Macro landscape stack using compact digital camera

[rjlittlefield]

In a recent pair of postings, Charlie Krebs showed us unique and wonderful views of the Quinalt rain forest shot with his custom OlyMinCan-28 DSLR system.

From a technical standpoint, the key element of that system is that it shoots wide angle from infinity to 1:1 (24 mm x 36 mm), while keeping the lens entrance pupil in exactly the same place. This prevents parallax and allows near-perfect stacking.

Inspired by Charlie's success, but daunted by the prospect of custom machining, I looked around for alternatives. One turned up rather promptly!

It turns out that the lens of my Canon A710 compact digital camera focuses entirely by moving lens elements that are behind the diaphragm. What this means, of course, is that as the lens focuses, its entrance pupil does not move at all. Perfect! And since the camera will focus down to about a 22mm field width with no attachments, it covers the same range of subject sizes as Charlie's DSLR setup.

Alas, I could not find adequate substitutes for either Charlie's subjects or his artistry, so I made do with an urban greenscape.





Canon A710 set for manual everything, 8 frames at f/8, 1/13 second, stacked with Helicon Focus.

This lens has quite a bit of barrel distortion at wide angle, and picks up even more as it focuses closer. I was concerned that I might have to correct for this before stacking, but at least for this stack, it wasn't a problem. For more extreme ranges, or more critical work, it still might be an issue.

Anyway, I know that some of you are interested in the stacked macro landscape effect, and I thought you might be interested in seeing a fairly simple way to pull it off, albeit at lower quality than Charlie's rig will do.

--Rik

[Charles Krebs]

Excellent! I'll have to check out the lens on my Canon A620.

How "fidgety" was it to vary the focus between shots?
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[rjlittlefield]

Adjusting focus didn't seem too bad. I could have shot a lot more steps, but I was a bit spooked because the air was starting to move. Even so, I had to throw out one frame, and the tallest grass isn't quite crisp.

You probably figured out from the 1/13 sec at f/8, this was early morning before the sun was really up. The shot of the camera and tripod was done a bit later, when I figured out I needed it to complete the posting.

--Rik

[Charles Krebs]

Rik,

Checked out my Canon A620 p&s and it appears to focus like yours. Could make for some fun images. And with the "flip-out" and "tilt-able" screen I won't need to eat so much dirt trying see what I'm doing.
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[acerola]

I have a Sigma 17-70 F2.8-4.5 DC lens. It has a little Macro capability. The front element did not move while focusing. I did a test shot, it is promising. It is interesting that the field of view is changing. It is wider in macro mode than in infinity. But CMZ is aligned it well.
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Péter

[lauriek]

Péter,

That doesn't surprise me (FOV changing) - some Prime macro lenses actually change focal length as you change magnification, some around the 100-105mm sort of size are more like 90mm when focused at 1:1!!

Interesting stuff!!

[rjlittlefield]

In searching the web, I ran into a couple of scripts for controlling focus from a PC. The comments indicate that the scripts provide finer control than what you can get by pushing the buttons on the back of the cameras.

I have not played with these things personally, but thought I would include the links here in case someone else is interested (and so maybe I can find them again if I ever want to ).

http://www.projectracker.com/digitaworld/viewscript.htm?scriptid=12 [Edit: as of March 21, 2010, this one has disappeared]

http://chdk.wikia.com/wiki/UBASIC/Scripts:_macro_DOFstacker

The second one specifically mentions Canon A620.

--Rik

[Charles Krebs]

Thanks for those links Rik. I'll definitely look them over more carefully.

Since you first posted this I've played around once or twice with my A620. The shots I did were merely "tests" and the subject matter not worth posting. But there is no doubt in certain situations you could make some very impressive images with this technique. And I don't think it would be that hard to do it "manually", although a script automated method would be neat.

The biggest practical problem is that you need a subject with no movement while shooting the stack. It would also be nice to have a wider lens. But it seems that an "equivalent" 35mm is about as wide as you can get in these P&S digtals right now. There are a few "28mm equivalents" around, but I'd have to check to see if any of those allow the extreme close focus that make this technique so impressive.
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[Rylee Isitt]

The Canon G9 seems as if it should work for this technique quite well. Possible the newer G series models, too.

The G9 has an 35mm equivalent field of view of about 35mm. Not very wide angle, but better than nothing... changing focus seems to have no effect on the field of view, and the front lens element remains fixed in position. Plus, these small sensor cameras have fairly wide depth of field.

The G9 has fully manual controls, including fly-by-wire manual focus. If this can be controlled by computer, that a small netbook with the proper cable connection might make this job a bit easier.

I have been planning to do something like this with some of the Cladonia lichen species we have growing around here. They're still covered in snow, though!

Edit: Oh no, I see to have brought a post back from the depths of time! I swear, I got to it from the front page somehow!

[rjlittlefield]

Thanks for information about the G9.

There's no problem at this site with awakening old threads. Anything that one person finds interesting enough to comment about is probably interesting to other people also.

You probably got here through some link in another thread that was already near the top of the list.

--Rik

[Chris S.]

Glad this thread resurfaced. It's a reminder to post something that long ago dropped off my radar screen: The Panasonic Lumix LX3 and LX5 point-and-shoot cameras also work well in this regime. Importantly, they have wide lenses (24-60mm and 24-90mm equivalents, respectively) made by Leica. Manual focus is available and not-too-fiddly, and the fronts of the lenses don't move while focusing. One or both of the cameras provide depth-of-field information on the LCD screen, apparently based on zoom setting, f/stop, and focus point, so that it's fairly easy to determine how far to change focus to shoot the stack. (I tested both cameras, on separate dates that were quite some ago, and do not have my old notes in front of me for this brief post--but both cameras got a "thumbs up" for this kind of photography.)

That said, building a full-frame DSLR rig in the vein of Charlie's OlyMinCan-28, but with a change or two, is on my radar screen right now, and I've recently been assembling the parts. Will it prove to be better than the point and shoot approach? I don't know!

--Chris

[elf]

[rjlittlefield]

CHDK still seems to be under active development (as always without Canon's support, of course -- these are hacks, not SDK wrappers).

--Rik

[gpmatthews]

I have a G9 and use Breeze software for remote control. Breeze states that software control of focus is not possible.
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Graham

Though we lean upon the same balustrade, the colours of the mountain are different.