Sigma 120-300mm f/2.8 DG OS HSM Sports Lens Sample Pictures

A black horse against a bright white sky becomes an autoexposure challenge. Since the lighting levels were stable on this very cloudy day, I opted for a manual exposure. Every shot in this session was perfectly exposed. Or nearly so.
 
I also took advantage of the white sky to create a high key look from this high altitude location. Using a low camera position emphasizes the height of the jump.

Environmental portraits, by my own definition, are usually captured with a wide angle focal length to show a subject's "environment". But this girl's riding gear tells me the full story.
 
The strong magnification of a telephoto lens makes the distant trees a nice blurry backdrop that makes the subject pop.
 
Note that I did not need a 1/1600 shutter speed to stop the action in this image, but the difference between ISO 160 and ISO 100 is not significant. I simply used the action settings I had been using.

I know there are lots of galloping horse pictures on the site, but there is a good reason for that. Because I can usually round up a rider and because galloping American quarter horses are very fast (called "World's Fastest Athlete" with some capable of over 50 mph), I have a consistently available and very challenging subject for testing camera and lens autofocus capabilities. Because I shoot this subject regularly, it is easier for me to differentiate the abilities of various DSLR cameras and lenses. Mix in some other scenarios and I can get a solid feel for a camera and lens' capabilities.

A small patch of beautiful flowers can provide hours of entertainment and endless composition opportunities. Choose a long focal length and wide aperture to add blur to some of those compositions.

Taking a picture of a textile as a primary subject, for purposes other than marketing that textile, seems a bit like cheating as someone has already done the design work including establishing complementing colors. But, textiles can still make a colorful photo. Use your creativity to work some blur into the shot.