I wanted this lens for astro and travel. My early use was astro (travel will resume when world is ready). I was able to shoot the 4 inner moons of Jupiter with the Lens plus 2x on a stable mount. I expected to have to shoot longer exposures but with this pair I was shooting in sub-second times and really happy with the results on my Sony A1. Focus, stability and range all winners.

Light lens with a lot of range. Impage quality very good.

I'm generally happy with all aspects of this lens. I only wish it had a zoom lock switch.

I purchased this lens to augment my 200-600 by having a smaller , lighter alternative. The lens is well built, sharp and relatively small and lightweight. Highly recommend this lens in situations where you need the reach but size and weight need to be kept at a minimum

Did heavy research before purchasing this item. I was stuck between this and the 200-600mm. Glad I chose this one. Great portability and overall great build.

I'm using this lens on a Sony a7r iii A. I was concerned about the price vs performance but that concern has proven to be unfounded. I made the move from Nikon over to Sony last year and I have been blown away by the performance of my Sony system in all respects. Don't get me wrong, my Nikon D850 was the best DSLR I've ever owned, the problem was finding lenses that could keep up with the camera. Not so with Sony. The Sony 100-400 G-Master is SHARP across all of the Zoom range and the color fidelity is true to life. As a Landscape/Nature photographer for more than 40 years, I can say that this is the best Long lens I have ever owned, including lenses that came at three times the price. Their is plenty of info on-line that will provide specific objective data on how the lens performs, the real life performance is even better. This is a High Performance lens in all respects and B&H is the only business that I trust to buy from. Thank You B&H, Thank You Sony.

This lens is so sharp and the focus is blazing fast!

I have used the Sony G 70-300mm lens along with the Sony G 24-105mm lens for nature hikes but purchased the 100-400mm GM lens to gain more reach for wildlife. It is not a cheap lens, but the photo quality is amazing, and you can easily see difference between it and the less expensive 70-300mm lens. Yes, it's sharp. But there's also something else that's hard to put into words. The images just look better.

This is not a lightweight lens, and I'm definitely not a weightlifter. However, it's just light enough to carry and use handheld for half a day or so. It actually weighs more than my camera body...

I went back and forth between this lens and the Sony GM 200-600mm since the latter is a better range for bird photography. I do wish the 100-400mm had a short throw like the internally zooming 200-600mm one. But at the end of the day, I chose portability over reach and am quite happy with the choice. The other lens is just too large for me to realistically pack and carry.

Anecdotally, I also tried the Sigma 100-400mm F 5-6.3 lens and was not pleased with missed auto-focus on burst shots or the actual image quality. It's not really a fair comparison since the Sigma is much more affordable. But the Sony lens, for me, had better auto-focus performance and image quality (actually the Sony G 70-300mm was also superior and remains my choice for long hikes when the 100-400mm is too heavy). The build quality of the 100-400mm is also superior over the Sigma, and it is compatible with Sony's teleconverters. The Sigma also has a fairly long (and variable) min focal distance and was not convenient for close-up shots of flowers and bugs on a narrow hiking trail.

100-400mm is useful range for most things on a hike except wide landscapes (assuming you have enough light since the Sony 100-400mm lens isn't particularly fast), and I highly recommend this lens if it is within your budget. It is a worthwhile investment you will enjoy for years.

Yes it’s a bit hefty but for sports, wildlife, and even portraits, it’s a great focal length zoom lens. Extreme sharp and fast reliable auto focus with stabilization to complement the Alpha cameras.

This lens is incredible for everything from close up shots of flowers or hummingbrids to fast paced action of breaching whales in rough seas. The image stabilization and autofocus are outstanding. It is also built like a tank without feeling excessively heavy or at all off balanced. Fantastic lens!