The New Sony 70-200 gm ii vs 100-400 GM

The New Sony 70-200 GM ii vs 100-400 GM Comparison

Sony just released the Sony FE 70-200mm GM ii OSS, and it’s probably the best lens in it’s class. It’s a pound lighter than the previous 70-200 2.8 and better in every way.

With the recent release of the Sony 70-200mm 2.8 GM ii, you may have wondered how it compares with a 2x extender to the Sony 100-400 f4.5-5.6..

The main difference between the Sony 70-200 GM 2.8 and the Sony 100-400 f4-5.6 is the weight advantage, but the 100-400mm is actually slightly sharper.

But is the 100-400 really worth it?

Why Compare the Sony 70-200 GM ii with the 100-400

I wanted to compare these lenses because I don’t like the weight of the Sony 100-400. It’s heavy, bulky, but there’s not a better 100-400 lens on the market in my opinion.

Sure there’s the Tamron 150-500mm, but it’s also heavy and has a smaller maximum aperture.

The new 70-200 2.8 has an all-new focus system that actually works better than other sony lenses that use the 2x teleconverter, and it’s about a pound lighter than the 100-400mm.

The 70-200 2.8 is actually more comparable in weight to the Sony 70-200 f4.

The 2x teleconverter essentially makes the 70-200 2.8 become a 140-400 5.6. And that’s why it’s a great match for the Sony 100-400mm with a maximal aperture of 5.6 at 400mm.

In other words, if the 70-200 2.8 can become a 400mm lens with the teleconverter, why would you want the 100-400mm with all that extra weight. 

Let’s see how they compare.


The new 70-200 2.8 GM is 30% lighter than the previous model. It’s actually pretty close in weight to the Tamron 70-180 2.8 (1.78 lbs) and lighter than the Sigma 100-400 for Sony (2.5 lbs).

Sony 70-200 GM ii f/2.8 (New version)2.3 lb / 1045 g
Sony 70-200 GM ii f/2.8 + 2x teleconverter (New version)2. 7 lbs/ 1250 g
Sony 70-200 GM f/2.8 (Old version)3.26 lb / 1480 g
Sony 100-400 GM f4.5-5.63.08 lb / 1395 g
Tamron 150-500 f/5-6.74.14 lb / 1880 g
Sigma 100-400 f/5-6.32.5 lb/ 1133 g
Tamron 70-180 2.81.78 lbs/ 807 g

Sharpness Comparison with 2x extender

The Sony 70-200 2.8 is ridiculously sharp, even at f2.8. The corners aren’t bad either. But when you introduce the 2x teleconverter, sharpness is slightly worse than the 100-400.

Is this a deal breaker? Not unless you’re a pixel peeper.  The difference between sharpness with these lenses is really not that bad.  

In this video below, Gerald Undone discusses the differences between sharpness with both lenses.  Like Gerald, I’d rather have the versatility of both lenses and keep the 70-200 2.8 (with teleconverter) over the 100-400. 


You might note that the 2.0x teleconverter gives you better reach, but if you want great reach with better sharpness buy the 1.4x teleconverter.  

Autofocus Speed

70-200 gm ii AF speed
Image Credit: Sony

Autofocus speed on both the 70-200 and 100-400 is about the same. Both lenses perform exceptionally well according to Lizzie Pierce’s video here.

The same is said for video autofocus.   

Minimum focus distance

Even with the teleconverter, the 70-200 has a better minimum focus distance. 

Minimum focus distance for the Sony FE 100-400 GM

  • 3.22’ (.98 Meter)
  • Maximum magnification .12-.35x

Minimum focus distance for the Sony 70-200 f/2.8 GM ii

  • 15.7 inches (0.4 meters) at 70mm and 32.3 inches (0.82 meters) at 200mm
  • Maximum magnification of 0.3x


The biggest con to buying the 70-200 is the price.  It starts at $2798. That’s $300 more than the 100-400 ($2498)

  • 1.4x teleconverter $548
  • 2.0x teleconverter $548

That brings the total price of the 70-200 2.8 with the 2x teleconverter to $3,346.  


Go with the lens that will do the most in your line of work. In my opinion, that’s the Sony 70-200 2.8 with the 2x extender.  If you shoot action and occasionally need more reach, this combination will not dissapoint. 

You might also want the 70-200 if you shoot the following

  • Wildlife
  • Action
  • Sports
  • Weddings
  • Landscapes

So who is the 100-400 lens for?

This lens is mostly for wildlife photographers, but it’s also a great lens for landscape photographers.  If you buy this lens used, you can find it for under $2000, but you’ll still be carrying around the extra weight.

If you have the money, buy the new 70-200 2.8 by Sony with a 2x extender. If you don’t have the budget but need the speed and reach of both lenses, buy the Tamron 70-180 2.8 and the Tamron 150-500.

The Sony will be the lighter package, but you’ll save about $750 with these Tamron lenses.

I hope this was helpful. Check out my article on the lightest cameras and lenses for photography, and don’t forget to subscribe below.