[evalon]

Hi Pentaxians,

I have a K5 that I am very pleased with, however, I can't make the aperture settings on my 24 mm/f2.8 (manual focus) work when the lens is fully mounted on the camera.

I can, however, make the aperture settings work if I don't completely mount the lens on the camera (that is don't rotate it all the way until it clicks to indicate mounted & locked), however, this is less feasible in the long run So I wonder if there could be a setting that I need to set to make the aperture work when the lens is fully mounted?

The camera is otherwise set to manual focus & "using aperture ring" and works fine.

Any insights appreciated

Jesper


P.S.: I found this link here on Pentax forums but it doesn't look as if I can use the 24/f2.8 lens with aperture settings e.g. in the K-5's "P" mode ...?

https://www.pentaxforums.com/forums/54-pentax-lens-articles/110657-how-use-me...ml#post1140019

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Last edited by evalon; 05-30-2014 at 10:28 PM.

[Adam]

Follow these instructions and you should be good to go:
https://www.pentaxforums.com/forums/54-pentax-lens-articles/110657-how-use-me...k-x-k-7-a.html

[Adam]

P.S.: I found this link here on Pentax forums but it doesn't look as if I can use the 24/f2.8 lens with aperture settings e.g. in the K-5's "P" mode ...?

Correct, you're limited to shooting in M mode.

[evalon]

Hi Adam,

& thanks for your quick reply. The thread you link to is very helpful and so now I know how it can be done. However, I admittedly would prefer to be able to use the camera with the lenses in "P" mode so will consider using them not mounted and locked ... The thought of it is a bit unsettling, though ...

Anyway thanks again for helping out

Jesper

[Adam]

Hi Adam,

& thanks for your quick reply. The thread you link to is very helpful and so now I know how it can be done. However, I admittedly would prefer to be able to use the camera with the lenses in "P" mode so will consider using them not mounted and locked ... The thought of it is a bit unsettling, though ...

Anyway thanks again for helping out

Jesper

You still wouldn't be able to use P mode, only Av (just like with Takumars). If you want full functionality, I'd recommend using A-series lenses.

[evalon]

Hi Adam ... thanks again for replying and suggesting. However, I actually am able to use the "P" mode if I mount the lens but don't quite rotate it so that it is fully locked in place. When looking from the outside onto the lens it is also visually apparent that the aperture is variably "closed" depending on the aperture setting. So, it's ok with me in this way ...

BTW: When you suggest the "A" series lenses do you then mean these:

Pentax A Prime Lenses - Reviews and Specifications - SLR and Interchangeable Lenses - Pentax Lens Reviews & Lens Database

or do you mean the FA lenses?

Cheers ;-)

Jesper

[stevebrot]

Hi Adam ... thanks again for replying and suggesting. However, I actually am able to use the "P" mode if I mount the lens but don't quite rotate it so that it is fully locked in place. When looking from the outside onto the lens it is also visually apparent that the aperture is variably "closed" depending on the aperture setting. So, it's ok with me in this way ...

BTW: When you suggest the "A" series lenses do you then mean these:

Pentax A Prime Lenses - Reviews and Specifications - SLR and Interchangeable Lenses - Pentax Lens Reviews & Lens Database

or do you mean the FA lenses?

Cheers ;-)

Jesper

In order to use P mode you need a lens with the electrical contacts on the base. Those provide data to the body so that it can properly set the aperture. As for partially mounting the lens in order to get the lens to stop down, what you are doing is not fully engaging the aperture actuator mechanism. The aperture you get is based on how far you disengage the lens.


Steve

[evalon]

Hi Steve,

Thanks also for your feedback. As it is I guess I'm rotating the lens so much that the aperture is no more influenced by the actuator mechanism but "permanently" set to any of the f/2.8-22 values as dialed in on the lens. I noticed, though, that when I rotated the lens somewhat less the available aperture depended on how much I rotated it. But not so now ...

Again, a bit unsettling but I prefer the resulting extra sharpness.

Greetings for your day

Jesper

[Lowell Goudge]

Hi Adam ... thanks again for replying and suggesting. However, I actually am able to use the "P" mode if I mount the lens but don't quite rotate it so that it is fully locked in place. When looking from the outside onto the lens it is also visually apparent that the aperture is variably "closed" depending on the aperture setting. So, it's ok with me in this way ...

BTW: When you suggest the "A" series lenses do you then mean these:

Pentax A Prime Lenses - Reviews and Specifications - SLR and Interchangeable Lenses - Pentax Lens Reviews & Lens Database

or do you mean the FA lenses?

Cheers ;-)

Jesper

But that only gives you the same effect as shooting AV mode

---------- Post added 06-03-2014 at 07:40 AM ----------

Hi Steve,

Thanks also for your feedback. As it is I guess I'm rotating the lens so much that the aperture is no more influenced by the actuator mechanism but "permanently" set to any of the f/2.8-22 values as dialed in on the lens. I noticed, though, that when I rotated the lens somewhat less the available aperture depended on how much I rotated it. But not so now ...

Again, a bit unsettling but I prefer the resulting extra sharpness.

Greetings for your day

Jesper

You get no additional sharpness, when shooting AV (or in your case P mode) than you get with the lens stopped down in M mode and set exposure by the green button. In fact you likely get more accurate focusing in M mode because you are focusing wide open where depth of field is reduced