Canon FDn 50mm F1.2L Vs Pentax K 50mm F1.2 SMC

Im planning on getting the Pentax 50mm regardless, because its cheap enough, compared to other F1.2 lenses. I know Pentax is world renown for its lens quality of the day. Im told the Pentax 50mm F1.2 is a sharp and contrasty lens. But that said, how does it compare to Canon's FDn 50mm F1.2L lens? The Canon has an aspheric lens in it, and it too is known to be sharp. Im not sure about color between these two lenses. The thing I dont like is the cost of the Canon lens. In some cases the FD lens costs more than the EF version, yet the EF is probably a better lens.

I did find a couple comments online in regards to these two lenses. One 'tb_a' said, -"According to an old test report of Popular Photo Magazine, the SMC Pentax K 50/1.2 was the best in terms of center resolution wide open, and even better than the so much appraised Canon L lens." A reply to this said, -"Somehow, that doesn't surprise me. Pentax has long been known for its crazy sharp optics." Another forum post said, -"The new Canon L is the best of its kind ever - period. The SMC Pentax 50/1.2 is pretty sharp, but not the sweetest bokeh. The only lens to break the rules is the new Canon 50L. And the Anniversary Zeiss."

So has anyone compared these two lenses? I plan on getting a K1000 for the Pentax lens, but I also already have a couple FD cameras. Which one would you choose, and why? Is the 3 to 4x price of the FD lens worth the extra cost?

The Pentax copy I have - bought used, performs very well. I don't have an FD yet.

Selection 39 by Les DMess, on Flickr

Of course the bright giant magnifications of the Pentax bodies (LX & MX) also makes getting critical focus wide open while handheld very easy.

If you plan on shooting wide-open, hard to beat any aspheric lens, that's why almost all fast lenses today use an aspheric surface(s). The Canon will be sharper with more contrast wide-open (and close to it) than the Pentax, with the differences evaporating once you stop down. Whether or not the Canon is worth the extra $$$$ depends on what you photograph and the size of your wallet.

Jim B.

Les Sarile said:

The Pentax copy I have - bought used, performs very well. I don't have an FD yet.

Selection 39 by Les DMess, on Flickr

Of course the bright giant magnifications of the Pentax bodies (LX & MX) also makes getting critical focus wide open while handheld very easy.

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So, of those which do you like the best?

ic-racer said:

So, of those which do you like the best?

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I've had the least success rates with the Olympus shooting wide open hand held. I will need to revisit it some more as it could be user error.

Although I have never owned the Pentax 1.2 lens, I have owned the Canon 50mm f1.2 L for about thirty years, and I can confirm that the "L" stands for the fact it contains low dispersion glass, and is one of best fast 50mm lenses ever manufactured even up to today, and if God ever made a better lens he kept it to himself !.

I've used the Pentax K 50mm 1.2 and the Nikon 50mm 1.2 Ai-s quite a bit on film, neither of them is what I would consider sharp and contrasty wide open by todays standards. I've never ran a side by side, but the Pentax had more clarity and crispness. the Nikon was very dreamy wide open, sometimes great looking strange results, sometimes it felt just like a ugly mush.
I've also briefly used the Canon EF 50mm 1.2 L on a 5DMkII. It definitely felt sharper than the Pentax or Nikon, but again not really crisp compared to a really modern lens or an older lens stopped down.

I've got some nice looking images with both of these lenses, but not many sharp ones These days I don't shoot at F1.2 anymore - I prefer having a bit more depth of field and better sharpness/contrast and less focus problems.
Even F1.4 looks rather soft if you print large, unless you use one of the bigger newer lens designs (like Zeiss Otus or Sigma Art etc), so I'm mostly at F2 or more closed, even though I have quite a few F1.4 lenses.

Shooting close subjects with a standard lens at f/1.2 is a dicey proposition for many reasons. The angle of the mirror must be perfect. The film must be absolutely flat. The focusing screen must be exactly in place. Focusing must be very careful. Even the more modern f/1.2 standard lenses will have some fall-off at the corners. The real question is what types of subjects your are shooting and how far away you are from the subjects. The look where the tips of a person's eyeballs are in focus and everything else in the frame is blurry is simply overdone.

When people shot Kodachrome 25 in lower light and needed the extra lens speed to make an image, there was some rationale for having very fast lenses. Now, because of non-film photography, very fast lenses are used primarily for artistic purposes. I have an 85mm f/1.4 lens and I might use it for portraits but never wide open. When might I use it wide open? If I am shooting a distant subject late in the day with Ektachrome (100).

I have four standard f/1.2 lenses. Mostly I like having them in my collection and a little for artistic purposes. In order of manufacture they are a 58mm f/1.2 Canon FL, a 55mm f/1.2 Canon FL and two silver and black 57mm f/1.2 Konica Hexanons. The Hexanons are sharper than the Canons. I wouldn't mind having the later (1972) Hexanon with all black cosmetics. It has improved coating. By today's standards, lenses like the 58/1.2 Rokkor and the 55/1.2 Nikkor have more "character." They served an important purpose until improved f/1.2 standard lenses were available. I wouldn't mind having a 50/1.2 Canon FD L and it might be a little better at f/1.4 than a 50/1.4 New FD at the same f/1.4 setting but I would probably rarely use it at f/1.2 or f/1.4. Stopped down a few clicks, these lenses are more alike than different.

dokko said:

I've used the Pentax K 50mm 1.2 and the Nikon 50mm 1.2 Ai-s quite a bit on film, neither of them is what I would consider sharp and contrasty wide open by todays standards. I've never ran a side by side, but the Pentax had more clarity and crispness. the Nikon was very dreamy wide open, sometimes great looking strange results, sometimes it felt just like a ugly mush.
I've also briefly used the Canon EF 50mm 1.2 L on a 5DMkII. It definitely felt sharper than the Pentax or Nikon, but again not really crisp compared to a really modern lens or an older lens stopped down.

I've got some nice looking images with both of these lenses, but not many sharp ones These days I don't shoot at F1.2 anymore - I prefer having a bit more depth of field and better sharpness/contrast and less focus problems.
Even F1.4 looks rather soft if you print large, unless you use one of the bigger newer lens designs (like Zeiss Otus or Sigma Art etc), so I'm mostly at F2 or more closed, even though I have quite a few F1.4 lenses.

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Just because you have a f1.2 lens doesn't mean you have to use it at full aperture all the time, because no optic gives it's best performance wide open.
The best lens I have with the best full aperture performance is the Canon F.D 35 mm f2 chrome nose Thorium lens.

You are generally correct but there are micro lenses like the Zeiss Luminars which were optimized for highest resolution wide open. My micro lenses include the 12.5mm f/2 and 25mm f/2.5 Minolta Rokkors and the 12.5cm f/6.3 Macro Nikkor. These are all very sharp wide open but I sometimes close them down when depth of field is not sufficient. Over the years, Nikon tweaked the design of its manual focus 50mm f/1.4 lenses. The later lenses are sharper at or near wide open but I find the earlier ones, like the first 'K' model, are sharper at f/8 or f/11.