Hello!
I'm using a FA 50 f/1.4 lens for about 5 years now, and I'm very happy with the image quality it delivers. It's my primary lens, and thus has travelled quite a bit - and suffered. The cylinder which contains the lenses and extends or retracts while focusing is suffering from quite significant mechanical play. It was already evident when I bought the lens, but it became worse. Now I'm using the lens in manual focus on a Pentax MX, and the play makes focusing rather hard as the cylinder containing the lenses can "flip", thus shifting the image slightly (though not knocking it out of focus).
I showed the lens to a local repairman, who in a failed attempt to open the lens lost 2 of the three screws which hold the decorating ring in front of the primary lens, and made an estimate I just can't afford (additionally, I wouldn't trust him my lens any more :P) . (I did pay 120 Euro in a clearance sale 5 years ago for the new lens, I'm more than surprised seeing how the price increased over the last years! - unfortunately, repair costs of ~100 Euro are just out of reach right now.).
I found several guides how to disassemble a FA 50 f/1.4, I've got JIS screw drivers and thus think it should be possible to solve the problem on my own. (...The crucial part seems to be to mark the position of the helix which guides the moving cylinder when disassembling as the thread has multiple entries.)
-> I will need new
lubricating grease when putting back together the lens - in fact I hope that new grease might solve entirely the mechanical play. Can you advice which product to use and where to buy it?
-> Looking through other disassembly guides, I did not find any retaining ring / screw which might cause mechanical play when loose - do you have any advice if there
might be other reasons for the play than issues with the lubrication? I never dropped the lens, thus I guess I can exclude significant internal mechanical deformations.
-> Do you have any suggestion where I might find spare screws that got lost during the "professional" (...) attempt to remove the play? You find a picture of the missing screws attached to this post.
Would be great to get some pieces of advice. As soon as I know how to proceed exactly and which lubricating grease to use, I'll keep you informed about the progress and of course post pictures of the disassembly.
Best regards,
Rapfl
http://dl.dropboxusercontent.com/u/9718909/IMGP5659.JPG
Last edited by Rapfl; 06-12-2013 at 03:46 AM.