Curiosity's cameras?

jnorman

what resolution are the cameras on the new Mar's rover "Curiosity"? i read somewhere that the high-res cam was only 2mp, but i am unable to find any real specs.
thanks.

russ_watters

The wiki says they are 2mp, with Bayer filters.

jnorman

when we now have extraordinarily high-res sensors available for consumer cameras, of 20-40mp, why would they use a measly 2mp sensor? do normal cameras not have bayer filters? what do the bayer filters do?
thanks.

Andy Resnick

The camera need to withstand solar radiation- the cameras we flew (and are still onboard) the space station crapped out after about 2 years- ionizing radiation causes 'latching', resulting in the steady accumulation of hot pixels.

I couldn't find clear evidence of who made the CCDs, possibly Kodak. In any case, it's most likely a rad-hardened CCD chip, which is also why it's not a (high end) consumer grade chip.

Moppy

Despite what the nice salesman at the camera shop wil say, resolution is largely irrelevant for picture quality these days.

A lot of high res cameras are in reality much lower resolution and produce additional pixels via mathematical computation. There is also the fact that the optical quality of the lens makes a huge difference.

The above I know for a fact as one of my hobbies is photography. Below is speculation.

I imagine the cameras on the rover must be massively hardened and extremely rugged. There is also the question of the amount of bandwidth available to phone home.

Vorde

More importantly, a robot can easily (and accurately) stitch together a larger picture from lots of small ones.

Moppy

Motorised tripods aren't that expensive. I have two. I can't see how that's a factor since human photographers have no trouble doing it.

russ_watters

A Bayer filter is the three-color filter most cameras use to see color. Each pixel is one color, so the effective resolution is lower than the spec.

Andy Resnick

Found the specs:

http://www.msss.com/msl/mahli/refere..._MarsMicro.pdf

"MAHLI uses a Kodak KAI-2020CM interline transfer CCD (1600 x 1200 active 7.4 um square pixels with RGB filtered microlenses arranged in a Bayer pattern)."

Here's the datasheet:
http://www.stargazing.net/david/QSI/...20LongSpec.pdf

It's been a while since I got that deep into CCD specs, but there doesn't seem to be anything super-awesome about the chip. Maybe it has a good track record....

jnorman

very interesting - thanks for the responses.

russ_watters

Googling it, it appears to be a staple of high-end amateur and low-end professional astro-cams. So it does have at least moderate awesomeness.

Also keep in mind that NASA wouldn't have changed it out right before launch, so it was probably picked 10 years ago, at which time it would have had super awesomeness.

sophiecentaur

Oh Moppy. A man after my own heart. You wouldn't believe the number of cameras that are sold with so-called high-res sensors and yet they have lenses like 'sucked acid drops'. What's the use of a 16Mpixel sensor if there's a crummy lens involved and the picture is seen by the world as a highly compressed mpg file on Facebook?
But there are Photographers and there are people who take photographs, my friend.

sophiecentaur

That goes for all the electronics on board, probably. No chance of a three fingered salute when you're half way there and it goes dodgy. I HAS to work.

cosmik debris

The size of the array, the pixel size and the build quality of the array have more effect on resolution than the number of pixels. As others have pointed out number of pixels is a sales pitch.

Khashishi

bear in mind that an ultra high resolution camera is useless if we don't have the bandwidth to transfer the images to us.

sophiecentaur

It's bandwidth times time that counts, not just bandwidth. It depends whether a lot of separate low res pictures are more interesting than one high res picture.

Moppy

Bandwidth is bits/time, not bits. The unit of time cancel if you multiplied bandwidth by time?