some of the current long zoom options with equiv. focal length and equiv. aperture:
* Panasonic FZ1000: 25-400mm, f/7.6-f/10.8; 0.83 kg
* Nikon 1 V3, CX70-300: 189-810mm, f/12.1-f/15.1; 1.0 kg
* EM1 with 75-300II: 150-600mm, f/9.6-f/13.4; 0.95 kg
* APS-C Tamron 16-300: 26-480mm, f/5.6-f/10; 1.3 kg.
* APS-C Tamron 150-600: 240-960mm, f/8-f/10; 2.7 kg.
(APS-C is mid-level Canon DSLR; Nikon 1 with EVF)
Several of these combo’s have similar equiv. focal length range, equiv. aperture and weight, despite big differences in sensor size. The real value will depend not just on sensor quality but more on optical quality, AF performance, framerate etc.
I think the Nikon 1 combo will perform very well for long zoom action, but it is very expensive. FZ1000 has great spec for the price, although the maximum zoom is a bit low for some applications.
Started out doing photography at the age of 6 using an uncle's old 1940 kodak brownie box camera. At 15 years of age, I decided to buy my very own 1975 Praktica SLR camera. I now shoot with a Nikon D850. I do unpaid TFP and commercial paid work.