EF 400mm F4 DO II vs EF 500mm F4 ii

[mikeaff]

Hi All

I mainly photograph birds (often small) and own the 400mm DO ii (also the RF 100-500).   I have been very happy with the 400 DO II, even with the 1.4 iii extender.  However, I'm looking to move to something with a little more reach that will take the 1.4 iii as well or better than the 400 DO II.

I'm thinking of buying the EF 500 F4 II, since I'm not able to justify one of the RF super teles.  I'd appreciate any input from those who have experience with either or both lenses. 

Is it worth the switch?

Is the IQ or the 500 significantly better (especially with that 1.4 attached)?

Thanks

Mike A

[ebiggs1]

If you are still wanting an EF mount than get the Tamron SP 150-600mm f/5-6.3 Di VC USD G2. If you want to buy RF get the Canon RF 200-800mm f/6.3-9 IS USM Lens. Like they say you can never have too much focal length.

IMHO, ditch the 1.4x tel-con and get DPP4 form Canon. It is a huge debate which is better a tel-con or crop in post edit. Crop in post doesn't suffer the penalties that the tel-con brings to the table.