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05-12-2016, 12:55 PM   #16
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I have had some success with setting a manual focus macro lens to 2x the actual focal length (e.g. a bellows with 100mm Leica R macro).
Notwithstanding, one should probably not rely exclusively on SR when dealing the macro lenses.

Michael

05-12-2016, 12:58 PM   #17
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QuoteOriginally posted by MJSfoto1956 Quote
I have had some success with setting a manual focus macro lens to 2x the actual focal length (e.g. a bellows with 100mm Leica R macro).
Notwithstanding, one should probably not rely exclusively on SR when dealing the macro lenses.

Michael
Interesting. That bears out the OP's quick test concluding that a focal length setting of 100mm with his 50mm macro lens yielded the best results.
05-12-2016, 05:01 PM   #18
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As you did the experiment, you need to know what maginification you were shooting at--as the effective SR setting should be a function of magnification (m). If the lens has a maximum m=1, and you do the test at closest focus, then m=1. (Or for many older macro lenses maximum m = 1/2.) If not the lens may have m values on it. If not there, you could include a ruler in the frame.

If the lens extension acts as increasing FL, you would find the optimum SR setting to be: (Input FL) = (Lens FL) x (1 + m), and if you were doing your test at m=1, then 50 mm lens would be best at SR set to FL=100mm. If not this it still should be related to magnification.
05-13-2016, 09:00 AM - 1 Like   #19
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I spent a little time this afternoon trying to gauge the impact of SR on slower shutter speeds. Using F16 and speeds of 1/30th through to 1/8th and... no SR, FL set to 50mm, 100mm and 135mm. Total of 36 images (two of each shot) taken with my K-5.


My findings on this limited experiment, being unable to gauge the amount my hands shook, (though I did rest my elbows to steady myself) were this;


Setting the FL for 50mm with SR were slightly worse for shake than without SR. To my surprise!
Setting the FL for both 100mm and 135mm was an improvement over the 50mm FL, but I would probably plump for setting a 100mm FL based on this.


No mathematics or science involved in this decision and this result should not be taken seriously as it is limited and obviously amateurish. Some not very busy K3 and K1 owners (with better SR) and a Sigma 50mm macro might like to see if they get similar results or better still, shoot me down.


Now I'm off to play with it again, the sun is out and I can get plenty of shutter speed and probably do not need SR.


Added note, images taken at 1:1.


Oooh look, a teeny weeny spider, can't wait to show my wife, she hates them. Apologies for too many images here, I still cannot figure out how to delete them
.



Last edited by Skodadriver; 05-13-2016 at 09:14 AM. Reason: Added a note and an image.
05-13-2016, 09:08 AM   #20
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Very interesting - and thank you for posting your results. Even unscientific tests can be very useful. Thanks to @dms also for that explanation
05-13-2016, 10:53 AM - 1 Like   #21
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I also experimented with this last night but without comparison shots per say. Used my SMC DA 40 Limited on an A series type deglassed teleconverter. I was able to try 40mm and 75mm - 75mm seemed quite a bit better. This was at about 1:2 or slightly larger. I did so at 1/4s handheld (braced).

05-20-2016, 01:44 PM   #22
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Shake reduction at close distances is difficult to get right, you will notice that it is only recently that macro lenses with optical sr have come on to the market, and as far as I know, Canon and Nikon macro lenses still do not have it.
05-22-2016, 04:43 AM   #23
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I think you should use the 50mm setting for that!

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