dkCambridgeshire Posted July 19, 2016 Share #1 Posted July 19, 2016 Advertisement (gone after registration) Yesterday when using the SL 24-90mm lens with recently acquired Polaroid and Canon 77mm diameter achromatic close-up lenses ... http://www.l-camera-forum.com/topic/262292-sl-macro-adapters/?p=3080877 … I found the whole set-up rather too front heavy and unbalanced for efficient close-up composition. Thus today considered ordering the latest £139 Novoflex ASTAL SL tripod collar - but it's not yet available in the UK. In my astro telescope 'bits box' I have a pair of 90mm internal diameter, telescope / guide 'scope mounting rings bought secondhand for £5 in a WEX Norwich 'SALE'. The SL 24-90mm lens is approx. 85mm diameter - thus the telescope ring fits over the SL lens' rear but with 2.5mm clearance. Fitting a 2.5mm thickness shim will take up the clearance. The 'scope rings have regular ¼" tripod screw threads 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! To make the 2.5mm (ish) shim I cut a strip of Daler art card and covered both sides with strips of self adhesive, black, 'VELOURSFOLIE' ( a self adhesive matt black velvet fabric used for flocking / light baffling telescope tube interiors) . Three strips of Velour stuck onto the card were sufficient to provide the required 2.5mm (ish) thickness. The soft velour is 'kind' and will not scratch the SL lens . Fitting the trimmed shim into the mount/collar The finished shimmed collar mount on the SL lens Finished collar supporting lens and camera The modified 'scope mount is secure and works fine; when slightly loosened the lens/camera combination can be turned easily through 360º; Collar mounted onto ball head via regular ¼" tripod screw thread. Rear view of lens mounted on an ancient Benbo ball head. The Benbo head is not really large enough / smooth enough for efficient close-up photography composition - but was convenient to use it this afternoon. The shim's velour covering compresses when the clamping screw tightens the collar around the lens - thus no risk of being over-tightened Time to construct approx. 45 minutes. Total cost less than £10 . Now unlikely I'll need to buy the £139 Novoflex tripod collar. In practice I will be using a larger Arca Swiss ball head plus a Novoflex Castel focusing rack . Best wishes dunk EDIT: If anyone wishes to construct something similar it's at your own risk! If made a too tight fit, the ring might compress the rear lens group. The golden rule with telescope mounts, especially SCT OTAs is, " do not over-tighten the 'scope rings" Link to post Share on other sites Simply register for free here – We are always happy to welcome new members! To make the 2.5mm (ish) shim I cut a strip of Daler art card and covered both sides with strips of self adhesive, black, 'VELOURSFOLIE' ( a self adhesive matt black velvet fabric used for flocking / light baffling telescope tube interiors) . Three strips of Velour stuck onto the card were sufficient to provide the required 2.5mm (ish) thickness. The soft velour is 'kind' and will not scratch the SL lens . Fitting the trimmed shim into the mount/collar The finished shimmed collar mount on the SL lens Finished collar supporting lens and camera The modified 'scope mount is secure and works fine; when slightly loosened the lens/camera combination can be turned easily through 360º; Collar mounted onto ball head via regular ¼" tripod screw thread. Rear view of lens mounted on an ancient Benbo ball head. The Benbo head is not really large enough / smooth enough for efficient close-up photography composition - but was convenient to use it this afternoon. The shim's velour covering compresses when the clamping screw tightens the collar around the lens - thus no risk of being over-tightened Time to construct approx. 45 minutes. Total cost less than £10 . Now unlikely I'll need to buy the £139 Novoflex tripod collar. In practice I will be using a larger Arca Swiss ball head plus a Novoflex Castel focusing rack . Best wishes dunk EDIT: If anyone wishes to construct something similar it's at your own risk! If made a too tight fit, the ring might compress the rear lens group. The golden rule with telescope mounts, especially SCT OTAs is, " do not over-tighten the 'scope rings" ' data-webShareUrl='https://www.l-camera-forum.com/topic/262653-modifying-an-astro-telescope-ring-for-use-as-sl-lens-collar/?do=findComment&comment=3081334'>More sharing options...
Advertisement Posted July 19, 2016 Posted July 19, 2016 Hi dkCambridgeshire, Take a look here Modifying an astro telescope ring for use as SL lens collar. I'm sure you'll find what you were looking for!
mike_j Posted July 19, 2016 Share #2 Posted July 19, 2016 I am a great believer in the value of a bits and pieces box - this is an excellent example of the use of an item in the "might come in useful sometime" category. Well done Dunk. Link to post Share on other sites More sharing options...
dkCambridgeshire Posted July 20, 2016 Author Share #3 Posted July 20, 2016 Thank you Michael. Making a second collar using the other 'scope ring; it will have an Arca plate attached permanently. dunk Link to post Share on other sites More sharing options...
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