I use it on a Canon 70-200mm 2.8 II to the close range to reduce L IS USM to 60 cm. The image quality and resolution here is excellent (on a 70D). The magnification is this about 0.6x. The structure is ideal to fotogarfieren to eg butterflies. With the 500D, a Canon Extender 2x III and the Canon 70-200mm L IS USM II gives a macro lens with a magnification of more than 1: 1 (approximately 1.1x) and a minimum focusing distance of 60 cm. In this structure, the resolution of the images decreases slightly. But they are still very good. Of course, this structure with lens + lens + Extender can not compete with a Canon EF 180mm 3.5 L. But he is more versatile and cost (at least if you already have the lenses) no 1500th The autofocus works perfectly in both cases.
Pro: halving the minimum focusing distance of the lens (thus higher magnification) -high optical quality -no Lensflares -no chromatic aberration -Autofokus Works
Contraindications: -hard and thick (for technical reasons)
I'm very satisfied. As long as you are not a passionate macro photographer, the solution described above works very well. The losses are minimal.
I'd make up my mind at any time for this solution.
