Re: Dimmers and auto-iris lenses

[Ian Shef <invalid@xxxxxxxxxxxxx>]

"Robert Green" <ROBERT_GREEN1963@xxxxxxxxx> wrote in
news:p5CdnZEN4qMCDm3YnZ2dnUVZ_tijnZ2d@xxxxxxx:

> I've got an odd issue monitoring the dog crate for my little bad-eyed
> Boodle.  I monitor the crate with an auto-iris IR cam and therein lies
> the problem.  It's very hard to tell remotely whether the light is
> barely dimmed or dimmed 90% because the autoiris compensates for the
> dimming.  All you see when you hit the DIM button on the X-10 controller
> is a slight "flaring" of the image as the light dims and the iris open
> up.  I thought sharpness might be a cue, but the auto-iris probably
> isn't an iris in the traditional mechanical sense.  I'm betting it's
> electronic because as it adjusts there seem to be no corresponding depth
> of field changes.
>
> The camera's got enough resolution to usefully image a 3" dial
> thermometer in the heated water bath along the side of her crate so I
> thought I'd get a solar cell and small electrical meter with a dial I
> could see via the remote cam and a potentiometer to calibrate lo and hi
> ranges.  That setup would consume no power, but it's probably going to
> be hard to read.  Any suggestions cheerfully accepted.  In the meantime
> I'm going to search the junkbox.
>
> --
> Bobby G.

How about an LED (or even a nightlight) that is within the image.  Its own
brightness is constant, so an open iris (due to dim lights) makes the LED
look bright.  A closed down iris (due to bright lights) makes the LED look
dim.
Dim LED implies bright room lights.
Bright LED implies dim room lights.

The LED could blink to reduce battery drain if battery powered.  Blinking
LEDs for decorative purposes can be picked up in many places.  I don't know
if there is going to be an interaction between the duration of the blink
and the scanning period of the video camera.

Could be cheap but consumes more power than your solution.

--
Ian Shef     805/F6      *    These are my personal opinions
Raytheon Company         *    and not those of my employer.
PO Box 11337             *
Tucson, AZ 85734-1337    *