Stop Down Metering Technique

[howard_tomlinson]

Can anyone help with how to do stop down metering on a

 

Pentax ME super or a Pentax P30 or both?

 

I have a 500mm tele lens with an aperture ring, but it is a non auto

lens and therefore does not tell the camera body what aperture is

set. The lens has apertures from 8 down to 32.

 

Thanks

 

H

[stemked]

Hi Howard.

 

With the P30 (and I suspect with both cameras) the beauty of Pentax is that the body knows how much light is comming through. That's all it needs for aperture priority. You can try this in your camera without film. With the P30 for example without film the camera is set to ASA 100. Now take the camera outside and try a few f stops with the camera on aperture priority. As you stop the lens down the camera will automatically increase the shutter time. In other words you don't need the electrical contacts that you have with an A, F or FA lens for aperture priority. I do AP with screw mount lenses all the time and they work fine.

[james_oneill]

See the little lever which sticks up from the mount ? Turn the apperture ring and watch it move. That's how the camera knows what apperture the lens is set to. If you have a body which supports program or shutter priority THEY need the contacts, but Apperture priority and manual do not.

[imaginator]

Some lenses require "stopping down" to desired aperture to meter, but it's hard to manually focus such a dark image so you have to "open up" temporarily to focus, then stop down again to take the shot.