Light fall off can be corrected in Photoshop and in most raw file editors, so fall off in the corners is not the end of world. Also, the fall off is only an issue at F4 or F5.6, and most pictures will be F8 or F11 anyway. Personally, if I am shooting a tight subject close-up, I like fall-off and often edit it BACK into the pictures.

Four years ago what struck me as most impressive was how well the 18mm’s distortion was corrected. The picture inside the restaurant (previous page) has plenty of straight and lines and the 18mm Distagon handles those straight lines with grace. That picture had NO Photoshop distortion corrections. Compared to the 21mm F2.8 Distagon and the 28mm F2.8 Distagon, the 18mm Distagon has less visible distortion to my eye.

The other impressive characteristic is the 18mm Distagon’s near focus abilities. The image to the left illustrates just how close the 18mm Distagon can focus. The black & white image on the next page is another near focus test (shot at F8). In regards to black and white image, It has been very windy here, so I probably should have boosted ISO to get a better shutter speed. As for the sunflower, that image was zone focused with my fingers crossed!

The 18mm Distagon colors are pure Zeiss with the electric sky blues and vibrant contrasts. With the 1Ds Mark III 14-bit file format, the subsequent 16 bits TIFF can be stretched, twisted and pushed to extremes in Photoshop (ie - the sunflower picture). I do not use a polarizer on the 18mm Distagon because polarizers tend to effect half the frame but not other half (as much) with focal lengths wider than 24mm. Also, the Contax 70-86 adapter ring rotates as the lens is focused, so using a polarizer would be tedious.

ADAPTERS FOR CANON EF AND EF-S BODIES

Reports concerning the Canon 5D and 18mm F4 Distagon have been mixed with some owners having problems with the rear element and the Canon 5D’s mirror. The most likely cause is the Distagon’s rear glass protruding to far into the Canon 5D’s mirror box (regardless of adapter thickness). The 18mm Distagon is NOT rear focusing lens, so the rear element’s location is fixed at all times, thus clearance issues occur at focal distances - not just at infinity focus. While some say the 18mm will not work with the Canon 5D, others report the 18mm F4 Distagon does indeed work on a 5D. It may take some experimentation on your part to find the right mix of body, lens and adapter.

The AE version appears more likely to work than MM version because the older AE version has a different type of retaining ring on the rear element (see the picture to the right). The AE’s retaining ring is angled, thus allowing more room for the mirror to clear as it swings past the rear element. Whereas the MM version has a low profile ring and the rear element actually sticks out past the ring (the element is convex). In fact, the rear element on the MM version could be damaged (scratched) by a mirror strike. The image below if a 18mm F4 Distagon MM - clearly Contax changed the design.

For Canon 5D owners, instead of experimenting with different adapters and 18mm Distagons, a quicker way to find a “good copy” would be to find a Canon 5D user who wants to sell their 18mm Distagon. My suggestion is to skip the 5D altogether and a buy a Canon 1Ds or Canon 1Ds Mark II. The Canon 5D has been hit or miss with Contax lenses, eliminating the 5D pretty much solves the problem. I experienced NO issues with a Canon 1Ds and 18mm Distagon AE several years ago. Currently I am using a 18mm MM on a 1Ds Mark III without any problems via a HappyPageHK adapter (latest version as of June 2008). For more on Contax/Canon adapters, click here.

THE CONTAX 70/86 ADAPTER RING

When searching for a 18mm Distagon, try to find one which includes the original Contax 70/86 adapter ring. The Contax 70/86 rings are difficult to find and sell for $75 to $150. The 70-86 adapter ring is needed if you plan to use a filter and/or hood with the 18mm Distagon. The 70-86 adapter is not a must have, but it is handy. The front portion of the 18mm Distagon’s barrel rotates as the lens is focused. The Contax 70-86 adapter ring attaches to barrel (held in place by pressure), thus the attached filter will also rotate. In the case of a polarizer or graduated filter this can be irksome. Each time the lens is focused, the filter needs to be adjusted.

The 18mm Distagon comes with a 70mm push-on rubber cap for the front element. These caps are also difficult to find too, so make sure the seller includes the 70mm push-on cap. A 70mm Kaiser push-on cap (available here at B&H Photo) should also work fine as a replacement. I will add one to my next B&H order just to make sure.  [June 24, 2008 - follow-up on the Kaiser cap - the cap fits fine, but for $9, do not expect much. It does not even come close to matching the quality of the original Contax cap. The original cap is thick, hard rubber-like plastic that provides impact protection. The Kaiser cap is a thin plastic which flexes easily. It covers the front element, but provides minimal protection from impact. Again, for $9 it is fine.

OVERALL IMPRESSIONS

Eighteen millimeters as a focal length on full-frame is dramatic. Shooting with the lens pointed slightly towards the sky produces a feel of the clouds racing across the sky and spreading out across a vast area. If the lens is held level with the horizon, then sweeping wide angle views with a huge field of view. I like to shoot low with the lens angled upwards, this picks up some of the foreground and gives the viewer sense of being right there. Wide angle lenses are a composition challenge for me, my comfort zone is the 35-100mm range, so the 18mm Distagon forces me to think outside of box.

The 18mm Distagon is a good wide angle prime. The corners are better than those from Canon 16-35L II. Wide open (F4) can be soft and the lens seems happiest when the subject is 5 feet or further away. I have tried focusing on subjects 2 feet away and results have been mixed. It was difficult to tell if there were focus errors on my part, or if the lens was struggling with such close subjects.  (Continue to next page)