Canon 35mm f2 FD vs Pentax 35mm f2 K-mount

Has anyone here shot both of these lenses, and if so, do you have a preference of one over the other? As a secondary question, aside from the quirkiness of the concave 35mm f2 for Canon FD, is there anything in particular about it that makes it better than the standard 35mm f2?

I have only used the concave version and it seems to work fine. It does have thorium glass in it, so it yellows over time. Probably fine for B&W work, but I wouldn't use it for colour.

Looks like there was 2 versions of it, one made from 1973-76, and revised edition made 1976-79, both of which had 9 elements in 8 groups. The new FD has 10 elements in 8 groups. The later AF version is a different design again, 7 elements in 5 groups.

I can't find any MTF charts of the FD lenses, just the EF ones. No experience with the Pentax, but I'm sure it's of an equal quality to Canon.

A comparison of the two FD lenses: https://phillipreeve.net/blog/guide-canon-fd-lenses-digital-age-2/#Canon_nFD_2035

35mm on SLR is super dificult to focus even with the split prism in the middle.

Concave 35mm f2 for Canon FD clears up fine with UV light or leaving in a window for a week. I've used it for slide film before I sold it, no visible cast.

Haven't used the Pentax version.

If you have a camera that can mount it, you may want to look into the more modern Tamron SP 35mm f/1.8 VC which should be sharper than both and also has image stabilization and weather sealing, as well as near-macro focus capability.

Radost said:

35mm on SLR is super dificult to focus even with the split prism in the middle.

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Not in my experience.

loccdor said:

Concave 35mm f2 for Canon FD clears up fine with UV light or leaving in a window for a week. I've used it for slide film before I sold it, no visible cast.

Haven't used the Pentax version.

If you have a camera that can mount it, you may want to look into the more modern Tamron SP 35mm f/1.8 VC which should be sharper than both and also has image stabilization and weather sealing, as well as near-macro focus capability.

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The cameras I have (and want to get a lens for) are a Pentax LX and a Canon F1 (old). So no to the Tamron.

Radost said:

35mm on SLR is super dificult to focus even with the split prism in the middle.

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As opposed to what? A rangefinder?

Radost said:

35mm on SLR is super dificult to focus even with the split prism in the middle.

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I use a Minolta 35mm f1.8 and find it easy to focus, partly because the wide aperture has such a narrow DOF.

The 35/2 concave front lens is very sharp. I use it with color print film and any color cast is easily filtered out. I wouldn't use it with slide film. Slide film is very expensive now and other lenses are more suitable. After the concave front lens there was a convex front 35/2 FD SSC, which is also very good. The later 35/2 New FD is smaller and lighter and also sharp but not as mechanically sturdy as the earlier two lenses.

Between 1975 and 1977, Pentax made a 35/2 SMC Pentax K mount lens. It looks like a carry-over design from the last M42 35/2 SMCT. There were then two versions of the smaller 35/2 SMC Pentax-M. I have one of those and it is very good. Other choices, if you don't need as much speed are the 35/2.8 SMC Pentax-M and the older 35/3.5 SMC Pentax. Both are good but the f/3.5 model is exceptionally good. It traces its design back to the 1950s. I have several M42 versions, which are also excellent.

For the Canon, if you do not intend to use slide film, the concave front lens (FD SSC) would be fine. If you will use slide film, I would recommend the convex front FD SSC. For the Pentax, I would get any 35/2 SMC Pentax-M that is in good condition.

Radost said:

35mm on SLR is super dificult to focus even with the split prism in the middle.

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Manual focus lenses can be difficult to focus on digital bodies because the focusing screen is made for AF lenses.

dynachrome said:

The 35/2 concave front lens is very sharp. I use it with color print film and any color cast is easily filtered out. I wouldn't use it with slide film. Slide film is very expensive now and other lenses are more suitable. After the concave front lens there was a convex front 35/2 FD SSC, which is also very good. The later 35/2 New FD is smaller and lighter and also sharp but not as mechanically sturdy as the earlier two lenses.

Between 1975 and 1977, Pentax made a 35/2 SMC Pentax K mount lens. It looks like a carry-over design from the last M42 35/2 SMCT. There were then two versions of the smaller 35/2 SMC Pentax-M. I have one of those and it is very good. Other choices, if you don't need as much speed are the 35/2.8 SMC Pentax-M and the older 35/3.5 SMC Pentax. Both are good but the f/3.5 model is exceptionally good. It traces its design back to the 1950s. I have several M42 versions, which are also excellent.

For the Canon, if you do not intend to use slide film, the concave front lens (FD SSC) would be fine. If you will use slide film, I would recommend the convex front FD SSC. For the Pentax, I would get any 35/2 SMC Pentax-M that is in good condition.

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I mostly shoot b/w, with the sporadic color neg in 35mm. I don't shoot slide film for the reason you mentioned (cost) and the fact that it has generally less dynamic range and exposure latitude.

Thank you for directly addressing my questions. I think for now I'm probably looking at the Pentax 35mm f2 or maybe the Pentax 30mm f2.8 as options - I love my Canon F1 but it's a big beast to haul around on vacation, and it's metered manual only, no aperture priority exposure, which slows me down when shooting, and because the shutter speed dial is small and on top of the body, it becomes effectively a shutter priority system because the aperture is easier to adjust to match the needles in the finder.

Radost said:

35mm on SLR is super dificult to focus even with the split prism in the middle.

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I was talking about film SLR bodies.

dynachrome said:

the older 35/3.5 SMC Pentax. Both are good but the f/3.5 model is exceptionally good. It traces its design back to the 1950s. I have several M42 versions, which are also excellent.

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I have read about the 3.5 being exceptional. Is the optical design similar to the older M42 35 Super-Takumar?

https://worldofdecay.blogspot.com/2017/03/testing-35mm-super-takumar-lens-in.html

FWIW, I have a large Pentax film SLR system including LX, MX, Spotmatic and SL bodies among others. In the 35mm focal length, I have the 35/2 SMCT, 35/3.5 SMCT, 35/2.8 M and 35/2 A. As it was specifically mentioned, I also have the 30/2.8 K. I purchased the 35/2 A new back in 1989 and have used it extensively over the years; I picked up the others second-hand more recently.

I have not done controlled comparisons of the optical performance of these lenses. The vast majority of my usage has been on-the-go held-held snapshooting on Tri-X, which does not stretch these lenses to their optical limits. So I'll limit my comments to just a few subjective observations. The 35/2 SMCT (and the corresponding 35/2 K) is a big lens by comparison with all the others. It's optically fine but for most purposes I prefer the relative compactness of the 35/2 A. The 35/3.5 SMCT (and presumably the corresponding 35/3.5 K) does not stand out in my experience as optically superior to the 35/2 SMCT. It's of course much more compact, but I also find it much more difficult to focus. The 35/2.8 M is the smallest/lightest of the lot. Just for fun I mounted it once to my GFX 100S with a K adapter and tried it in 35 crop mode, which records 60 MP; it did surprisingly well, but for both focusing and taking with a film SLR I find the extra stop of the 35/2 A very useful to have.

If 35mm is the way you naturally see, I wouldn't bother with the 30/2.8 K. On the other hand, if you want something wider than 35, I'd look at the many options in the 28mm focal length as well rather than restricting your search to the 30.

I have the 35mm 2.3 in M42, along with a 35 3.5 and the 35 2.8 in K, All 3 are sharp little distortion wide to stopped down, compact. The only reason to buy a 35 2.0 is for the extra stop which could be useful if the 35mm is your normal lens. I have not experienced any issues with focus. I have used the 35mm K on my AF SF with a split screen focusing screen I salvaged and cut down from a Miranda EE.

My 35mm f2.0 smc-m is a very nice lens, both optically and mechanically. The f2.0 makes it very nice to focus on my LX and MX bodies. It is sharp as well. The only downfall is that it has quite noticeable light fall off to its corners when used wide open or 1 stop down.

When considering a 28mm Pentax lens: i prefer the f2.0 smc-m over the f2.8 one - it is easier to focus and the f2.0 is considerably sharper.

I have a number of 28/3.5 Super Takumar and 28/3.5 SMCT lenses. In the 1975-1977 window, another lens which I think was a carry-over design was the 28/3.5 SMC Pentax. I have this lens and like it. The slower 28 M lens in the U.S. market was the 28/2.8. I have a few of those too. For overseas markets there was a 28/3.5 M, which I also have. I don't think it has the same design as the older 28/3.5 models. In the future I may add a 28/2 SMC Pentax or an M version. For now I have a Vivitar 28/2, the version made by Kino Precision (22XXX...) in K mount. In OEM 28mm lenses which are (relatively) fast I have the 28/1.8 Konica Hexanon, 28/2 'K' Nikkor and 28/2 Canon FD SSC. It would be nice to have a Minolta 28/2 (manual focus) to round things out. For Minolta I have both versions of the Vivitar 28/2 and a 28/1.9 Vivitar Series 1. Finally, I have the 28/1.9 in M42 mount.

Radost said:

I was talking about film SLR bodies.

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I never noticed this. Seems to work just fine, with or without split prism.

koraks said:

I never noticed this. Seems to work just fine, with or without split prism.

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everything from 24-60mm is hard for me. 28 35 40 50. When you have no contrasty edges for the internal prism splitter it takes me longer and I miss focus often. Especially with moving kids.
And especially in low light!!!
The same with medium format SLR cameras. Only the waist level with the loop has enough definition.
Rangefinder are quick an can be advance setup to fire the shutter when the range finder aligns.

Radost said:

35mm on SLR is super dificult to focus even with the split prism in the middle.

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Where did you get your information from? I have owned a Canon FD 35 mm f2 concave Thorium lens for forty years, and have never had any problems focusing it either with a split image or microprism focusing screen.This is rubbish.

Maybe just say "That has not been my experience," rather than saying another member's opinion is rubbish.

My own experience—I have a Nikkor 35mm f/2 and a Super Takumar 35mm f/3.5. I have not had any problems focusing with these lenses (at least not any more than I have with any other lenses), although the f/3.5 is a bit dim for focusing indoors. One nice feature of the Pentax wide angles is they have super clear hyperfocus distance markings for f/8 so if you can get away with shooting at that aperture, everything from about 2.3 m to infinity will be in focus, just set it and forget it.