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DX on FX, a success, with a TC!

Started Sep 23, 2020 | Discussions thread
E Dinkla Senior Member • Posts: 2,613
Tested the Canon EF-s 55-250 IS STM + Kenko more
1

Done some handheld testing with my converted Minolta MD I 200mm 4.0 and the Canon 55-250 with and without the Kenko. On an A7RII camera. with Metabones IV adapter. I do not have more lenses of that length to compare with. I have good images made with the Minolta lens. https://www.dpreview.com/forums/post/59944050

The distance to that wall is a bit more than 80 meters / 27 feet. Handheld, IS either lens (Canon) or camera (Minolta).

Usable square image area 24x24mm of the 55-250 set at 250mm focal length compared with 200mm cropped to the same image content. No Kenko used here.

M 200mm 8.0 M 200mm 4.0 C 250mm 5.6

Near the center. Same view percentage in Capture One

Bottom right corner

Canon is much better in the center and somewhat in the corner. A 5.6 take with the Minolta was lost, but that lens gains little from 4.0 to 8.0 so it does not matter

I did not use the 200mm setting of the Canon as my interest is in getting as much information of a distant subject. Hence the square format too. I have used the Kenko with the Minolta MD I 200mm 4.0 before and it did not deliver. So that combination was skipped here.

Next I compared the Canon with (350mm) and without (250mm) the Kenko at the same wall/distance. The format is what the 350mm captured and a crop for that applied on the 250mm images. In theory the wide open shot with the Kenko should be at 8.0 but it either was 5.6 or 9.0 that I could select and get reported. Maybe the 5.6 shot is wide open or the 9.0 one, little difference between them.

250mm top row , 350mm bottom row,

Near the center, 400 and 300% view in Capture One

Near the right bottom edge , 400 and 300% view in Capture One.

I shot a church tower at 500 meters with the Kenko and that showed a good image but I am not happy with the Kenko results here. The Canon on its own is better than expected so I am not disappointed.

full frame 350mm

Have to test them both on that distance too.

Met vriendelijke groet, Ernst
No photographer's gear list is complete without the printer mentioned !

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