tag:blogger.com,1999:blog-4577546745078520453.post1081640159107969902..comments2024-03-28T00:16:56.038-04:00Comments on Lens Bubbles: Strange 1D Mark III Phenomena with Manual Focus LensesLens Bubblehttp://www.blogger.com/profile/06445561503570800312noreply@blogger.comBlogger6125tag:blogger.com,1999:blog-4577546745078520453.post-78873162856055034502015-04-09T00:04:46.125-04:002015-04-09T00:04:46.125-04:00Any recommendations for Canon M and Samsung NX1000...Any recommendations for Canon M and Samsung NX1000 mirrorless cameras. I have a 200mm and 50mm Rollei lenses. a Pentax 35-80mm and a Canon 75-200mm old zoom lens. Any issues with focusing to infinity?Anonymoushttps://www.blogger.com/profile/15160376031212658936noreply@blogger.comtag:blogger.com,1999:blog-4577546745078520453.post-70986481096607373022011-07-18T09:12:57.882-04:002011-07-18T09:12:57.882-04:00Thanks to everyone. Looks like the it's a mir...Thanks to everyone. Looks like the it's a mirror issue. I am disappointed this happens on a 1-series camera. All of my previous cameras, 1D, 1Ds, 1D II, 1D IIn were perfect and dead on with the split screen. This kinda re-enforces my feeling that Canon's quality control is going down hills.Lens Bubblehttps://www.blogger.com/profile/06445561503570800312noreply@blogger.comtag:blogger.com,1999:blog-4577546745078520453.post-20215733740715713782011-07-18T05:19:19.715-04:002011-07-18T05:19:19.715-04:00As I understand it the AF system is symetrical fro...As I understand it the AF system is symetrical from the viewfinder using the partially silvered region of the reflex mirror. Therefore its not surprising that you can have perfect AF performance while the focusing screen is slightly off. As other people mentioned it really seems to be a matter of shimming the screen until it is perfect.soulnibblerhttps://www.blogger.com/profile/11934209395781755291noreply@blogger.comtag:blogger.com,1999:blog-4577546745078520453.post-61647966577198776602011-07-17T05:48:49.845-04:002011-07-17T05:48:49.845-04:00I agree about the focus screen being the issue. Th...I agree about the focus screen being the issue. This is not part of the AF chain either IIRC. I used to tune that on film cameras (where one has access to the film plan + ground glass + a hand held microscope)<br /><br />I recommend using a good quality manual focus lens which you can tape down and determine how much its out. Then you know which way to shift the focus screen.obakesanhttps://www.blogger.com/profile/13743339737847465926noreply@blogger.comtag:blogger.com,1999:blog-4577546745078520453.post-64867084596829435462011-07-16T20:57:54.805-04:002011-07-16T20:57:54.805-04:00@Adam: Thanks for the information. I also suspect...@Adam: Thanks for the information. I also suspected it was the mirror, but it doesn't seem to affect auto focus. With auto focus lenses, when focus is achieved, the split lines do line up correctly. Very odd indeed.Lens Bubblehttps://www.blogger.com/profile/06445561503570800312noreply@blogger.comtag:blogger.com,1999:blog-4577546745078520453.post-70446621785274715562011-07-16T08:38:52.450-04:002011-07-16T08:38:52.450-04:00It's most likely an incorrectly shimmed focus ...It's most likely an incorrectly shimmed focus screen. Simply put the viewfinder focus is slightly off from the sensor focus. The amount should shift with differing lenses as focal length and depth of focus vary (the later is the sensor side equivalent of depth of field and it changes with different lens designs).<br /><br />This is unusual on a 1 Series body as Canon calibrates this at the factory. 5D's are notorious for the problem though.Anonymousnoreply@blogger.com