I don't no what some of you are talking about saying it dose not work with sigma. It dose work with both of my Sigma 70-200mm sport and 150-600mm Sports but the Auto Focus dose not work with I don't mind and it dose not fall off. I love it and it works really well. I just got it.

Very sturdy and securely holds my DSLR plus 500mm lens via a gimbal.

Instead of attaching this to my camera, I attached it to my 500mm lens tripod ring.

Fantastic value for the money. I got two, deeply discounted at around $10 each, and am still wondering whether the low price was a mistake. These would be worth it even at regular price. Very sturdy!I attached one to a Pentax K3 with no issues. The other went on my vintage Pentax 35mm, and for that I needed to use a standard hole punch to make the small hole in the little protective leather flaps just a tad wider. On both cameras, the straps hang just right.I am a short woman, and the length is just fine for me with no adjustments. I can either place it over one shoulder, cross-body, or around my neck. The reverse side is a soft suede-like fabric. I especially like how the part right where it hits my shoulder has extra padding.The color is a beautiful cognac brown and looks amazing. (My picture has pretty dark lighting.)I will report back if anything changes, but so far, so good!

Fits my Pentax DSLR. It’s lightweight, and works well.

Not sure exactly what I was expecting...something between a useless toy and cheap-n-good. Mostly, something to get a better idea of how long a lens I'll want when it comes time to buy a 'real' supertelephoto (I.E.: mortgage my life for a Canon "L"). I've been shooting with SLRs and now DSLRs for a half-century, but somehow I've never used anything longer than 200mm. I figured that 500mm would be another world--and it is.None of the review examples posted here gave me more than hint at what this lens would do, but I bought one anyway. Mine came branded Vivitar, but that doesn't mean much of anything these days. It's reasonably pretty and the T-mount-to-EF adapter mated nicely. It focuses past infinity. Focus is smooth if a bit stiff, and the f-stop detents are positive. The stop-down ring is much too stiff for my taste. I have no interest in the 2x teleconverter.It has a minimally effective AR coating, but I wasn't expecting any. I thought that it might be a simple telescope at this price. But being physically shorter than it's effective focal length, it is a real telephoto lens.After a much less than successful attempt at taking shots of the moon, I was convinced that I wouldn't learn much from it. So I requested a return.The night that I was packing it up to ship back, I decided to give it another chance. Just an informal quickie. Printed up part of the standard ISO 12233 target and taped it to a toolbox 3 rooms with open doors away, for about 32 feet. An ancient Canon 1D MkII N was all that was handy, but it's 8.2M pixels were fine for this test. (APS-H sensor, so 500mm x 1.3 = 650mm equivalent.)f/16 (two stops down) for more sharpness and depth of field, indoors at 1/5 second and ISO100. The three pix I've posted are the same photo, full frame resized to the maximum width of a review photo, plus two crops at 100% (400x420). Otherwise, straight from the camera. As printed, the finest pitch of the lines on the target measured 1/32".So this lens is resolving a surprising 32 lines per inch at 32 feet, with decent contrast and only moderate chromatic aberration. If you've stared at many resolution targets, you'll appreciate at how good that is for any lens in this price range. (Check out reviews of the Canon EF 500mm f/4L IS II USM to see how much sharpness $9k will buy,)Now, cheap lenses like this generally have a lot of unit-to-unit variation in quality, and I wasn't getting that kind of resolution throughout the frame (at least partly because the paper target wasn't lying completely flat). YMMV.Some other caveats: There aren't many tripods that are solid enough (mine wasn't) for a resolution test at this slow shutter speed and I was in too much of a hurry to figure out how to lock up the mirror. Plus, this lens is physically very light adding little mass for stability. So I put the camera on a heavy table, shimmed the lens up to a useful angle, and used the self-timer.The rule-of-thumb for hand held without image stabilization is a maximum exposure time that is the reciprocal of the focal length. So 1/500 second for a 500mm lens. But that’s the maximum for reasonable sharpness with a reasonably stead hand. To show off this lens' sharpness, maybe an extra stop or two faster shutter when out and about. Sunny16 would suggest full daylight at f/16, 1/1000 second and ISO1000.At f/8 wide open, this is a mighty slow (dim) lens. I wasn't able to get an accurate focus indoors without a 2.5x viewfinder attachment, and even that was a challenge with 20-20 and OK night vision.Conclusions? 500mm is probably somewhat more than I want on a full-frame body and about half what I'd like from a telescope. I really will need to rent an expensive lens before popping the cash to purchase, but this gives me a rough starting point.All said and done, I'm glad that I bought it, and will definitely keep it to fool around with.

I ordered the 52mm filter because the 30mm f1.4 sigma lens for sony e-mount cameras has a 52mm thread but after lens arrived, I couldn't fit it on.But after-service support was pretty helpful in telling me this

Why i first went with the Sigma 35 i have no clue! Ended up getting this one after my sigma took a fall and was getting repaired. I know am selling my Sigma 35m because it can't compete with the canon version. Its worth every penny.