p.1 #1 · Group Portraits: Focus Stacking vs. Aperture
Hi All - To get everyone in focus in a group shot, especially with 2 or more rows of people, do you ever use focus stacking / bracketing over a smaller f-stop?
I plan to do a family shot of 6 people (in 1 row and again in 2 rows) and would still like to take advantage of a nice background blur (using f/2 or so) while keeping all faces in focus. Clearly, stopping down to f/5.6 or greater would solve the 'faces in focus' issue but it would ruin the shallow DOF an f/2 lens could provide.
p.1 #2 · Group Portraits: Focus Stacking vs. Aperture
I would think that trying to get two rows of people to freeze long enough to do any sort of stacking to be very difficult (between head and body movement, facial expressions, and eye blinking). A single person? Maybe. If you move the people farther from the background and use a longer prime lens, you can get the DoF you need and still fade out the background using your lens' sharpest aperture (usually between f7.1 and f9). Caveat is that if you use a zoom lens at longer focal lengths, you might see some lens compression, magnifying background elements.
p.1 #4 · Group Portraits: Focus Stacking vs. Aperture
I agree wholeheartedly with Greg's explanation of possible issues regarding focus stacking.
Regarding depth of field in a group.....think of how you sensor is positioned. If you stand flat footed your depth of field will be, more or less, straight up vertical. In this case the front row will be in focus and then drop off with each subsequent row. If you were to stand on a small box or stepladder and angle the sensor down just a bit, you are changing the angle of the plane of focus to include more rows. Does that make sense?
Also, as the old saying goes....."f8 and be there."
p.1 #5 · Group Portraits: Focus Stacking vs. Aperture
Not only "No" ... but, "No".
Entirely too much emphasis is being put on the DOF of f/2.
+1 for Larry's point about elevation to shift the angle. Depending on the composition / environmental aspects of the shot, this can be an employed technique.
Also, depending on your focal length being used, you may find that f/4 is suitable to have sufficient DOF and still have a decent transition into the BG falloff. Any difference between f/2 an f/4 can be emulated in post more easily than trying to fix three sets of blinks.
That said ...
Shoot your safety shot first (f/5.6 or f/4) ... GET the SHOT.
Which, btw is about capturing the people, not creating an f/2 BG.
Now, with your safety shot in your tin, you can "play" with the prospect of stacking a pair (or more) from f/2. Also, that way, when you do need to do some facial / blink edits in post, you've got your safety shot to pull from. Also, if you mention to folks that you "got the shot" and want to try / play something for a couple more ... that can put them at ease, and they'll relax a bit more for your f/2 stacking shots (i.e. less facial tension).
And, here's the biggie ...
Pre-scout (or emulate) your location and do some test shots BEFORE the day of your shoot. You can easily ... even if you only can have two people as stand-ins ... shoot some test comps at f/2 - f/5.6 and get a vibe where f/3.5, f/4.5, etc. lands you on your DOF vs. BG paradigm for your chosen focal length (which may be another choice to evaluate for FL vs. subject distance).
Personally, as I began with ... I'd forego the notion of f/2 stacking as the means to GET the SHOT. But, if you want to "play" with focus stacking at f/2 to see how it goes, that's fine. Just understand the difference between getting the shot vs. creatively messing around to push the envelope.
Do you homework on where you want to land your shot (i.e. single frame). It can be tough enough to get a group to have simultaneous eyes open, looking toward camera, no scowls, etc. (which can already involve using multiple frames for surety). Doubling down on that challenge by adding in the need repeat it (while changing to different planes focus) exponentially ( ^2 ) changes your probability of success.
Homework / pre-scout / pre-test ... game plan to GET the SHOT, first.
2nd / different game plan to have some fun and play with focus stacking afterwards. And, this could even include taking a shot with NOBODY in the frame (before or after) at f/2 - f/5.6 to achieve your BG to blend in with your safety shots, etc. Here again, pre-test > game plan.
First order of business is your responsibility to ... GET the SHOT. Play all you want, after that.
Looking forward to seeing how it goes for both. Game plan + (training day) batting practice = a pair of Home Runs on Game Day.
p.1 #6 · Group Portraits: Focus Stacking vs. Aperture
One other thing you can play with is take the people photo at something like f/4 or f/5.6 with everyone in focus, making sure you can remove the background in post processing. Take another of the background blurred to taste and then combine the two in post processing.
