http://www.photomacrography.net/forum/v ... php?t=4864
and
http://www.photomacrography.net/forum/v ... mpus+angle
for example.
I started trying to emulate this with my Nikon equipment, but a fair bit of work would be needed. The main requirement is a lens whose entrance pupil remains stationary with respect to the subject as the stack is made at different focal distances. Usually this means keeping the lens absolutely stationary while moving the camera for each different focal distance, but without adding any extensions (such as normal bellows) that would keep the lens from focusing at infinity.
Some people on the forum found that some little compact cameras keep their entrance pupils stationary when they focus, so they can be used right out of the box for this special application. Drawbacks of most of these cameras are: lenses not as wide as we'd like, poor close-up image quality, and (sometimes) less close-up magnification than we'd like.
So, hoping for another directly-out-of-the-box solution (I don't have time to make very elaborate contraptions, though I envy and admire those who do), I tried my Panasonic FZ300. It turned out that I couldn't see anything move inside the lens when it focuses, and the front lens doesn't extend during focusing either, so I guess the focusing mechanisms are behind the entrance pupil. That means it should work. At its lowest zoom setting it has a 25mm equivalent lens which gives a nice perspective, and it can focus on objects that nearly touch the lens. At that distance its field of view is 35mm, so it is getting the same view that a full-frame camera would get at 1:1 magnification.
I tested it and indeed it does work amazingly well. Here is a quick stack of the mess in my house. I manually focused, and missed several important slices so there are stacking errors (this was stacked in Photoshop). But there are no perspective errors.
Note the butterfly wing in the foreground, mounted on a solid cube of crystal glass. Nicely detailed though a bit soft because of the small aperture I used.
To check the close-up image quality I took some pictures of the wing itself, with the wing about 1.5-2 cm from the front of the lens. I made a series from f3.2 to f8. The maximum aperture of the lens is f2.8; f3.2 was best in this test, 4 was also excellent, and 8 showed diffraction but would still be usable in many situations. This is an uncropped view:
This is a crop of the actual pixels (100% magnification) from the image above, at f3.2 on a jpg directly from the camera:
I think this camera is perfect for this application. It has an electronic shutter so there are no camera vibrations, and I think everything can be controlled remotely and wirelessly. I suspect I can just lay it in the forest without even a tripod and get decent stacks.
This camera has a Leica lens that keeps its f2.8 maximum aperture even at the highest zoom setting (600mm equivalent). That means this is probably the only bridge camera that could be used for long-lens macro landscapes without getting diffraction at the longer lengths.