Since the end of October, I can call the Sony GN 400 mm f2.8 my own. After a short testing phase, I will briefly share my first impressions and pictures from my sessions with the Sony GN 400 mm f2.8 OSS. In a later post, I will go into the details, but I want to gain more experience with the lens first.

The areas where I tested the GM 400 were in a wildlife park in the forest (deer, nuthatches, etc.), a pond in the forest (White-tailed eagle perch), and a riverbed with a forest edge (white-throated dipper ).

The wildlife park was a testing environment for me to get familiar with the lens in peace. During the eagle perch sessions, the weather conditions were not optimal. On my three attempts on different days, there was always heavy fog that only cleared by late noon. I had a bit more luck with the dippers, with one cloudy and one sunny day. Nonetheless, from my perspective, the 400 mm lens demonstrated above-average performance in all situations.

If you want to skip ahead and see the pictures right away, you can find them distributed throughout the article. The descriptions are embedded and become visible when you click on the images. Last weekend, I was able to photograph some native songbirds in the forest, which I have also included—blue tits and great tits.

Additional accessories for the Sony 400 mm f/2.8 GM

The Tripod foot

A point of criticism for all Sony telephoto lenses with a tripod foot is their lack of ARCA-Swiss compatibility. Thus, I have to attach an additional ARCA-Swiss plate underneath for tripod mounting. That's why I bought a corresponding tripod foot with an ARCA-Swiss mount from a third-party supplier. With this, I can attach the lens to the tripod quickly and without any fiddly screwing.

GM 400 mm f2.8 OSS Lens coat / Lens cover

On all my telephoto lenses, there is a so-called lens coat / lens cover. This protects the exterior of the lens from scratches and light moisture. It is not intended as rain protection per se, but light drizzle is not a problem. If unexpected heavy rain occurs, a lens coat /lens cover can still protect the lens from the worst of it.

Additionally, I got the lens coat/lens cover with a camouflage pattern, which blends better into nature. While many other manufacturers design their telephoto lenses in black, Sony has kept them in white. Therefore, the lens coat is also ideal for minimizing the conspicuousness, i.e., the reflection of the white lens. A white lens stands out too much among green trees or bushes.

Handling of the Sony 400 mm f2.8

The GM 400 is not a lens I take with me while walking around. I prefer a lightweight combo for that, such as the Sony GM 100-400 mm f4.5/5.6 with a Sony body without a battery grip (2130g total weight). In comparison, the GM 400 mm alone weighs 2895g. Nevertheless, the lens is a lightweight in its class and is perfectly balanced. The center of gravity is very far back, allowing for excellent handheld shooting for a while. However, in my opinion, it is not optimal for long hikes or terrain scouting as it is not light and compact. Ultimately, this is up to personal preference.

My focus is more on handling it in my workflow when shooting from a stationary position. This starts with preparation at home and ends with packing up the equipment at the end of the day.

Packing a telephoto prime lens and a backpack

Fortunately, I already use a camera backpack with a 45L volume. This size still fits the 400 mm well. I would have had a problem with the GM f4 600 mm. Nevertheless, the space in the backpack is limited, and another telephoto zoom lens does not fit in. Unless I forgo other equipment. Additional equipment would require another backpack. When stowing, I now also have to detach the camera from the lens, which was not the case with the compact tele-zooms.

Setup at the Hide

The next point focuses on setting up at the hide, and I’m not talking about an existing photo hide. This involves places where camouflage and camera equipment need to be set up first. In my case, this happens 90% of the time and usually in darkness.

To explain, when I am in a hide, the planned sessions are in areas I have previously scouted and know what to expect. I aim to get specific photos of a species. In most cases, these spots are in accessible terrain. To photograph the animals without being detected, I start my day 1 ½ to 2 hours before sunrise. This means that the setup is mostly done in darkness or twilight.

With the new prime lens, additional steps have been added. Previously, I could mount two cameras with already attached telephoto lenses directly from the backpack onto the tripod. Now, I have to connect the camera to the 400 mm lens on-site. I also need to bring another backpack if I want to use a second camera with a telephoto lens.

The lens cap and the lens hood on the 400 mm are more cumbersome to handle than on the telephoto zooms. On the Sony 100-400 mm or the Sony 200-600 mm, the lens cap has a snap closure, allowing for quick removal. On the Sony GM 400 mm f2.8, the cap also encloses the lens hood and is simply slipped over. What takes a few seconds with the telephoto zooms takes a bit longer with the 400 mm. The lens cap is awkward to remove, and attaching the lens hood takes more time since you have to unscrew the fixation and then screw the lens hood back on in reverse.

This is not meant to be high-level complaining, but for me, this equipment is a tool I want to handle effectively. Each additional step I need to take before I can even take a photo is a time investment and has potential for errors. For example, when attaching the lens hood, it’s easy to leave a fingerprint on the exposed front glass. For better understanding, with the telephoto zooms, I can attach the lens hood first and then remove the lens cap. With the 400 mm or 600 mm GM, this is not possible. Here, the lens cap must be removed first before the lens hood can be attached. I would have preferred a better solution without having to purchase it separately later.

Brightness & Autofocus of the GM 400 mm f2.8

Now to the points that don't sound quite so gloomy 😀

With an aperture of f2.8, every photographer knows that a lot of light hits the sensor, which is a huge advantage for a telephoto lens used for wildlife photography. This became immediately apparent during my first outings, especially during the transitions between different light phases from night to sunrise. As I mentioned in my last blog post - Sony GM 400 mm f2.8 instead of Sony GM 600 mm f4 -, one of the most important deciding factors for the 400 mm f2.8 was its brightness. This is because the environment where I mostly shoot tends to be low-light, such as forest areas. To put it simply, the 400 mm shows why this lens is in this price category.

I had the Sony GM 100-400 mm alongside the Sony GM 400 mm f2.8 for comparison. The GM 400 mm f2.8 could be used much earlier in the twilight, and the autofocus had no problems focusing on birds in flight in low light. This was also true under difficult conditions such as dense fog, like during my hide session for white-tailed eagles. The 100-400 mm f4.6/5.6 could not do this; the focus wandered back and forth without being able to fix on the subject under these conditions.

A surprise?

No, but experiencing this performance firsthand in practice was a joy and confirmed that I had made the right decision.

GM 400 mm f2.8 + TC 1.4x vs. GM 600 mm f4

If you read my last blog post about why I chose the 400 mm from Sony, you know that it was important for me to use teleconverters without significant quality loss. This allows me to achieve nearly 600 mm or, to be precise, 560 mm with high performance.

A photography buddy who uses the Sony GM 600 mm f4 joined me for a white-tailed eagle photo session. This gave me the opportunity to get a small impression of the Sony 600 mm f4. As expected, it is amazing! But my main question was about the image quality and focus performance of the Sony GM 400 mm f2.8 + TC 1.4x at 560 mm compared to the Sony GM 600 mm f4.

I was able to take a few comparison shots. I switched my camera between both lenses and photographed under the same lighting conditions and distances. In terms of image quality, the 400 mm + TC 1.4x is on par with the 600 mm when stopped down to f5. The use of the TC 1.4x shows a slight softness at f4, which is resolved by stopping down to f5.

The topic of teleconverters has occupied me intensively over the past few weeks. I will write a separate article about it. It is difficult to summarize this topic in one sentence. I also want to gain more experience with using TC’s on the lens before giving a final opinion. However, I can tentatively say that the Sony TC 2x can/should only be used conditionally with the 400 mm. The Sony GM 600 mm, from my first impression, handles the TC 1.4x and TC 2x much better.

Focus Performance with TC

Regarding focus performance, I can't give a definitive opinion yet since I haven't tested many scenarios with both lenses. However, I felt that the GM 600 mm f4 performed slightly better than the GM 400 mm f2.8 + TC 1.4x. This is not surprising, but I would describe the difference as marginal. The difference is as minimal as the one I notice between the 400 mm f2.8 and the 560 mm f5 with TC. I can't think of a situation where this would be a downside for the 400 mm. The autofocus performance is outstanding in both cases.

White-throated dipper in flight - Left: Sony A1 + 400 mm - f2.8 - 1/1250 Right: Sony A1 + 400 mm f2.8 + TC 1.4X - at 560 mm - f5 - 1/2000

CONCLUSION:
All in all, my purchase decision has been validated. With the Sony 400 mm f2.8 GM OSS, I feel like I've made a quantum leap in terms of focus speed and brightness. 😀 The sharpness of the lens is also a bit better compared to the Sony zoom lenses G 200-600 mm or GM 100-400 mm. However, this is not a criterion for buying this lens; that would be splitting expensive hairs!

The performance with the TC 1.4x has been as expected so far, although I had hoped for significantly better performance with the TC 2x. A new version of the TC’s, better tuned to the prime lens, could potentially offer even more. This can be seen with Nikon, who have integrated a TC specifically matched to their new 400 mm lens.

These are my first impressions for now, and I hope you enjoy the photos.

See you soon!

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