This was a feral cat - taken at 1/25 sec, hand held, using a 150-600mm Sigma Sport - I did not have to hire a mason to pour the concrete to minimize even the tiniest movement. I did switch on the optical stabilization, though. I just breathed normally and gently squeezed the shutter at the end of an exhale, assuming a shooter with a long gun with my left shoulder leading towards the cat. I was at or near the minimum focus distance of around 16 ft, where any movement (cat or me) would have resulted in obvious blur -the only softness you see is from the extreme cropping. Ferals are known to be skittish, but since I had been feeding her and providing shelter for the past 3 years, she put up with me.

FWIW, I often shoot in the "forbidden" range of shutter speeds with that lens. The stabilization is good enough to provide me with good images from 1/160 on up. The Sigma literature says its stabilization is good for up to 4 stops. I can't disagree. I haven't used a tripod with this lens. In contrast, I used a tripod 100% of the time with my 600mmF4 which weighed 10.5 lbs and had no stabilization.

Thanks!

Nah. I've been shooting lots of wildlife for many years. With cameras. I've never shot a gun, but I use sniper training methods - well-proven and have yet to fail me. It doesn't hurt that I forego coffee/tea on shooting days, and I completely avoid soft drinks and energy drinks.

But this completely blew me away. A kill shot at 2.2 miles.

https://www.military.com/video/canadian-sniper-reportedly-hits-isis-fighter-22-miles-away-breaks-record

The Canadian snipers are pretty amazing:

https://www.businessinsider.com/canadian-snipers-set-longest-kill-records-amid-fighting-in-afghanistan-2021-3

This was a feral cat - taken at 1/25 sec, hand held, using a 150-600mm Sigma Sport - I did not have to hire a mason to pour the concrete to minimize even the tiniest movement. I did switch on the optical stabilization, though. I just breathed normally and gently squeezed the shutter at the end of an exhale, assuming a shooter with a long gun with my left shoulder leading towards the cat. I was at or near the minimum focus distance of around 16 ft, where any movement (cat or me) would have resulted in obvious blur -the only softness you see is from the extreme cropping. Ferals are known to be skittish, but since I had been feeding her and providing shelter for the past 3 years, she put up with me.

FWIW, I often shoot in the "forbidden" range of shutter speeds with that lens. The stabilization is good enough to provide me with good images from 1/160 on up. The Sigma literature says its stabilization is good for up to 4 stops. I can't disagree. I haven't used a tripod with this lens. In contrast, I used a tripod 100% of the time with my 600mmF4 which weighed 10.5 lbs and had no stabilization.

I have a 600mm and absolutely love it. With that being said, I typically shoot wildlife, so I'm using higher shutter speeds. While in Africa, I could get tack sharp images where you can count ear hairs or eyelashes or chin hairs on a giraffe without using a tripod. I rested it on the roll bar of the jeep and fired away. The disadvantage with the lens is in low light conditions. With any f/4 to get tack sharp images with moving subjects you need to crank up the iso and the shutter speed and with my 600 it works very well. If you shoot wildlife, that 600 will allow you to photograph at greater distances from your subject creating less reason for critters to take off or have birds fly away. You may need to lift some weights and build up your biceps and triceps to haul it around. I'm 70 years old and pack the 600 beast around all the time. If you have the cash, you won't regret it.