Sigma150-600mm 5-6.3 Contemporary DG OS HSM Lens for Nikon

I'm totally amazed with the way this lens shoots, both with the matched Sigma 1.4 Teleconverter and without... The highly rated 1.4 Teleconverter is also worth every penny, and takes 'No' sharpness away, I also believe only adds to it. Auto focus worked perfect also with the TC and is so fast.I'm using this wonderful lens mounted on my new beloved Nikon Z6 Mk2 full frame Mirrorless camera for both wildlife and astrophotography, including quite a bit of deep-sky work... The lens and camera are mounted on a gimbal equipped heavy-duty tripod I used in my Photography business for 14 years.After reading everything I could on this Sigma 150-600 Contemporary lens, I also read so many who compared the sharpness of this C lens very close, and even equal in several cases to the 1lb heavier Sport lens which also costs $1k more... The S lens is probably a tiny bit sharper with it's extra glass group but for a grand more and a pound heavier this Lens has totally amazed me.I've intended for 2 years to finally purchase a high-quality Telescope and GoTo Equatorial tracking mount but simply haven't been able to chose which type, so this Samsung 150\210mm to 600\850mm (with 1.4 Teleconverter) lens has been perfect for the interim.Zooms traditionally being a bit soft wide open, as well as at the full zoom position are well known compared to Prime lenses and individual lenses each have their own personality for sweet spots... With this in mind I truly believe I've purchased a very fine piece... I can only pray they are all coming out of manufacturing with this great quality.As many have attested my lens is a tiny bit soft at 150mm yet still very acceptable, but from there out to 600\850mm its razor sharp... I've found f9 to be it's sweet spot, but f11 out to f40 are almost just as sharp, it's very close all the way including out to 850mm.One of the images I'll add shows two bucks measured on Google Earth at 3\4 mile and was shot at 850mm with the matching 1.4 Sigma Teleconverter.. The heat distortion was huge considering it was shot off my car hood last week at our record 16°. The image is a bit fuzzy but considering it was shot hand held off my car hood at 3\4 mile with so much heat distortion and 850mm I was impressed. I'll add a couple others as well.This lens is an amazing accomplishment for Sigma and is well worth every penny.

First off, I'll say I'm an advanced enthusiast not into pixel peeping. But this lens is great! I got it primarily for some random nature walks and the 2 airshows I attend each year. Optically, it's very sharp in the middle all focal lengths but definitely visibly falls off in the corners as I'm using it on a full-frame Canon 6D. Not deal breaking but the outer edges are noticeably less sharp without pixel peeping. Color rendition is very good, similar to my Canon L lenses, but probably just a bit less saturated/dull. Focus speed is very good, I haven't missed any shots because of it yet. If you use the focus distance limiting switches, it's even faster because it limits the focus hunting. I haven't done any high speed tracking/panning with it yet, but that's not a super strength of the Canon 6D to begin with. Build quality is excellent for the price. Zoom and focus rings have good tension, no rough spots throughout the range. All the parts fit together nicely, no play or wiggle while zooming. The first part of the body (last 2" near the mount) is metal, the rest is thermally stable plastic as is pretty much the norm these days for non-professional grade lenses. The tripod foot is also removeable and the lens includes a nice silicone ring to protect the foot mounts when removed. It's also worth noting the lens comes with a nice padded, Sigma labeled bag with a strap to store/transport the lens. This is a nice touch and saved me a few bucks since any third party lens case big enough to hold this size lens is at least $40. Weight could definitely be an issue for some. At 4.25lbs its my heaviest lens by far. I use a Black Rapid RS-5 sling strap and it makes it relatively easy to carry, but a standard neck strap wouldn't work for anything more than a short stint. For days at the airshow, I plan on using my monopod. As a matter of habit and good practice I always put a B+W UV MRC filter on all my lenses. So just a warning that at 95mm, that size filter cost more than 10% of the lens' cost! I waffled between this lens and the twice as expensive Sport model. From the few online reviews available, the only real "cons" to this lens verses the sport is slightly lower optical clarity (but I'm not a pixel peeper as previously noted), slightly slower focus (could be an issue, but I'm no pro to begin with), and lack of the tank-like build quality and weather sealing. So given these 3 cons, the only one that would really affect my personal use is build quality and I couldn't justify another thousand dollars for that. The other obvious comparison for this lens is the similarly priced Tamron 150-600. So the following is what swayed me to the Sigma: I'll say that I generally prefer Sigma to Tamron for third party lenses (though I do own Tamron's excellent new SP 15-30mm F2.8), I really like the look of Sigma's new Global Vision lens line (personal preference), the Sigma included a nice padded case, and the final one up over the Tamron is Sigma's USB dock. And lastly, to cover the USB dock. This lens has two "Custom" mode positions, and I made C1 a setting to prioritize speed in it's focus and OS and C2 a setting to prioritize accuracy in its focus and OS.Update 11-16-2015: I still stand by this lens, it really is great. Added some pics from the Great New England Airshow. It was a cloudy, hazy, summer day and the lens still captured some pretty good color saturation. Pics taken with my Canon 6D, all handheld, really shows off the len's OS. Most pics were keepers (or at least good enough) given the fairly high-speed tracking.