Sigma 500mm F4 + XH2S?

[Stogursey]

I think my Fuji 150-600 F8 is a brilliant wildlife lens in terms of sharpness, portability and value but the small aperture does cause issues at the start and end of the day - even pushing the ISO as far as I dare, I can see shutter speed down to 1/25s - stabilisation isn't an issue but asking a deer to stand still for that is too much! In the same situation, an F4 would give 1/100s so the difference to the success rate would be phenomenal... and that's without the other improvements like shallower depth of field.

I also find that the Fuji's subject detect AF gets pretty iffy in low light - I keep updating to the latest firmware but it doesn't seem to get any better.

I was originally looking at the Nikon 500mm F4 E but good examples secondhand are still reasonably expensive but like-for-like Sigma lenses are around half the price. Reviews I have read suggest that they are as good optically, AF performance and IS-wise but you gain a few hundred grams of weight (but less than the older Nikon model). For a couple of grand, I can live with that.

Does anyone have any experience mounting one on an XH2S? What about with the 1.4 teleconverter? It feels like that is pushing it anyway - hefty lens + TC + Fringer all sounds a bit...wobbly?

It is on the Fringer approved list but I am wary about AF speed in particular.

I had also considered looking for a used Nikon 400mm F2.8, which would be even faster (and heavier) and could couple with a TC to give 560mm F4 but again, it is that lens+TC+Fringer combination that worries me as being just too many links in the chain.

Of course, what I really want is a native Fuji prime but that doesn't seem to be on the horizon - and if you look at what Nikon and Sony are doing, if Fuji do ever bring out a 500mm prime, it will probably be a small, light and cheapish F5.6, which is only 2/3 stop better than my zoom at the same focal length.

Any thoughts anyone?