A great lens, not quite as good as the new Leica 18mm, but much, much cheaper. This test was done on a Sony NEX 5n, so it will not represent true corner performance on a full frame. You can get an ides of the lenses characteristics though. The lens itself is tiny, it weighs 350g and is 71mm long. Distortion is well controlled, you can expect some lateral chromatic aberration in the corners, but it is easily corrected. Specs:

Probably the best 28mm F/2.0 lens in existance right now! This is a stunning lens, with NO chromatic abberation, excellent bokeh, and its super sharp right from F/2.0. In fact stopping it down only adds to the depth of field, it does not get any sharper from F/2.0 onwards! A feat of engineering thats for sure. Anyway, a picture is worth a thousand words, so have a look.

This is the last version prior to the Summilux Asph. Designed by Peter Karbe, it sort of transitions between ealier Mandler designs and the current Asph, which is also designed by Mr. Karbe.

It is a 7 element, 5 grouping design with a 12 blade aperture mechanism. This mechanism yields almost perfectly circular bokeh throughout the aperture range. You can expect half click stops between the aperture settings.

Yep its quite a mouthful, but the Contax 17-35mm N Mount – EOS conversion lens offers very good wide angle performance on the Canon SLR. Its a big lens, that is no lightweight, weighing in at 900g or 2lbs! it requires 95mm filters. Optical performance is very good for a wide angle zoom, it is not perfect, with somewhat softer corners at wide apertures. With one or two exceptions this type of wide angle zoom performancer is the norm for almost all manufacturers. Lets talk about the good, and there is plenty of that Zeiss look! The lens renders with that 3d zeiss look that we all like! It shows great macro contrast, good shadow illumination and reasonable chromatic abberations or CA for short. CA is almost a non event these days, and lightroom deals with very well. Wide open at 17mm you can expect a full stop of fall off (vignetting) this decreases to about 2/3rds of a stop at F8. Fall off at 35mm is less, with about 2/3rds of a stop wide open and a little less than 1/3rd of a stop at F8.

We have added some images from this exotic and quite rare lens! Have a look and tell us what you think. Zeiss ZM 85mm. Shot on a Sony NEX 5, so its a cropped image. More to come.