My Up Camera Octoring Light

[Mark Harris]

Quite awhile ago I published an up camera light idea to github, using an angled octogon of lights panels: https://github.com/issus/Pick-And-Place-Lights

I finally got around to assembling them! I'm still waiting for the 3d printed base, it was set to run before we left work on Friday, and should have finished some time yesterday morning.

With over 2000lumens of light, it's rather bright. I'm using good CRI leds (only 80 CRI but still much better than the 40-60 you get in LED rings from aliexpress/ebay) which means I should get very good colour rendering from it, hopefully helping the vision system do it's job. There's 128x https://www.digikey.com/product-search/en?keywords=1214-1212-2-ND in the octoring. They were the cheapest decent CRI, high lm/W leds I could find.

That panel then folds up to make the final octoring. Each panel is individually powered, able to be shut down independently, and they are all independently current limited. So the next test was to power them up with the current limiter on my powersupply set very low, then get it to just the point that the leds would be visible to see how evenly lit they are. If the LEDs are good quality they should all turn on at basically exactly the same voltage, and with exactly the same brightness.

They certainly appeared to, i'm very pleased with the matching of the LEDs!

Its very difficult to photograph how bright these are, so I put them up against my desk magnifying lamp. For comparison, it's rather painful to look at the panel of lights - but there is no discomfort at all looking at my lamp. The light from my octo creates shadows in the light from my lamp from around 10 times the distance.

I'll try them tomorrow night with the camera mounted in it to see what happens.

- Mark

[SMdude]

That's very neat!
Hope it tests up as good as it looks.

[Mark Harris]

Well, the test went really well. Below is an image of ambient light vs octolight - camera on full auto. The white PCB does confuse its exposure setting somewhat, i'd say its about a stop underexposed from that. both shots are at about the same height with me trying to get the camera in the spot that looked sharpest on screen. With all the extra sensor noise from the camera jacking the ISO up so high the top image looks very fuzzy no matter what. The white balance is also vastly superior with the LEDS.

Obviously i'm using this as a downcamera for these shots. So here's a shot with the lights mounted on a couple of screw boxes to keep it perfectly still.

So the overkill of light again shows a huge reduction in noise. The top image is me matching ambient light hitting the paper to remove the shadow cast by the boxes/light ring, and the bottom is full blast.

Test setup as ambient vs blasting.

On 11 September 2016 at 20:39, SMdude <spiteri...@gmail.com> wrote:

That's very neat!
Hope it tests up as good as it looks.

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[Anthony Webb]

... and Mark said... Let there be light... and there was light, and bright was the light thereof! :)

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[Mark Harris]

Its actually kinda painful it's so bright haha. My plan is to only have the lights on when the camera needs it, with the camera set to manual exposure and all manual settings so it doesnt need any time to adjust.

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[Mark Harris]

Another couple of comparisons, in 1080P. With the 6mm lens I have on this camera (have not gotten around to ordering new lenses) I prefer the 720p screenshots, as they seem to use a smaller area of the image which reduces the blurring around the edges. These lenses are not amazing.

Again, the camera at a low light level:

At a high light level the camera is much nicer. These don't really show off much of note for the light panels, just wanted to put them up for people who might be looking to improve their ELP image quality - add more light :)