|Landscape by Andy Boyle|
There was a lot of discussion on focusing for landscape photography last night. Advice ranged from how to pick up the camera and shoot to how to plan a shot (that ‘one in a million- “I just happened to be in the right place at the right time” shot’. ;-) )
I would normally arrange a follow up to answer your questions but the next two meetings are booked and then we have a summer break. So I have tried to answer some of the issues here. There are, as we discussed last night, several different approaches; the main factors being time and experience.
My first recommendation would be – GET THE SHOT! If time is critical then get the shot, it might just be that ‘one in a million’. If you shoot in raw then you have some ‘wiggle room’ re. the exposure* but not with the focus so this is key. The quick, down and dirty answer is to reduce the aperture size (not number) and set the focus to just below infinity. This will give you the quickest shot but won’t give you the maximum usable depth of field** (assuming having everything in focus is your goal). If you have a foreground that you want to be in focus then you need to start thinking about focusing on the ‘middle ground’. (“But there is no ‘middle ground” they chorused.) This is the hyperfocal distance that Bill mentioned last night.
Imagine you are focussed on infinity; the depth of field is then centred on infinity, with half of it ‘behind’ the subject of your camera. This means that, although you are technically achieving the longest depth of field available for your aperture, you are not using it all in your photograph. Reducing the depth of field but centring it on an area which is nearer the foreground maximises the amount of your picture which will fall inside the depth of field and increases your chance of having everything in focus. Find out more about it here.
Another handy post which also briefly explains the lens diffraction issue that Andy Boardman mentioned and focus stacking which KenRane spoke about can be found here.
* Underexpose slightly with DSLR cameras to preserve detail in the shot. Overexposed (blown out) areas will lose detail but underexposed areas will have detail that post-processing software can use. Very important for sky detail. If in doubt then use bracketing.
**To be in focus an item must be within the depth of field which is a distance that centres around your point of focus. The smaller the aperture the larger the depth of field.
Useful apps for mobiles:
Apps for calculating hyperfocal distance on Android
Compass link for Android