Perhaps one of the most famous telephoto zoom lenses is the now discontinued Sigma 50-500mm EX HSM. For a long time this was the de facto standard in how much technology and sharpness you can put into a 10x optical telephoto zoom lens – At least for the DSLR market.

The 50-500mm focal length range is still unique and to this date Sigma is the only one who have this type of lens in their repertoire.

With this new 50-500mm F4.5-6.3 APO DG OS HSM length Sigma added a couple of things the most important being the OS or optical stabilizer.

The massive 10 times zoom span gives the user an impressive ability to switch between a number of tasks often done with multiple lenses. Ranging from portrait to motorsport to wildlife photography. Sure it would be quite awkward to carry a lens of this size to a portrait session but you have the option to do so. The most obvious choice of use for this lens would be wildlife photography and it is for such I´ve been using it for.

Compare it to the older non-OS version they are very alike. They both feature the same superb tripod collar with the built in grip. Although it only have threads for one bolt it´s long and solid. Locking or unlocking the collar goes with ease and the lens rotates very smooth within the collar if you´re switching to portrait orientation or back to landscape orientation.
Another great thing in the space for the tripod colar strap so the user carries the camera plus lens from the lens and not from the camera preventing stress on the lens mount. The lens includes the tripod collar strap as well!

The front element is increased to roughly 82mm probably to prevent vignetting on a full frame body being slightly larger than required for a 500mm F6.3 lens. Sigma´s includes and adapter if´s you´re using a APS-C size body. Otherwise the lens requires 95mm filters!

The lens features a couple of obvious buttons with the new one being the one for the built in optical stabilizer or OS.  This will allow the user to select either Off or mode 1 or 2.
In mode 1 the lens stabilises both in vertical and horizontal while in mode 2 its horizontal only. I found mode 1 to be the most useful. It function very well adding a couple of stops of “light” to play with.

The lens also features a lock/unlock button that allows the user to lock the lens at the shortest focal length 50mm to prevent lens creeping. Oddly Sigma didn´t add the same option for 500mm. I tried to roll back to 50mm and walk around with it for some time with the lock button unlocked and didn´t notice any lens creeping. Either way its a useful feature!

There´s also the typical AF / M focus button, where you choose auto focus or manual focus. Worth mentioning is this Sigma lens features a full-time manual focus override. If you´re in a situation where the auto focus fails to achieve whatever you´re aiming at, you can always manual focus afterwards. – You do not need to hit the AF / M switch.

Being a 500mm F6.3 zoom lens adds quite the weight. Bare in mind this lens is, although heavier than the Tamron 200-500mm F6.3 still a lot lighter than a 500mm F4 or F4.5 prime. Weighing in at barely 2 kg´s (1970 grams) you can in fact hike or walk with it all day. Compared to a prime 500mm F4 it´s more compact and less cumbersome albeit being slower F6.3 at 500mm. Worth mentioning it´s cost a fraction of the bare 500´s and adds 10x optical zoom. – As with everything it´s a compromise!

For a F6.3 at 500mm zoom lens the first thing that surprised me was the focus speed. It´s not lightning fast as a 500mm prime but despite the lack of focus limiter it´s quite good. Slower than Sigma´s own 100-300mm F4 it´s probably close to the 70-200mm and remember this is a 10x zoom lens. Highly impressive if you ask me but since I´m using a 1d series body so expect slower speeds on consumer orientated bodies. Either way it boggles me that Sigma didn´t went all the way and added a focus limiter. – Perhaps some day this would be a built in function on a camera body?..
The photo above of the yelling coot wasn´t to much of a challenge for the auto focus as it tracked it nicely. – I recon the Coot was at full rudder

One of the most important things if not the most important thing of any lens if the sharpness. I´ve been reading the few reviews of this lens available only and I didn´t know what to expect. Luckily I was in for a pleasant surprise.
The Sigma 50-500mm F4.5-6.3 APO DG OS HSM is sharp lens wide open at pretty much any focal length. So far I´ve been shooting most at 500mm and F6.3 and each and every time I´ve been blessed with sharp shots thanks to the SLD glass and the OS. Most shots are done without tripod some in very low light and some as slow a 1/80 in shutter speed! Since I´m usually shooting with the Sigma 300-800mm F5.6 EX HSM lens which weighs the same as three 50-500mm lenses and does not feature optical stabilization the 50-500mm is quite pleasant to use. So a big plus for sharpness and another for the OS.

The power of the 10x 50-500mm zoom can be very addicting. This above shot is taken a 50mm and 500mm. That is going from landscape photography to wildlife photography in a second!
Framing your subject is also much easier with a zoom lens. If it´s too tight just zoom out slightly and if you want a tighter framing just zoom in accordingly.

Downloadable samples straight from RAW. – Right click and choose “save as..”
Sample 1
Sample 2
Sample 3

Conclusion
To be honest I could probably go on about this lens and cover all focal length but choose to concentrate of the focal length I suspect most would use.
Overall the Sigma 50-500mm F4.5-6.3 APO DG OS HSM is a great lens. A true pendant to the famous Canon EF 100-400mm L being  wider and longer.

It´s quite sharp wide open on all focal lengths and therefore perfectly usable at F6.3.
There´s few things I wished for. One is the focus limiter and the other is that it would be a F5.6 lens up to around 450mm and not as it is now, around 200mm. There´s certainly the right amount of glass for it.

Either way it´s wonderful landscape, portrait, motorsport and wildlife lens – And that is quite the acheivement in itself!