johnloumiles Posted July 18, 2011 Share #1 Posted July 18, 2011 Advertisement (gone after registration) I have a pretty beat up Canon 50mm 1.5 lens that needs to be cleaned of haze badly. I want to take this opportunity to work with a lens by taking apart and cleaning it. If something goes wrong, not a big deal. I've scoured online but there's nothing about this particular lens which is not surprising but where I'm stuck is the screws on the back of the lens. They are shallow flathead screws but none of the drivers in my kit can get a grip on the screw. Does anyone here have a goto screwdriver or other tool when it comes to taking vintage lenses apart? Of course if you have any other advice to go with it I would be happy to hear it. Thanks Link to post Share on other sites More sharing options...
Advertisement Posted July 18, 2011 Posted July 18, 2011 Hi johnloumiles, Take a look here Taking apart screw mount lens... I'm sure you'll find what you were looking for!
marknorton Posted July 18, 2011 Share #2 Posted July 18, 2011 Are the screws slotted? If so, I suggest you buy a screwdriver of the correct width and grind it down to exactly fit the screw slot. Link to post Share on other sites More sharing options...
pico Posted July 18, 2011 Share #3 Posted July 18, 2011 John Lou, I have been in such a situation often and over a great deal of time I did find screwdrivers that fit properly. I had to take the part to shops that sell such and actually try each one, although there are supposed to be standards, things vary. I think you will find that a sufficient remedy. As a very last, dire resort, if you can remove one, then purchase replacements plus a few spares so one or two can fall off the bench without driving you crazy. Then to remove the rest, use a low voltage electrical welder to weld a short piece of steel rod (piece of clothes hanger works) to the screw head and turn it out with pliers. It takes the merest tap to attach the short steel rod. Link to post Share on other sites More sharing options...
johnloumiles Posted July 18, 2011 Author Share #4 Posted July 18, 2011 Thank you Mark and Pico! Here are a couple photos so you can see what I'm talking about. I will continue the search for the right tool otherwise I will grind this down. The last resort, pico, sounds like fun (who doesn't like to weld?) but I'm lacking the equipment and space to do it in. I appreciate your feedback and we'll see where it goes from here. Welcome, dear visitor! As registered member you'd see an image here… Simply register for free here – We are always happy to welcome new members! Link to post Share on other sites Simply register for free here – We are always happy to welcome new members! ' data-webShareUrl='https://www.l-camera-forum.com/topic/157227-taking-apart-screw-mount-lens/?do=findComment&comment=1738451'>More sharing options...
Xmas Posted July 18, 2011 Share #5 Posted July 18, 2011 Hi As previous poster, I would file down a larget screwdrive so it is a push in fit, minimal clearance on sides. Nice lens I'd not want to damage it. Unless you are lubing the helicoid you may only need to undo the outer (rear) ring nut and the whole lens cell should 'drop' out the front of the focus mechanism, with associated shims... Not had a 1.5 apart... Noel Link to post Share on other sites More sharing options...
marknorton Posted July 18, 2011 Share #6 Posted July 18, 2011 Thank you Mark and Pico! Here are a couple photos so you can see what I'm talking about. I will continue the search for the right tool otherwise I will grind this down. The last resort, pico, sounds like fun (who doesn't like to weld?) but I'm lacking the equipment and space to do it in. I appreciate your feedback and we'll see where it goes from here. My advice remains the same. Find a screwdriver which covers the full diameter of the screw and grind it down to fit the slot, not just approximately, but exactly. I have at least a dozen screwdrivers which I have done exactly this to. Welding is, IMHO, a ridiculous solution. Link to post Share on other sites More sharing options...
johnloumiles Posted July 18, 2011 Author Share #7 Posted July 18, 2011 Advertisement (gone after registration) That will be my next course of action, finding the right fit. I have one thats the right width but it's a bit too thick so I will need to find a friend with a grinder or I will do it with some elbow grease. Xmas, it is a nice lens and if the the back element does not fall out easily I will not force it. I'm under no delusion that it's a easy fix but I'm curious to try. Link to post Share on other sites More sharing options...
250swb Posted July 18, 2011 Share #8 Posted July 18, 2011 As a very last, dire resort, if you can remove one, then purchase replacements plus a few spares so one or two can fall off the bench without driving you crazy. Then to remove the rest, use a low voltage electrical welder to weld a short piece of steel rod (piece of clothes hanger works) to the screw head and turn it out with pliers. It takes the merest tap to attach the short steel rod. A somewhat less drastic approach and one more liable to success for your average bloke is to heat the screw heads up with the tip of a soldering iron. The localised heat is often enough to beak the seal caused by years of gunk, especially if they were originally put in with a dab of threadlock. Alternate it with a careful application of WD40 around the screw head and make a screwdriver to do the final job. Steve Link to post Share on other sites More sharing options...
jaapv Posted July 18, 2011 Share #9 Posted July 18, 2011 Actually a minidrop of acetone is recommended, and first try to turn clockwise and then unscrew. Link to post Share on other sites More sharing options...
marknorton Posted July 19, 2011 Share #10 Posted July 19, 2011 The screws may or may not have locking compound but Job #1 is to get a screwdriver which allows the torque to be applied across the entire diameter of the screwhead. Judging by the current state of the heads, someone has used too small a screwdriver in the past. You do not need a grinder, much too aggressive, just use a fine metal file. Take your time, do it right. Link to post Share on other sites More sharing options...
johnloumiles Posted July 19, 2011 Author Share #11 Posted July 19, 2011 I'm going to the hardware store in the morning to pick up a file along with some acetone. I have a soldering iron and WD40 if need but I hope to take these off as naturally as possible. Once I do get the back off I will be careful to document how the lens come apart. As I stated earlier the haze is on the back element only. I have a variety of lens cleaners but will they work? I've never dealt with haze so I'm not sure how viscous or hard it is. You can see it in the picture below along with a stray hair that sticks straight out into the lens. How that ever got in there is a mystery. Welcome, dear visitor! As registered member you'd see an image here… Simply register for free here – We are always happy to welcome new members! Link to post Share on other sites Simply register for free here – We are always happy to welcome new members! ' data-webShareUrl='https://www.l-camera-forum.com/topic/157227-taking-apart-screw-mount-lens/?do=findComment&comment=1738706'>More sharing options...
250swb Posted July 19, 2011 Share #12 Posted July 19, 2011 Once I do get the back off I will be careful to document how the lens come apart. As I stated earlier the haze is on the back element only. I have a variety of lens cleaners but will they work? I've never dealt with haze so I'm not sure how viscous or hard it is. To be brutally honest John its the Rangefinder Forum that is awash with boffins that take lenses apart and clean them out. I recommend searching there on haze and you will almost certainly find a thread with a real camera repair guy with a DIY tip or two. Don't limit yourself to just the Leica forums on RFF, Russian lenses seem to be taken apart more than most. Steve Link to post Share on other sites More sharing options...
johnloumiles Posted July 19, 2011 Author Share #13 Posted July 19, 2011 Mission accomplished. I was able to remove the screw after filing dow both the screwdriver as well as the grove in the screws which was incredibly shallow. After that is was easy. Simply unscrewed a connecter ring (bottom left of group picture) then unscrewed the back element which had the haze. Cleaned thoroughly and put it back together, again the hardest part putting the screws back in. It seemed reminiscent of a Summicron in terms of the element unscrewing from the housing except in this case a few more steps were involved. The lens still has a good deal of surface scratches but they do not affect the photo anywhere close if at all next to the haze. The haze was actually pleasing if you shot late in the day in the direction of the sun. The pictures had a nice dreamy quality to them, but for the other 70% of the time it looked terrible, especially at night. Sorry I do not have a direct before and after but here is a quick snap of the after. Thanks for your help and I think I'm ready to start cleaning your vintage lenses, just send em over;) Welcome, dear visitor! As registered member you'd see an image here… Simply register for free here – We are always happy to welcome new members! Link to post Share on other sites Simply register for free here – We are always happy to welcome new members! ' data-webShareUrl='https://www.l-camera-forum.com/topic/157227-taking-apart-screw-mount-lens/?do=findComment&comment=1739340'>More sharing options...
Washington Posted July 20, 2011 Share #14 Posted July 20, 2011 Good for you!!! Link to post Share on other sites More sharing options...
250swb Posted July 20, 2011 Share #15 Posted July 20, 2011 Yes well done, I like to see people having a go at things like this:) Steve Link to post Share on other sites More sharing options...
johnloumiles Posted July 20, 2011 Author Share #16 Posted July 20, 2011 Thank you very much! I enjoyed it quite a bit. Getting all the feedback helped alot. Link to post Share on other sites More sharing options...
Xmas Posted July 20, 2011 Share #17 Posted July 20, 2011 Actually a minidrop of acetone is recommended, and first try to turn clockwise and then unscrew. Confirmed, but... When assembling do not use anything on threads, instead flash a layer of nail laquer across the heads of the done up tight screws, and wipe of any proud residure with rag dipped in acetone. The lens rings do not need to be too tight, I rarely dab nail varnish on a ring... pick a lurid color so you can detect it has been sealed, only use a dab. And one never uses WD40 near a camera, it is too corrosive and will creep. All the early Canon LTM lenses have a tendance to fog, this can etch the glass so needs removing immediately you detect it and it can recurr... inspect regular, some early Leitz lenses are similar... Noel Link to post Share on other sites More sharing options...
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