Sony 400 mm f/2.8 OSS GM Wildlife Photography Long-Term Test
Sony 400 mm f/2.8 GM + TC 1.4x in use for photographing ospreys in Japan
Is the Sony 400 mm f/2.8 OSS GM suitable for wildlife photography?
Table of Contents
What does this article show you?
Previous articles about the Sony 400 mm f/2.8
A brief review
Where have I used the lens?
Handling – Balance & Weight
Autofocus Speed
Subject Isolation
Aperture Brightness
Focal Length Flexibility and Image Quality
Accessories
In practice
Summary
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For more details on pros and cons & pictures, read the extensive text below the dropdown.
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What does this article show you?
Is the Sony 400 mm f/2.8 GM OSS worth the money? Since October 2022, it has accompanied me on all my wildlife tours. This article summarizes my experiences and insights, which can help you in making your purchase decision.
A Brief Review
In October 2022, I opted for the 400 mm f/2.8 GM OSS. Information was scarce and often uncritical. Now, after intensive use, I can share my experiences.
Handling – Balance & Weight
The lens weighs 2895 g. It is well-balanced, especially with a battery grip on the camera. However, it is not a lens for extended handheld shooting. A tripod or monopod is often necessary.
Autofocus Speed
The autofocus is super fast, especially in combination with the Sony A1. With the 1.4x teleconverter, the speed remains very high. The 2x teleconverter noticeably reduces agility and precision.
Subject Isolation
Isolation at 400 mm f/2.8 is excellent with a dreamy bokeh. At 560 mm f/4 (TC1.4x), the quality remains very high. With the 2x teleconverter (800 mm f/5.6), the bokeh is still good.
Aperture Brightness
In low light, the 400 mm f/2.8 GM shows its strength. It allows for early shooting and faster exposure times without high ISO values.
Focal Length Flexibility and Image Quality
At 400 mm f/2.8 and 560 mm f/4 (with 1.4x TC), the images are detailed and brilliant but need to be stopped down to f/5. With the 2x TC, 800 mm is possible, but the quality decreases, especially over greater distances.
Accessories
An additional Arca-Swiss compatible lens foot and a lens cover are useful. Changing the teleconverters is cumbersome and poses risks in extreme temperatures or dusty conditions.
In Practice
The Sony 400 mm f/2.8 GM OSS is robust and reliable even at extreme temperatures. It is heavy but well-balanced. The 2x teleconverter is not optimal, but the overall performance of the lens is impressive.
Summary
The Sony 400 mm f/2.8 GM OSS largely meets my expectations. The 1.4x teleconverter works very well, the TC2x less so.
Weight and handling can be challenging handheld, but the image quality and light intensity convince. A few improvements such as a built-in teleconverter and weight reduction would be desirable.
Pros and Cons of the Sony 400 mm f/2.8 GM OSS
Pros:
Excellent image quality at 400 mm f/2.8 and 560 mm f/4
Dreamy bokeh
Fast exposure times in low light
Very fast autofocus
Well-balanced
Extendable focal length with teleconverters
Cons:
Heavy (2895 g)
Performance of the 2x teleconverter drops significantly
Original lens foot not Arca-Swiss compatible
Cumbersome changing of teleconverters
High price
For more details, read the extensive text below the dropdown.
What does this article show you?
Now it is time to take stock: Does the Sony 400 mm f/2.8 GM OSS live up to its promises? This lens has been my constant companion on my wildlife tours since October 2022.
This article shares my experiences with the Sony 400 mm f/2.8 GM OSS since October 2022. I'll tell you whether my decision was the right one. What positive and negative experiences have I had? This might help you if you are currently considering purchasing such a lens.
For those who are simply interested in how the Sony 400 mm f/2.8 GM performed in my experiences, there are plenty of insights.
The lens has not left my side since October 2022. It has been with me everywhere, whether in my local area or on trips, such as my tours through Japan.
So, stay tuned!
Previous articles about the Sony 400 mm f/2.8 GM
Reminder: I have already written two articles about this lens. They cover initial impressions and tests of the high-aperture prime lens. You can also find out why I decided against the Sony 600 mm f/4 GM in those articles. If you haven't read these articles yet, I recommend doing so to get a complete picture of my decision-making process leading up to the purchase.
Sony GM 400 mm f2.8 First Impression
Sony GM 400 mm f2.8 instead of Sony GM 600 mm f4 E-Mount
Brief Summary Review
If you don't want to read my other two articles right now, here's a summary.
In 2022, I decided to take the next step in lens quality. To do this, I spent a lot of time thinking beforehand, trying to gather as much information as possible from the internet, and exchanged views with various photographers who owned the Sony 400 mm f/2.8 GM. Information on the internet was very scarce, even in English-speaking areas. Most of it was either praise or clickbait articles like "I test an expensive Sony lens, etc." A critical perspective was rare or not found in relation to wildlife. It was difficult to get answers to the questions I had.
I can already say that the Sony 400 mm f/2.8 GM is excellent in terms of image quality. Otherwise, the price wouldn't have been justified, and I would have returned it immediately.
For me, other points were important, which I would have liked to know beforehand from the experiences of other wildlife photographers. This was complicated since the release of Sony's 600 mm f/4 OSS GM, as it seemed the majority of wildlife photographers wanted this prime lens for their Sony cameras.
Why did I consider the 400 mm f/2.8 instead of the 600 mm?
Like all my decisions regarding equipment, I reflected on my years in wildlife photography and asked myself what I needed and what I wanted to improve. The pure focal length was not at the top of my list. With the Sony 200–600 mm f/5.6/6.3 G, I already have 600 mm, and that lens is damn good, although a bit weak in terms of light intensity at f/6.3. Still, until then, this lens was my main tool, as one would say in English, "My workhorse."
Aperture Brightness
I photograph, when not traveling, in Germany. Most of the time, the areas where I operate are on the edge of or inside forests. With the Sony 200–600 mm, I often reached my limits in many cases. When you add the weather to that, you often don't have optimal light conditions even in summer. Especially on trips targeting species that are very active early.
Focal Length Flexibility and Image Quality
Sony Telekonverter 1.4x & 2x
Since the next step from zoom lenses was a prime lens, I would rather not commit to 600 mm, even though I mostly shoot at this focal length. It was also clear that I wouldn't get the Sony 600 mm f/4 GM. On many trips and in many situations, 600 mm was simply too much. Therefore, my idea was to cover the 600 mm range with the 400 mm and teleconverter (400 mm f/2.8 + TC 1.4x = 560 mm f/4). Or even use the TC 2x to reach 800 mm f/5.6. And this with hardly any loss of quality, which is usually not the case when using a teleconverter, despite what theory might suggest.
Autofocus Speed
AF-Speed: Since I photograph birds in flight a lot, this was an area where I wanted an improvement—or rather, it was an expectation for such a lens. My Sony 200–600 mm G OSS and Sony 100–400 mm GM OSS already have excellent autofocus performance. The 400 mm f/2.8 GM is slightly older (released in 2018) and came to market before the Sony 200–600 mm G and the Sony 600 mm f/4 GM. With Sony, you never know if they incorporate the latest technology into newer models. Take their camera update philosophy, for example, as seen with the Sony a6700: it includes the latest AF features, while the flagship Sony A1 is still waiting for such improvement updates. The price difference is about 5000 euros...
The autofocus of the Sony 200–600 mm G and the Sony 100–400 mm GM doesn't need to hide, as you can see from the sample images above.
Can the Sony 400 mm f/2.8 GM surpass that?
Subject Isolation
Experienced photographers know that good subject isolation is not only about the aperture. However, soft bokeh and the distance behind the subject to achieve it are highly dependent on the aperture. Especially in nature photography, there is often not enough space behind the subject, which a low aperture number can significantly compensate for. With an aperture of f/2.8 or f/4, which the lens has with a 1.4x TC, it should theoretically provide exactly what I was looking for.
Weight and Balance
The lens is not lightweight, but until now, it has been one of the lighter ones in its class. Still, it is quite a device, and I wasn't sure how the balance would be with its weight of 2895 g when used without a tripod. I had read that it is excellently balanced. But what does that mean in reality?
This brought me to my main questions:
How is the image quality with the 1.4x and 2x teleconverters?
How is the autofocus without and with the respective teleconverters?
How does the autofocus compare to the latest generation lenses?
How is the handling when shooting handheld?
Do I need any additional accessories?
These were my initial thoughts beforehand. Whether I still stand by my decision, you'll find out now. You can read more details in my other two articles, including the conclusions I drew from my test with the Sony 600 mm f/4 GM.
Sony GM 400 mm f2.8 First Impression
Sony GM 400 mm f2.8 instead of Sony GM 600 mm f4 E-Mount
Where have I used the lens?
Mainly, as mentioned, in Germany, but also on my annual trips through Japan. Especially there, the flexibility of the focal length was important to me. Unlike in our latitudes, in Japan, you get much closer to white-tailed eagle, Steller's sea eagles, deer, or cranes. In some cases, 600 mm is already too much here.
Handling – Balance & Weight
Let's start with handling. The lens weighs 2895 g, which is quite substantial. When I first held the lens, I was surprised. It didn't feel like almost 3 kg at all. The Sony 200–600 mm, at 2225 g, is also not lightweight. But the 400 mm f/2.8 GM felt better balanced. So, my preliminary information was correct on this point.
For the best balance, I also use a battery grip on the camera. This increases the overall weight but provides a more stable balance. The lens's center of gravity is far back, so it is not front-heavy and requires less effort when shooting handheld, which is further enhanced by the battery grip.
All in all, excellent. Even though it's not a lens, I can use handheld for long periods. It is usually advisable to use either a monopod or a tripod.
Autofocus Speed of the Sony 400 mm f/2.8 GM
Autofocus Speed
Not many words are needed here. The AF is incredibly fast at Sony 400 mm f/2.8 GM, and in combination with the Sony A1, it's like a Ferrari with twin turbo. The real interest lies with the teleconverters. You notice a difference with fast-moving subjects like birds in flight. With the Sony 1.4x TC, I couldn't detect any difference. With the Sony TC 2x, it's different. The AF is less agile, fast, and precise. It is still good, but not good enough for a GM lens.
To answer the question: Can the Sony 400 mm f/2.8 surpass the fast AF of the 200–600 mm & 100–400 mm? I can unequivocally say YES!
Subject Isolation of the Sony 400 mm GM
Subject Isolation
Also, a no-brainer: At 400 mm f/2.8, you get excellent subject isolation with dreamy bokeh. At 560 mm, it's the same, although not comparable to 400 mm f/2.8 wide open, but we're still talking about a very high level. With the TC 2x, the background becomes more noticeable due to the stopping down to f/5.6, but the bokeh is still nice and creamy.
Sony 400 mm f/2.8 - Low Light Performance
Low Light Performance of the Sony 400 mm f/2.8
As I had anticipated, I was not disappointed. When the blue hour begins, and I am in light-permeable environments, the advantage of such a lens becomes obvious. I can start photographing much earlier with a decent exposure time. The more light available, the faster I can shoot, which is especially beneficial for birds in flight. This allows for the possibility to photograph earlier or longer in the day and use faster shutter speeds without having to increase ISO compared to tele-zooms. This was not really a surprise. The next point was crucial for me.
Focal Length Flexibility and Image Quality of the 400 mm f/2.8
This was the deciding factor for me, and I struggled to find relevant information. There was one source, but unfortunately, the test was not specific to wildlife. Once I had the lens, I conducted my own tests and was able to compare it to a friend's Sony 600 mm f/4 GM.
My experiences with the flexibility and image quality after about 1 ½ years are as follows:
At 400 mm f/2.8
Sony 400 mm f/2.8 GM at 400 mm f/2.8
At 400 mm f/2.8: Check! There's nothing more to say; this is the lens's native focal length. The image quality is "amazing," to put it simply: very high detail and photo brilliance.
TC 1.4x - 560 mm f/4
Snow bunting (Plectrophenax nivalis) on Hokkaido — Sony 400 mm f/2.8 GM + TC 1.4x at 560 mm f/5.
560 mm with TC 1.4x: This is where the first minor issue arises, which is not new when using a teleconverter. With the TC 1.4x, the 400 mm f/2.8 GM becomes a 560 mm f/4 lens. Based on the specifications, you almost get the same as the Sony 600 mm f/4, just 40 mm less. However, I need to stop down two steps to get the same sharpness as the Sony 600 mm f/4 GM. This means f/5, so you have slightly less light than with the 600 mm, but the image quality is then comparable. I do think the brilliance decreases a bit, but that's mostly due to my pixel peeping. For 99.9% of viewers, it’s not noticeable, especially if used only on digital media. At f/4, the photographed object becomes blurry, especially at a distance, and this is particularly noticeable with small birds.
Sony 400 mm f/2.8 GM + TC1.4x at 560 mm – 100% cropped in image — blurry, unclear at 560 mm and f/4
TC 2x - 800 mm f/5.6
RAW – The image is not edited or cropped. In close range, the 400 mm with the TC 2x still delivers good results. Sony 400 mm f/2.8 GM + TC2x at 800 mm f/5.6
800 mm with the TC 2x: This is only an option for me when the subject is nearby. I prefer cropping more at 400 mm or 560 mm rather than generally using this combination. In the close range and depending on the size of the subject, it can work. But at greater distances, it is not satisfactory for me. If there is enough light available, you can get something decent at medium distances and a higher aperture (f/8). So, the TC 2x is a last resort in this combination. I prefer cropping. However, I also think it’s a compatibility issue; the TC 2x does not harmonize well with the 400 mm f/2.8. The Sony 600 mm f/4 GM delivers better results here. At least, that’s what I found in my small comparison test with the Sony 600 mm f/4.
Thus, the flexibility is not 100% as I had wished, but it’s not a deal-breaker since 800 mm is usually not on the agenda. But you never know how your photography requirements might change or what situations might arise. If I were exclusively photographing songbirds, I probably would have opted for the 600 mm.
At longer distances, the image becomes rather coarse. Even though I like the expression of the bird, the fine detail is lacking. The brilliance is lost compared to 400 mm f/2.8 or 560 mm f/5. It needs to be heavily stopped down to achieve such a result from a distance. Osprey — Sony 400 mm f/2.8 GM + TC2x at 800 mm f/8
Additional Accessories for the Sony 400 mm f/2.8 GM
As is often the case with new equipment, additional accessory upgrades are needed depending on the requirements. For me, there were two additions that were clear from the start: the lens foot and the lens protection with camouflage.
Lens Foot for the Sony 400 mm f/2.8 GM OSS
At the top of the image, you can see the original foot, and below it the aftermarket one with Arca-Swiss compatibility
The lens foot from Sony always comes bare, without Arca-Swiss compatibility, which I find quite lacking, especially in this price range. So, I had to buy and mount it afterward.
Lens Protection and Camouflage for the Sony 400 mm GM
There aren't many options for a camouflage lens cover for the 400 mm f/2.8 GM. It was primarily important to me that it wasn't a neoprene cover, but a solid material that fits perfectly and doesn't slip or fray.
Since Sony telephoto lenses are manufactured in white, I needed camouflage that also protects the lens from scratches, rain, etc. I would have gotten this even with a black lens.
Using the Sony 400 mm GM in Practice
Handling Sony Teleconverters
There is one major negative point regarding the TC’s for me personally!
Changing or mounting the TC is a real hassle, in the truest sense of the word. The focal length flexibility becomes a test of patience for me. Switching from 400 mm to 560 mm takes time and is fiddly, which creates agitation, especially when waiting in a hide. A dream solution would be an integrated TC that can be engaged at will, as seen in the latest lens generations from Nikon and OM System. That would be ideal!
Besides my personal issue with changing TCs, it also brings along another problem that affects every nature photographer.
Changing the Teleconverter in Cold or Heat
Fine ice crystals in the air, visible only at a low sun angle – a hazard for the camera sensor
During my winter trips to Hokkaido, I had to decide whether to shoot with or without a TC before the day’s tour started. One reason for this is that in snowy environments, fine ice crystals can float through the air, which can cause problems. These ice crystals are usually not visible to the naked eye but can be seen when sunlight hits them at the right angle. This can damage the camera sensor if it comes into contact with them. We are talking about an environment that constantly stays at -20 °C. A similar issue arises in extremely dusty environments, like on a safari. This is also why photographers carry multiple systems with different focal lengths on such tours. My examples were outside of Germany, but the same issue can occur here and is not necessarily country-specific. This must always be considered and addressed according to the situation. With a zoom lens or built-in TC, this problem can largely be ignored.
If you’re thinking, "That can be solved 100%, so what's the problem?" It's not that simple. Additionally, there is the risk that the sensor may fog up due to extreme temperature differences as soon as the lens is detached. This is also not optimal. However, there is always a solution, but the question is whether it is practical in use. In nature photography, you need to be able to react quickly to all situations. If an event is missed, it won’t happen again. Especially on trips!
Extreme Temperatures and Sony's 400 mm Prime Lens
On my trips, I used my equipment in extreme temperatures. However, there were no failures or limitations with the AF. At -20°C in Hokkaido, Japan, the lens performed excellently. In Tokyo, when I was photographing the "White-bellied green pigeon (Treron sieboldii)" by the sea in blazing sun at 40°C, there were also no problems. The camera was the weak point while filming, as it quickly overheated, but the lens remained stable.
Weight of the Sony 400 mm f/2.8 GM OSS
Generally, I prefer photographing with a tripod, but there are also tours where photos are taken handheld. In these cases, the Sony 400 mm GM becomes very heavy after a while, and it gets increasingly heavier over time. A monopod can provide relief for mobile use. However, for me personally, this is not necessarily practical, as I have to carry additional weight while walking. If there is enough light available, I prefer to use the Sony 100–400 mm GM, which is 1 kg lighter, or the Sony 200–600 mm G, which is still 600 g lighter. Another option is to carry the lens with a strap, which facilitates mobility but does not solve the weight problem.
Camera Backpack Challenge
Camera Backpack Challenge
You naturally encounter limits with a camera backpack. Previously, with the Sony 200–600 mm G, I could pack another lens, a backup camera, and accessories in the same compartment. This is no longer as manageable with the Sony 400 mm f/2.8 GM. Of course, you can somehow fit it in the backpack, but alongside the high weight, it's no longer as conveniently packed for quick access, especially when you need to move fast.
This brings me to the point that packing the lens with the mounted camera is not easily or only partially possible if other accessories need to be carried. One major advantage of the tele-zooms was arriving, reaching into the backpack, pulling out the gear, and starting to shoot. This process is now more complex in most cases, as the system first has to be "assembled" and later disassembled again.
Summary of My Long-Term Experience with the 400 f/2.8 GM
Do I still stand by my decision?
Yes, absolutely!
Most of the points that were important to me have been met, and I have great fun with the lens. A downside is the TC 2x. If this combination could match the performance of the 1.4x TC, it would be perfect. Therefore, I have nothing more to add. It delivers what it promises.
The negative points for me personally are the Sony TC 2x, the lack of an Arca-Swiss lens foot, and the process of changing TCs itself.
My Wish for a Sony 400 mm f/2.8 GM II OSS
In a new version of the lens, alongside an integrated TC and an Arca-Swiss footplate, a reduction in weight would be desirable. If the Sony 400 mm f/2.8 GM II could come close to 2 kg, that would be ideal. With the new Sony 300 mm f/2.8 GM OSS (1475 g), Sony has shown that they are moving in this direction. With these adjustments, it would be the perfect lens for me.
Pros and Cons of the Sony 400 mm f/2.8 OSS GM
Pros
Excellent Image Quality
Very high detail and image brilliance.
Beautiful bokeh at 400 mm f/2.8.
Aperture
Allows for earlier shooting in low light.
Fast shutter speeds without high ISO, especially for birds in flight.
Autofocus Speed
Very fast and precise autofocus.
Good performance even with the 1.4x teleconverter.
Balance and Handling
Well-balanced, making handheld shooting easier.
Center of gravity is far back, so it's not front-heavy.
Flexibility with Teleconverters
Extends focal length to 560 mm and 800 mm.
Minimal quality loss with the 1.4x teleconverter.
Robustness and Reliability
No failures in extreme temperatures.
Stable even in high temperatures.
Cons
Weight
At 2895 g, it is quite heavy.
Handheld shooting becomes tiring over time.
Performance of the 2x Teleconverter
Autofocus is less agile and precise.
Image quality decreases noticeably at 800 mm.
Lack of Arca-Swiss Compatibility
The original lens foot is not Arca-Swiss compatible and needs to be replaced.
Handling of the Teleconverter
Changing and mounting the teleconverter is cumbersome and time-consuming.
Risk of sensor damage from ice crystals or dust when changing in extreme environments.
Transport and Packaging
Difficult to pack in camera backpacks, especially with the mounted camera.
Complicated access and handling compared to zoom lenses.
Price
High purchase price, which may not be justified for every photographer.
