In contrast, your degree of control from using the script "pushes the envelope" - in your series of shots, you will observe the near focus boundry moving outward 1mm, predictably and consistently, across each frame.Īlthough this script will allow you to automate stepping the cam through any focus range. Prior to experimenting with CHDK, on a good day (heh) I recall having been "quick enough" at my manual keypress to count 45 presses between the 10cm mark on the slider and the left end of the slider scale. Even with a quick/light touch, the time required to perform a "single" (click/release) keypress causes the camera's focus distance to jump by a multiple "steps". As a practical matter, you cannot direct the camera "by hand" to do so via manual focus left/right keypresses. The script steps through a user-specified range of focus distances, generating a series (or 'stack') of frames which, when fed to CombineZm, yield a "continuous DOF" image.Īt short subject distances, the A6xx series cams are able to step through (address) discreet subject distances in 1mm increments. The primary goal for this CHDK script is to facilitate macro (erm, "extreme closeup") shooting. Although this removes the necessity for a physical shutter press for each shot, shooting the "slices" still requires you to adjust the macro rail for each frame. So tedious, in fact, that success in avoiding misaligned subject framing across frames really demands cabled (aka 'remote pc') shooting. However, shooting those myriad frames is a tedious chore.
We can setup the cam on a "macro focusing rail" ("Velbon", and other manufacturers) and shoot a series of "slices", then process these sets of frames using "stacking" software (the freeware CombineZM software, for instance) to achieve a single combined-slice photo in which the entire distance of the dimensional subject is in sharp focus. The resulting photo of any dimensional (non-flat) subject will be less than satisfactory due to the DOF constraint (approx 1mm DOF), the photo can depict only a "slice" of the subject in clear focus. That's a wonderful spec, but at such an extremely short focus distance the depth of field is prohibitively shallow. The PowerShot A6xx series cams have great potential for shooting extreme closeups of very tiny subjects, or detail shots of larger subjects, because they can achieve focus with subjects as close as 1cm. DOFstacker Written for/on: A620 Also works on: A610 / A630 / A640
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