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I also have the 70-200mkii with both TC’s. But I honestly have mostly done video and not photography. So the sharpness in 4k is just as good. Also, I do use the 1.4x more which is definitely as sharp. The 2x does take it down a notch but it’s still quite good. If you have both and it’s not to your liking, I would recommend the 1.4x highly. Also, I did end up keeping the 50-400 and selling the 70-350 and the 100-400GM once I also got the 70-200 with both TC’s. I really do highly recommend the 70-350 for its size and weight and overall performance. I do think the Tamron adds just a nominal amount of size and weight for way more reach on both ends. It also is about 90% as sharp and accurate. So it is a compromise but for me is worth it. Doesn’t mean it would be for you as the Sony has its merits.

Maybe the Sigma might be sharper, which in my uses it wasn’t or was a wash really. But, the Sigma AF couldn’t keep up with anything quick moving in my uses. The Sony and Tamron AF motors did way better for sports and wild life than what sigma offers. Also, you mention the Sony getting dark quickly but the Sigma is almost the same f stops so not sure how that’s a limiting factor??? Also, having the best you can get Sony 100-400 GM, I found the Tamron ever so slightly less sharp. But the additional reach, great AF still, lighter weight, all outweighed and I ultimately did sell my 100-400GM for the Tamron. You sound like someone paid by Sigma. Their 100-400 is great for the price. But the 70-350 is lighter, faster and more accurate AF, and I would argue as sharp or sharper. The Tamron is way better AF in all regards at the same weight with better reach. IQ is maybe a toss up but not clearly one way or another. At this day and age in 2023, most lenses are more than sharp enough and I would say the AF performance and handling matter more.

​@@TechGearz_Levi Sigma not "maybe sharper," it's a lot sharper. I'm shooting mostly birds with long telephoto with A7Riii, I don't foresee any other use for those lenses. It's not hard to examine the pictures to see that Sigma is the only one of three that resolves details in feathers, the other two aren't even close. As to AF, I've never experienced any problems with any of those lenses. I do shoot dogs on the beach sometimes, but using 400mm lens for that is pretty ridiculous so it never occurred to me. I'm not advertising Sigma, it's just the best light and inexpensive telephoto for Sony, which I don't even use often nowadays. On my other body I'm using Nikon Z 400/4.5 which is a lot better optically, but it also costs more.

That Tamron 18-300 is a sleeper all-in-one lens that is great for the price and still has image stabilization. I'm more a full frame user and have the A7Cii but the 6700 with that lens was my other choice. No wrong options really. Definitely personal preference.

I speak on that later in the video. Even though it is an APSC lens, it actually works perfectly normal in full from 70-200 actually. In video, with active steady shot, it goes all the way to about 310mm. So even though it isn’t necessarily full frame, it’s a legitimate light weight and cheaper option with super fast autofocus.

I ended up selling the 100-400mm myself for similar reasons. That 400mm prime is elite.

Is the 70-350mm long enough for little birds ? Idk if to go olympus just for more reach but I already have sony full frame and apsc bodies. Thanks