A long focusing travel seems to me to make focusing easier, and it certainly spreads out the depth of field scale, which is marked for f/2.8, then f/5.6-f/16. Two unmarked lines either side of the central f/1.2 index presumably correspond to f/2, and there is an IR focusing mark--a red R and a dot--just to the left of the far-distance depth of field mark. The equally-spaced diaphragm ring at the front of the lens is click-stopped at f/1.2 and f/1.4 and thereafter at whole-stop intervals (no half stops) to f/22; the diaphragm has 11 blades.

User's eye view of the 50mm f/1.2 showing equidistant stop settings on the diaphragm control ring--always a sign of quality--and the huge depth of field scale.

All right. Enough background. What's it like? Well... First, I tried it on a test chart using Kodak's Ektachrome EBX: not the sharpest film in the world, but far from the least sharp, and one that I know can deliver at least 75 lp/mm (line pairs per millimeter) with the very best lenses.

At middling apertures, f/4-f/11, the 50mm f/1.2 was far better than you might expect: quite unreasonably good, in fact, and more than usable for general photography. At f/2-f/2.8 it was fair, and f/16 isn't too bad, but at f/22 it was really very soft--which is one reason why so few lenses for 35mm, let alone fast lenses, stop down to f/22. As you open up beyond f/2, the performance rapidly deteriorates: by f/1.2 you are in the realms of desperation, at least as far as resolution is concerned.

At f/1.2 I saw about a bit under 50 lp/mm at the center, and maybe 30 lp/mm at about 10mm out. Stopping down to f/1.4 raised this to a bit over 50 lp/mm center, but did very little for 10mm out. By f/2.8 it had hit 60 lp/mm center, 50 at 10mm, and it peaked at around 75 lp/mm center, 60 at 10mm, by around f/8. Thereafter it deteriorated gently (but ever more rapidly) until at f/22 it was about the same as f/1.2.

Now, given that the main reason you might want a lens like this is for the extra speed, the resolution figures at wide apertures might seem unacceptable. This is not, however, entirely fair. When you are pressed to the limit (as you more or less have to be to need a lens this fast), you may well lose more sharpness to camera shake and to subject movement than to a frankly soft lens. Even half a stop can help, and if your usual 50mm lens is an f/2, f/1.2 is a stop and a half: well worth bothering.

It's also entirely true that for certain kinds of pictures, especially portraits, you don't want too much sharpness: this is one reason why relatively low-resolution digital cameras (6 megapixels and below) often seem to deliver such excellent results.

Then again, sharpness is not the only consideration. At wide apertures, the Canon is also very flaring and flat. A deep lens shade helps considerably, but also eats into the viewfinder area. But like poor resolution wide-open, flatness and flare may seem like a far greater disadvantage than they really are. As a general rule, when I am shooting at very low-light levels, I am also shooting at very high contrast levels: flare is positively welcome, to reduce on-the-film contrast.

In color, in daylight, flare makes for excessive blueness, but under tungsten it warms the image up: again, an advantage as often as not. It also increases the effective ISO speed of the film: there's more shadow density at a given exposure than there is with a contrastier lens. This was one reason why old, fast Leica lenses such as the 50mm f/1.5 Xenon remained in professional use for so much longer than might have been expected.

In other words, the 50mm f/1.2 has what the French call "les fautes de ses qualites": the faults of its qualities. At normal apertures--f/5.6 and f/8--you can't really fault it, so it is a perfectly good general-application lens. When you need real speed, you can't compare f/1.2 with f/2. Yes, it is soft and flaring wide-open, but as I have already said, this is often better than risking camera shake with a slower lens.

A kind friend lent me a 50mm f/1 Leica Noctilux for a year, and there is no doubt that objectively the Noctilux is vastly superior. Certainly, there's no question about which I would rather have. But as I can't afford a Noctilux, and as I already have a 50mm f/1.2 Canon, I have to admit (having tried both) that the 50mm f/1.2 is not as inferior for real-life pictures as it might seem it is for theoretical ones.

At least it isn't as inferior for the kind of shots I want to take, and I've seen a number of surprisingly good shots (often better than mine) taken by other Canon 50mm f/1.2 users. This all goes to prove the old saying that most lenses and cameras are better than the majority of photographers who own them. I was going to sell it, and I suppose if someone offered me enough money for it--$350, say--I'd still do so; but for the $250 or so I was thinking of asking, well, I think I'll keep it.