Using a Reversed Lens with a 5DsR

[Phil3921]

According to Canon, if a lens does not communicate with the camera.  The camera will not shoot.  That rules out a treasure trove of fabulous optics available, like a reversed lens or the Mitutoyo microscope objectives, reversed enlarger lenses, etc...  Anybody aware of a hack???

[Tronhard]

Hi Phil and welcome to the forum:

I have used a  reversing ring on several cameras, but the 'trick' is that you have to do everything manually - that is focus, exposure etc., and you are liable to be focusing with the aperture wide open - which is rather challenging for macro work. The point is that a reversing ring attaches to the front of the lens, where there are absolutely no contacts to communicate between the camera an lens for focus, aperture control. So, shoot in M mode any autofocus features turned off, focus manually and set your exposure by varying aperture, ISO and shutter speed manually.

Given that for the kind of shot you are referring to, the subject is unlikely to move much forwards and away, this can work but the results are not really worth the effort.  Be aware that the depth of field is usually miniscule with a reversed lens compared to the alternative options.

That said, a proper macro lens is going to be much easier to use and will deliver far better results.  You can get extension tubes to extend the effective FL, and some allow significant control over the lens - some not so much.

The best solution is a dedicated macro lens which offers full control, along with optics designed for that  purpose.  This is a perfect example of where putting the money into the glass is more important than the camera body itself.  For Canon, if you are using an APS-C body, the EF- 60mm f/2.8 macro lens is cheap and good, rendering a Field of View equivalent to 96mm.  The EF 100mm f/2.8 macro is a similar optic for FF, but on a crop body will render a FoV of about 160mm.

The 5DsR is a great camera, however with its 52MP sensor and its cancelled low-pass filter, it will show any flaws in technology and technique.  I have one and love it.

[Waddizzle]

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@Phil3921 wrote:

According to Canon, if a lens does not communicate with the camera.  The camera will not shoot.  That rules out a treasure trove of fabulous optics available, like a reversed lens or the Mitutoyo microscope objectives, reversed enlarger lenses, etc...  Anybody aware of a hack???

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I do not know where you heard that assertion, but that is a false statement.  Canon DSLR bodies can work with fully manual lenses. Always have.  

However, the default behavior for MILC is to not fire the shutter with lenses that do not communicate with the camera.  Once you change a menu setting, the MILC camera will fire the shutter with lenses that do not communicate with the camera.

[Phil3921]

Great!  What is the menu setting I must change???

[Lotus7]

Menu, Settings (wrench #4), Custom Functions, Release shutter without lens.

With the dozens of simple adapters available, and using the "Release shutter without lens" setting there are literally thousands of manual lenses that can be used on Canon DSLRs and Mirrorless bodies.   I often use my old FD lenses and even one from a Canon 7S Rangfinder.  It's even possible to produce vintage pinhole images by literally "releasing the shutter without lens". 🙂

[Waddizzle]

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@Phil3921 wrote:

Great!  What is the menu setting I must change???

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Only MILCs have that setting.  It helps to protect the camera from damage when a lens is not mounted on the camera.

DSLRs like your 5Dsr do not have or need that setting.  Your DSLR should fire the shutter every time you press it because no auto focusing is taking place.