ralphh Posted July 16, 2016 Share #1 Â Posted July 16, 2016 Advertisement (gone after registration) Hi guys, Â Still a relative Leica noob, just wanted to check that things are normal, and ask a couple of questions. Â My lenses are much looser to focus when not mounted on my camera. Given that they're equally stiffer in both directions I presume this is not due to pushing the RF arm, but due to having to push and pull air. The design of the lenses looks like they'd push and pull air. Â When I've not used the camera for a couple of days, the lens will often initially be very very stiff then loosen up and is back to normal within 1/4 of the focus throw. It doesn't feel like the short, sudden release of stuck grease- it feels more like the slow spongy stiffness of stuck air. Â Is this all normal, and also, where does the air go through? Is it pulled in through the lens, the body or around the mount? Â Thx! Link to post Share on other sites More sharing options...
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TomB_tx Posted July 16, 2016 Share #2 Â Posted July 16, 2016 I find some lenses get stiffer to focus on my oldest M3, where the mount fit is also the tightest. I believe the tight mount must distort the body very slightly, adding friction. I believe a similar issue caused Leica to recall the early 21mm Super Elmar, when they made the body thicker. Link to post Share on other sites More sharing options...
jdlaing Posted July 17, 2016 Share #3 Â Posted July 17, 2016 When off the camera they are not moving the focus cam. Link to post Share on other sites More sharing options...
pico Posted July 17, 2016 Share #4 Â Posted July 17, 2016 When off the camera they are not moving the focus cam. Â The in-camera RF lever has almost no resistance. Link to post Share on other sites More sharing options...
jaapv Posted July 17, 2016 Share #5 Â Posted July 17, 2016 Pumping action is more a thing of big one-ring telezooms. The Canon 100-400 L was notorious for it. I do not think that the relatively small movement of RF lenses would make this an issue -I certainly have never heard my M hissing with escaping air. I think the explanation is that when you turn the focus ring off the camera you use the muscles of both hands, whilst on the camera it is just one, giving the impression that you need double the force. Link to post Share on other sites More sharing options...
ralphh Posted July 17, 2016 Author Share #6 Â Posted July 17, 2016 Definitely not the case jaapv, I'm still just using a fingertip of the focus tab, using the other hand to hold the lens still. It's definitely for the RF cam either. As I said, it's the same in both directions. If it was he RF it would be stiff towards infinity only. Â Edit: jaapv, just to double check your theory I've measured it, and the tab needs just over twice the force to move it when on the body. (130g vs. 60g). It's not unpleasantly stiff, just curious as to the cause. Â Also doesn't explain the initial stiffness, which does feel wrong. I'd blame the lens but exactly the same thing happens in my 50 and 90, though not the 28 2.8. In fact that feels the same (quite stiff) on or off camera, but it's newest and least used of my lenses and still has that initial stiffness Link to post Share on other sites More sharing options...
IWC Doppel Posted July 17, 2016 Share #7  Posted July 17, 2016 Advertisement (gone after registration) Strange I have my M9-P with 28 on at the moment, had a play, if anything it's smoother and lighter on. As I have an MM as well and after selling a bunch of lenses something like 7 left I am always swapping lenses around. As I was with friends last night I took a 35 off and popped the 28 on.  I have never noticed your phenomenon  Sounds to me like there might be some twist with the camera mount is it easy to mount the lens ? Link to post Share on other sites More sharing options...
jaapv Posted July 17, 2016 Share #8 Â Posted July 17, 2016 Definitely not the case jaapv, I'm still just using a fingertip of the focus tab, using the other hand to hold the lens still. It's definitely for the RF cam either. As I said, it's the same in both directions. If it was he RF it would be stiff towards infinity only. Â Edit: jaapv, just to double check your theory I've measured it, and the tab needs just over twice the force to move it when on the body. (130g vs. 60g). It's not unpleasantly stiff, just curious as to the cause. Â Also doesn't explain the initial stiffness, which does feel wrong. I'd blame the lens but exactly the same thing happens in my 50 and 90, though not the 28 2.8. In fact that feels the same (quite stiff) on or off camera, but it's newest and least used of my lenses and still has that initial stiffness In that case, try whether the torque on the screws holding the mount is approximately the same. I found that it varies wildly on most lenses. I loosened the screws on all my lenses and re-tightened all of them to 30 Ncm when a Summilux 75 went all wobbly after all its mount screws worked loose. Link to post Share on other sites More sharing options...
ralphh Posted July 17, 2016 Author Share #9 Â Posted July 17, 2016 Thanks, I'll give that a try. Can you buy torque screwdrivers? I don't think my car torque wrench is th right tool Link to post Share on other sites More sharing options...
ralphh Posted July 17, 2016 Author Share #10 Â Posted July 17, 2016 Strange I have my M9-P with 28 on at the moment, had a play, if anything it's smoother and lighter on. As I have an MM as well and after selling a bunch of lenses something like 7 left I am always swapping lenses around. As I was with friends last night I took a 35 off and popped the 28 on. I have never noticed your phenomenon Sounds to me like there might be some twist with the camera mount is it easy to mount the lens ? I don't have any Leica experience to compare it to, but they're very very stiff to mount compared to some like a canon or Nikon Link to post Share on other sites More sharing options...
jaapv Posted July 17, 2016 Share #11  Posted July 17, 2016 Thanks, I'll give that a try. Can you buy torque screwdrivers? I don't think my car torque wrench is th right tool Well, I don't think you will like to buy the one I used. It is a miniature torque wrench for dental implants and costs 680 Euros - plus VAT. Link to post Share on other sites More sharing options...
jaapv Posted July 17, 2016 Share #12 Â Posted July 17, 2016 I don't have any Leica experience to compare it to, but they're very very stiff to mount compared to some like a canon or Nikon They shouldn't be. Link to post Share on other sites More sharing options...
IWC Doppel Posted July 17, 2016 Share #13 Â Posted July 17, 2016 Ahh that sounds like the problem they should mount with a smooth twist and click when done. It feels precise and well engineered but not overly tight Link to post Share on other sites More sharing options...
ralphh Posted July 17, 2016 Author Share #14 Â Posted July 17, 2016 It feels overly tight to me, though the lenses are much less easy to grip than an DSLR lens obviously, but it doesn't feel 'nice'. I just kinda assumed that's how Leica was, but I did think 'yuck' when I first mounted a lens. It stars smooth but gets very tight just before it clicks. Â Oh dear, maybe buying a second hand M was a bad idea after all. It doesn't affect the images at all. Â My 50 was massively tight to start with, though it's loosened up a bit now. Â This doesn't sound like a cheap repair. Given it doesn't affect the images I think I'll probably just have to live with it. Eyeballing it, it doesn't look obviosly twisted, but the tolerances are likely so small I'd not be able to see it. I will try to get to a Leica store to have a play with a new and definaltely non-bent M so I know what I'm comparing to Link to post Share on other sites More sharing options...
IWC Doppel Posted July 17, 2016 Share #15 Â Posted July 17, 2016 You haven't said what camera and if new used or other ? Link to post Share on other sites More sharing options...
ralphh Posted July 17, 2016 Author Share #16 Â Posted July 17, 2016 Typ 240 second hand Link to post Share on other sites More sharing options...
IWC Doppel Posted July 17, 2016 Share #17 Â Posted July 17, 2016 Good idea to compare to a new or other used camera. Assuming it is in good condition it might be something that Leica might be sympathetic over if there is no obvious damage if a problem exists plus it's possible it has even repaired in the past and if so they should be sympathetic too Link to post Share on other sites More sharing options...
ralphh Posted July 17, 2016 Author Share #18 Â Posted July 17, 2016 Okie dokie. There's no serious marks on it (no brass) so I don't think it's been dropped or abused significantly. I'll play with a 240 in a shop and see if it's different. Link to post Share on other sites More sharing options...
jaapv Posted July 17, 2016 Share #19 Â Posted July 17, 2016 And if it is too tight ( and it certainly sounds as if it is ) send it to Will van Manen, and send the lenses too, to check calibration on the whole system -not expensive and good turnaround. Link to post Share on other sites More sharing options...
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