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Review: SONY 400MM F2.8 GM OSS

Sony 400mm f2.8 GM OSS with 1.4x teleconverter on the Sony a9,

on top of the MrJan Gear - Boris IV - photo backpack

In the end of December I could pick up a piece of equipment I have been waiting a long time for. …the Sony 400mm f2.8 GM OSS lens. Until that moment, I used the Sony 100-400mm for wildlife. This is an incredible good lens, but with f5.6 on 400mm it is not possible to get this smooth bokeh which you get with a f2.8 lens. Also, you lose a lot of light on f5.6 compared to f2.8. Since most of the wildlife is active in the early mornings and late evenings, having this extra light to work with, is more than welcome!

Field testing the lens

Once I got the 400mm f2.8 I made some drives in the forests in the area I live in. But the wildlife didn’t want to play ball. Not a single opportunity to test the lens in the field. I had to wait until my musk-oxen in winter conditions tours started, to finally start working with this new piece of equipment. I have used the lens now for a total of 9 days to photograph musk-oxen. My findings I present here, are based on those 9 days. Once I get to use the lens on the black grouse and capercaillie in April and May, I will update my findings.

Just to be clear. I used the 400mm f2.8 on the Sony a9 camera body and in some occasions with the Sony 1.4x teleconverter. My findings are based on these combinations. I can’t say anything about how this lens works on any of the other Sony bodies or with the 2.0x converter. Hopefully I can say more about this, later this year.



When I still was shooting with Canon, my main wildlife setup was the 1DX (1.35 kg) with a 500mm f4 (4.26 kg) prime lens. The weight of this combination added up to 5.61 kg. Now with the Sony a9 with the battery grip (0.673 kg + 0.272 kg) and the Sony 400mm f2.8 (2,895 kg), with a total weight of 3.84 kg, my setup is 1.77 kg lighter. Since I do a lot of hiking with my gear and mainly shoot from the hand, this loss in weight is very welcome in as well my backpack as in my hands. The lens is of course shorter than the 500mm, so a bit of extra space is created in my backpack. The diameter of the 400mm f2.8 is however larger than a 500mm f4. But the lens still perfectly fits in my MrJan Gear – Boris IV – backpack.

(For all the other specs of this lens, check the Sony website.)


The first thing I really notice when shooting is that this set up is not just a whole lot lighter, but also better balanced than my previous set up. Sony has put most of the heavy glass to the back of the lens, close to the camera. This makes it much easier to shoot handhold for longer periods, since it puts less stress on the hand which is supporting the weight the furthest from your body. The hand which holds the camera, supports most of the weight.

Me in action with the Sony 400mm f2.8. Picture by Peter v.d. Veen.

Auto focus

The auto focus speed is just ridiculous fast. As soon as you push the focus button, the focus snaps on to the subject. I played a bit around with subjects standing on different distances. Focusing happens ridiculously fast, but still very smooth! I didn’t see any shocks while changing the focus or when the focus was locked on to a subject with tracking activated. The focus tracking capability of the a9 makes sure with 60 auto focus measurements per second, that the focus stays locked on the subject. Now I know that photographing musk-oxen is not exactly comparable with photographing birds in flight, but we got plenty of action of musk-oxen running through the snow and crashing into each other at full speed.

On the first trip in the mountains, which lasted 5 days, I took 2200 images. So far I have not found a single image where the auto focus missed the subject or where the focus didn’t manage to track the subject. This is something I have never experienced before. I still haven’t had the chance to look at every single image. But the series of action shots I have looked at and some other interesting shots, were all in focus. Normally there will always be some shots where the focus just missed, yet here the camera and lens just nailed it every single time.

Just to clarify, I used a single focus point for most of the shooting. In some occasions where two bulls charged at each other, I used the expendable focus modus where the camera freely tracks the subject you have chosen to track. Both worked excellent.


Also when shooting with back-light, the focus keeps doing an excellent job. Even shooting almost straight into the sun, the focus managed to find the subject and nail the shot.

The bigger the front glass, the bigger the chance for flairs. To see how the flair of this lens would be, I shot in different angles against the light to try to get a flair on the image. The flair I got was very soft and only present in the exact right angle. The flair I used to get with the 500mm f4 was much stronger present. Sony did a very good job with the glass on this lens!

A small soft flair is visible just over the animals.

In the mist

One day we had very dense mist in the mountains. I noticed that my camera did a much better job with the auto focus compared to the Canon and Nikon shooters I had with me. They were shooting with the Canon 1DX mkII, Canon 1DX, Nikon D5 and Nikon D500 and all of them with 600mm f4 prime lenses. I could hear their lenses hunting, while my Sony a9 with 400mm f2.8 kept the focus on the animal. I had the same experience last year when shooting with the Sony 100-400mm on the a9.

No problems with focusing in thick mist. Also with the 1.4x teleconverter on.

Low light

During the early mornings and late evenings the auto focus kept doings it’s job. I have the impression that the a9 performed better with the 400mm f2.8 than with the 100-400mm in these conditions. This should be logic, since the lens lets through more light which makes it easier for the camera.


The stabilizer does its job well. I managed to get sharp shots al the way down to a 1/20s, when shooting bursts. Not all of the shots were sharp, but about 1 out of 3 or 4 were. During the tours I tried to keep my shutter speed above 1/200s anyway, to account for the movement of the animals.

Sharpness and contrast

The images taken with the Sony 400mm f2.8 are really razor sharp from edge to edge and corner to corner! I love to put the subject somewhere in the corner of the image. It is great to see that I can do this now without any loss in sharpness. The contrast comes out perfectly thought the glass, which gives the images an absolute crisp sharpness.

Since the lens produces images which are also sharp in the corners, the lens can perfectly be used for shooting panorama landscapes. The image below consists out of 11 vertical images, shot at iso80, f11, 1/1000s.


The whole reason why I wanted to get a 400mm f2.8, is the bokeh. And boy, what a sweet, creamy, soft bokeh it has got! It does perfectly what a lens of this caliber should do.


Since the lens is so light and well balanced, it is much easier to pan images than with the 500mm f4. My arm doesn't get tired that fast and doesn't start shaking. I only panned the musk-oxen in one occasion and got several keepers from that short session. Yet, if I would have to choose between the 400mm f2.8 or the 100-400mm for panning, I would go for the 100-400mm. I normally shoot from about f8 and up to get a low enough shutter speed. Therefor I wouldn't gain anything from shooting with a f2.8 lens which weights more than the 100-400mm. But good to know that the 400mm f2.8 also does a great job for this purpose.

Shot with the Sony 400mm f2.8 on the Sony a9 with 1.4x teleconverter, at iso320, f8, 1/10s

1.4x teleconverter

In combination with the 1.4x teleconverter the auto focus still nailed every single image. I didn’t notice any difference with or without the converter. On the camera display the images also looked sharp. Once I opened the images on the big screen at home, I could notice a difference in sharpness and a slight loss of contrast. The images shot with the converter definitely need more sharpening. To be honest, I’m slightly disappointed with the converter. I didn’t expect this loss in sharpness, since the Canon converters do not have this loss of sharpness with their mkIII 1.4x teleconverter. The strange thing is that all other photographers who have this teleconverter or have tested it, do not notice a loss in sharpness or contrast. So I’m wondering if I just happen to have gotten a bad one or if others have not been so critical on the images as I’m. I hope to do some more testing with the converter and try someone else’s converter to see if there is any difference.

Find below two images I took almost straight after each other. The first one is with 1.4x teleconverter and the second one without. The first two images are sharpened after I resized them. The two combined images are not sharpened at all to give a true representation of the difference between the two images.

0% crop, taken with 1.4x teleconverter.

0% crop, taken without teleconverter.

50% crop of non-sharpened images. On the left the image with the 1.4x teleconverter and on the right the image without.

100% crop of non-sharpened images. On the left the image with the 1.4x teleconverter and on the right the image without.

Overall conclusion (for now)

The Sony 400mm f2.8 GM OSS is an absolute beast of a lens! The weight and balance make it a great joy to work with when shooting handhold. The auto focus has a speed I have never experienced before and follows the subject very accurate and smoothly. In low light and other difficult light situations the lens performs very well and produces razor sharp images with the smoothest bokeh you could wish for. In combination with the 1.4x teleconverter, contrary to findings of other Sony photographers, my images lose a considerable amount of sharpness. I have to look further into this to see if this is to be expected or due to a problem with the converter.

If you wish to join me for a trip to the musk-oxen in winter time, then take a look at my touring schedule for coming winter. There are still some spots available.

I want to send out a big thank you to Sony Scandic for getting me on the top of the waiting list for the Sony 400mm f2.8 and also a big thank you to InterFoto in Oslo for the great service I have received!

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