Data Set Test Again

New stand, new data, new problems.

While working with the stand is much easier now, it would appear that the red camera holder is glued with together with a slight tilt to the right.

Back to the "shop".

Meteors and the Moon

Moon rising on the night of Perseid meter shower.

Meteors

Perseid meteor shower captured with the Canon's A2200 camera using CHDK to override the exposure to 20 seconds and a script to continuously take pictures till the battery runs out.

But even with ISO set to 1600, the majority of the meteors were to short lived and not bright enough to be captured.

Data Set Test

Time to collect some sample data!

The plan was, take a stereo picture with the lenses apart from 155 mm to 955 mm with 50 mm intervals. After that, process them and see how the space between lenses correlates between produces images. That was the plan.

What I did discover is that there is a small design flaw in the set up. The mount that holds the camera is prone to swivel when moving the camera left or right on the tubes. Which means that if not really careful, the cameras weren't always pointing perpendicular to their location. Which means the depth perception doesn't correlate with the camera position.

But the pictures are awesome!

3D Glasses Needed

With the stand built, remote trigger working and synchronisation tested, it's time to take some 3D pictures!

Left eye - Righty eye

"Third" eye :P

The process works. Time for actual science!

With the lenses 24cm apart it's a bit to much perspective for humans (at least for the object in the front). But for a computer, who knows.

Camera Synchronisation

And now, the whole adventure that was porting the CHDK comes to this, taking synchronised images from multiple cameras at once. But it's still not that simple!

First we need some more hardware that will trigger the cameras:

Build after schematics on CHDK wiki, the voltage trigger works.

But now it needs to be tested with two cameras, to see if the image acquisition is synchronised, so we need one more piece of hardware:

A true scrap heap project composed of an unused electric motor from a model plane, some spare electronic elements, a CD holder from an ancient MacBook's CD drive and a brand new DVD which was drilled trough so a LED and a battery was mounted on it.

With this the synchronisation wheel came to be. By using the known exposure values on the camera and tracing the light trail made by the LED, the rotational speed was calculated to about 10.36Hz.

Now with this information the synchronisation between the cameras can be calculated:

Taking the same picture with both cameras at the same time with the trigger, the angles from the start and en of the light trail can be measured and compared.

So far, the exposure time was the same and worst calculated delay between the cameras was 0.3ms. Not bad, but this may still vary a bit, since so far it has only been tested with few pictures and on one set of settings.

Transit of Venus

Some more fun you can have with your hacked camera. Take a picture of a once in a life time event!

How to take a picture of Venus passing in front of the Sun. Simple, buy two pairs of sunglasses from the 1€/1$/(insert your version here) shop, to make a scrapheap version of shading and a polarising filter. Attach said creation to the camera:

After that, abuse the settings for the lowest possible ISO and exposure settings:

 

Moving Pictures

Some more fun with CHDK!

Time lapse of the stars from my window. Twenty second exposure per frame, 360 frames. That's how long the battery held on my Canon's A2200.

Lightning

Now that the cameras mostly work it's time to do something fun with them. And by fun I mean hunt for lightning:

The script used was Fudgey's motion detection script.

After CHDK Hacking

The features a there, just a few bugs left.

And that means it's time to stop working on the camera and start using & abusing it. That and to make some other cool stuff which will combine in to even cooler stuff.

Live Picture in a Picture

Some more sorcery, colors are now converted correctly and with some group efforts, the screen is now continuously pulled and dumped trough a pipe in to VLC player for live preview.

Night as Canvas

Light painting with CHDK. Title: Logic of the XOR Gate.

Starry Sky

Night photography with CHDK. Orion with the glow of a distant city in the background. Turns out that even in 30 seconds stars themselves move across the sky enough to blur the picture.

Fun With Protocols

Playing with the CHDK, pulling preview screen frame buffer trough USB cable with ptp and saving it as a picture (using python and openCV).

The colors are off since the camera uses YUV and the pictures are RGB. Conversion needed, but the process works.

It's Over 256

One of the bugs that was bugging me for a while now, has been squashed! Miss aligned zebra now finally shows the correct over and underexposed regions.

Now, colors on the other hand ...

Buffers and Pointers

One of the last buffer addresses traced down! Fast motion detection now works. Although using a stand might improve results here.

More Data per Picture

Saving RAW images works! For comparison (top->down): RAW photo, JPG produced by camera, manually manipulated RAW photo.

P.S. Photo taken at night with 15 second exposure on ISO 400.

Thousand Words

One of the first pictures taken under CHDK using Ultra Intervalometer script. A lot of things are still buggy, but the grunt work is done!

Press Any Key

Keyboard working! Now the CHDK menu can be finally accessed. Games and calendar work, but needs more work to be able to take photos.

Wear and Tear

Recompiled and reloaded the SD card, while debugging the firmware so many times, it fell apart.