Luminous Landscape Forum

Equipment & Techniques => Digital Cameras & Shooting Techniques => Topic started by: Michael Erlewine on January 24, 2016, 09:48:00 am

Title: Shooting One Layer or Few/Many Stacked Layers
Post by: Michael Erlewine on January 24, 2016, 09:48:00 am
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-layers

This 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]
Title: Re: Shooting One Layer or Few/Many Stacked Layers
Post by: Michael Erlewine on January 24, 2016, 09:49:57 am
[The Previous Blog Continued]

(5) Superimposition of an Image on a Background

I seldom if ever do this, but we should point out that it can be done. Take a photo of a background with pure bokeh and then (using another layer) superimposed a section of the same thing at f/11 or f/16, so that you have the same photo, but featuring one flower or whatever. Here is a crude example I just threw together.

There are no winners here, no free-lunch. Whatever we do enhances one aspect of the photo at the expense of others. Each approach has its merits, but also its disadvantages.

MICROCONTRAST      

What worries me most about stacking is the potential loss of what we can call microcontrast. I know, some argue whether microcontrast even exists, but to me, it does. Lenses like the new Zeiss Otus series seem to me to have better microcontrast, which for my work is very desirable.

When we stack photos, especially with many layers (as mentioned earlier), the very fact that by definition a stacked layer involves digital sampling of an “analog” image means that something is excluded and left out. This, coupled with the minute alterations that occur from changes in lighting (if outdoors) or somehow jarring the camera/tripod, etc. seem to affect the overall microcontrast of the photo. The result is something similar to diffraction. We could just call it, as a joke, “sampling” error. It is unavoidable and usually quite visible, if we look closely. The fact is: most people (as viewers) do not look closely, unless we are purposefully doing so. Photography is about impressions.

However, focus stacking, as mentioned, is a digital impression of an analog image, which is itself an impression. If the impression is satisfying in some way, then I guess it does not matter how many artifacts are embedded in what we are looking at. We get the impression.

DESIRABILITY

We have discussed the disadvantages of stacked photos.
There is also the popular consensus that there is something about a stacked photo image (warts and all) that appears “different” from a single-shot photo. Many people like it. Perhaps it is that messing with the overall (or selective) focus pushes our envelope just a bit, making that photo seems a little bit realer or more vivid than life, almost a touch of a 3D (or psychedelic) look.

And there is also the fact that, unlike a traditional one-shot photo that has a single focus point in the image, with focus-stacking usually there is no single focus point as dictated by the lens, but rather anywhere you want to look is the focus point, so where do you want look first? In other words, there is no focus point embedded in the image that leads or directs your eye, so your eye in some sense is free to look around. There is no doubt that this is liberating, unless you like being led.

Anyway, just some thoughts on all of this.


Title: Re: Shooting One Layer or Few/Many Stacked Layers
Post by: muntanela on January 28, 2016, 05:07:42 am
Thanks for these reflections, Michael.
 

When I  shoot landscapes with my D800E, usually I take few shots with high enough aperture (9-11). For the close ups I often do manual blended stacks of few photos, usually taken with aperture f/5.6. With large part of the image out of focus, it is easier to blend the few elements in focus, but it's also easy, I would say nearly unavoidable, to have incoherence in the succession order of sharp and blurred areas. The first attachment is a stack of two shots, the second one is one of the original shots of the stack, it was made last year, perhaps today I would make it better (perhaps...). For the Astrantia maior I used 3 shots , the wet Saxifraga aizoides is made of 7 shots.
Title: Re: Shooting One Layer or Few/Many Stacked Layers
Post by: Michael Erlewine on January 28, 2016, 05:17:30 am
Looks good. I would probably add a few more layers, with a layer focused on the bottom of the left yellow flower, etc.
Title: Re: Shooting One Layer or Few/Many Stacked Layers
Post by: muntanela on January 28, 2016, 06:50:21 am
I note also a maybe residual part of the blurred layer under a sepal of the Saxifraga
Title: Re: Shooting One Layer or Few/Many Stacked Layers
Post by: BAB on January 28, 2016, 09:25:20 am
All is well and fine when the entire sensor is filled, either with a blurred background having a large group of flowers in front or landscape. The real issue of micro contrast, diffraction of light, slight nano vibrations and color shifts in exposure comes into play hard when your only using part of the sensor. By moving the camera back to obtain a compromise of depth and limit the amount of stacked images, to avoid a majority of those nasty issues you of course lose resolution or megapixels. The best we ever had was 10um pixels but the large size dint come in ultra high Meg backs. Hasse multi shot backs give us what we want but stacking then becomes a bigger issue. Intergated step focusing would help the image making process, but Manufacturers of cameras all chase the same market. They sell to reproduction users, museums and product photographers who's subjects are much larger than 25 X 25 mm. Even using a titl,swing and shift camera can only reduce the amount of stacked images by approximately half so if the final image is not intended to be printed larger than 8" you can easily cheap the whole process but at 40" for the final image moving the camera back is at some point like walking on water! The solution might be self focusing pixels that also could be programmed for a minus and maximum exposure curve allowing us to not only control depth but highlights, midtones and shadows thus giving the photographer huge dynamic range with computerized depth of field.

Using a longer focal length would also help when moving the camera back but finding the sweet spot of current lenses and using all the tricks puts the photographer back in the same place when printing large images of really small objects it just you got there a different way.

Transparent objects are the most difficult to shoot because of the internal refraction of light varying between shots when stacking. Also shinny metal objects have the same issues requiring hours of post prossesing to make large prints hence shooting jewelry is maddening.

I have shot some floral it has its own set of issues movement is a big one and watching the focus zone move around the sides of the Object the focus slice sometimes can't be seen so your basically stacking some images that will not contribute to the sharpness. That also complicates the Intergated step focusing giving multiple layers and adding time that's not really needed.

For another day is the conversations of image stacking programs their issues, the multiple ways of using t hose programs to achieve the final result.
Title: Re: Shooting One Layer or Few/Many Stacked Layers
Post by: muntanela on January 28, 2016, 10:28:50 am

Transparent objects are the most difficult to shoot because of the internal refraction of light varying between shots when stacking.


This is made of 15 auto- (Photoshop...) and  (fewer) manual- blended shots. Generally icycles like  these are easier to stack (they are already very messy) than flat ice, which is also more difficult to focus.
Title: Re: Shooting One Layer or Few/Many Stacked Layers
Post by: EricWHiss on April 07, 2016, 12:34:56 pm
When your goal is to make art, I think the sky is the limit and in that case you also have the options to not have anything in focus or sharp at all, to include motion blur, compile wtih other subjects, mix with other media, and so on.
 
Michael, that said, I do like it when you use the wider apertures and selectively stack to bring out certain salient facets of an image while keeping smooth bokeh in the OOF areas.  The trick is to make it believable.  Go too far and it can become gimmicky. 
Title: Re: Shooting One Layer or Few/Many Stacked Layers
Post by: Peter McLennan on April 07, 2016, 01:42:51 pm
This is made of 15 auto- (Photoshop...) and  (fewer) manual- blended shots. Generally icycles like  these are easier to stack (they are already very messy) than flat ice, which is also more difficult to focus.

Fantastic image, munatela. Amazing that it's only 15 images.

There is only a very brief window in November when I can do ice photography, but it's very satisfying.  I've only shot "flat" ice and your image breaks new boundaries for me. Can't wait for next winter!  :)
Title: Re: Shooting One Layer or Few/Many Stacked Layers
Post by: Gandalf on June 20, 2016, 06:18:37 pm
I'm not sure if the purpose of this discussion is artistic or commercial. Artistic, as many as you need to create the image you want. Commercial, get it in camera, at least as much as possible. Photoshop time is expensive unless you have a full time retoucher, or you are a full time retoucher. This isn't to say don't stack layers, but the fewer the faster.
Title: Re: Shooting One Layer or Few/Many Stacked Layers
Post by: Zorki5 on June 26, 2016, 08:18:31 pm
I happen to have a very definite answer to this question -- for myself.

I only use stacking when it's absolutely necessary: for microphotography (through microscope), and some high-magnification macro shots. I bought a copy of Helicon Focus Pro (with which I'm very satisfied) but, again, I'm only using it if absolutely necessary.

For everything else I prefer to get the shot in camera; no amount of extra sharpness is a substitute for lost 3D look (or "natural look" for that matter) -- for me. My answer to "See? You couldn't get that effect w/o stacking!" has always been "And I shouldn't."
Title: Re: Shooting One Layer or Few/Many Stacked Layers
Post by: kers on June 26, 2016, 09:08:15 pm
Fantastic image, munatela. Amazing that it's only 15 images. ..
+1  beautiful image
and i also love the alpine flowers; I will be looking at them soon again... :)
Title: Re: Shooting One Layer or Few/Many Stacked Layers
Post by: muntanela on June 29, 2016, 01:39:14 pm
and i also love the alpine flowers; I will be looking at them soon again... :)

Kers, I usually see many NL cars in Valtelline... really many, much more than of other, greater, nations.

Kalmia procumbens in Western Grosina Valley, (stack  of 17 shots, manually blended, RR 1:1).
Title: Re: Shooting One Layer or Few/Many Stacked Layers
Post by: John R on August 31, 2017, 07:33:17 pm
I just tried photostacking for macro imagery in PS and am very pleasantly surprised. Still learning but I think I can live with what I see. Did about 22 images with a tamron 90mm on Pentax using extension tubes. Unfortunately for me, the tubes are not dedicated so I had to shoot wide open. Still pretty good.

JR

(https://photos.smugmug.com/On-the-Road/i-3QZZ49g/0/b89e2e20/M/New%20blend%20photostack-M.jpg)
Title: Re: Shooting One Layer or Few/Many Stacked Layers
Post by: John R on October 21, 2017, 09:03:19 pm
While the one I posted before was more successful, this second image shows the limitation of photostacking. If you want something creative, like where one part is in focus and the remainder out of focus, there is lots of unwanted ghosting. Good if you want a whole cluster or flower in focus; not so good for creative work. At least that's my experience.

JR

(https://photos.smugmug.com/On-the-Road/i-xrBFCsc/0/4b5ebbfa/M/Oct%2021-%202017%20Geranium%20macros_0537%20copy1000-M.jpg)
Title: Re: Shooting One Layer or Few/Many Stacked Layers
Post by: BobShaw on October 22, 2017, 06:49:22 pm
From my perspective, I never focus stack. In product work you should be shooting at f18-20 with a really really good macro lens that goes to f45 or beyond.

If you are outside with say flowers then they move, so how can you focus stack?

Apart from that it looks unnatural and changing the focus plane changes the focal length which changes the magnification. So you are chasing your tail.

If nothing else it is an awful lot quicker to take one shot.

I think there is some sort of Facebook cred in saying it was a 15 shot macro or pano image.