swatch Posted July 28, 2020 Share #1 Posted July 28, 2020 Advertisement (gone after registration) Hello to everyone, May I ask for your advice on Summicron 35 asph mark 2 with back focus ( close distance at about 1 to 1.5 meter ) to be sent for calibration together with my M9. My M9 don't have focus problems with other lenses but only with Summicron 35 asph mark 2 therefore I am wondering the back focus being with my copy of the lens or common phenomenon of this lens. My aim is to achieve spot on focus for any distance at f stop from 2.0 to 8 with this combo. Would calibration being a solution? Thanks Link to post Share on other sites More sharing options...
Advertisement Posted July 28, 2020 Posted July 28, 2020 Hi swatch, Take a look here need advice on Summicron 35 asph mark 2 with back focus. I'm sure you'll find what you were looking for!
lct Posted July 28, 2020 Share #2 Posted July 28, 2020 If it happens only at 1 to 1.5 meter i would rather think of a rangefinder miscalibration issue. My experience is limited to the 35/2 asph v1 though. 1 Link to post Share on other sites More sharing options...
convexferret Posted July 28, 2020 Share #3 Posted July 28, 2020 I have a 35/2 ASPH that back focuses and another that's perfect. No idea why. The offender will be off to the mothership sometime soon (for 6-bit-coding too). If your camera seems fins with all lenses except one then it's reasonable to suspect the lens. And I have seen lenses that are worse over one particular range. Link to post Share on other sites More sharing options...
lct Posted July 31, 2020 Share #4 Posted July 31, 2020 On 7/28/2020 at 2:04 PM, convexferret said: I have a 35/2 ASPH that back focuses and another that's perfect. No idea why. One is not calibrated for digital i suspect. Should be done with 6-bit coding if Leica does the job. Link to post Share on other sites More sharing options...
convexferret Posted July 31, 2020 Share #5 Posted July 31, 2020 1 hour ago, lct said: One is not calibrated for digital i suspect. Should be done with 6-bit coding if Leica does the job. This whole "calibrated for digital" thing is starting to get on my nerves. The lens that's perfect is from 1999, the back-focussing lens is much newer and is off by miles. Another 50mm lens that I have that's off by a long way is from 2012. Link to post Share on other sites More sharing options...
lct Posted July 31, 2020 Share #6 Posted July 31, 2020 Just now, convexferret said: This whole "calibrated for digital" thing is starting to get on my nerves. The lens that's perfect is from 1999, the back-focussing lens is much newer and is off by miles. Then you were lucky on the early sample and not of the later i guess... Two of my film lenses (90/2 v3, 90/2.8 v2) had focusing issues on digital and were both fixed when i had them coded by Leica. Link to post Share on other sites More sharing options...
Jeff S Posted July 31, 2020 Share #7 Posted July 31, 2020 Advertisement (gone after registration) 5 minutes ago, convexferret said: This whole "calibrated for digital" thing is starting to get on my nerves. The lens that's perfect is from 1999, the back-focussing lens is much newer and is off by miles. Another 50mm lens that I have that's off by a long way is from 2012. No matter the cause or date, it’s still worthwhile IMO to have the lenses adjusted if possible by Leica or a reliable third party technician. Here in the US, DAG does this routinely. Jeff Link to post Share on other sites More sharing options...
convexferret Posted July 31, 2020 Share #8 Posted July 31, 2020 7 minutes ago, Jeff S said: No matter the cause or date, it’s still worthwhile IMO to have the lenses adjusted if possible by Leica or a reliable third party technician. Here in the US, DAG does this routinely. Jeff At the moment both are unusable so they'll be off to Leica next week. Link to post Share on other sites More sharing options...
Jeff S Posted July 31, 2020 Share #9 Posted July 31, 2020 1 minute ago, convexferret said: At the moment both are unusable so they'll be off to Leica next week. And they use expensive gear to adjust lenses and cameras to close (digital) tolerances. 😊 Jeff 1 Link to post Share on other sites More sharing options...
swatch Posted August 8, 2020 Author Share #10 Posted August 8, 2020 Thank you for those share their thoughts on this topic. Before my M9 need CLA service to be sent together with Summicron 35 asph II for dedicated alignment/adjustment, I will just be aware of back focus at close distance ( 1 meter and below ) to turn focusing ring further a bit clockwise by estimation. These two pictures may better explain the current situation. Both are focusing on her right eye f/2.8 at 0.8 meter. May you all have a nice weekend 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/311769-need-advice-on-summicron-35-asph-mark-2-with-back-focus/?do=findComment&comment=4023336'>More sharing options...
dkmoore Posted August 10, 2020 Share #11 Posted August 10, 2020 If you focused on the right eye, as you indicate above, I don’t see the back focus. Did you mean to say left eye? Also, I would not send the camera and lens in together unless the 35 Cron is your only lens. If you have multiple lenses/cameras you should send them to leica separately as needed if you have been able to identify which is the culprit. Link to post Share on other sites More sharing options...
jankap Posted August 10, 2020 Share #12 Posted August 10, 2020 The first picture is sharp on the left eye. The second on the nose (so both eyes). Link to post Share on other sites More sharing options...
Jean-Michel Posted August 10, 2020 Share #13 Posted August 10, 2020 Hi, Sending your camera and lens for calibration will result in SEPARATE calibrations of your camera's rangefinder, and of the lens. There is no such thing as calibrating a matched camera/lens set. If that were the case, you could only have one correctly adjusted camera-lens combination! The best you can do to check if you have a calibration issue is to correctly photograph a focus target. You can get a commercially available target or make your own such as the one from http://squit.co.uk/photo/focuschart.html. It is a bit time consuming, requires a tripod, proper lighting, checking the image at 100% in an application such as Lightroom. And, ideally, you need to do this with all of your lenses to determine if the issue is with the lens or rangefinder. Focusing on someone's eyes with a handheld camera to check calibration introduces way too many variables. 1 Link to post Share on other sites More sharing options...
swatch Posted August 13, 2020 Author Share #14 Posted August 13, 2020 Thank you for pointing out the situation/outcome of only one camera-lens combination should I send my M9 and Summicron 35 asph II for calibration together. I will think about it again when my M9 need CLA in the future. Thank you also for telling me a commercially available kit to check focus issue, it is good to know such DIY tool which I may try especially during COVID-19 staying at home. Cheers and wish everyone have a nice day. Link to post Share on other sites More sharing options...
Maarten Posted August 13, 2020 Share #15 Posted August 13, 2020 To check the calibration of your lenses I recommend to check infinity focus: do the range finder patches cover 100% at infinity on your camera? Use a remote tower as infinity object (it should be more than 1 mile away). I bet the lens giving you the back focus issues will be off on your camera at infinity. In that case the lens needs calibration. When infinity focus is obtained looking through the rangefinder, focus at close distance will be fixed as wel in 99% of the cases. At least this is my experience. Link to post Share on other sites More sharing options...
Jean-Michel Posted August 13, 2020 Share #16 Posted August 13, 2020 See Julian Thompson's post: The diagram and photo shows how to adjust the infinity setting on the rangefinder. You just need to get the proper Hex key for that. If your other lenses are OK at infinity, then you have an issue with the one lens. And you really need an object that is really far away, as Maarten writes, at least one mile or 1.5 km away, and ideally even further, and clear air between you and the object 2 Link to post Share on other sites More sharing options...
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