There is one lens that wildlife photographers seem to have in their camera bag wherever they are going and whatever they are shooting – the Sony 100-400mm f/4.5-5.6 OSS G Master lens. Spanish wildlife photographer Javier Aznar is no exception, with his 100-400mm lens a permanent fixture in his camera bag.

“The Sony 100-400mm is such a versatile lens because it is so small and light,” says Javier. “The optical Steadyshot, combined with the light weight, make it easy to use handheld. If I have to bring a telephoto lens, I always bring it with me. I use it for many things; landscapes, wildlife, birds and even small insects!”

Javier pairs his 100-400mm lens with the Sony Alpha 7R IV and Alpha 7R V. The cameras provide him with an incredible 60 megapixel resolution, allowing him to crop into images where needed; in the APS-C mode images are an impressive 33 megapixels, which is more than enough resolution for the demands of most photographers.

With a high resolution combined with close focusing distance of less than one metre, the Sony 100-400mm allows Javier to take close-up wildlife images whilst maintaining a good working distance from his subject.

Besides the size and weight, it is the image quality that photographers love, with it exceeding expectations for a zoom lens. Javier describes the image quality as “insane - it doesn't matter what aperture I use, it produces sharp images.”

Like most photographers, Javier prefers to compose his images as much as possible in-camera. “The beauty of the lens is that I can compose with the zoom lens and in-camera crop mode. This reduces the time I need to spend editing on a computer afterwards. “I will often set the custom button on the 100-400mm to the APS-C crop mode, so I only need to press this button to get a tighter crop on the subject when I want to take a close-up shot. And I can see it happen instantly through the viewfinder, without going into any menus.”

There are some compromises when you compare shooting with the 100-400mm and a lens such as the Sony FE 400mm f/2.8 GM OSS or the FE 600mm f/4 GM OSS lenses, mainly due to the larger apertures of these much more expensive fixed focal length lenses. However, the benefits far outweigh any compromises. “Even if I sacrifice some light, as it is not an f/2.8 or f/4 lens, I use it much more often than if I brought just one fixed lens, such as a 400mm or 600mm. Those lenses are great if you have a particular use, but I can use the 100-400mm for a greater variety of images.”

There are shots where the 100-400mm made it possible to get an image that would have been otherwise difficult to obtain. One is a beautifully composed shot of white storks perched on top of lampposts. However, what is out of the picture made the image particularly awkward to take.

“It was shot next to a landfill site, with a fence all around,” Javier recalls. “If I had a fixed focal length lens, I probably wouldn't have been able to take this shot because the lens would be heavier. As it was, I had to put the camera and lens over the fence to compose and take the shot. I took it at 212mm, and I could only get this because I had the flexibility of using a zoom lens.”

There is another often overlooked feature of the 100-400mm that Javier loves, and that is the filter thread. The zoom lens uses a 77mm filter thread, saving valuable space in Javier's bag. “That makes it perfect because travel-wise, I'm always looking for small and light kit. The lens has the same 77mm filter thread as my FE 24-70mm f/2.8 G Master lens, so I can use the same filters on both lenses.”

With a passion for photographing wildlife in such impressive detail, Javier needs a lens that can perform at the highest level – and he’s found the perfect partner in the Sony 100-400mm f/4.5-5.6 OSS G Master.