Our Photography Courses Blog

Depth of Field Questions

We had a couple of questions from Janet – an ex-student (we encourage this) that we thought might be useful to make available to other readers:

- taking a portrait shot for example of a bee on a flower where the flower
is quite ‘deep’ eg: foxglove / alium, how do I get the bee and flower in
focus – would I increase the F-stop so it’s not on the very lowest setting
for example?

Yes that’s right the smallest f-stop/largest aperture will tend to give the shallowest depth of field, so you will need to adjust it to a more middling aperture – say 4.5 or 5.6 or even 7 rather than 1.8 or 2.8 Also remember that aperture is not the only thing at play here – the more zoomed in you are the shallower the dof as well, so if you can physically get closer and zoom out (at the same time to give the same size bee) you may be able to have a wider aperture and still not have too shallow a depth of field. If you’re using a fairly long lens (to prevent bee attack!!) then you may need what seems like a small aperture, which means that you need a long exposure, which probably results in a blurry bee.

- I recently took a pic of a group of friends getting ready to go diving so
in dark wetsuits. I used a high F-stop number (small aperture) working on
the basis that I wanted to get everything in focus – so a type of
‘landscape’. I was about three yards from them. The pic came out fine but
seemed to lack a bit of depth and clarity and I wonder if I should have
used a mid-point F-stop so that they were in focus but the background was
less so, that being less important of course.

Again, you need an intermediate f stop. The difference in distance from the closest to the furthest diver to you was probably not that great. You probably weren’t (for example) photographing a load of people watching someone else far away in the water and trying to keep them all in focus. That would require a big landscapey f stop. It is more likely that everyone could have been kept in focus by using f5.6 or 7 or so, depending on the amount of zoom on the lens.

We teach that all pictures are portraits or landscapes (of one kind or another), but there is plenty of room for finesse. Really shallow depth of field pictures isolate a subject, but can completely pull it out of context – even to a bee being our of the context of a flower it’s in, or even parts of the bee out of focus. Really deep depth of field can give the viewer no idea of what they’re supposed to be looking at. So intermediate f stops and zooms are often the way to go.

This, for example was shot with an intermediate f stop – we wanted to give plenty of context while still giving the viewer an idea of where to look. So the people in the background’s expressions are visible, but we still know where to look.

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