Desperately seeking birds
- Aug 16, 2012
I've been thinking a lot about the 100-500mm vs the 100-400mm II on the R5 and will make up my mind when I can get the RF and test them directly against each other. Unlike you, I have decided not to go with the 800/11 as an accompaniment to a zoom because I couldn't go on a hike carrying both the 100-500mm and 800mm - you may well be younger and fitter than me and use cameras in a different way. So far, I am very, very happy with the 100-400mm II + TCs on the R5 and get up to 800mm. But, if the 100-500mm is better then I'll upgrade.In all fairness to Canon, the whole benefit of the new R... camera bodies and lenses is that there is a short 20mm flange-to-sensor distance, and an even shorter possible back-focus distance from the furthest lens surface (which may stick out past the flange towards the sensor). This much-reduced distance allows them to design lenses with much better optical performance.
The RF 70-200mm f2.8L IS lens takes advantage of this new option in lens design to give a better performance for all of us that buy it. But that better performance comes at the cost of not having a big enough back-focus distance with which to design a new RF TC to fit it, since there is not enough room for the lenses it would need.
I, for one, am very glad that Canon made such a design decision for their RF 70-200 f2.8L lens to get the best optical performance in a more compact and lightweight form as possible. Since it can not accept the RF TC, I have chosen to also buy the RF 100-500 lens. And since that lens can only accept the RF 1.4X TC if the lens is set to 300mm or beyond, I have chosen to not use the TC on it and instead also buy the RF 800mm f11 lens. I'm very happy to have new lenses with their optimal performance, even if it means that I can't use a TC in the ways that other users have previously enjoyed.
If you would rather Canon provided less optimal RF lenses just for the sake of allowing the normal use of a TC, then I would suggest that you try to be happy that their EF lenses and EF-to-RF TC's can do just that, and in fact they perform better on the R... bodies than they used to on the EF bodies.