Shallow DoF with 'slow' lenses

[@imagesBV]

It may have taken me a long time to realize what everyone else probably already knows but this occurred to me....

Instead of relying on a wide aperture like f2.8 to get out of focus background, you could just use f8 and focus in front of your subject so the subject is at the far end of the depth of field....then all of the background will be out of focus.

This might be difficult to do as autofocus will try to focus on the subject, but you could manually focus and check the depth of field preview.

This potentially saves breaking the bank with fast lenses being so much more expensive.

..............I shall go forth and experiment!

[Daisy M]

Brian, Please go forth & experiment & tell us your findings.

[Brian Sugden]

Interesting point. However, there are a couple of things to consider. Firstly, the focal length of lens you are using. The longer the focal length the shallower the depth of field, so I would probably be shooting at f8 anyway. Secondly if your subject moves checking the depth of field preview may mean a missed or out of focus shot.

[Farider]

You would also be restricted to manual focus only, static subjects and it would almost certainly mandate the use of a tripod as there will be some amount of setup and test shots to take as it is unlikely that you will be able to get your subject perfectly in focus first time. I also think that you will loose some freedom in the choice of depth of field.

I’d be interested to see the results of your experiments but can’t help thinking that it may not be as successful as you hope. I will await with interest.

Ian

[@imagesBV]

Good points...as I'm using the R so I can use focus peaking with the depth of field preview held down....

[@imagesBV]

This shot is focussed on the tree - using autofocus single point - using f8 at 70mm
a3-3 by brianvickers, on Flickr

this second shot is by using manual focus with focus peaking..........and turning the focus ring until the background no longer shows any focus peaking.
a3-2 by brianvickers, on Flickr

You can see in the second that the background leaves are lots softer than in the first.....so at least we now know this technique works.....but I'm sure the technique can be improved.

[John Liddle]

Interesting - what is the small cylinder with an orange cap that's hidden in the hole in the tree?

[@imagesBV]

Its a bottle and orange bottle top....I've not noticed it until these shots, you cant normally see it from the ground.