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Sometimes it's desirable to know if you're clearly in the field of view of a camera. Without access to
the image being generated, even if you know the lens size it's going to be a guess - unless you're obviously
in the exact centre.
Following up on the clamour of appreciation of our brow-mounted
laser pointers, BorgCo engineers have produced
a new device employing a scanning laser to end the problem of "Can I be seen ?"*
The beam generator can be attached to the lens of the camera, or you can purchase direct** from
BorgCo one of our new "Field of view" webcams. The low power solid state laser is directed onto an oscillating
mirror, then through a variable zoom lens stack, to produce an elipsoid "cone" of laser light, selectable as 4:3 or 16:9 aspect
ratio.
When positioning and aiming the camera, the red oval clearly defines what is and isn't in view; for those
who are subject to the camera's scrutiny, it will always be clear when they are or aren't in view of the lens.
This might also make CCTV surveillance in "sensitive" locations like public toilets marginally more acceptable.
*For top tips on "How Not To Be Seen", an instructional video (which usefully highlights some basic mistakes)
is already available.
**Offer not available in the shops. First to see will buy. No tyre-kickers.
Laser viewfinder for camera
[xaviergisz, Feb 06 2019]
How Not To Be Seen
https://www.theverg...rial-patches-google
Magic toaster turn banana into a toaster [not_morrison_rm, Feb 06 2019]
Dambusters March midi
https://drive.googl...00rRNndanqpy-kKFlii
lots of zeros and ones [not_morrison_rm, Feb 07 2019]
[link]
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//the red oval// Would a red rectangle not be a better
shape? |
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Yes. But the ellipse is a simple Lissajous figure, generated by phase- and amplitude-shifting a sine wave. Very simple, cheap drive circuitry and actuators. Generating a reasonable facsimile of a rectangle demands much more complex drive waveforms and more precise actuation. |
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We can do rectangles, if you're prepared to put your hand in your pocket, or more likely someone else's pocket ... |
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I've considered the same idea myself. Either a dot for each
corner (if you are the photographer) or (a la those
"projected shape" laser pointers) a rectangle shouldn't be
too hard to generate (I think they use an etched diffusion
plate...). |
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So, what happens if a ring of tiny LEDs are mounted (or
manufactured) around the edge of the camera sensor array?
Since the lenses of the camera are focusing the image onto
the sensor, I would expect that any image on the sensor
would be projected in focus on the subject of the photo. |
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I'm sure that you wouldn't want to run the LEDs when
actually taking a photo, but those can be turned on and off
rapidly enough. |
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// Generating a reasonable facsimile of a rectangle demands
much more complex drive waveforms// |
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Yes, either a complex X/Y driver synchronized with a pulse
generator, or a 20p piece of transparent plastic and a fixed
laser. |
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And [scad]'s idea is even eleganter. |
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Comes with complementary banana to toaster machine
vision link. |
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// a 20p piece of transparent plastic and a fixed laser // |
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... which has to be much more powerful to give the same effect. |
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Not that we object to high power lasers; quite the reverse ... |
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Not so. You're spreading a laser beam out into a rectangle.
Either you do it by scanning with moving mirrors (so, the laser
power is smeared out in time), or by a clever fixed lens and
(just possibly) some half-silvered surface (so, the laser power
is smeared out in space). Either way, the power requirement
should be similar. |
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I thought that all you needed to do was grin all the time to fool AI since every picture used is expressionless... |
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Grinning like an idiot everywhere ='s anonymity.
No? |
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<grins anyway just in case> |
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Might a gentle hued light of two or three different colors, broadcast onto a group of people let them know where they were at in the image being taken? |
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I have to say it: "Without access to the image being generated", unless I misunderstand, is obsolete as cameras now have video viewfinders. |
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As to the "let them know if they are onscreen" thing: the gentle broadcast of light would not distract or bedazzle the people being photographed. |
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// I have to say it: "Without access to the image being
generated", unless I misunderstand, is obsolete as cameras
now have video viewfinders. // |
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I think you do misunderstand. This is for notifying you that
you're seen, when the camera is held by someone else—or
the wall or ceiling. |
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Hang on...didn't Barnes Wallis and Grommet sort this
one out
ages ago? Their novel use of two theatre lights on the
Dambusters raids and stuff like that. |
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Link to tinkly ringtone of Dambusters March above and
the left, except in the southern hemisphere - of course |
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