Their day job primarily involves harassing the herd bulls, but the satellite bulls will also fight each other. These two young Rocky Mountain National Park bulls seemed to be sparing vs. having an all-out battle.
To keep the eyes of both bulls in the sharp plane of focus, a side-on position was taken. A low shooting position gives the elk a larger apparent stature and increases the background distance, letting it go strongly blurred.
This fight took place early in the day. With limited light, an all-action-stopping shutter speed required a very high ISO setting. I opted to shoot with a slow shutter speed to avoid the high noise levels. This decision reduced the keeper rate, but often a small number of great images is better than many mediocre ones, and I had a nice quantity of sharp images from the fight.
That said, the ISO 4000 setting yields a noticeable amount of noise. Subject detail, such as hair, hides noise better than evenly colored areas, such as the smoothly blurred background. Strong noise reduction destroys details, but it is especially helpful for removing noise from a blurred background.
So, this image was processed once with weak noise reduction and once with strong noise reduction. The two images were loaded into photoshop layers, with the subject-selected mask hiding the strong noise reduction layer. The subjects retain details (and noise) and the background appears similar to a low ISO setting. A similar tactic can be used in Lightroom.
A larger version of this image is available here.