Those who have read about hyperfocal distance will naturally first look at what this focusing approach can do; however, they will soon realise that a single image approach will simply not do.
So, focus stacking to the rescue and the first step is the trusty FocusStacker App from George Douvos: http://www.georgedouvos.com/douvos/Intro_to_Focus_Stacker.html
With a one foot to infinity objective, the App tells me at a focal length of 14mm, and using a combined blur spot diameter of 19 microns (for my Sony A6000), I need to shoot at 1.2 ft, 2 ft, and 5.9 ft at F/9. Using a single image, I could cover 2.5ft to infinity, if I shot at F/10. In other words, I would not cover my objective of a foot to infinity.
But then we begin to experience real-world practicalities. For instance, if I was to use any of my Canon auto focus lenses, I would find it virtually impossible to set those three distances, ie you will not be able to manually set an auto focus lens, as the focus ring floats; and who wants to be setting up distance targets in the field!
Thus, for landscape (as opposed to macro) focus stacking I have settled on another strategy, namely using a manual lens.
My manual lens of choice at the moment is the Rokinon 14mm F/2,8: http://www.amazon.com/Rokinon-FE14M-C-Ultra-Canon-Black/dp/B003VSGQPG At less than $300 a bargain that every wide angle shooter should have. I can use it on my 5DIII full frame and of course my A6000 APS-C.
The advantage with this lens is that it has a focusing scale that covers under a foot to 10 feet in about 180 degrees of the fixed focus ring rotation. It has markers all through the focus range. It also has a manual aperture, which means I have no image to image variability, ie for timelapses the aperture is locked in, thus minimising flicker.
Workflow is simple:
- Dial in the aperture (F/9 on this occasion);
- Focus at 1.2 ft and take the first image;
- Refocus at 2 ft and take the second image;
- Refocus at just under 7 ft and take the third image;
- Take a fourth image at infinity for insurance;
- Ingest into Lightroom;
- Export to Photoshop as layers;
- Auto align the layers;
- Auto blend the layers;
- Merge the layers;
- Bring the merged image back to LR and ‘finish off’.
Bottom line: For focus stacking wide angle landscapes, where you will likely have a strong near field component to your image, I believe manual focusing, with a manual focus lens, is the way to go; and the Rokinon 14mm F/2.8 is a winner. Where as you would not wish to focus stack every image, for those occasions where you need a huge depth of field, I believe the ‘technology’ and workflow above can’t be beat: IMHO :-)