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mtumut
12-31-2009, 11:52 PM
I found a semiconductor electronic piece called photodiode at Thorlabs Catalog , extremelly wide range powerful sensivity and 11 dollars.
If you attach a Analog Digital Concerter , an ─▒ntegrated circuit and a memory card , you can build your camera. But you take single pixel image.
I read some people is thinking to put a mylar mirror and move it and get full image in 10 seconds.
Any idea , how can We take full picture with single diode.

Best ,

Mustafa Umut Sarac

Istanbul

rayh
01-01-2010, 02:00 AM
hmm, i'm thinking that an image captured by one pixel would somewhat lack detail

mtumut
01-01-2010, 02:24 AM
Of course ;)but when you find to scan the scene , everything differs.
This is not a toy concept , in 10 years , we will see these cameras at the market.
I am asking a bright idea for scan the scene before waiting 10 years.

moot
01-01-2010, 02:39 AM
Mustafa, think about a drum scanner. It works similarly, but uses a photomultiplier tube instead of a photodiode. There were some old satellites that had scanning cameras that used rotating optics to scan the surface of the earth line by line. Very primitive, however.

I think the mechanics of scanning would make this more difficult to build than a regular digital camera. The fastest single-pixel scanners I know of are the rotating polygon mirrors used in laser barcode scanners.

Jim Jones
01-01-2010, 04:36 PM
Experimental television cameras of many decades ago scanned the image onto phototubes with prisms, mirrors, scanning discs, and perhaps magnetic fields.

MartinS
03-01-2010, 08:06 AM
Basically, you would need two mirrors movable around perpendicular axes. The most intriguing for an amateur project would be the synchronization between the mirror movement and the output signal -- i. e., you have to know where in the output signal a new line of the image starts...
The meteorological satellites still work that way, especially because of they use several sensors for different wavelengths. The mechanism is simplified to one mirror only, and the perpendicular movement is substituted by rotating the whole satellite. Also the Mars Vikings in the 1970s had similar scanning cameras.

The meteorological satellite scanning mechanism is well described e. g. here: http://www.eumetsat.int/groups/ops/documents/document/pdf_ten_msg_seviri_instrument.pdf