Estimated reading time: 07 minutes and a half. January/2015 - The EF Extender 2X III is a teleconverter that mounts between you camera and your EF compatible lens to effectively multiply its focal length by two. It does that simply enlarging 25% of the middle of your frame, discarding most of the light; thus reducing two stops of exposure (a f Forget using an extender on the 55-250, unless you don't mind to focus manually. Second, the 70-300 will give you better better results than a 55-250+extender. Third, I doubt if there are any extenders that fit EF-s lenses. Kind regards, Sandor. maarensv's gear list: Canon 6D Mark II Canon EOS R Olympus E-M5 III Canon EOS R7 Canon EF 100mm F2 Canon EOS 5D Mark II Canon EF 24mm f/1.4L II USM Canon EF 85mm F1.8 USM Canon EF 135mm F2L USM Canon EF 200mm f/2.8L II USM +4 more Canon EF 135mm F2L USM Canon Extender EF 1.4x III Canon Extender EF 2x III A few things may not work as you expect, however. First, you can’t use the extender with all your lenses. As of this writing, you can only use it with six Canon RF lenses: the RF100–500mm F4.5–7.1 L IS USM, the RF100–400mm F5.6–8 IS USM, the RF600mm F11 IS STM, the RF800mm F11 IS STM, the RF400mm F2.8 L IS, and the RF600mm F4 L IS. (2) the Canon 70-200 2.8 II + Canon Extender EF 2X III Obviously, buying the extender would be a lot cheaper and lighter than carrying around another heavy zoom. The Tamron would give me a little more reach, albeit the reviews say it's quite soft above 500mm. Forget hand holding it, use a tripod. Also because this is a 2X extender, you're losing a LOT of light. With my Canon 300mm 2.8, with the 2.0 mk III I'm now shooting at aperture of f/5.6. You're also losing a LOT of autofocus speeds. Canon is saying as much as 75%, but it didn't feel that high. I was pleasantly surprised. At 19m distance from the charts, the RF 2x performs far better on the 100-500mm than does the EF 2xTC on the 100-400mm II. The 100-500mm at 1000mm produced crisp lines, and gave 40% more resolution than the bare lens and about 20% more than the 100-500mm at 700mm. News Reviews Articles Buying Guides Sample Images Videos Cameras Lenses Phones Printers Showcase Forums Canon Extender EF 2x III Q&As. Announced Aug 26, 2010 Extender EF 1.4x III compatible with EF mount? in Camera Accessories 12-18-2023; 600/800MM lenses vs RF 2x Extender for Kenya Safari in EF & RF Lenses 12-06-2023; Extender EF 1.4x compatibility with Mount Adapter EF-EOS R in Camera Accessories 12-05-2023 Xgp75Bu.

canon extender ef 2x iii review