70-400G lens

A point, herons around here it would be close for them to be only 100yards away.  One at 12 feet we have only had once, perched on a live tree that had fallen into the river, and we were quietly moving along with the current in our new shallow water boat. Normally even in that sort of situation herons will spook at above 100 yards.

I don't whine about the light levels, just take photos.  And generally prefer and use the 70-400G stopped down a stop or two and no higher than ISO 800, usually less.  All a matter of obtaining a long enough shutter speed and the necessary stability to do it.

Seems to me this is an argument for not using long lenses wide open for the best quality shots.  That has been known for a very long time.

There are a lot of folks who want to claim that using short focal lengths can resolve distant wildlife better than longer focal lengths of the same or better lens quality. I'm of no such belief.

So the 70-400G weighs a little bit.  It's a lot lighter than my Tamron 300mm 2.8 or 400mm f4, both of which exceed 5 lbs.  And which, at times I do use handheld, though mostly I use it via shoulder mount or tripod and gimbal. And I'm OLD! on the distinct downhill of losing strength in old age. Young folks that are complaining maybe need to get more exercise

Look at what the folks that make a living off wildlife shoot.  They won't be using a 300mm for distant shots of relatively small animals, in fact are far more likely to be using a 600mm rather than a 400. Also simply putting the effort into getting closer with those longer lenses.

For long work at times I use my HX200v with it's zoom that gets out to better than 800mm equivalent.  With all that extra reach it often can be the best choice if you can tolerate a EVF Cybershot for what you are shooting. And are willing to spend a little more time on PP.

I know you are not a long tele person, not too surprising you attempt to do things with the sort of shorter shooting lenses you are used to.