I have been doing close-up and macro photography since 1956, so I guess that dates me. Since the advent of digital photography and the various Nikon systems I have been using them. And over the last many years I have been experimenting with stacking focus. As many of you know, this can be a relatively elaborate procedure and I have written two books on the subject, many articles, and some 22 or so videos on the topic, all free.
Books and Articles Here:http://dharmagrooves.com/e-Books.aspx#Photography
I am not a professional photographer, of my own choosing. To me the process of photography has been a passion, and sometimes the results are OK too.
I have also been into digital video for many years, but more as a dabbler than anything else. I had a Panasonic HVX-200 early on and followed the advent of DSLR video as it came along, but was never too thrilled about the results.
Instead I stayed with still photography, and my interest with that increased with the Nikon D3x and 24 MP, and most certainly with the Nikon D800e, and getting rid of the AA filter. That was a huge step for me because those 36 MP and the increased clarity possible made focus stacking much more rewarding.
And it was never lost on me that the whole process of focus stacking could be done several ways, and some of them had better results than others. I was an early adopter of Zerene Stacker software, and learned a lot from its designer Rik Littlefield, including the best way to reduce artifacts when stacking photos to make it easier on the stacking software. Here are the main three I am aware of. I will start with the worst and move to the best.
According to Littlefield, the method most prone to creating artifacts in your finished stacked photo is mounting your lens and camera on a focus rail and then moving camera and lens forward along the rail, shot by shot.
The second best method is just turning the heliocoid (focus ring) on your lens and stepping through a series of layered focus, taking photos as you go.
And the very best method is to mount the lens on one end of a bellows and the camera on the other end and then only move the back-standard forward to focus. Of course, this is difficult for many lenses, although some few lenses (Nikon 35mm f/1.4G) have back-focus built in).
True to form, I have of course tried all three methods for focus stacking, taking over the years many hundreds of thousands of photos in the process. As I pointed out, the process is what I like, even more than the results.
And it did not escape me some years ago that another approach to the very tedious process of focus stacking would be to have a video camera in focus on the front of a subject and just slide it forward while recording in some form of progressive-frame codec. Then, take the video, export each frame as a .TIFF, and process it as you would any other layered focus stack.
In fact I had Krysztof Hejnar at Hejnar Photos build me a custom focus rail that, instead of being a geared rail, was just a very smooth slide. I then mounted my cameras via an Arca Swiss clamp on the video rail, started recording, and just gently slide the whole camera forward, toward the subject. Below is the video slider built by Hennar, top and bottom.
The result was a stacked series of layers, accumulated much more smoothly than I could ever have done it by hand. And it worked. The only problem is that the frame size of something like 1920x1080 was just too small a photo for really fine focus stacking.
With 4K video now available (and perhaps larger formats threatening), it is time to revisit this technique, using the larger 4K format (3840x2160) and its increased frame size.
There is no reason this would not work with a focus rail by turning the helicoid on the lens, on a focus rail, or by mounting the lens and camera on opposite ends of a bellows and moving the rear standard on the bellows. And it does.
I include here a stacked result of a series of TIFF files from a 4K (3840x2160) clip taken on the new Lumix GH4 camera. It was then loaded into Premiere Pro CC, and the frames were exported as TIFF files, which were then fed into Zerene Stacker. The resulting stacked photo was loaded into Adobe Lightroom and tweaked, etc.
I was shooting here with the Zeiss Sonnar 135mm f/2 APO lens, an exquisite lens. I would never call the resulting photo a "keeper" (a good example of a stacked photo), but it does show that for those interested, it is possible to (in a second or so) to quickly produced a stacked photo which otherwise would take a much longer time to create.
I am too busy just now shooting a documentary film to take time to refine this procedure, but some of you may want to play with it, so I put the idea out there.
My guess is the 4K could, with finessing, produce some fairly decent video stacks. However, a 6K or 8K video stream would be much better. It is clear that sometime in the future this technique could be usefully implemented.