Summary: i got this lens for an african safari trip. it's way big and heavy for carrying in your hands for hours at a time. but those are the only downsides. as i started taking pics of wild animals, i was happy that i bought this lens. focus is very fast and images are sharp despite the jeep was constantly in motion so even a monopod or tripod would not have helped. i got some gallery shots from the trip so i'm happy with it.
Summary: When you can shoot this lens at f/8 or smaller the lens is very sharp. If you are using this lens for action photography you are limited to daytime shooting. This lens is all but useless when shooting in poor lighting. Would not recommend for inside action or sports under the lights. When shooting wide open the image becomes very soft to the point I thought the lens was not focusing properly. I was so bothered by the images wide open that I contacted a Sony Technician.
Heavy lens but optical quality will impress every time. A bit $ maybe.
10 August 2012
Summary: I decided to switch from Nikon (D300 & D7000) to the Sony Alpha A77 in part because I was looking for a better feature set (like 12 FPS, 1080p/60 video) and maybe hoping for outstanding optics too. I was also frustrated by the lack of a modern lens of this very handy range. Sony also has the connection to Zeiss which has a pretty good rep. for quality optics! I have the Nikon 80-400 VR and it's okay (see other my review) but it was never outstanding, just okay.
I use this lens for 400mm shots and find it a little heavy to hold.
10 June 2012
Summary: I did a comparison with my SAL70300G and the lenses at 300MM are extremely close as far as sharpness. The 70400G just tweaks out the 70300G by the skin on my teeth. The 400mm photos are not the same quality and need to be inhansed in Photoshop to make them as sharp, compared to the 300mm photos of the same subject. What I been reading is that when you use a zoom at the end of the range, it will always lacks in sharpness. This is true with using the aperture wide open.
Summary: Although this is not a prime lens, it has image quality rivaling primes in all it's focal length. Simply the best zoom lens in this focal range compared to competitors. Wish it had weather sealing. Very good companion to my A900.
Summary: This is the first lens I have bought beyond the "kit" lenses that come packaged with a body. So, my expertise for evaluating this lens is limited. I bought it primarily to give me the capability of capturing faster wildlife action (birds) in lower light situations. At this point I am still learning to use it to best advantage. However, after one 5 day birding trip, I can say it meets my expectations.