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2bit Astrophotography with the Game Boy Camera

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Re: 2bit Astrophotography with the Game Boy Camera

#11

Post by jacquesm »

rocky1138 wrote: post #10
jacquesm wrote: post #2

That's worthy of the term 'hack'. Very neat :) There should be some silly way of doing this with just a single photo diode and a speaker to provide one axis of motion and to let the Earth's rotation provide the other axis.

Can you explain what you mean?

To make an image you need two axis, one horizontal, one vertical. Because the earth is already moving if you have a single photodiode looking at the stars you will scan a line if you wait a while. By adding a second axis of motion such as a speaker which you modulate with a saw-tooth curve you can add a second axis. If you then scan over time you can re-constitute the image by plotting the dots with the intensity captured by the diode taking into account the driving voltage of the speaker and the time that has passed.

Re: 2bit Astrophotography with the Game Boy Camera

#12

Post by orbital-decay »

jacquesm wrote: post #2

That's worthy of the term 'hack'. Very neat :) There should be some silly way of doing this with just a single photo diode and a speaker to provide one axis of motion and to let the Earth's rotation provide the other axis.

You can do this even without any motion and possibly even with no focusing optics, just with a single sensor, diffraction grating and a lot of math. This is called single-pixel imaging and is an ongoing research topic in computational imaging.

Re: 2bit Astrophotography with the Game Boy Camera

#13

Post by pepijndevos »

Jyaif wrote: post #6

I doubt the CMOS is only 2 bits, otherwise we wouldn't have such nice dithering pattern. Somewhere in RAM there's probably at one point a representation of the image with at least 3 bits per pixel.

It is the Game Boy screen that has only two bits.

Re: 2bit Astrophotography with the Game Boy Camera

#14

Post by anfractuosity »

orbital-decay wrote: post #12
jacquesm wrote: post #2

That's worthy of the term 'hack'. Very neat :) There should be some silly way of doing this with just a single photo diode and a speaker to provide one axis of motion and to let the Earth's rotation provide the other axis.

You can do this even without any motion and possibly even with no focusing optics, just with a single sensor, diffraction grating and a lot of math. This is called single-pixel imaging and is an ongoing research topic in computational imaging.

Could you explain in laymans terms how that would work? If you're only obtaining a single value for a single pixel and there's no movement, how does the pixel value change even if there's a grating in front? Or do you mean the grating can still move?

Re: 2bit Astrophotography with the Game Boy Camera

#16

Post by keithpeter »

anfractuosity wrote: post #14
orbital-decay wrote: post #12

Earlier quoted context omitted.

You can do this even without any motion and possibly even with no focusing optics, just with a single sensor, diffraction grating and a lot of math. This is called single-pixel imaging and is an ongoing research topic in computational imaging.

Could you explain in laymans terms how that would work? If you're only obtaining a single value for a single pixel and there's no movement, how does the pixel value change even if there's a grating in front? Or do you mean the grating can still move?

And noise? I used to do long exposure photos of interiors of buildings on film (~2h) but digital cameras seem challenged to me.

Re: 2bit Astrophotography with the Game Boy Camera

#18

Post by anfractuosity »

keithpeter wrote: post #16
anfractuosity wrote: post #14

Earlier quoted context omitted.

Could you explain in laymans terms how that would work? If you're only obtaining a single value for a single pixel and there's no movement, how does the pixel value change even if there's a grating in front? Or do you mean the grating can still move?

And noise? I used to do long exposure photos of interiors of buildings on film (~2h) but digital cameras seem challenged to me.

That's very interesting re. film. I'd be curious why that is. I've only ever done exposures less up to around a couple of minutes with film & digital. Do you have any examples that you shot for 2hr out of curiosity. Was that with ISO 50 or less, or did you use a darkening filter too?

Edit: I wonder if it is due to reciprocity failure with film - https://en.wikipedia.org/wiki/Reciprocity_(photography) ?

Re: 2bit Astrophotography with the Game Boy Camera

#20

Post by ljf »

app4soft wrote: post #17

CASIO WQV-1 is would be much better choice for 2-bit astrophotography.[1] [0] ftp://ftp.casio.co.jp/pub/watch/wc/WQVLink_Manual_K.pdf [1] http://www.3wheelers.com/elvis/body_wqv-1.html

Man I loved that watch - I still have it in my watch box somewhere, but it miss behaves now. I regret not buying the black plastic versions for spares when they were about £12 each. Ho hum!
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