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Is it possible to use a teleconverter and speedbooster with M50?

Started Jun 17, 2021 | Questions thread
Larry Rexley Senior Member • Posts: 1,238
Re: Is it possible to use a teleconverter and speedbooster with M50?
1

mcsk wrote:

I'm curious - will the modified 55-250 mount onto the speedbooster & how bad is the vignetting if it does?

The EF-S 55-250 IS STM with the rear mount modified to fit on EF accessories works well on the Viltrox EF - EOS M2 speed booster. There is some vignetting in the corners of the frame, but if you crop the frame to 16:9 or 4:3, you'd be cropping off almost all the vignetted parts.

Samples below with lens set at 55mm and 250mm using the speed booster. Samples were at small apertures which show less vignetting than large apertures, but the lens is fairly sharp at all apertures and focal lengths with the booster.

Note: All corrections including digital lens optimizer at 50% was applied in DPP 4 to both images. For the 55mm shot, the distortion correction corrected significant barrel distortion and 'pushed' the corners farther out, helping to hide the vignetting.

Canon M6ii, Canon EF-S 55-250mm IS STM on Viltrox 0.71x EF - EOS M2 speed booster, lens set at f11 and 55mm (actual f8, 39mm)

Canon M6ii, Canon EF-S 55-250mm IS STM on Viltrox 0.71x EF - EOS M2 speed booster, lens set at f16 and 250mm (actual f11, 177mm)

 Larry Rexley's gear list:Larry Rexley's gear list
Canon EOS M6 II Canon EOS M200 Canon EF-M 18-55mm f/3.5-5.6 IS STM Canon EF-M 22mm f/2 STM Canon EF-M 11-22mm f/4-5.6 IS STM +21 more
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