50mm primes and can be used on NEX cameras. With the 50mm f/1.8 OSS still being quite hard to come by because of various manufacturing delays that plagued Sony for a few months after the major flood in Thailand, as well as because of the unexpected demand for this lens, users have been resorting to exploring various alternative 50mm lenses. We recently did a couple of such reviews with 8 different rangefinder 50mm lenses (see Alternative 50mm Lenses for NEX), including Zeiss Planar 50/2 ZM. With the final part of that review coming up next week, we will include Sony's 50/1.8 OSS into the group to give you a better idea where the Sony's lens stack up against much more fancy glass. Another comparison but against SLR 50mm lenses will be coming up in mid to late May. But in the meantime, this of this quick test as a preview of things to come. And without dragging things any further, here're our test conditions:

• NEX-7 with v1.0 firmware
• Manual, bracked focusing
• RAW with Adobe RGB color space
• 3m focusing distance
• ISO 400, WB set to Tungsten (2,500K, Tint: 0)
• Adobe ACR with default settings: Blacks +5; Brightness: +50; Contrast +25

Resolution

Weather has been somewhat unpredictable lately here In San Jose, so when the clouds finally cleared up on Sunday, I grabbed my bag of photo gear and finish a couple of long-delayed tests. Last week I run through a quick comparison of 50mm rangefinder lenses on Sony NEX-5n and I wanted to finish testing this setup before moving on to something new.  This time around I used Sony NEX-7, but also changed focusing distance, moving closer to the MFD for all lenses - this is where I'm hoping we will see the most difference among all lenses. As in the previous section, this part of the review focuses on bokeh, DOF and color rendering, not resolution or various artifacts like vignetting. I did not use focus bracketing and did not refocus lenses when moving from one aperture to another - this would put lenses that have focus shift (i.e. Sonnar, Nokton, Jupiter...) at a disadvantage, and hence I would not recommend using the samples below for evaluating lens sharpness. In part 3 of this review I will do a bit more comprehensive test for resolution, lateral CA and vignetting. Again, no commentaries - figure out what you like on your own or wait for part 3 if you're curious to know which lens(es) I liked personally.

In the meantime, here's a summary of the shooting conditions:

• Sony NEX-7 with v1 of firmware
• WB set to Daylight (5,500K, +10 tint)
• RAW, Adobe RGB space
• ACR with default settings: Blacks +5; Brightness +50, Contrast +25
• JPEG max quality
• 1.5m focusing distance
• 2 shots per lens - max aperture, and stopped down to f/4

With Sony being quite slow in ramping up production of new E mount native lenses, and particularly the E 50mm f/1.8 OSS (I've been on a waiting list with Amazon for over 2 months now), the ever increasing community of NEX users has been actively evaluating a variety of alternative 50mm primes easily adoptable to the NEX mount. This particular comparison traces roots to fredmiranda.com's alternative gear forum, where a bunch of die-hard alternative glass users have been debating the properties of a number of Zeiss 50mm lenses on NEX cameras. I got curious in the topic and volunteered to do a quick test with a few popular, and often considered high-quality, 50s.

This section of the review will showcase bokeh rendering of 8 alternative lenses on NEX-5n. Results below are presented without much commentary - considering that tasted vary quite widely, I will let the reader decide which of the lenses have the most appealing characteristics. I will repeat this test on NEX-7 in a couple of weeks, but will use a different focusing distance, which hopefully would present the readers with a more diverse overview of the tested lenses. Finally, a third part of the review will compare more general characteristics like resolution, vignetting and lateral CA (expect very opinionated commentary in this section).

Before we jump to results, let's touch base on the test conditions:

So the rumor mills are working and the latest news is that Carl Zeiss will soon be announcing the new Distagon T* 15/2.8 lens in Nikon ZF.2 and Canon ZE mounts. Originally reported by zeissrumors.com and most recently by photorumors.com, the news spread to the rest of the web within a day. As a long time Zeiss user and aficionado, I got pretty excited about this little piece of news, but then mental gears kicked in and I started to think what does it really mean to the end users like you and me? Should we all get jiggeddy-jaggedy about this and rush with pre-orders, or what?

Original Zeiss Distagon 15/3.5 was first released in Rollei mount back in late 70s and at that time was quite a master-piece. Later re-released for Contax and most recently in Leica M mount, the lens was very popular, primarily because of its price. The current version of Distagon 15/2.8 ZM goes for ~$4.600, making it pretty much out of reach for most of us. Ole Contax 15/3.5 sells for ~$2,500 these days. Still a ton of money, particularly when you consider it against what else is available on the market. For Leica mount we have Voigtlander Super Wide Heliar 15/4.5 ASPH goes for ~$600. In Nikon mount we have a couple of interesting options, starting with the uber zoom 14-24/2.8G, than 14/2.8D and finally old 15/3.5 Ai-S. All three cost less than used Contax or new ZM versions. For Canon mount we have the 14/2.8L and slightly longer, yet absolutely superb 17/4L TS-E. Again, both cost less than either of Distagons. Finally, we have a bunch of oddball alternative and 3rd party lenses, some of them now discontinued, from Sigma, Tamron, Tokina, Samyang etc. Bottom line is that there are a lot of 14-15mm lenses out there, so it's not like Zeiss is going to be filling in an empty niche... Because of that, I expect that the price point for the SLR version of Distagon 15/2.8 to be significantly below the Leica version of the lens - probably somewhere in the $2,000-$2,500 range.

Now, some of the cheaper options available out there are not particularly.good - resolution, distortion, CA etc. So naturally many who are not happy with the alternatives are looking at Zeiss as a premium lens designer who can solve all of these problems, in which case, the argument goes, the premium price for Distagon 15/2.8 is going to be justified. But is it a realistic expectation? At a minimum, I expect that the new SLR version of Distagon 15/2.8 will have a fairly good resolution. ZM version certainly improved in this domain over the old Contax version - see MTF charts below (Distagon 15/2.8 ZM is at the top and Contax 15/3.5 is at the bottom).

This is Part Two of the rolling review of the 100mm macro lenses for Canon EF mount.

Studio Test. Ok folks, we are starting off with a fairly standard Imatest evaluation of our primary candidates. Just as a reminder, we will limit this test to only one focusing distance - 10m. Why 10m? For all 100mm lenses, 10m focusing distance roughly falls into medium range and closer to the infinity than to the MFD. I cannot test lenses at longer than 14m focusing distance due to the space constraints. And testing at very close focusing distances with Imatest does not really make sense due to the software's and imaging target's limitations - we will be testing the resolution of the target (printer that is) rather than the lens at anything closer than 2m (20x focal length of the lens). At 10m we get a 100x focal length ratio, which should be good enough to get us accurate results out of Imatest (as accurate as the software is capable of giving us, of course). Plus, we will do macro (MFD) and infinity tests separately, so, yea, 10m sounds like a good start.