For the record, I found
this article on the best mirrorless cameras for wildlife photography very useful and interesting, as well as the dpreview photo comparison that Vespobuteo linked to.
Thanks to everyone for their advice!
Reading through that article, reinforces a bit that (like the rest of us !
you are looking for the holy grail, and once weight and cost become factors, I tend to agree with Jim -
"Frankly, I don't think the camera you want exists"
I think you have several options for better performance based on how much you want to carry and how much you want to spend.
i) 1" sensor Sony RX-10 MKIV . This has an in-camera crop to give you 900mm equivalent at about 10(12?) MP. Importantly the max aperture at the long end is f4, the BSI-CMOS 1" sensor is cutting edge, and so is the AF for a bridge camera - being the first with phase detect.
It will give you an improvement over your current camera though more incremental. Weight is ~ 2&1/4 lbs. Cost ~ $1500.
ii) m43 sensor Olympus OM-D EM-1 MkII + 300mm f4 PRO + 1.4x TX . This is currently state of the art in m43 and will give you 20MP of 840mm at f5.6 The sensor in this camera performs very well for its size and is near APS-C performance, as it is for AF.
It should give you better improvement over your current camera. Weight is ~ 4&1/2 lbs. Cost ~ a bit over $4500.
iii) APS-C sensor Nikon D7200 + 300mm f4 PF + 1.4x TC. High resolution 24MP sensor which you would best use on centre point continuous AF. 630mm f5.6 , or use the 1.3x in-camera crop for 15.4 MP of 840mm at f5.6.
It should give a quite good improvement over your current camera. Weight is ~ 4lbs. Cost ~ a bit over $3000.
iv) APS-C sensor Nikon D500 + 200-500mm f5.6. Pro level AF, with the larger sensor providing much better high ISO image quality. You can either shoot at full res 20MP of 750mm at f5.6, or use the 1.3x in-camera crop for ~12MP of 1000mm at f5.6
This should give you noticeable improvement over your current camera. Weight is ~7lbs. Cost ~ a bit less than $3500.
v) FF sensor. Here you are looking at the Canon 1DX MkII , Nikon D5 , or the Sony A9 , and (5/)600mm f4 + TC's .
You will see the best performance available and a huge step up over your current camera. Weight will be ~ 11 or 12lbs , you will probably want a tripod or rest or something, and there won't be much change from 20 grand ! :eek!:
As you can see, you rapidly move up in size, weight, and cost from bridge camera levels. Probably the best bang for the buck is option iv) , and probably the best bang for the size is option iii) .
Where you lob will be up to you !
I have no real idea what each of these rigs would cost to rent in your location, but assume that the rates would be somewhat proportional to the buying cost. :h?:
Chosun :gh: