Thought those of you interested in the Canon 50mm f1.0L lens might be like to see a comparison to the 50mm f1.4 and 50mm f1.8 MkI lenses. Many have stated their avoidance of the f1.0 lens due to its price on the used market and the relative lack of benefits as compared to the less costly 50mm lenses. In particular I have seen it stated that the f1.0 lens is not as sharp as the other 50mm lenses. I decided to compare them for myself after recently obtaining the f1.0 lens. A set of comparison photos is shown below.

First, the usual disclaimers - I am not a pro. These results obviously are only accurate for my copies of the lenses. The 50mm f1.4 and 50mm f1.8 lenses represent the best I have obtained so far of multiple samples. In the case of the f1.8 lens, it is the best of four copies. The f1.4 sample is the best of three. All shots were captured with a 1D MkII tripod mounted, and with MLU. Sharpness was set to 4. Multiple shots were taken for each lens and aperture combination, with the best of several shots selected for the comparison. My copy of the f1.0 lens appears to back focus slightly on this camera. I am considering whether to send it to Canon for a check up, or to leave well enough alone. Will probably do the latter.

Many have complained that the 50mm f1.0 lens is not useable wide open. My conclusion is that it depends on what you need for the shot. Though the wide open sample shown is quite soft out of the camera, it becomes what I would call "useable" with some mild sharpening, but surely would not win a sharpness contest. This has been confirmed with some other "more real world" test shots I have taken with the lens. The lens becomes significantly sharper at f1.1, or stopped down only one-fourth of a stop.

I also concluded that for my samples the 50mm f1.0 lens is sharper at f1.1 than the f1.4 lens is wide open. However the f1.4 and f1.8 lenses "catch up" by f5.6.

Of course there are factors other than sharpness to be considered like color saturation, flare control, etc. when evaluating a lens. My experience so far has been that if a lens does not consistenly autofocus accurately and yield reasonably sharp results, the other attuributes will not matter for my use. I will obviously be interested in the overall performance of the lens, but so far, so good.

Whether or not the f1.0 lens is worth the cost is an individual decision in my view. I am not trying to convince anyone one way or the other. I am simply sharing some data with you.

Dave

http://www.pbase.com/davew/image/42885269/original.jpg