dkCambridgeshire Posted October 6, 2014 Share #1 Posted October 6, 2014 (edited) Advertisement (gone after registration) Some months ago I purchased a 400mm f6.8 Telyt R lens 'head only' i.e. without the rear tube. I assumed that the 400mm head would fit the rear tube of my 560mm f6.8 Telyt R - but the rear tube's retaining ring would not fully screw onto 400mm head - thus there was approx 3mm 'fore & aft play' in join. Close examination of the threads did not reveal any defects or thread crossing. 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! 400mm head attached to the 560mm rear tube - retaining ring will not fully screw onto the 400mm lens head thus there is fore and aft play. 560mm head attached to its rear tube - note no threads visible Today a retired engineer friend, Ray M, examined the two lens heads' attachment threads and after measuring same discovered that each was same diameter but each had different thread pitches. The 560mm is 0.75mm pitch and the 400mm is 0.5mm pitch - hence the 560mm lens rear tube attachment ring will not fully screw onto the 400mm lens head. Ray suggested the easiest solution to take up the play would be to fit an aluminium spacer ring - and after calculating/measuring the required dimensions he machined same on his lathe. Aluminium spacer ring 'made to measure' to take up the fore and aft play Spacer ring almost in place on 560mm tube and 400mm head partly fitted before retaining ring screwed on 400mm lens head and 560mm retaining ring in place before securing with the retaining ring. The slot in the 400mm lens does not fully cover the grub screw when the spacer is fitted but the slot does grip the top of the grub screw sufficiently to enable correct alignment. Cont'd … Edited October 6, 2014 by dkpeterborough Quote Link to post Share on other sites Simply register for free here – We are always happy to welcome new members! 400mm head attached to the 560mm rear tube - retaining ring will not fully screw onto the 400mm lens head thus there is fore and aft play. 560mm head attached to its rear tube - note no threads visible Today a retired engineer friend, Ray M, examined the two lens heads' attachment threads and after measuring same discovered that each was same diameter but each had different thread pitches. The 560mm is 0.75mm pitch and the 400mm is 0.5mm pitch - hence the 560mm lens rear tube attachment ring will not fully screw onto the 400mm lens head. Ray suggested the easiest solution to take up the play would be to fit an aluminium spacer ring - and after calculating/measuring the required dimensions he machined same on his lathe. Aluminium spacer ring 'made to measure' to take up the fore and aft play Spacer ring almost in place on 560mm tube and 400mm head partly fitted before retaining ring screwed on 400mm lens head and 560mm retaining ring in place before securing with the retaining ring. The slot in the 400mm lens does not fully cover the grub screw when the spacer is fitted but the slot does grip the top of the grub screw sufficiently to enable correct alignment. Cont'd … ' data-webShareUrl='https://www.l-camera-forum.com/topic/235117-400mm-560mm-68-telyt-r-lens-anomaly/?do=findComment&comment=2684558'>More sharing options...
Advertisement Posted October 6, 2014 Posted October 6, 2014 Hi dkCambridgeshire, Take a look here 400mm & 560mm 6.8 Telyt R lens anomaly. I'm sure you'll find what you were looking for!
dkCambridgeshire Posted October 6, 2014 Author Share #2 Posted October 6, 2014 (edited) Continuation … After securing the retaining ring, thread is still visible as in picture 1 above - but the fore and aft play has been taken up by the spacer 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! Proof of the pudding is in whether the lens will focus to infinity. A 1.4x APO extender was attached to the lens and the combination was fitted to my R9/DMR to photograph a dove on a TV aerial approx 75 metres distant R9/DMR & Telyt-R 400mm f6.8; with 1.37 crop factor and 1.4x extender affective focal length = 767mm … the original image has been further cropped in PP Taken 'handheld' in poor light but so far so good and now seem to have a usable 400mm Telyt R lens. The 400mm lens head cost £70 I'd be interested to find out if anyone has a set of 400mm and 560mm Telyt R lens heads which share a common rear tube. I was under the impression that at one time such a kit of two heads and one rear tube was available - in which case each lens head would have the same thread pitch - unlike my examples. Best wishes dunk N.B. … all apparatus pics taken with Leica C compact … JPEGS with no PP … the 'C' is a super pocketable notebook camera. Edited October 6, 2014 by dkpeterborough typo 2 Quote Link to post Share on other sites Simply register for free here – We are always happy to welcome new members! Proof of the pudding is in whether the lens will focus to infinity. A 1.4x APO extender was attached to the lens and the combination was fitted to my R9/DMR to photograph a dove on a TV aerial approx 75 metres distant R9/DMR & Telyt-R 400mm f6.8; with 1.37 crop factor and 1.4x extender affective focal length = 767mm … the original image has been further cropped in PP Taken 'handheld' in poor light but so far so good and now seem to have a usable 400mm Telyt R lens. The 400mm lens head cost £70 I'd be interested to find out if anyone has a set of 400mm and 560mm Telyt R lens heads which share a common rear tube. I was under the impression that at one time such a kit of two heads and one rear tube was available - in which case each lens head would have the same thread pitch - unlike my examples. Best wishes dunk N.B. … all apparatus pics taken with Leica C compact … JPEGS with no PP … the 'C' is a super pocketable notebook camera. ' data-webShareUrl='https://www.l-camera-forum.com/topic/235117-400mm-560mm-68-telyt-r-lens-anomaly/?do=findComment&comment=2684583'>More sharing options...
k-hawinkler Posted October 6, 2014 Share #3 Posted October 6, 2014 Thanks Dunk. Could you also please show a photo showing the entire lenses? TIA. Quote Link to post Share on other sites More sharing options...
dkCambridgeshire Posted October 6, 2014 Author Share #4 Posted October 6, 2014 Thanks Dunk. Could you also please show a photo showing the entire lenses? TIA. Unfortunately there is not sufficient room in my den to take decent pics of the whole lens assemblies … but will try and take photographs outside later this week … maybe as part of another planned project. However, photos of the entire lenses with 1.4x extender and R9/DMR will not illustrate the attachment anomaly. Best wishes dunk Quote Link to post Share on other sites More sharing options...
k-hawinkler Posted October 6, 2014 Share #5 Posted October 6, 2014 I understand. I just wanted to make sure I had the correct lenses in mind. Are your lenses the ones with a trombone like focusing mechanism? If true, good. If false, too bad. I have the 400 and 560 mm f/6.8 Telyts. One with an R and one with an V end mounting piece. The end pieces can be swapped and fit perfectly. A little pin fits into a short notch to keep the tubes aligned. Both Telyts are shown here. http://www.l-camera-forum.com/leica-forum/leica-collectors-historica/254586-telyt-400-560-mm-f-6-a.html 560/6.8 400/6.8 Quote Link to post Share on other sites More sharing options...
dkCambridgeshire Posted October 6, 2014 Author Share #6 Posted October 6, 2014 (edited) Yes mine are the trombone action f6.8 Telyt R lenses and the grub screw mentioned in my previous post is the alignment 'pin'. Unfortunately I have mislaid my 2x APO extender which wish to try with both lenses. The regular non-APO Leitz 2x extender works very well with the 560mm Telyt on a cropped digital format … especially 4/3 format. Some decry the original Leitz 2x Extender R but it can be a bargain buy (as little as £50) when used with a cropped format. My first 560mm Telyt R was the f5.6 version - but it was too unwieldy and heavy for regular use so it was sold. I regret parting with it because the wider aperture would be useful … and now I have sturdier tripods (Berlebach and Linhof) which are more capable of supporting heavier lenses. Best wishes dunk Edited October 6, 2014 by dkpeterborough Quote Link to post Share on other sites More sharing options...
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