Is there a single word or phrase that means a group of very similar photos, such as when a photographer takes a burst of 7-8 shots with the hope of catching the right instant, or to get the best focus?
I think you are referring to a sequence of photos:
- Sequence photography is the technique of combining different shots of the same subject to present its course of action in a final single image. Capturing a subject in motion will provide you with images which, basically, have the subject at different moments of its movement throughout the frame, usually with the same background (in the case of the most popular type, where the camera is fixed but the subject moves).
Burst or Continuous Shooting
Burst or Continuous Shooting mode is the digital camera's ability to take several shots immediately one after another, similar to a film SLR camera with a motorwind.
a burst of 7-8 shots
“Burst” is the correct term of art. You’ll see some cameras have a feature called “burst mode.” Instead of shooting just one shot of one setup, you shoot a burst of shots of one setup, and then later pick the best out of the burst. A burst of 7–8 shots might be taken in only 1–2 seconds. Instead of tapping the shutter just once for a single photograph, the photographer holds it down just once and shoots a burst.
A “sequence” is bigger than a burst. A sequence implies each photo had some thought behind it. A sequence of 7–8 shots might be taken over 15–30 seconds.
Larger than that would be a “gallery” — a gallery of 7–8 shots might be taken over the course of an hour or a day.
Photographers often bracket their shots to maximize their likelihood of obtaining the optimal exposure:
4 c : to take photographs of at more than one exposure in order to ensure that the desired exposure is obtained
The related noun is also bracket:
4 : a section of a continuously numbered or graded series (as age ranges or income levels)
(Definitions from Merriam-Webster.com)