The new Zeiss Distagon T* 21 mm f/2.8 ZF—worthy heir to the throne?

[Specularist]

I stepped into this dark alley by making a wrong turn at The Online Photographer. But now that my eyes have adjusted, I reckon it's cosy enough. ;)

I've been checking the Zeiss website every day or two for the datasheet on the new Distagon 21 mm. Okay, perhaps twice a day. They finally published it, and to my relief, the MTF charts are a lovely sight. If you haven't seen the datasheet head over here (http://www.zeiss.com/C12567A8003B8B6F/EmbedTitelIntern/Distagon28-21ZFen/$File/E_2.8_21ZF.pdf) (PDF) and have a glance to make up your own mind.

The old Contax/Yashica-mount version was an astonishing performer: so much so that second-hand prices got a bit silly even though no-one used the lens on a Contax. It was particularly cherished for its fine rendition of obscure lens-testing charts when ghetto-rigged to Canon hardware.

I think it's fair to say that many doubted whether Zeiss could equal this legendary lens using only environmentally friendly glass types (no lead, arsenic, etc.), with possibly limited manufacturing capabilities, and a retail price below 1400 euros. It's a tough ask, and an impartial observer would note that not all ZF lenses have been masterpieces, even though the design effort demanded by a double-Gauss fast fifty or a short tele is moderate compared to a stellar 21 mm f/2.8.

Zeiss must have dusted off the old blueprints, for the new 21 mm Distagon is very similar to the old in performance and optical arrangement. But it does gain another element, 90 grams, and that perplexing chrome filter ring. As to performance, see my comparisons below. Red lines represent the old Distagon, while black is the new.

MTF at f/2.8 (with the usual conditions, etc):
http://img257.imageshack.us/img257/6391/zeissdistagon21wideopenyl8.jpg

MTF at f/5.6:
http://img257.imageshack.us/img257/7587/zeissdistagon21stoppeddcp0.jpg

Light fall-off at f/2.8 and f/5.6:
http://img257.imageshack.us/img257/94/zeissdistagon21illuminaeh5.jpg

Geometric distortion (scale goes to -3%, so they peak around -2.5%):
http://img253.imageshack.us/img253/9784/zeissdistagon21distortiuy1.jpg

I think a round of applause is in order!

[Olivier]

I too am extremely excited by the new Distagon-21.

These are substantial improvements on a design which alread left the Japanese designs far behind. Must humiliating for Canon to fail to impress anyone with their wide-angle designs (repeatedly) when Zeiss casually beats their own record because, well, just because they can.

Between this lens and the Biogon-21 ZM, Zeiss has two masterpieces at 21mm, someone at Zeiss must love this FV.

[Specularist]

Judging by the MTF curves, wide-open performance has improved to the extent that it will be noticeable in actual photographs as a higher contrast for small structures. It's quite amazing for a wide-angle lens at f/2.8 to produce 80% contrast at 40 lp/mm!

At f/5.6 the new lens has slightly better performance with objects in the sagittal orientation (like spokes on a bicycle wheel), but slightly poorer contrast transfer compared to the old Distagon for tangential objects (the edge of the wheel's tyre). As the predominant type of chromatic aberration in wide-angle lenses affects the contrast of tangential objects without affecting sagittal objects, it's therefore conceivable that this behaviour is the result of an ever-so-slight increase in chromatic aberration in the off-axis regions, relative to the old lens.

Even if this proves to be the case, it must be viewed in context: the old lens was absolutely peerless in this regard, and the differences are very small. And this slight downside, if present, would have to be balanced against the significantly improved full-aperture performance.

Let's hope the flare and ghosting performance matches the sharpness! The 25 mm Distagon ZF is extremely resistant to flare and ghosts, but its sharpness and colour correction don't challenge the new 21 mm (though at half the price it's still a nice lens). The 18 mm Distagon, on the other hand, sprinkles ghosts liberally over the frame, though it has good resistance to veiling glare.

The Japanese companies seem to be content to replace primes with zooms (excepting high-speed primes). Some of the zooms are very good (like the 14-24 mm Nikkor, though it's a little overrated in my opinion), but for sheer optical quality they can't compete with primes that are made with a similar glass effort. They're also much larger, heavier, and usually more expensive, and often have plastic filter rings and other distasteful features.

Someone at Zeiss has loved the 21 mm focal length for a long time (http://www.cameraquest.com/zeissbio.htm). :)

[johan1967]

The ZF Distagon 21/2.8 appears to be available:

http://cgi.ebay.com/CARL-ZEISS-objectif-DISTAGON-T-2-8-21mm-ZF-pour-NIKON_W0QQitemZ330305590149QQcmdZViewItemQQptZFR_I Q_PhotoVideo_Photo_Objectifs_Zooms?hash=item330305 590149&_trksid=p3286.c0.m14&_trkparms=66%3A2%7C65%3A3%7C39%3A1%7C240%3A1318

I didn't hear from Zeiss about this, so I wonder if it is true.

[klaju]

The ZF Distagon 21/2.8 appears to be available:

http://cgi.ebay.com/CARL-ZEISS-objectif-DISTAGON-T-2-8-21mm-ZF-pour-NIKON_W0QQitemZ330305590149QQcmdZViewItemQQptZFR_I Q_PhotoVideo_Photo_Objectifs_Zooms?hash=item330305 590149&_trksid=p3286.c0.m14&_trkparms=66%3A2%7C65%3A3%7C39%3A1%7C240%3A1318

I didn't hear from Zeiss about this, so I wonder if it is true.

No, definitely not. This is what Zeiss announces:

"Due to a capacity constraint volume production of the Distagon T* 2,8/21 could not start as scheduled. The estimated date of delivery for the ZF version will be the end of the first quarter 2009. The ZE as well as the ZK version will be available by the mid of 2009."

I don't think it is serious to sell a lens now that is available by the end of March or maybe April.

[johan1967]

Here some (for me) first examples with a D700:

http://www.flickr.com/photos/silver2silicon/sets/72157607618146937/

[klaju]

Yesterday I got a mail from Zeiss that the Distagon T* 2,8/21 is now shipping for Nikon. However, in their own shop it is already sold out.

[Specularist]

It's still sold out on the Zeiss online shop, but so are many other lenses. However, I believe I saw a sample in a Parisian shop window. I might try to have a look at it later this week.

There is some discussion of the new Distagon in issue 31 of Camera Lens News. More interestingly, the second part of Zeiss' treatise on understanding MTF curves features a comparison between "a Zeiss Distagon 2.8/21" and an unspecified standard zoom. Here's the link (add www to the front as I can't yet post links here):

zeiss.com/C12567A8003B8B6F/EmbedTitelIntern/CLN_31_MTF_en/$File/CLN_MTF_Kurven_2_en.pdf

And here's a quote from that PDF:

"In order to explain what we mean let's use a comparison of two lenses, each of which was measured by purely optical means using an MTF measuring device as well as being measured by an 21 MP camera,. One of these lenses is a Zeiss Distagon 2.8/21, the other is a good standard zoom with a shortest focal length of 24 mm."

Reading between the lines, it looks like that might be Canon's 24-70 mm f/2.8 L or perhaps the 24-105 mm f/4 L.

The results are heavily in favour of the prime, particularly in control of chromatic aberration, e.g. see this image (add www):

zeiss.com/C12567A8003B8B6F/GraphikTitelIntern/CLN31MTF-KurvenBild6/$File/Bild_06.jpg

Unfortunately, even though there must be dozens or hundreds of copies of this lens out there by now, I've yet to find a good sample image online. This is a bit unsettling, frankly. Are buyers unimpressed with their new lens?

[johan1967]

This thread has several pictures taken with the Zeiss 21/2.8:

http://www.nikoncafe.com/vforums/showthread.php?t=218723

I like what I see up to now.

Lloyd Chambers also tested the Zeiss against the Nikon 14-24 (www.diglloyd.com). His first conclusions are very much in favour of the Zeiss.

[cabo]

I got mine a week ago in Cologne. So far I'm very happy with it; generally it seems to have somewhat more 'punch' than my Nikon 14-24 and is very resistant to flare and ghosting. I was surprised by the excellent close-up performance.

Carsten

[bkapella]

Anyone tried the 21 w/ an extension tube?