Working a Subject
The screen capture visible below from Canon Digital Photo Professional (DPP) of multiple dragonfly photos gives an example of how I work a subject. Of note, I was in Av (aperture priority) mode with Auto ISO which is something I rarely use. Just like with film, high ISOs result in additional noise/grain. Thus, I typically try to stay at ISO 200 and not go above ISO 320 to minimize the noise in my photos unless necessary to get a sharp photo. The minimum ISO I can set is 200 because I leave highlight tone priority (HTP) enabled so that I capture more highlight detail in my RAW files. Only if I were to disable HTP, which I have done less than a handful of times to get the absolute longest shutter speed possible, am I able to drop my ISO to the baseline 100. You can also see through the sequence in the screen capture how the camera automatically adjusted the ISO slower by one third of a stop (from 1250 to 1000). That can only be attributed to a slight increase in the total amount of light.
While on the topic of Auto ISO, I configure my cameras so when they are in Auto ISO mode the maximum ISO they will set is 3200 even if the camera supports something higher. That's done to minimize noise. I expose to the right for all my photos, but doing so is even more vital when I have to push my ISO up past 320. If I don't expose to the right in those situations, depending on the subject, I end up with horrible noise and delete the resultant photo. I do see the 7D Mark II doing a better job of controlling noise at higher ISOs than all previous digital Canon's I've owned, even more so than the full frame 5D Mark III. Hopefully that noise performance improvement trend will continue in any future DSLRs they release.
All the photos in the DPP screen capture were shot off a tripod but with a loose ball head essentially being used like a monopod which allowed me to quickly make minor adjustments to composition. Since the available light gave me really slow shutter speeds at ISO 200 at the f/7.1-f/8 range I wanted, I put the camera in Auto ISO mode so I could keep those apertures while still getting enough shutter speed to freeze the dragonfly motion. I used the depth-of-field preview to determine that was the aperture range I wanted to sufficiently blur out the background while still getting enough detail in the dragonfly.
The screen capture doesn't show the full sequence, but you can see I actually opted to drop shutter speed from 1/320 to 1/250 between the first and second shot in order to allow the ISO to drop a third of a stop (1600 to 1250) so I would end up with a little less noise. When shooting macro I often use flash to help with this situation of not having enough ambient light to freeze motion at the aperture I want, to even out the subject lighting, or to independently control the illumination of the subject and background, although I chose not to use flash for this dragonfly. You can see how flash or a reflector can be used to even out subject lighting in the following two photos of an orchid. One was using natural, diffused light from the cloudy sky. The other used fill flash to brighten the shadows. Personally, I have a strong preference for the latter with fill flash, since I find it makes the subject orchid look more colorful and appealing.
Back to the DPP screen capture, the first two shots (8068-8069) were with the dragonfly parallel to the sensor. I intentionally positioned the camera like this to keep the whole insect in focus. However, I didn't like the 2-dimensional result which left the dragonfly looking out the left side of the frame and leading the viewer's eye right out of the photo. I also didn't like that dark area on the middle right edge of the frame since I also found it distracting and leading the viewer's eye out of the photo instead of back into it. Fortunately, the dragonfly shifted position slightly giving me a better composition (at the expense of no longer having the whole dragonfly body in focus), but I still had that distracting dark area on the right edge of the frame. So I moved the whole camera slightly to my right, pushing that dark area outside the frame and giving me a more balanced background for shots 8072-8073. As I always do, I deleted all the previous raw files keeping only one of these final vertical composition shots. The final two shots were composed horizontally. Unless a subject doesn't support both a good horizontal and vertical composition or it flies away before I can capture both, I always try to shoot vertical and horizontal compositions of subjects so I have versatility in the use of the photos later.
Why multiple shots of the same composition? Simply put, insurance. I almost always take at two or more photos of a subject in the same orientation (vertical or horizontal) in case one is blurred due to motion, had a distracting bird or insect fly through during exposure, or the focus is off. When shooting macro or moving subjects, I take even more photos slightly changing the focus point to ensure I have the eyes in sharp focus. When editing, I choose the best of the bunch and delete the rest.
Canon DPP Displayed Information:
For those who are curious, you'll notice the filenames below each image, the aperture, shutter speed, and ISO at the right of each image, and a couple icons at the bottom left of each image. What are those icons? Well, they quickly tell you something about the image you are viewing in the browser window of DPP. The circle at the top shows that my camera had lens aberration correction loaded for the particular lens I was using (the Canon 180mm f/3.5L). There's a very similar looking icon for JPG images that shows the digital lens optimizer was used. However, I never shoot JPG (nor RAW+JPG) so don't see it. Whenever I get a new camera or lens, I connect my cameras to my laptop and load all possible lens and tele-converter combinations I have into the camera body using the Canon EOS Utility. If I recall correctly Canon digital cameras will hold up to 40 lens combination settings, which seems to be just enough to cover all my lenses, especially when you consider that my 180mm, 70-200mm f/4, 70-200mm f/2.8, 300mm, and 500mm lenses each require five of those 40 total slots (i.e. lens by itself, with 1.4x v2, with 1.4x v3, with 2x v2, and with 2x v3). That's 25 of 40 slots just for five lenses.
Anyway, back to the icons in DPP. The next icon down from the aberration correction icon says "GPS". Not surprisingly, that means GPS data has been recorded with the image. This is an amazing feature that I wish I had had since I first started out. I keep a running log of where I was on each particular day when I take photos which I can refer back to and determine more or less where any photograph was taken. However, with a GPS receiver, the actual GPS coordinates where the photograph was created are saved with the RAW file. Thus, if you want to know where any photograph was taken, you can simply copy the coordinates from the RAW file to a mapping utility and it will show you exactly where the photo was taken.
The final icon says "R" which means this is a RAW (in this particular case a CR2) file. I really don't know why they include that since the filename extension already tells you whether a file is a raw or JPEG image making that "R" redundant.