reversing a 50mm

[toasty]

Hi,

can anyone advise me whether it is a good idea to reverse my EF 50mm F1.4 on a 28-70 F2.8? The 28-70 has a 77mm thread while the 50mm has a 58mm thread (I think). Can I buy a threaded ring to join these two lenses together? Does CP sell these things?

I also have a 35mm F2.5 nikkor lens (For my nikonos V). Dunno the thread diameter. Anyone know if would it be better for me to reverse that one instead?

TIA.

 

[Sgt. Pepper]

I would choose reversing the 50mm 1.4 for 2 reasons:
1) It wont give too high magnification
2) Less vignette problem as it has 1.4 widest aperture

I suggest you test for vignette first: Set your 50mm to 1.4 aperture, focus to infinity. Then hold it (on reverse position) in front of your 28-70mm mounted on the cam. Zoom to 70mm, then see how bad is the vignette. I’m 100% sure it will vignette even you’re using DLSR with 1.6X crop factor.

Best way to lessen/remove the vignette is to mount an extension tube.

 

[toasty]

I would choose reversing the 50mm 1.4 for 2 reasons:
1) It wont give too high magnification
2) Less vignette problem as it has 1.4 widest aperture

I suggest you test for vignette first: Set your 50mm to 1.4 aperture, focus to infinity. Then hold it (on reverse position) in front of your 28-70mm mounted on the cam. Zoom to 70mm, then see how bad is the vignette. I’m 100% sure it will vignette even you’re using DLSR with 1.6X crop factor.

Best way to lessen/remove the vignette is to mount an extension tube.

I don't know if this is a stupid question, but I set the aperture for my 50mm lens using the camera, not by a knob or ring on the lens. How can I set it to maximum aperture when it is not connected to the camera?

Sorry, I've never done this before... and I don't have the lens in front of me to play with right now.

And also, can I assume that CP will have the appropriate rings to join these two lenses together? Or do people normally do some make-shift attachment gluing some rings together?

 

[Sgt. Pepper]

I don't know if this is a stupid question, but I set the aperture for my 50mm lens using the camera, not by a knob or ring on the lens. How can I set it to maximum aperture when it is not connected to the camera?

You have to mount it on the camera first to set the aperture to 1.4, then set the focus to infinity using MF, fire one shot.

And also, can I assume that CP will have the appropriate rings to join these two lenses together? Or do people normally do some make-shift attachment gluing some rings together?

The probability of having macro coupler with 55-77mm thread is not so good. I suggest you just make one, it's very easy. Use a reliable glue or plastic cement to join 2 stepup rings together.

You will need 55-Xmm and X-77mm stepup rings. Wherein X should equal or greater than 77mm.

 

[toasty]

You have to mount it on the camera first to set the aperture to 1.4, then set the focus to infinity using MF, fire one shot.




The probability of having macro coupler with 55-77mm thread is not so good. I suggest you just make one, it's very easy. Use a reliable glue or plastic cement to join 2 stepup rings together.

You will need 55-Xmm and X-77mm stepup rings. Wherein X should equal or greater than 77mm.

Thanks, your replies have been very helpful and informative, I'll give it a try this weekend.

 

[Helbreath]

when it is not connected to your camera....... it is always set to maximum aperture........

 

[Sgt. Pepper]

Thanks, your replies have been very helpful and informative, I'll give it a try this weekend.

No problem. Good luck, have fun!

 

[toasty]

when it is not connected to your camera....... it is always set to maximum aperture........

So does that mean if, for some reason, I want to set it to F4.0 off my camera, I cannot? Or does the technique Sgt Pepper described allow me to set the aperture off the camera?

 

[Helbreath]

if you wanna set it to F/4........ just adjust the aperture in your LCD to 4.0, then press and hold the DOF button, the aperture will step down to F/4. ANd while holding DOF button, press button and remove the lens.

If you want the lens to go back to F/1.4......just connect it to your camera......