Question on reverse mounting a Canon 50mm f/1.4 lens

[Suddie1215]

Hi, I have a Canon 100mm f/2.8 macro lens and I would like to reverse mount a Canon 50 f/1.4. Is this possible when the 50 f/1.4 does not have a manual aperture ring?

And if it can be done, how do I get the aperture on to 50mm lens open?

[tonylong]

Originally Posted by Suddie1215

Hi, I have a Canon 100mm f/2.8 macro lens and I would like to reverse mount a Canon 50 f/1.4. Is this possible when the 50 f/1.4 does not have a manual aperture ring?

And if it can be done, how do I get the aperture on to 50mm lens open?

The second lens "stays" wide open unless you set it to a different aperture. You do this by mounting the lens, setting the aperture to what you want, then dismounting the lens while the camera/lens is still set to the needed aperture.

Beyond that, I really haven't messed with doing this, so others can chime in and add or totally correct anything bad I've said!

[LordV]

Just to add, with the lens mounted normally and the aperture set on the camera that you want, you have to press the DOF preview button and then dismount the lens whilst keeping the DOF preview button depressed.
Brian v.

[tonylong]

Originally Posted by LordV

Just to add, with the lens mounted normally and the aperture set on the camera that you want, you have to press the DOF preview button and then dismount the lens whilst keeping the DOF preview button depressed.
Brian v.

Ah, right, I knew I must have forgotten something! Thanks for chiming in!!!

[Suddie1215]

Thank you both for the tips. I tried reversing my 50mm on my macro lens yesterday and couldn't get it to work but now I see what I was doing incorrectly.

Another question, to focus I only need to rotate the focus ring for the non-reversed lens, right?

EDIT:

Here's the equipment I'm using: 1D Mk III camera, Canon 100mm f/2.8 macro lens, Canon 50mm f/1.4 lens, mounting ring.

Following the advice from LordV I first attached the 50mm directly to the camera and set the aperture to f/1.4. Then while holding down the DOF Preview button I removed the 50mm and attached the 100mm macro. I reversed the 50mm and screwed it on to the macro lens thread. But try as I might I can't get the combination to focus manually or by autofocus. Any advice greatly appreciated.

[LordV]

Originally Posted by Suddie1215

Thank you both for the tips. I tried reversing my 50mm on my macro lens yesterday and couldn't get it to work but now I see what I was doing incorrectly.

Another question, to focus I only need to rotate the focus ring for the non-reversed lens, right?

EDIT:

Here's the equipment I'm using: 1D Mk III camera, Canon 100mm f/2.8 macro lens, Canon 50mm f/1.4 lens, mounting ring.

Following the advice from LordV I first attached the 50mm directly to the camera and set the aperture to f/1.4. Then while holding down the DOF Preview button I removed the 50mm and attached the 100mm macro. I reversed the 50mm and screwed it on to the macro lens thread. But try as I might I can't get the combination to focus manually or by autofocus. Any advice greatly appreciated.

Hi - Sorry I assumed you were reversing the 50mm lens directly onto the body, if you are reversing it onto the front of the macro lens then leave the 50mm lens focused on infinity and the aperture wide open. Aperture and focus control is done using the main macro lens. Remember though the focus point will be fairly close to the front of the reversed lens.

Brian v.

[RobinH]

I am thinking about the same setup - reversing a 50mm 1.4 on a 100mm 2.8.

So would the aperture on the reversed 1.4 have any effect? Since in normal use it is quite soft at 1.4, would setting the aperture to 2.8 make sharper pictures when reversed? Or do you just lose some light?

[Suddie1215]

Got it working now. I mistakenly assumed that reversing the 50mm would increase the minimum working distance so I was moving the lenses away from the subject but as you pointed out "Remember though the focus point will be fairly close to the front of the reversed lens." Once I made the adjustment it works fine and I can now achieve 3:1 magnification. Thanks again for all your help, now I only have to find interesting things to shoot.

Originally Posted by LordV

Hi - Sorry I assumed you were reversing the 50mm lens directly onto the body, if you are reversing it onto the front of the macro lens then leave the 50mm lens focused on infinity and the aperture wide open. Aperture and focus control is done using the main macro lens. Remember though the focus point will be fairly close to the front of the reversed lens.

Brian v.

[LordV]

Originally Posted by RobinH

I am thinking about the same setup - reversing a 50mm 1.4 on a 100mm 2.8.

So would the aperture on the reversed 1.4 have any effect? Since in normal use it is quite soft at 1.4, would setting the aperture to 2.8 make sharper pictures when reversed? Or do you just lose some light?

Really not sure, I suspect you will have to suck it and see- starting off with it wide open and then perhaps trying a few set apertures down to say F2.8.
Brian v.

[adamsheehy]

Originally Posted by RobinH

I am thinking about the same setup - reversing a 50mm 1.4 on a 100mm 2.8.

So would the aperture on the reversed 1.4 have any effect? Since in normal use it is quite soft at 1.4, would setting the aperture to 2.8 make sharper pictures when reversed? Or do you just lose some light?

It will have an effect, but it's always been negligible compared to the trade off for me. The aperture on the 50mm will be constant when shooting, so you'll lose a ton of light that is typically much needed to even find the subject at times.

Originally Posted by Suddie1215

Once I made the adjustment it works fine and I can now achieve 3:1 magnification.

I could be wrong, but I think it's a 2:1 magnification with a 50mm stacked on a 100mm.