i have a 90d body , i want an 800mm lens but the canon one is £13k ouch ! canon make an rf 800 lens. Is it possible to get an adaptor so that i can use the rf 800 lens
i doubt there is an adapter, its also an ƒ11 lens, this is ok for the R series but the lesser mounts might struggle how about going with a sigma 100-400mm and a canon 2x converter i used that combo for the image below, just a jpeg so if you shoot raw it will probably be better still that being said if you can stretch your budget to a sigma 150-600mm and dump a x2 on it you will be well over your planned 800mm
The RF uses a shorter flange distance, there will not be an adapter. That 800mm 5.6 need 5.6in of diameter to its aperture, its all just basic math. So you end up with a gigantic expensive lens in the L lineup. At f11 you only need a 2.86 inch diameter aperture wide open, its a much easier and smaller lens to produce. The is no perfect way to get that long of reach, you can see why if you want a good L lens at 800mm it will cost money for the better quality and usability. 1.You can buy a shorter lens and use an extender, but they suck light and will take away some IQ. And a good extender will cost a fair amount of money. 2. You can always crop a image down if you have the resolution to do so. 3. You can by a super zoom bridge camera just for these type of shots, also cost money, and I recommend going all the way to 2000-3000mm super zooms so you can crop and sharpen a bit as the quality will fall off on the long end also. Options 1&3 are probably the best bet depending on if you can find a good 400/500/600 lens for a good price and it performs well. The 2x extender pulls out 2 stops of light quickly changing your f4 to f8 and not all cameras can focus at f8 or darker.
