thighslapper Posted February 5, 2014 Share #21  Posted February 5, 2014 Advertisement (gone after registration) Don't worry......  Mine's identical  seems to be there for a reason..... 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/221513-metal-part-scratchedpeeled-off-is-this-normal/?do=findComment&comment=2526352'>More sharing options...
Advertisement Posted February 5, 2014 Posted February 5, 2014 Hi thighslapper, Take a look here Metal part scratched/peeled off, is this normal?. I'm sure you'll find what you were looking for!
250swb Posted February 5, 2014 Share #22  Posted February 5, 2014 There is a cutout 180 degrees opposite, but I cannot see it well. I does look dark though.  Yes, so your lens isn't missing anything, no metal has chipped off, it is supposed to be like that. Often the cutout is blackened but maybe some of the black came off when you had it repaired. The finish of the brass helicoid can often look crude.  Steve Link to post Share on other sites More sharing options...
StephenPatterson Posted February 5, 2014 Share #23 Â Posted February 5, 2014 It certainly appears as though the OPs lens is rough compared to the second example but I hope it's normal and there are no pieces floating around. Link to post Share on other sites More sharing options...
earleygallery Posted February 5, 2014 Share #24 Â Posted February 5, 2014 Don't worry, it's precision hand made German engineering. Â If it was finished in a neat 'smooth' manner that would be a sign of cheapness, rather like you'll find on Japanese made equipment! Link to post Share on other sites More sharing options...
Universalb50 Posted February 5, 2014 Share #25 Â Posted February 5, 2014 I'd like to get one of those Summicron 75mm, but am now confused. Is that "finding" a normal characteristic of that type lens? Link to post Share on other sites More sharing options...
BrianUK Posted February 5, 2014 Share #26 Â Posted February 5, 2014 As ugly as it looks, that 'chunk' missing is normal. ... Â Eh? Â To my eye it doesn't look at all 'machined', rather some sort of metal tear/shear or defect in the brass that has failed during manufacture. Â mirekti, have you emailed copies of these photos to Leica for a comment? Link to post Share on other sites More sharing options...
mirekti Posted February 5, 2014 Author Share #27 Â Posted February 5, 2014 Advertisement (gone after registration) mirekti, have you emailed copies of these photos to Leica for a comment? Â I did an hour ago, but if others have the same "feature", not sure there'll be much to discuss. Link to post Share on other sites More sharing options...
thighslapper Posted February 5, 2014 Share #28 Â Posted February 5, 2014 finish is pretty crappy on mine. Â it's a rather crudely machined out slot in the brass barrel .... and the blacking looks like it was there before to mark something and has been part machined away. Â There is a similar chunk chopped out on the MATE, 50/2.8. 35/2 and 24/2.8 ..... but it never rises to become noticeable as in the 75/2 .... and is a bit neater ........ Link to post Share on other sites More sharing options...
LocalHero1953 Posted February 5, 2014 Share #29 Â Posted February 5, 2014 I have a similar cut out. The brass/black colouring within the cutout is neat/geometrical. With no knowledge of the manufacturing process it looks like the helicoid is brazed to an inner black cylinder, with the brass colouration being brass paint used to mask the brazing. Could be the brass paint is peeling off in the OP's example. Just speculation. Link to post Share on other sites More sharing options...
Bill W Posted February 5, 2014 Share #30 Â Posted February 5, 2014 My 75 Summicron does not have the same issue nor do any of my other lens. But is does not hurt to have it looked at if it bothers you. Link to post Share on other sites More sharing options...
250swb Posted February 6, 2014 Share #31 Â Posted February 6, 2014 My 75 Summicron does not have the same issue nor do any of my other lens. But is does not hurt to have it looked at if it bothers you. Â But your lens will have the same slots machined into the helicoid so what can the 'issue' be? Its just that a bit of blacking has come off and the photo is exaggerating the jaggedness because the rebate is cut across the threads. Â The slots are there to stop grease being pumped out as the helicoid rotates and to stop air compressing and making the focus stiff. The blacking is likely to be a vestige of the manufacturing process and nothing to do with the final function of the lens. Â Steve Link to post Share on other sites More sharing options...
StephenPatterson Posted February 6, 2014 Share #32  Posted February 6, 2014 I still don't like the look of the area outlined with the red circle in Mirekti's photo from post #19. To me this doesn't just look as if the paint fell off, but I accept that macro photos can make a proverbial mountain out of a…well, you know.  Combined with the defective aperture ring and the incorrect 35mm paperwork included with the lens would be a red flag for me, and at least warrant an explanation from Leica or the dealer. Link to post Share on other sites More sharing options...
Bill W Posted February 6, 2014 Share #33  Posted February 6, 2014 But your lens will have the same slots machined into the helicoid so what can the 'issue' be? Its just that a bit of blacking has come off and the photo is exaggerating the jaggedness because the rebate is cut across the threads.  The slots are there to stop grease being pumped out as the helicoid rotates and to stop air compressing and making the focus stiff. The blacking is likely to be a vestige of the manufacturing process and nothing to do with the final function of the lens.  Steve There is a slot on the opposite side of where others have an issue. But my lens helicoid looks nothing like the OP's 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/221513-metal-part-scratchedpeeled-off-is-this-normal/?do=findComment&comment=2526926'>More sharing options...
Erik Gunst Lund Posted February 6, 2014 Share #34  Posted February 6, 2014 ...The slots are there to stop grease being pumped out as the helicoid rotates and to stop air compressing and making the focus stiff....Steve  Can I ask where you have this information from? Thanks in advance.  I have never heard of or seen such a slot in the threads of any lens helicoil.  In almost all lenses there are slots for the guides to prevent rotation. They also provide ventilation.  Any thread with a slot will work as a Threading Tap scraping off and collecting the grease, eventually removing all of the grease.  So very interesting... Link to post Share on other sites More sharing options...
wattsy Posted February 6, 2014 Share #35  Posted February 6, 2014 But my lens helicoid looks nothing like the OP's  What about if you move the focus to around 1.5m? You won't see anything with the focus racked out to infinity. Link to post Share on other sites More sharing options...
250swb Posted February 6, 2014 Share #36  Posted February 6, 2014 There is a slot on the opposite side of where others have an issue. But my lens helicoid looks nothing like the OP's  Although it is out of focus I can see one of the slots on your lens in the first photo.  Steve Link to post Share on other sites More sharing options...
Guest Ansel_Adams Posted February 6, 2014 Share #37 Â Posted February 6, 2014 This is perfectly normal. No need to worry. The slot is there for a reason (to house a part of the lens assembly) Link to post Share on other sites More sharing options...
Bill W Posted February 6, 2014 Share #38 Â Posted February 6, 2014 What about if you move the focus to around 1.5m? You won't see anything with the focus racked out to infinity. No, it looks the same as you see in my first photo. Link to post Share on other sites More sharing options...
Bill W Posted February 6, 2014 Share #39  Posted February 6, 2014 Although it is out of focus I can see one of the slots on your lens in the first photo. Steve I have no clue what "slot" you are talking about. The only "slot" is in the second photo. Link to post Share on other sites More sharing options...
mirekti Posted February 6, 2014 Author Share #40  Posted February 6, 2014 There is a slot on the opposite side of where others have an issue. But my lens helicoid looks nothing like the OP's   It might be you have similar blackening, but it is placed somewhere behind the silver mount part when you pull the helicoid out. Mine just happen to be right in the most visible part of it. Does this sound like plausible assumption? Link to post Share on other sites More sharing options...
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