How About a Gigapixel Digital Camera?

vcullen writes "Ever wondered where digital cameras will end up? What about a 1 Gigapixel digital camera? It would certainly beat the latest array of new digital cameras - the biggest of which only has an 8.2MP sensor! The 1 Gig Digital Camera might not quite fit in your pocket but the thought of it does make one's mind spin a little. The European Space Agency is building this massive camera (actually it's made from 170 cameras) for its Gaia space telescope, due for launch in 2010. Why? They want to map the entire universe 'down to a resolution one million times fainter than the human eye can see.'"

Comments

Been there, done that...

['t is DjiM]

Gigapixel photography using several camera's is not nearly new.

Nitpicking

[KilobyteKnight]

It would certainly beat the latest array of new digital cameras - the biggest of which only has an 8.2MP sensor!

Not quite right

"Only" 8.2MP

[rawgod0122]

OK there are a few things that need to be said about that number.

First you can get cameras that have 25 MP sensors. They are called medium format. Only problem is you will be looking at tens of thousands of dollars (US) up to about $30k.

Second I have a ~6MP Nikon D70. I can print 8x10" just fine and if I had a printer large enough 11x14 with a little bit of interpolation. One just does not need that many pixels to get good prints, and even less for a computer display.

If you don't beleive me go check out
http://www.luminous-landscape.com/reviews/sho otout .shtml

and for what 3MP gets you
http://www.luminous-landscape.com/reviews/cam eras/ d30/d30_vs_film.shtml

Pixels don't matter - CCD size does

[DoctorRad]

The best quality optics in the world won't get you past the diffraction limit, so the physical size of the CCD matters too. The diffraction limit imposes the condition that cramming ever more pixels into the same area eventually becomes fruitless: there's no more information to be had in that area. You want more information? Increase that area.

That said, I have no handle on how the cost/benefit curve looks assigning funds to improving either the optics or the CCD in different proportions.

Matt...

Re:Pixels don't matter - CCD size does

[Christopher Thomas]

The best quality optics in the world won't get you past the diffraction limit, so the physical size of the CCD matters too. The diffraction limit imposes the condition that cramming ever more pixels into the same area eventually becomes fruitless: there's no more information to be had in that area. You want more information? Increase that area.

It's actually the size of the aperture, not the image plane, that imposes diffraction limits. On the image plane, the limit is imposed by the size of the beam waist you can get given the focal length of the lens and its aperture (which give the angle at which the beam converges, which gives the beam waist size for any given wavelength).

In the best possible case, you get a pixel size comparable to a wavelength of light (say one micron, for visible light). This requires a lens (or mirror!) with a diameter comparable to its focal length.

Typical pixel dimension is something like 5 microns. This is imposed by fabrication constraints (which change as process technologies get better) and by the fact that you have to have enough light falling on the pixel to produce a useful and low-noise signal (S:N improves as the square root of photon count, as long as circuit noise is low; more photons = less noise). There is a limit to how much light you can concentrate into a small region of a detector before damage occurs.

(For more information than you ever wanted to know about at least one type of image sensor, see our research group's web page.)