broken Sears 55mm/1.4

awwwnuh · Joined: 07 Jun 2009 Posts: 21 Location: California

I mentioned this in my intro thread...
I have this rather nasty habit of fidgeting with the focus rings of my lenses when I'm waiting around at concerts, and one day the Sears literally fell apart in my hands.

this is what it looks like right now:

before this happened the focus ring had started to be loose, but worked fine if I squeezed while turning it.

I've tried and tried to screw it together, and I feel like I'm really close to getting it right, but it never attaches all the way and can be unscrewed again.

I should probably just invest in a replacement, but I like this one...

Arkku · Joined: 28 Feb 2007 Posts: 1416 Location: Helsinki, Finland

Have you disassembled the lens further than this? You need to, or you cannot get the focusing helicoid coupled to the lens; that thin metal piece protruding upwards upper left in the first photo (and another just like it opposite on the other side, but hidden behind the edge of the lens?) must be unscrewed from the bottom (which you can't access without further disassembly). The lens is then screwed onto the focusing helicoid as far is it goes and only then are these metal pieces re-inserted.

Also note that the focusing helicoid can be screwed on from numerous different positions, each leading to a different orientation and depth. If it's left too high, you will lose infinity focus and the lens may unscrew when focusing (as those metal pieces that keep it coupled to the helicoid are not long enough). Only one position is correct for the original infinity focus position, but alternatively you may be able to adjust the infinity focus position by rotating that bright ring to which those famous metal pieces are attached (it changes height as you turn it, in almost imperceptibly small increments, so count the revolutions).

If the lens still keeps falling off the threads, you can try to set it up so that it focuses a bit beyond infinity (i.e. lens closer to sensor/film than normal).

awwwnuh · Joined: 07 Jun 2009 Posts: 21 Location: California

Thank you! I hadn't tried unscrewing the thin metal pieces though I noticed I could. I figured if they hadn't moved when the lens fell apart they didn't need to be moved to fix it. But I will definitely try now.

And I noticed that.... so finding the right placement is going to be interesting. ah, well, another way to spend the evening.

Arkku · Joined: 28 Feb 2007 Posts: 1416 Location: Helsinki, Finland

Oh, forgot to mention; those thin metal pieces go into the slots on the sides of the helicoid; you can see one of the slots on the left in the second photo (and far right in the first photo). When they are not in the slots, the two halves rotate independently (and can be unscrewed), but when they are in the slots the two halves are coupled (and ideally cannot be unscrewed)—which is what you want, but not until the position is correct.

awwwnuh · Joined: 07 Jun 2009 Posts: 21 Location: California

I noticed the slots too, and was rather frustrated about them. haha.
I tried to unscrew the tabs but it appears the screws are glued. Is it possible to unglue them?

Arkku · Joined: 28 Feb 2007 Posts: 1416 Location: Helsinki, Finland

mo · Expire: 2016-07-30

Go gently....take photos,and put in pencil marks of positions you have already tried when trying to re-screw them back together.

awwwnuh · Joined: 07 Jun 2009 Posts: 21 Location: California

Just wanted to say that I got it fixed... and not to brag, but I got the positioning right the first time Very Happy

I managed to leave off the ring that points to what the distance and aperture are, but it seems to work fine without it. More of an aesthetic issue I guess.
but thank you so much for your help Smile

I am so excited to be able to use this lens again.

Laurence · Expire: 2016-06-19