Pentax K1000 Aperture stuck fully open when lens is locked in.

[travone_logan]

<p>I have a Pentax K1000 that I bought not too long ago. With it I have a SMC Pentax-M 1:2 50mm lens. When I first got the camera and would change the aperture on the lens when it was locked into the camera I could see the eye opening and closing. Also, when looking through the viewfinder I would be able to see more or less light being allowed in as I adjusted it. Recently I've noticed that when I lock the lens in this no longer happens. When I take the lens off and adjust it the eye opens and closes like it should, but every time I lock it back into the body it's stuck wide open once again. I would really like to find out what the issue is because I'm eager to start taking shots. Is it a lens problem or is it the body? How do you fix this? I appreciate any help I can get.</p><div></div>

[john_shriver]

<p>The current behavior is normal. The aperture stays wide open while you focus and meter, and closes down only when you take a picture. This was considered a big innovation at the time.<br>

If it wasn't working originally, something was wrong with the lever inside the lens mount at the left, or the mating lever on the lens. Easy for the lever on the lens (or protective plastic tab next to it) to get bent.<br>

Also, you get this behavior if you don't turn the lens enough to engage the locking catch when putting it on the camera.</p>

 

[travone_logan]

<p>Wow.. really? So before when I could see the aperture moving while I was taking shots something was wrong??? Thank you very much. This makes me so happy.. I can go take new shots now! :D</p>

[travone_logan]

<p>Thanks so much... I tested what you said and it works! I don't know what was up before but I'm happy this is working for me now.</p>

[paul_noble]

<p>Two possibilities come to mind: first, the lens or camera mechanism may have been sticking, due to hardened lubricate or grime due to age.</p>

<p>Second, you may not have had the lens fully locked on. In fact, this is a trick that some photographers use on cameras that lack a depth-of-field preview option. After you focus and set the aperture, unlock the lens and turn it to the release position. This releases the aperture lever and allows the lens to stop down to the selected aperture.</p>

<p>Paul Noble</p>