[ducdao]

Hi all - my LBA just hit me again resulting two extra lenses that I don't really need.

They are both Fujinon EBC M42:

1) 50/f1.4 EBC
2) 135/f3.5 EBC

They are both in fact M42 lenses and besides the fact that they don't have the A/M switch that I can easily fix it with the Q-tip trick, they can't seem to sit on my Pentax K100D properly.

The bottom on the lens has that little piece of metal that prevent the lens to be screwed tightly to the Pentax body. Do I need to trim that little piece of metal off? I just want to make sure before I do anything crazy and irreversible.

I will try to post some pictures later as I don't have the lenses with me right now.

[epqwerty]

You will not have to trim that piece down to make it work. However I do suggest being careful with it as the extra trim is metal and may wear out the adapter. If I recall correctly the extra trim was originally for the later generation Fujica bodies that had a different metering system than the old style. Serves no real purpose on our DSLR bodies or older screw mount systems.

[epqwerty]

after posting my response I saw this on another thread

https://www.pentaxforums.com/forums/pentax-slr-lens-discussion/126702-square-...aks-mount.html

It should be the same thing as you are referring to but for Fujica. Read more for details.

[ducdao]

#1


#2

You will not have to trim that piece down to make it work. However I do suggest being careful with it as the extra trim is metal and may wear out the adapter. If I recall correctly the extra trim was originally for the later generation Fujica bodies that had a different metering system than the old style. Serves no real purpose on our DSLR bodies or older screw mount systems.

As you can see on both pictures above, if I don't trim that piece then I won't be able to screw in the lens completely and it also prevents me to turn the aperture ring. It looks really to me that I have to trim that one off but I'm only concerned about losing the infinity focus once I do so.

after posting my response I saw this on another thread

https://www.pentaxforums.com/forums/pentax-slr-lens-discussion/126702-square-...aks-mount.html

It should be the same thing as you are referring to but for Fujica. Read more for details.

I'm afraid this protrusion is different than the one on the Tak. The position of the protrusion is right between the aperture ring and the mount.

[epqwerty]

Yes. I do believe that the infinity focus will not be available without filling it off. If you do modify it I think you will not have to worry about taking too much off as the rest of the lens body will prevent it from screwing past the point I think but I'm not 100% sure.

[Big Dave]

I modified a 50mm F1.4 and it worked well. In addition to removing the square tab on the mount face, I used a little epoxy to hold the auto diaphragm actuator pin depressed. This keeps the lens in manual as required for use on our dslrs. My buddy is using it since I got a eight element f1.4 Super Takumar, which I like much better.

Dave