Posted by: Bruce | December 8, 2014

SMC Pentax-M 100mm f4 Macro lens: remove front element.

I wanted to remove the front element of this lens to check if the haze I could see, was on, not in, the front element. The front element apparently consists of two (or more) bits of glass joined as one by specialist glue.

I had trouble finding any specific information but eventually succeeded and added a little guesswork. In the end, the process is pretty simple (as long as things aren’t stuck too tight) and I was able to remove the element and find, not happily, that the haze is IN the join of the element.

There is really only two (2) steps.

-Remove (unscrew) lens front cover/information bit/trim and….

-Unscrew the front element.

I have very limited knowledge when it comes to servicing a lens. The correct tools are always best, but substitutes can sometimes work.

The lens cover/trim in this instance is threaded; on other lenses it might click in or even be lightly glued. It can be hard just figuring out how to remove a trim if one is fitted.

There are no handy little tabs or other convenient features on this lens that helps remove the front lens trim. Therefore, a non scratching, grippy assistant is needed. Other times, I have used a lid off a spray can (as long as diameter is good) with grippy rubber stuff you can buy in supermarkets (the stuff sold to help people who have difficulty removing lids off jars etc). Just don’t touch the lens surface.

The following pictures should tell the story and hopefully are of assistance to others. I like things to be explained very simply and hopefully the images do that. Ask if I haven’t covered something.

Click on a pic for quick presentation of large gallery images.

Word for today;     Haze – better off without it.




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