Strodav Loc: Houston, Tx

PCMag.com, which is known for fair reviews rate the Tamron 150-600mm f5-6.3 G2 as EXCELLENT and the Nikon 200-500mm f5.6 ED as GOOD.

https://www.pcmag.com/review/344657/nikon-af-s-nikkor-200-500mm-f-5-6e-ed-vr?source=autosuggest
https://www.pcmag.com/review/351247/tamron-sp-150-600mm-f-5-6-3-di-vc-usd-g2?source=autosuggest

Made the decision to go with the Tamron because is weighs less; 100mm more reach than the Nikon; price; not much difference in sharpness and I can tune the Tamron using the Tap-in for best results over 18 different points (3 distances and 5 zoom factors). Yes, the Nikon is sharper in the corners, but the corners are gone on my D500 DX. Unless you can drop the $9,000 or $10,000 for the Canon or Nikon 500mm f4, the best choice is any of the the 5 zooms which will give you good results. You might want to look at one more new option, which is the Nikon 500mm f5.6 at $3500, but right now they are on backorder.

DennisC. Loc: Antelope, CA

I did a comparison of the G2 and the 200-500, shot a fixed target, on a tripod in live view to see how sharp of an image I could get. I used a D810 and a D500. It was very hard to tell the difference in the images when shot at F8 or smaller, wide open the Nikon seemed to be a tad better. I also shot birds in in flight and they both performed vey well. The stabilizers is very good in both lenses, I ended up keeping the Nikon.

kb6kgx Loc: Simi Valley, CA

I don't know if this post will produce responses since the main threat is almost three years old, but I didn't want to start a new topic as everyone always says "Did you do a search for the same thing first?" Anyway…

I am looking to add a lens to my arsenal that will get me closer to my subjects than my 70-300 will allow. By the way, my 70-300 is the "FX" version.

I'm considering either the Nikon 200-500 or the Sigma 150-600 Contemporary. I shoot with a D7100 and D7200. I don't care about losing the 50mm on the short end by going with the Nikon. (and the fixed aperture is nice), but I'm not sure I really need the extra 100mm on the long end if going with the Sigma. Based on the comments, here, so far, the Nikon seems to be the better lens overall with better sharpness, faster AF and better stabilization. BUT is the Sigma that much worse?

No, I don't do birding. We've been on one Alaska trip and I'd love to go again and shoot whales and eagles, as my 70-300 left me wishing I had another 200mm or so. What I do most of the time is "Fire" photography. Involves a lot of helicopters and fixed-wing air tankers which are often far enough away that the longer the lens the better.

There's a significant price difference between the Nikon and the Sigma, but is the Nikon worth a few hundred dollars more? I get it that neither is a low-light lens. However, most of my shooting will be in bright (hopefully) sunlight. I couldn't imagine taking out such lenses at night when it's dark.

Suggestions and recommendations?

MT Shooter Loc: Montana

Looks to me like all your concerns have already been addressed in previous responses.

larryepage Loc: North Texas area

I've spent quite a bit of time in general aviation aircraft and been in helicopters a few times. My concern with either lens would be whether the length would be manageable in the limited space available. I'd probably speak in favor of the 200-500, because I have one and am familiar with what it can do. But if I were wanting to do what you are wanting to do, I'd probably be looking for a camera with more resolution and cropping to get what I needed. Just a lot more agility, less weight, but mostly less lens sticking out in front of me in the very limited space. This would be especially beneficial when the air is rough. And consider if you would have room to shoot at all if in a plane without the door removed.