Several months ago I rented the Sigma 150-500mm f/5-6.3 DG OS HSM APO from Camera Lens Rentals to take on my trip to Alaska.
First off, I really appreciate the quality service from Camera Lens Rentals. They have a nice selection of Pentax compatible gear for me since I use Pentax cameras.
Second, I read by most people traveling to Alaska, that if I wanted to get wildlife pictures, I would need a lens 300mm or longer and the biggest I owned was up to 250mm so I decided to rent the next best thing and that was the Sigma.
Since the aperture’s widest opening is f/5.0 I figured that I would need a little higher ISO than I was used to using. I was able to use a setting on my camera that allowed me to set my aperture and shutter speed manually but leave the ISO on auto and this was how I shot my pictures about 80% of the time. I also did not just leave the lens aperture wide open all the time but did close down to f/8.0 occasionally.
I did notice a sharpness difference between shooting at 400mm (which is sharper) and 500mm (which is less sharp). When I was in a crowd on a boat trying to get humpback whale pictures it was nice to pull the lens back in, narrow and lock it down so that the lens would not creep out when pointed down. But there were times I forgot to unlock the lens and zoom close to the whales to get pictures when they reappeared. I was trying to be courteous to others by pulling the big lens in so not to block or bump someone with it.
The one thing I noticed when photographing wildlife was that with the camera set to continuous shoot mode, the lens gave me more images in focus when I used the medium speed instead of the high speed. When I shot with my DA* 60mm – 250mm Pentax lens there was no problem with the lens keeping up with the focus at high speed. So the Sigma lens was slower at focusing even on a bright day.
I would rent this lens again if a situation arises. My general review is that it is a good lens and worked well for me once I figured out it’s short comings.
My suggestion would be that if you are in the market to purchase a lens in this focal length range do not hesitate to rent one first and try it out. Also, consider renting from Camera Lens Rentals.