Forum: Pentax SLR Lens Discussion
04-12-2009, 08:28 PM
|
|
Hope this is of use to some. I recently purchased a Helios 44M-4 from eBay, but found out I could only shoot wide-open (f2) when mounted on my K10d with the M42 adaptor. Modern Pentax DSLRs do not have the M42 provision to activate the aperture pin on the bacl of the lens. Thus, despite what the aperture dial reads, the lens will always remain at max aperture. This mod will change the aperture, as the dial indicates.
Conversion is very easy. You will need a small flat head screwdriver, a paperclip, and some wire cutters.
Start by removing the rear cover of the lens, 4 screws. When removing, careful not to lose the silver pin. Note orientation of the cover, it can only be re-installed one way.
Note the silver pin at the 9 o'clock position:
Remove the pin from the cover, and wrap a short section of paperclip tightly around the end as shown. This will act as a washer to keep the pin permanetely depressed.
Re-install the pin as shown in the pic, and mount to lens back. Careful to keep the cover orientation the same.
That's it. The aperture should change in unison with the aperture ring. Results: |