The Canon EF 70-200mm f/2.8L USM is not a new lens, but still offers very good performance on both full-frame and APS-C DSLRs. Optical construction includes four UD (ultra low-dispersion) elements to correct chromatic aberrations, and it is compatible with Canon's Extender EF 1.4x II and 2x II teleconverters. Canon EOS R6 + EF 100-400mm f/4.5-5.6L IS II USM lens + EF 2x III Extender. . I wanted to spend more time with the EF 2x III Extender on the EOS R6. I prefer the EF 1.4x III Extender for its wider aperture range and much smaller size and image quality from the EF 1.4x III is very close to what you get from the lens unaided. 1. 2X III works really well and maintain a reasonable sharpness only on Superteles, 100-400 II and on on 70-200 II and unfortunately not included the 100-400 I. It's a waste of money. kingfishers are one of the skittish creatures, it posts a challenge even with 600mm + 2x. EOS 6D + EF 100-400mmL II + EF 2x III Extender. Shot with the Live View LCD.. Using the EF 2x III Extender on the popular EF 135mm f/2 USM lens, I noticed that the 'negative aspects' of the lens were magnified. Specifically Chromatic Aberration. Note that this is a property of the lens and NOT the Extender. It autofocuses fine on just the body. I purchased a 1.4x and 2x Tamron (non-SP) teleconverters, neither of which work well with the the Sigma and result in lots of hunting and failing to lock in. I purchased the Sigma 1.4x and it works brilliantly with the 70-200. For kicks, I put the 1.4x Tamron onto the 1.4x+70-200 combo and took photos. SLRgear Review October 3, 2011 by Andrew Alexander. The Canon 1.4x lens extender extends the focal length of a lens by 40%, making (for example) a 200mm lens function as a 280mm lens. The Canon Extender EF 2x III is also quite small and light. By putting the Extender between your telephoto lens and the camera, you reduce the field of view and bring everything closer. A Canon EF 70-200 mm f/2.8 L IS III USM thus becomes a 140-400 mm f/5.6. It becomes even more spectacular with a super telephoto like the EF 400 mm f/2.8 L IS The Sigma 70-200mm f/2.8 works great on a Canon 5D Mark IV using the Canon 2x Mark iii Extender. The Sigma 70-200mm f/2.8 works great on a Canon 5D Mark IV using the Canon 2x Mark iii Extender xvrphAI.

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