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Novoflex makes the EOS-RETRO lens reversal adapter that, unlike other adapters, has a second ring that is attached to the EF mount side of the reversed lens, and electrically connects it to the body's EF mount. Thus, it maintains full controlability of the reversed lens.

This is a slick solution for macro photography. However, at 300 EURO ($540 here), this is also an extremely expensive one.

Is there a cheaper alternative to this kind of device?

Note that I am aware of the multiple Macro solutions. I am interested in this specific configuration.

UPDATE: also, I wonder, will the AF work correctly, or reversed? With phase detect AF the camera knows if you are shorter or longer than the exact focus and activates the AF motors accordingly. But here, the lens is reversed, so the feedback loop is actually a positive feedback. Am I right?

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You will not normally be using AF in a macro setting anyway, so that is a moot point.

The critical bit with EF objectives is that the aperture is electronically controlled, so unless your adapter supplies power and the electronic stop-down command from the camera you will be shooting wide open always which is not a good thing. Dare I suggest using a lens from Nikon or Olympus or something, an older one with an aperture ring, instead of a Canon one? That way you don't need the electronic connection and can use a much cheaper adapter setup. You can get a lot of lens for three hundred euro! Heck, you could get an old manual-focus Canon lens, they go for a song because they are not compatible with any current DSLR. I don't really see the point of the Novoflex (at its price point) unless it would be to use something very exotic and very Canon-specific like an 85L reversed.

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  • Why not use AF? This is certainly one advantage of using, for example, rings with contacts over simple rings. – ysap Jul 3 '11 at 14:58
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    Well, AF is rarely all that useful in macro photography. Macro is more the realm of the heavy-tripod, focus-rail approach :) Google it. Suffice to say that the effective max aperture of a nominal f/2.8 macro lens is inevitably in the region of f/5.6-f/8 or thereabouts at 1:1 magnification, which makes autofocus difficult at best. – Staale S Jul 3 '11 at 17:26
  • 1. If you want to shoot live insects outdoors, you do not necessarily want a fixed setup. 2. I never had problems focusing with my lenses at f/5.6-f/8. That said, I never had the chance to use AF for macro photography, so I can't testify on its effectiveness. – ysap Jul 3 '11 at 17:30
  • Staale S, what's so special about the EF 85L reversed? – ysap Jul 3 '11 at 17:32
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    You misunderstand I think. The question is: Why would you want to reverse an EF lens in the first place, instead of a Nikkor (for example)? Reversing EFs is expensive, reversing anything else is cheap. – Staale S Jul 4 '11 at 6:47
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There is the self built alternative shown in this incredible video - I guess considering the price of a cheap kit lens it might be worth go

It basically involves taking apart the lens and using ide cable to make the connection

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  • Absolutely fantastic DIY. You have to be either very brave or very stupid to go through this (OK, very rich may work too...). I am definitely not brave, so I may get stupid enough one day for trying this... – ysap Apr 2 '12 at 13:32
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If the auto focus works at all, despite the changed characteristics of the lens, it will work correctly.

Reversing the lens doesn't change how the optics work. Changing the distance between two lens elements still has the same effect when you look through the lens from the other end.

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  • Guffa, what you say makes sense, but if you have equations to back it up I'll be happy to learn. But, there is another way of seeing it - Since the focus-plane to subject-distance is constant, focusing is determined by changing the lens position. If, for a given configuration, the image is in front of the sensor, then the lens should move backwards. But in the reversed lens, the control will actually make it move towards the subject (which is backwards in the lens' reference frame), thus increasing the lens-sensor distance and the focus error. – ysap Jul 3 '11 at 14:56

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