[chaza01]

Hi
Very question question.

I have bought my first super takumar m42 lens, a 35mm f3.5.

I bought a cheap third party adapter for it (its okay, the lens aperture ring is slightly off but that doesnt bother me), but i notice, when I press the green button in manual , i do not get the usual mirror flop thing when shutter speed is calculated. Why is this exactly? With m42 do you put onto manual and then just make do with a dim viewfinder?

Also, the lens has a small pin by the screwmount, do I need to tape this? It doesnt seem to interfere with anything?
Many thanks

Charlie

[lytrytyr]

Charlie, this page should answer your questions:

https://www.pentaxforums.com/forums/54-pentax-lens-articles/110657-how-use-me...k-x-k-7-a.html

The green button exposure measurement is only for K mount lenses.

[chaza01]

Charlie, this page should answer your questions:

https://www.pentaxforums.com/forums/54-pentax-lens-articles/110657-how-use-me...k-x-k-7-a.html

The green button exposure measurement is only for K mount lenses.

Thank you very much for the link - there is one thing still confusing me however - does the 'A' mode on the takumar work as teh 'A' mode on a k mount? Or am I basically permanently in m mode but with no aperture held open?
I cant figure if the article is referring to k mount or m42 for that last bit .
Does Av mode basically continuously change the shutter speed as required whereas M requires green button?

Many thanks,

Charlie

[Adam]

Thank you very much for the link - there is one thing still confusing me however - does the 'A' mode on the takumar work as teh 'A' mode on a k mount? Or am I basically permanently in m mode but with no aperture held open?
I cant figure if the article is referring to k mount or m42 for that last bit .
Does Av mode basically continuously change the shutter speed as required whereas M requires green button?

Many thanks,

Charlie

The A mode on a takumar allowed open-aperture metering on Spotmatic cameras, which was a built-in feature on all future K-mount lenses. It has nothing to do with aperture automation. Make sure you keep it set to M, otherwise the lens won't stop down at all.

Adam
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[chaza01]

The A mode on a takumar allowed open-aperture metering on Spotmatic cameras, which was a built-in feature on all future K-mount lenses. It has nothing to do with aperture automation. Make sure you keep it set to M, otherwise the lens won't stop down at all.

Thanks Adam, do some set it to A in order to keep the viewfinder bright, and then switch to M to take the photo?

[Adam]

Thanks Adam, do some set it to A in order to keep the viewfinder bright, and then switch to M to take the photo?

Yup, it's either that or using the aperture ring itself.

[manntax]

Thank you very much for the link - there is one thing still confusing me however - does the 'A' mode on the takumar work as teh 'A' mode on a k mount? Or am I basically permanently in m mode but with no aperture held open? I cant figure if the article is referring to k mount or m42 for that last bit . Does Av mode basically continuously change the shutter speed as required whereas M requires green button? Many thanks, Charlie

With M42 screw mount lenses you basically have two alternatives, ways of using them for shooting that is .. One is when the camera is in 'M' mode. In this mode you usually follow the ligting conditions - similarly to old days and fully manual camera - you learn to 're-meter' when lighting condition change. In this mode you usually want your aperture set to whatever f-stop you want, and keep the switch on the lens itself on 'Auto' - for focusing wide open with bright viewfinder. When you are about to shoot (or re-meter) - you simply flip the switch on the lens to 'M' mode and either release the shutter or click the green button so that the camera can meter and set the shutter speed accordingly. NOTE: In this mode the ISO has to be set on fixed value for green button to work.

Another option is using the camera in AV mode with ISO set to auto or fixed value and shutter speed selected automatically by the camera. In this mode you usually keep the switch on lens on 'M' position and stop down with aperture ring while composing the shot. You can use similar technique to that one from 'M' mode - with switch on the lens on 'Auto' and flipping it over to 'M' just before you shoot - either will work OK. In this mode you are free from the need to 're-meter' with green button - which is usually the good thing, especially when you know how to employ exposure compensation or exposure - lock - to modify or lock the exposure to a specific place.

It is a bit confusing at first - but once you grasp the basics it all will all become clear and obvious

[Not a Number]

The green button may work in M mode - depending on what body you have or if the data pin on the mount is shorted. The green button should be set to Tv shift in M or TAV mode in the eDial customization menu. Also ISO should not be set to AUTO. DOF preview should also be set to Optical - depending on which body you have operating the DOF preview will turn on TTL metering and the exposure bars in the viewfinder in manual mode. The K-01, K-30, K-50 and K-500 are some of the bodies that the green button may not work with screwmount lenses unless the data pin is shorted. I believe they also do not have the exposure bar feature in manual DOF preview.

[manntax]

The K-01, K-30, K-50 and K-500 are some of the bodies that the green button may not work with screwmount lenses unless the data pin is shorted.

Not sure how accurate that is - because I just tested my K-01 with takumar lens mounted and pins weren't even touched by the lens (with adapter being genuine pentax it is deep inside the mount ) and ISO set manually , and my camera is fully working as intended - green button will adjust the shutter speed when lens is stopped down or wide open - accordingly.

[Not a Number]

Not sure how accurate that is - because I just tested my K-01 with takumar lens

I did say "may not work". Some people report it not working, some do. It may be those that report it not working may have over looked a setting, or may be a difference in firmware or just some random whim of the Pentax gods. It is difficult to try to tease out all the variables when you have people of varying "tech savvy" abilities as well as language barriers. And many times people just stop replying to a thread and you can get no further information out of them. Imagine what Customer Support has to go through.

[manntax]

I did say "may not work". Some people report it not working, some do. It may be those that report it not working may have over looked a setting, or may be a difference in firmware or just some random whim of the Pentax gods. It is difficult to try to tease out all the variables when you have people of varying "tech savvy" abilities as well as language barriers. And many times people just stop replying to a thread and you can get no further information out of them. Imagine what Customer Support has to go through.

yeah, agree - this might be the case with older firmware perhaps. I run the latest and just did the test - K-01 is metering even without the lens on. I have no experience with other mentioned cameras so your info may well be accurate in those case.

[chaza01]

Many thanks all - I used the lens yesterday and it performed well. Changing from a K mount to M42 is very cumbersome however, especially give how dark it was at the time. That is one reason Im wondering about a mirrorless body down the line (with a different mount), presumably adapters would work much easier when they do not have to be so shallow so as to keep infinity focus (ie because with mirrorless Id want to add distance from rear element to sensor).

All the best!