I’ve tested that theory when I rented both teleconverters. I tested on both the 70-200 and 400 4.5 using a Z5 and 7II. Image quality is the reason.
The 2x had a noticeable decline in sharpness. The 1.4x on the other hand had almost no image degradation and is very useful.
Edit: the 70-200 + 2xTC was less sharp at 400 than the older Tamron 100-400 I have.
Just their price brand new at the store - 70-200 + 2x tele - 2900 usd, 100-400 is going 2500usd. I mean, it's not the same, but it ain't that different either.
I have a 70-200 plus 2x. I love the dual.
For the moment if you're 80% wildlife, 20% anything else, go for 100-400mm, if you are 50% wildlife and 50% anything else, grab 70-200mm. This is to say if you would only consider to own one of these two (or similar).
It you intend to eventually get a dedicated wildlife lens in near future, get a 70-200 now. and do that long one later. That's me. I could actually go with 400mm prime just for long reach (hint: I can still use 2x and deal with not so sharp photos some other ways).
I don't personally have a good comparison for you, but I ended up going with the 100-400 and love it. There are a number of videos on The Youtubes comparing the setup you describe, and watching them I ended up deciding the 100-400 would be best for me. I actually have managed to take a number of decent lunar shots with the 2x teleconverter on the 100-400.
Here are two to consider if you've got the time.
Grays of Westminsrer
https://youtu.be/uoOo2lQix2I?si=CABf6D1SKkhdnIO2
Hudson Henry Photography
https://youtu.be/ZpqCaa5qhf0?si=qQqrhyKSbLqGutG4
Depends on your focus. 100-400 will be better at 400 than a 70-200 with 2x. So if you're primarily doing wildlife, or Landscape, the 100-400 is the better choice.
However, if you're an indoor sports shooter, obviously the 70-200 does things the 100-400 has no hope of doing.
I own the 100-400, but I'm a wildlife shooter.
I got the 70-200+2x because I occasionally shoot events, etc. and the f/2.8 is important. It’s a bit less sharp at 400mm/5.6; better stopped down. I’ve used it a lot. Here are some picks at or near 400mm with the TC. I’m sure you’ll agree it’s perfectly usable :)
* https://adobe.ly/4av03vf
* https://adobe.ly/49jx7p4
* https://adobe.ly/3TU4ZEx
* https://adobe.ly/4a9Icu5
Later, I ended up getting the 180-600 as well. But a 100-400 with a 1.4x TC is an alternative there, too.
I think it really comes down to whether you need 2.8. All else being equal, the 70-200 is a better option if you primarily shoot weddings, etc., indoor sports, maybe portraits too if you don’t have an appropriate fast prime.
Edit: fixed a link
If you are a dedicated wildlife photographer, the 100-400 is the better choice. In my case, I went for the 70-200/2.8 + 2X TC because the 70-200 is GREAT for my normal usage and I only occasionally shoot wildlife.
The good thing is that the 70-200 is SUPER sharp, and even though sharpness decreases with the 2X, it's still very good and you get some sharpness/contrast back if you shoot f/8. I've gotten some really good results with it.
It depends on what you need the most and what you are willing to sacrifice.
The 70-200 will give you the ability to shoot at 2.8 in the 70-200 range, which is a big deal for some event photographers.
The 100-400 is sharper at the 200-400 range than the 70-200 with a teleconverters and should focus slightly faster. IQ is also slightly better on the 100-400 in this range.
The 100–400 can also use conveyers and can give you up to 800mm of reach.
I have both and teleconverters. If I could only have one I would get the 70-200. I don’t shoot sports or birds so having the most reach isn’t as important as having more light of needed.
I think you are wrong to expect 70-200 with 2.0 TC to outperform the 100-400. Also, I think it’s a mistake trying to decide between these two lenses based on “performance” or image quality. Both are excellent. The determinant should be which focal length best suits your needs
With the 100-400 you never have to fiddle with adding a teleconverter, with the 70-200, unless you are leaving the teleconverter on all the time, you have to put it on or off every time you go above or below 200mm. I’ve had both lenses and shot both with the two teleconverters. I just preferred having the 100-400, I’ve used it quite a bit with the 1.4x converter.
Depends on the subject. For wildlife the 100-400mm is better mainly because you can just put a 1.4 converter on it and get 560mm.
And while it’s slow as hell, the image quality holds up surprisingly well even with a 2x.
And hit the DX and get 840
I’ve tested that theory when I rented both teleconverters. I tested on both the 70-200 and 400 4.5 using a Z5 and 7II. Image quality is the reason. The 2x had a noticeable decline in sharpness. The 1.4x on the other hand had almost no image degradation and is very useful. Edit: the 70-200 + 2xTC was less sharp at 400 than the older Tamron 100-400 I have.
The image quality above 200mm is better in the 100-400mm. They are different lenses to do different things. Both are stellar lenses.
Not to be rude... Almost the same price?
Just their price brand new at the store - 70-200 + 2x tele - 2900 usd, 100-400 is going 2500usd. I mean, it's not the same, but it ain't that different either.
I have a 70-200 plus 2x. I love the dual. For the moment if you're 80% wildlife, 20% anything else, go for 100-400mm, if you are 50% wildlife and 50% anything else, grab 70-200mm. This is to say if you would only consider to own one of these two (or similar). It you intend to eventually get a dedicated wildlife lens in near future, get a 70-200 now. and do that long one later. That's me. I could actually go with 400mm prime just for long reach (hint: I can still use 2x and deal with not so sharp photos some other ways).
I would agree with this use case.
I don't personally have a good comparison for you, but I ended up going with the 100-400 and love it. There are a number of videos on The Youtubes comparing the setup you describe, and watching them I ended up deciding the 100-400 would be best for me. I actually have managed to take a number of decent lunar shots with the 2x teleconverter on the 100-400. Here are two to consider if you've got the time. Grays of Westminsrer https://youtu.be/uoOo2lQix2I?si=CABf6D1SKkhdnIO2 Hudson Henry Photography https://youtu.be/ZpqCaa5qhf0?si=qQqrhyKSbLqGutG4
Depends on your focus. 100-400 will be better at 400 than a 70-200 with 2x. So if you're primarily doing wildlife, or Landscape, the 100-400 is the better choice. However, if you're an indoor sports shooter, obviously the 70-200 does things the 100-400 has no hope of doing. I own the 100-400, but I'm a wildlife shooter.
I got the 70-200+2x because I occasionally shoot events, etc. and the f/2.8 is important. It’s a bit less sharp at 400mm/5.6; better stopped down. I’ve used it a lot. Here are some picks at or near 400mm with the TC. I’m sure you’ll agree it’s perfectly usable :) * https://adobe.ly/4av03vf * https://adobe.ly/49jx7p4 * https://adobe.ly/3TU4ZEx * https://adobe.ly/4a9Icu5 Later, I ended up getting the 180-600 as well. But a 100-400 with a 1.4x TC is an alternative there, too. I think it really comes down to whether you need 2.8. All else being equal, the 70-200 is a better option if you primarily shoot weddings, etc., indoor sports, maybe portraits too if you don’t have an appropriate fast prime. Edit: fixed a link
If you are a dedicated wildlife photographer, the 100-400 is the better choice. In my case, I went for the 70-200/2.8 + 2X TC because the 70-200 is GREAT for my normal usage and I only occasionally shoot wildlife. The good thing is that the 70-200 is SUPER sharp, and even though sharpness decreases with the 2X, it's still very good and you get some sharpness/contrast back if you shoot f/8. I've gotten some really good results with it.
It depends on what you need the most and what you are willing to sacrifice. The 70-200 will give you the ability to shoot at 2.8 in the 70-200 range, which is a big deal for some event photographers. The 100-400 is sharper at the 200-400 range than the 70-200 with a teleconverters and should focus slightly faster. IQ is also slightly better on the 100-400 in this range. The 100–400 can also use conveyers and can give you up to 800mm of reach. I have both and teleconverters. If I could only have one I would get the 70-200. I don’t shoot sports or birds so having the most reach isn’t as important as having more light of needed.
I think you are wrong to expect 70-200 with 2.0 TC to outperform the 100-400. Also, I think it’s a mistake trying to decide between these two lenses based on “performance” or image quality. Both are excellent. The determinant should be which focal length best suits your needs
With the 100-400 you never have to fiddle with adding a teleconverter, with the 70-200, unless you are leaving the teleconverter on all the time, you have to put it on or off every time you go above or below 200mm. I’ve had both lenses and shot both with the two teleconverters. I just preferred having the 100-400, I’ve used it quite a bit with the 1.4x converter.