[OldChE]

I purchased, but don't have yet, a camera I've long wanted to acquire, a 1957 Pentax "AP" - the original "Pentax" model. The body will come with the Takumar 58mm F2.0 preset lens. The body is in working order, refurbished by Mark Hama, and I am excitedly looking forward to using it. The 58mm/F2 will be my only M42 preset Takumar lens so far, since I've never owned a Pentax earlier than my Spotmatic (which I've been using for 52 years). I have 6 of the M42 Super-Takumar lenses to use with the Spotmatic, all of which I believe have the little "M/A" switch on the barrel. I have 5 other non-Pentax M42 lenses that I've used with the Spotty, but I'd have to check if they all have M/A switches as well.

My question is this - Will I be able to use these later-model M42 lenses with the Pentax AP, by focusing with the lens on "A" mode (i.e., fully wide open), and then selecting the desired f-stop and moving the A/M switch to "M" to stop down the lens prior to exposure? It seems to me that this would work, and I believe this was one of the reasons Asahi designed these lenses with an A/M switch, to be backwards-compatible with the earlier cameras. Alternatively, I could just keep the A/M switch on M all the time, opening the lens with the aperture ring to wide open to focus, then selecting the desired aperture with the ring just before shooting, and then re-opening the aperture to focus for the next shot.

I searched the forum here to see if this questions was already addressed, but I didn't find it.

In the Super-Taks, I have 28, 35, 50 macro, 55, 135, and 200 mm lenses, so if I can use them in this manner with the AP body that would be neat. I "could" set out to acquire a range of the older pre-set Takumars, but if I didn't have to that would be good. Particularly because I explained to my wife that even though I was buying yet again another camera, it didn't mean I was then going to want to buy a bunch of new lenses to go with it. She was somewhat suspicious of that assertion.

Thanks - Richard.

[FozzFoster]

Can I use M42 Super-Takumar lenses in "M" mode on my 1957 Pentax "AP"?

yep!
...except for the 8-element super tak 50 1.4

[ismaelg]

yep!
...except for the 8-element super tak 50 1.4

Hello,

Question: Why not? The AP has no aperture pushbar. Nor the K for that matter. I may be missing something but I would think it would be ok.

Thanks,
Ismael

[OldChE]

yep!
...except for the 8-element super tak 50 1.4

Thanks!

---------- Post added 10-16-22 at 06:30 PM ----------

Hello,

Question: Why not? The AP has no aperture pushbar. Nor the K for that matter. I may be missing something but I would think it would be ok.

Thanks,
Ismael

I don't have an 8-element 50/1.4, nor actually any 50/1.4 in M42 mount, so I'm not concerned about that issue. I thought the issue with that lens was the protruding rear element could be damaged by some of the cameras aperture push plates - which of course the AP lacks, so I would agree with you. I don't know if there is any other clearance issue to worry about with the AP and that lens - maybe the mirror would hit the rear of the lens? Or maybe there are other components in the mirror box that present clearance issues? I suspect there is no issue with the AP and that lens, but I don't know and it wouldn't matter to me anyway. This article explains some of the warnings on that lens and different model cameras. 1 : 1.4 / 50 (358) 8 element - Takumar Field Guide

[leekil]

From the link above:

"The rear glass of this lens protrudes into cameras further than any other lens because of the extra 8th element. Push-plates for actuating lenses inside cameras were changed from rectangular to curved to provide more space just before the earliest Spotmatic onwards (Photokina 1961?). (Some earlier cameras models were converted as shown by their red "R" rewind buttons ). (Most importantly, no other lenses are affected by this warning.)"

---------- Post added 10-16-22 at 05:17 PM ----------

I figured the problem was that the camera parts could get damaged by that lens hitting them?

[FozzFoster]

Why not?

do'h - silly me, I was thinking of the mirror not the aperture...

I'm wrong!

[titrisol]

Hello,

Question: Why not? The AP has no aperture pushbar. Nor the K for that matter. I may be missing something but I would think it would be ok.

Thanks,
Ismael

If they have no aperture push bar, the only other thing that could go wrong is the mirror touching the rear element
I haven used any of those camera so I'l guessing

[nickthetasmaniac]

Hello,

Question: Why not? The AP has no aperture pushbar. Nor the K for that matter. I may be missing something but I would think it would be ok.

Thanks,
Ismael

There is some vagueness about whether early Pentax's were incompatible with the 50/f1.4 8E due to the potential for fouling with the mirror, aperture plate, or both.