[Ahsaaan]

Dear all, i am new to this forum and to photography the problem is from last week i cant change aperture from aperture ring in pentax ks2. Lense remains wide open even if i stop down can anybody help me out? Thanks in Advance.

---------- Post added 09-28-19 at 12:21 AM ----------

Mostly i use manual lenses, in start i was able to change their aperture but now they remain wide open even if i stop down.

---------- Post added 09-28-19 at 12:22 AM ----------

Mostly i use manual lenses, in start i was able to change their aperture but now they remain wide open even if i stop down.

[Adam]

Make sure you're in M mode when using the aperture ring. Also, if the lens isn't manual, it's best to leave the aperture ring set to A.

[Ahsaaan]

Make sure you're in M mode when using the aperture ring. Also, if the lens isn't manual, it's best to leave the aperture ring set to A.

My lense is Manual smc M 1.7 the problem is i cant change aperture mechanically when attached to camera something inside is keeping it wide open whereas when ever i detach lense and change aperture of lense from ring it changes.

[slartibartfast01]

My lense is Manual smc M 1.7 the problem is i cant change aperture mechanically when attached to camera something inside is keeping it wide open whereas when ever i detach lense and change aperture of lense from ring it changes.

There is a menu setting to allow aperture ring use but I assume you have already set that.

[RKKS08]

You know the lens will only close the aperture during green button metering and while the exposure is taken?
All the rest of the time the aperture stays fully open (as long as the lens is fixed on the body).
Detached from the camera, the aperture will follow the ring setting.

This behaviour is different from that of M42 lenses.
Sorry if you already know all this.

[pschlute]

Make sure you're in M mode when using the aperture ring

Adam is correct. The camera must be in Manual mode

[Kozlok]

You may want to review the instructions again. Also pasting this here for anyone else who has the same issues.

How to use/meter Manual & M42 Lenses on all Pentax DSLRs (K-1, K-3, K-5, K-30, etc) - PentaxForums.com

[stevebrot]

My lense is Manual smc M 1.7 the problem is i cant change aperture mechanically when attached to camera something inside is keeping it wide open whereas when ever i detach lense and change aperture of lense from ring it changes.

Welcome to the Pentax Forums!

That is how lenses with auto aperture actuation work.* Most (almost all) K-mount lens when used on a K-mount camera only stop down for the exposure, depth of field preview, or for stop-down metering. When using the aperture ring to control the iris, this is only allowed in M or B modes on your camera with metering limited to M mode with set ISO. One must also enable aperture ring in the menu settings. Basic instructions are on p115 of the user guide. All other modes operate as Av mode with the lens staying wide open, even during exposure.


Steve

* Since the early-to-mid 1960s, the vast majority of SLR lenses (all makes) work this way with very few having fully manual aperture.