This is one of those topics that get me running in circles. What are my best options, taking a traditional single-shot photo or stacking an image? And if I stack, should it be many or just a few layers. I thought it interesting to go over some of the options. I can’t promise you will get anything of value out of this, but differences may be visible, and the comments at least should make sense.
[Note: I have posted 2048 pixel images of the above at this link as a PDF.
http://spiritgrooves.libsyn.com/photography-shooting-one-layer-or-fewmany-stacked-layersThis is a look at some of the options we have when shooting a single photo, an elaborate stacked photo, a photo stacked with just a few layers, and things like that.
(1) Traditional One-Layer Photo (Sharpest f/stop)
Of course, we can shoot a one-layer photograph. That’s photography’s history, and there is no need going over what that entails. We all live with it. For an f/stop, we can use the f/stop with the overall peak sharpness for that lens, often f/5.6 or thereabouts. Or, we can push the aperture higher until the effect of diffraction stops us. I don’t tend to go this route. No image is shown for this option.
(2) Traditional One-Layer Photo (Highest f/stop)
On the other hand, we can choose only narrow, high apertures, pushing the lens to greater overall DOF, but also increasing diffraction. With very fine lenses like the Zeiss Otus series, we can shoot at something like f/16 and apparently not see (I am sure diffraction is still there) the effects of diffraction all that much. With Adobe Lightroom’s new “Dehaze” feature, some of the effects of diffraction (seemingly) can be removed.
I have been learning to shoot single-shot photos at apertures around f/16 and getting pretty good results, especially with the better lenses. But even at f/16, the results of a single-shot layer does not have the sharpness of a well-done stacked photo. Close, but no cigar. I keep trying this, but so far always go back to stacking.
(3) Stacked Photo, Many Layers
We can stack multiple layers, a great many layers, which puts more and more of the image into focus at the expense of potential artifacts and a kind of “rounding error” in sharpness. Yes, taking 50 or 100 layers puts everything generally more in focus. However, the various factors involved in matching up 100 layers, the ever-so-slight shifts, etc. add up and appear as what we could call “noise” or increased low-level artifacts.
MEDIUM APERTURE
In addition, we can take one of several approaches in multi-layer stacking as far as f/stop is concerned. We can choose the midrange “peak” f/stop for that lens as far as overall sharpness is concerned (and stack away) or we can stack at one of the extremes, wide-open or high aperture.
HIGH APERTURE
Taking the high-aperture route (for stacking) has few advantages, mostly due to increasing diffraction. Stacking is perhaps best done at the peak-sharpness aperture for that lens, although that is not what I prefer.
WIDE APERTURE
I like to shoot wide-open, but this takes a fast lens (if you want bokeh), one that is already very sharp wide-open. Additionally, shooting wide-open means that each layer has a razor-thin DOF, a tiny slice of the overall photo, which means many layers may be required. However, it has the advantage of allowing you to paint focus and have just the bits of the image in focus that you want, and not just in one area of the photo.
We could, for example, have areas of the foreground in focus, the midrange out-of-focus, and then areas of the background in focus. We can select and paint-in focus.
(4) Stacked Photo, Selected Layers
Another alternative is to stack focus at a higher aperture (like f/16), but use very few layers, perhaps picking out the parts of the photo you most want in focus and making each of those a layer. The result is a photo that is sharper and with less noise or artifacts, but also, when looked at carefully, less sharp overall. From a distance it looks quite sharp, but close-up examination shows, of course, only those areas for the particular layers we selected in peak sharpness.
[TO BE CONTINUED IN NEXT POST]