Sigma 170-500mm F5-6.3 APO Aspherical A-mount lens review by Miranda F

reviewer#44034 date: Mar-20-2018
sharpness: 4.5
color: 5
build: 5
distortion: 4
flare control: 4
overall: 4.5
tested on:
  • film camera:Film camera
  • APS-C: 6MP6 MP; 10MP10 MP; 12MP12 MP; 14MP14 MP; 16MP16 MP; 20MP20 MP; 24MP24 MP
  • full frame: 12MP12 MP24MP24 MP36MP36 MP42MP42 MP
ownership:I own this lens
compared to:Minolta 75-300, 100-300, 100-300 APO
Sony 55-200, 55-300, 18-250, 70-400
MF primes 300, 350, 450, 500
MF Mirror lenses 300, Tamron 500 (55B & 55BB)
price paid:£180
positive:Maximum Focal length
Removable tripod mount
Not that heavy for the FL.
negative:Slow AF
Heavy for hand-holding
Slow at the long end
Quite long MFD (though not the longest I've used).
Zoom creep if you hand-hold it.
comment:Handling: It's the heaviest lens I have by quite a long way, but it's also the only AF lens I have over 300mm and AF lenses reaching 500mm are not that light. It has a very good tripod mount which rotates, locks, and is easily removable for hand holding. Mine came in a very nice (original?) soft bag which is strong and well-padded and makes a good transit bag.
The bayonet lens hood is a little loose (I added some tape) and reverses onto the lens which is useful. I didn't notice a lot of flare or veiling without it, though.
On a tripod with a pan & tilt head it seems well balanced with a big camera like the A900 on it.
Sharpness: I'd echo Roo's comments. If you test it the way you test any other lens isn't as sharp as some, but the longest lenses never are. In comaprative tests over a fixed distance it gave sharper results than any of the xx-300mm zooms I have and at 500mm results were almost as sharp as the Tamron 500mm mirrors (which are very sharp), but of course the Sigma has AF which makes it a whole lot less difficult to get a sharp result (MF lenses can be a bit hit-and-miss). I have several long film-era MF present primes which I've also used for birding, and this beats them all except for weight.
I've had good results birding with this, especially with tripod, but if the light is good then hand-holding with IBIS on can work well but I wouldn't want to do that for long unless I can build my muscles back up! But carrying the tripod around with the camera and lens still fitted is actually quite easy. Interestingly enough, I didn't find any problems leaving IBIS switched on when mounted on a tripod, unlike shorter lenses.
The lens seems quite good in the corners with little CA, and is quite useable fully open. I got some very nice moon shots with it, and at 500mm found not a lot of difference between f6.3, f8, and f10. MFD is a bit on the long side and more than ocne I've had to lift it off the tripod and mvoe back when an enthusiastic bird comes too close, but for more wary birds like Kingdishers it's fine. I tried the 70-400 SOny in a shop and quite liked it, and that's very sharp too.

It's by far the cheapest zoom available in its length, and on a tripod will give better results than any of the 300mm lenses, but it's not the casually carried lens like some of the others are. If you need something of this size and don't have much money to spare, it's a good choice.
Oh, I should say that my copy has no MF due to a freely-spinning MF ring, but that hasn't been an issue for me as the AF works well. AF is a trifle slow, like most long lenses, and AF definitely works better on the A900 than the A58.

rating summary

lens image
  • total reviews: 16
  • sharpness: 4.16
  • color: 4.19
  • build: 4.25
  • distortion: 4.63
  • flare control: 4.50
  • overall: 4.34 - Home of the alpha system photographer
In memory of Cameron Hill - brettania