Linux for time lapse and wifi?

Joshua Judson Rosen rozzin at hackerposse.com
Wed Jun 28 16:25:55 EDT 2017


On 06/28/2017 10:53 AM, David Rysdam wrote:
> Ken D'Ambrosio <ken at jots.org> writes:
>> On 2017-06-28 10:31, Richard Kolb II wrote:
>>> Hello all,
>>>
>>> I'm looking into using a pine a64 running ubuntu mate to setup a time
>>> lapse photo using a standard digital camera controlled over USB. I
>>> haven't done a ton of research into it yet, but I wanted to see if
>>> anyone else has done something similar and had some advice/opinions. I
>>> was thinking of setting this up first as a way to capture an event
>>> going on, and second as a wildlife/security camera.
>>
>> Well, I bought the Pinebook, and -- given its price, among other things 
>> -- seems like it would do a fine job using its webcam.  But if you want 
>> high quality stuff, I suppose a "real" camera is the way to fly, and not 
>> a webcam (be it part of a Pinebook or something external).
> 
> I've been wanted to do some OpenCV projects, so I looked into
> webcams. You can get 1080p for under $50 now. Plug and go in Debian
> 8. (I actually bought 720p for $30, but had to do it twice because the
> first time I got one that was for video chat and didn't autofocus.)

Huh--the last time I had  a problem like that, it was exactly the opposite issue:
I go one that was meant for video chat and _did_ autofocus--continuously,
based on what it thought was the most interesting bodypart in the image
(I guess; I've heard that some of these things try to do face-detection and
 just fail miserably if they can't find *a hairline* or other
 popular facial features...).

> Obviously you can use a video cam for snapshots too, so this might be a
> good way to go.

Not-so-obviously..., it depends:

Some video cameras have frame exposure-times etc. that work fine (or even work *well*)
for video because of how noise and motion-blur generally are neuroprocessed
in moving images..., but then produce unsatisfying stills in the many situations
where motion-blur etc. are undesired.

Also the `rolling shutter' with CMOS sensors can easily lead to other awkward
visual distortions, e.g.:

	https://en.wikipedia.org/wiki/Focal-plane_shutter#/media/File:Bundesarchiv_Bild_183-1991-1209-503,_Autorennen_im_Grunewald,_Berlin.jpg

YMMV--depends greatly on your subjects.

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