Next January i will have the opportunity to go to Costa Rica where i will obviously try and shoot as much of the amazing wildlife as i possibly can. For this purpose i will be upgrading from my 70-300 G lens (of which i am not really overly impressed) to a better and longer telephoto lens. Obviously there are 2 options, 100-400 GM (possibly with 1,4 extender) and the new 200-600 G. I shoot with the A7Riii and i am really struggling to make up my mind as to what would be the best choice? Apart from the obvious, longer range with 200-600 but needing more light due to aperture, there are some other issues that concern me. First, Image quality, is the GM really better when it comes to sharpness ( if there is anyone on this forum that has had the pleasure of getting hands on with the new optic)? But secondly, the rainforest and its extreme humidity? Having never shot in a rainforest kind of situation, i was wondering if the internal zoom of the 200-600 would be preferable to the extending barrel of the 100-400 when it comes to the effect of high humidity on the lenses?
If anyone has experience with these kind if situations i would love to hear your thoughts and advise