Is there life after aperture block failure?

flektogon wrote:

Futax wrote:

You can't set the aperture using the camera's thumbwheel to match the lens - it doesn't work. So you need EV compensation instead.

Maybe Pentax views this as a bug with the K-50 firmware - I don't know. Doesn't matter, I hope they haven't "fixed" it with a firmware update (I'll give you my camera's firmware details in due course).

Also, this may apply to cameras other than the K-50 (for example, K-30, K-500 etc. - I don't know - I hope so).

I believe that all Pentax cameras behave identically.

They certainly do NOT. Take a K2000, for example - it won't stop down with an M lens in Av mode. It'll take a nicely exposed shot wherever you set the aperture ring BUT TAKE A LOOK AT THE SHUTTER SPEED WHEN YOU SHOOT AT F22.

I'm rapidly getting fed up with these tedious interchanges. If you don't understand what I'm saying, try it for yourselves. I was only trying to help - perhaps some are beyond that.

O.K. I let you breath I didn't realize that the camera with the aperture ring enabled doesn't allow you to set the aperture value on the camera, in the Av mode for example, that the camera always assume a fully open lens. Then of course, only the EV compensation can help.

Well, the thing is, a K-mount lens which has an aperture ring and no "A" setting cannot tell the camera what aperture is set to.  In all Pentax DSLRs, you have to set the menu item to "Enable Aperture Ring" and set the camera to M mode - and then you need to allow the camera to perform its metering by using the green button.  The camera will operate the aperture lever fully (whether or not it is a K-50 with the aperture block problem) and you can then take the shot.

That was the only way you could use such a lens in most Pentax DSLRs (certainly the earlier ones).

Problem is that metering with the lens stopped down isn't necessarily very accurate - and it's a bit tedious to use the green button before each shot.

Now, with the K-50, it seems to do things differently.  Instead of refusing to stop down in Av mode unless it was a modern lens (or a lens set to "A" mode), it actually operates the aperture lever, and the lens stops down to the set aperture.  But since it has no knowledge of apertures, it just uses the metering information that it gets with the fully open lens.

That's why you need to get it to expose correctly using compensation.

I think a lot of K-50 owners might benefit from this insight.