[LensBeginner]

I sort of agree. The 35/2 is not really all that sharp at f2. Anyway, i never really bought the lens for that express purpose - more its capacity to deliver good colour rendition and satuation.
*snip*

I was suggesting to test them stopped down precisely because one would rarely shoot them wide open, if at all possible...
The advantage of having a f/2 lens is, a little paradoxically, that you can probably use it stopped down at f/3.5 and have an acceptable level of sharpness across the frame... I wouldn't be comfortable shooting at f/3.5 an f/3.5 lens.
Except if they were essentially the same design and one had been "enlarged" to f/2 for marketing purposes, that is.

[Wild Mark]

I was suggesting to test them stopped down precisely because one would rarely shoot them wide open, if at all possible...
The advantage of having a f/2 lens is, a little paradoxically, that you can probably use it stopped down at f/3.5 and have an acceptable level of sharpness across the frame... I wouldn't be comfortable shooting at f/3.5 an f/3.5 lens.
Except if they were essentially the same design and one had been "enlarged" to f/2 for marketing purposes, that is.

I agree. Shooting such a lens wide open is only done in rare circumstances where there is an artistic intent.

The more glass in the lens the less light transmittance so the wider the aperture required to deliver the light. Why design a lens with more glass? to correct for optical limitations - but that does not mean that wide open performance will be good, But as you say stopped down the performance should be better than a comparable FL with smaller maximum aperture.

What I am trying to find out is why did Asahi produce the 35/2. From its performance I suspect it was for better near range use indicating a less traditional wide angle purpose (a mix of portrait and scenery perhaps). Even stopped down the background OoF is pleasing to the eye so the lens might have been designed for candid group photos at social scenes or the like. Something a little wider than a 50mm without the distortions introduced by the 28mm.

Anyway, the purpose of the 35/2 is not exactly that of the 35/3.5 - the differing designs create different effects and as such we should respect the differences for what they are. I for one will retain a copy of both in my collection as they both seem to deliver equally good outcome withing their individual strengths.

[LensBeginner]

I agree. Shooting such a lens wide open is only done in rare circumstances where there is an artistic intent.

The more glass in the lens the less light transmittance so the wider the aperture required to deliver the light. Why design a lens with more glass? to correct for optical limitations - but that does not mean that wide open performance will be good, But as you say stopped down the performance should be better than a comparable FL with smaller maximum aperture.

What I am trying to find out is why did Asahi produce the 35/2. From its performance I suspect it was for better near range use indicating a less traditional wide angle purpose (a mix of portrait and scenery perhaps). Even stopped down the background OoF is pleasing to the eye so the lens might have been designed for candid group photos at social scenes or the like. Something a little wider than a 50mm without the distortions introduced by the 28mm.

Anyway, the purpose of the 35/2 is not exactly that of the 35/3.5 - the differing designs create different effects and as such we should respect the differences for what they are. I for one will retain a copy of both in my collection as they both seem to deliver equally good outcome withing their individual strengths.

One of reasons I've always been curious to know transmittance figures for older M lenses (4, 5-elements designs) and newer glass (even a lowly 18-55mm WR)...

[Wild Mark]

Anyway, the purpose of the 35/2 is not exactly that of the 35/3.5 - the differing designs create different effects and as such we should respect the differences for what they are. I for one will retain a copy of both in my collection as they both seem to deliver equally good outcome withing their individual strengths.

I acquired a copy of 'The Asahi Pentax Way' this week and have had a short read. I found a very insightful section on the differences between the 35/2 and 35/3.5 on p84

""While the additional speed of the f2 may be extremely valuable to many photographers for use in low light, the large aperture also has an additional advantage. Wide angle lenses are undeniably harder to focus than longer lenses. The short focal lengths have far greater depth of field at any given aperture and subject distance than longer lenses. As a result it can be more difficult to find the exact plane of sharpest focus when focusing a wide angle lens. However, the wider the maximum aperture, the shallower is the depth of field. If you view through the 35mm, f2 Takumar you will quickly see that it is a faster and easier focusing lens than the f3.5. The subject "snaps" in and out of focus far more precisely than with the f3.5 lens."

SPOT ON I say.

My comments regarding 'fickle focusing' for the 35/2 remain. The contrast detect focusing method gives variable and repeatedly disappointing results. Maybe it is front/ back focusing! Anyway, no such problem when using a split prism to focus as previously mentioned.

So if you use a 35/2 lens be sure to know that contrast detect focusing can be misleading. It is a lens that is best visually focused to get peak sharpness on the subject. That at least is my experience with the K30. Other contrast detect camera bodies might be less of a problem - that I cannot verify.

So again I will keep both lenses in the bag. But if focusing is critical in a particualr shot, I will make sure I have the 35/2 and a split prism focusing screen on standbye.

Regards

[Jonathan Mac]

I also have both and find the f/2 much easier to use due the much brighter viewfinder (I have a Katzeye and no live-view). I think I prefer the rendering of the f/3.5 though.

[LensBeginner]

*snip*

My comments regarding 'fickle focusing' for the 35/2 remain. The contrast detect focusing method gives variable and repeatedly disappointing results. Maybe it is front/ back focusing! Anyway, no such problem when using a split prism to focus as previously mentioned.

*snip*

Front/back focusing and related adjustments is a thing related to PDAF only.
If using CDAF you don't use the focus sensor, but the processor analyzes a "snap" directly from the camera sensor, so there's no way the focusing sensor can be off.

[Dartmoor Dave]

What I am trying to find out is why did Asahi produce the 35/2.

Back in the film era, 35mm was the preferred "normal" focal length for many photographers who found the more usual 50mm too long (it certainly was for me). So a relatively fast 35mm/2.0 was a big advantage in the Takumar range, particularly when you consider that the Spotmatic/Takumar combination was a widely used professional system back in the sixties. It was routine in those days to push Tri-X to ASA800 or even higher, so with the 35mm/2.0 it was possible to work in very low light. The lens was just about sharp enough wide open to produce an acceptable 8x10 print, and that's all that really mattered. 100% corner crops wide open are very much a digital era obsession.


Edit: Whenever we talk about Takumars, we need to remember that they were designed in the 1960s to suit the film and cameras that were around at that time, and to satisfy the photographic aesthetics of the era. It's a wonderful historical fluke that we can still use them on DSLRs and get great results, but we must be careful never to judge them as if they were designed for that purpose. It's when people commit that simple fallacy that we end up with the type of flaky reviews that were mentioned in the original post. Like the guy who focused on the tip of his subject's nose rather than her eyes, and then complained that the lens was soft.

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Last edited by Dartmoor Dave; 11-26-2014 at 03:45 AM.

[Wild Mark]

Front/back focusing and related adjustments is a thing related to PDAF only.
If using CDAF you don't use the focus sensor, but the processor analyzes a "snap" directly from the camera sensor, so there's no way the focusing sensor can be off.

I love this site. I used the wrong terminology. I was meaning phase detection .... when you get the beep beep and little green light! Be wary of that type of focus confirmation for the 35/2 - it is not always true.

[LensBeginner]

I love this site. I used the wrong terminology. I was meaning phase detection .... when you get the beep beep and little green light! Be wary of that type of focus confirmation for the 35/2 - it is not always true.

Sorry if I've been too picky, my bad!

I tend not to rely much on the green hexagon, because it simply signal the beginning or the end of an area of acceptable focus... sometime it's enough, sometime it isn't - also depending on the characteristics of a particular lens, as you say.

[Wild Mark]

No problem - happy to be corrected. It helps me learn!

I must say this, using the takumars on my digital bodies have enable to to learn SOOOOOOOO much about digital photography, good, bad and ugly. No knowing the 'limitations' of the 35/2 on digital I can begin to appreciate it even more.

[tim60]

A couple of really interesting posts.


The reason for the 35/2 being the shallow DOF for focusing. Interesting.


I bought a whole set of the Takumars (one at a time) because I liked the aesthetic they give. They are different than modern glass which seems to aim for all over sharp. I do find getting reliable focus to be a challenge with a number of them (my eyes in the VF). I usually use the red rectangle in the K3 but maybe I should move to trusting my eyes more.

[monochrome]

I liked the aesthetic they give. They are different than modern glass which seems to aim for all over sharp

That's the key. Desired aesthetics have changed over time.