Le 10/08/2012 20:39, nemesis nous fit lire :
> how about less photographs and more color? ;)
> 
Ever though about the light intensity on planet Mars ?

The B&W pictures might indeed use more width spectrum than a real colour
picture.

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On Fri, 10 Aug 2012 19:28:17 +0100, Stephen wrote:

>> kidding aside, why in 2012 we still need to look at B&W photographs
>> from outer space?
>>
>>
> Bandwidth, old chap.

Oh, I don't think that's it.  Curiosity started with 5 Mbps of bandwidth 
and once they cranked it up, it's at 40 Mbps of bandwidth.

I have 3 Mbps of bandwidth (down) on my DSL line, and it handles colour 
images fine. ;)

I think it's more to do with the complexity of the hardware.  B&W imaging 
hardware is perhaps less complex and less prone to failing.  But that's 
just a guess.

I suppose I could ask a friend of mine who works on satellite tech, or my 
wife could ask a friend of hers at JPL who might know.

Jim

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Jim Henderson <nos### [at] nospamcom> wrote:
> On Fri, 10 Aug 2012 19:28:17 +0100, Stephen wrote:

> >> kidding aside, why in 2012 we still need to look at B&W photographs
> >> from outer space?
> >>
> >>
> > Bandwidth, old chap.

> Oh, I don't think that's it.  Curiosity started with 5 Mbps of bandwidth 
> and once they cranked it up, it's at 40 Mbps of bandwidth.

> I have 3 Mbps of bandwidth (down) on my DSL line, and it handles colour 
> images fine. ;)

> I think it's more to do with the complexity of the hardware.  B&W imaging 
> hardware is perhaps less complex and less prone to failing.  But that's 
> just a guess.

> I suppose I could ask a friend of mine who works on satellite tech, or my 
> wife could ask a friend of hers at JPL who might know.

You all talk like the rover has no color cameras. Naturally that's not so.

Why some cameras are color and some B&W, that's an interesting question.
I haven't researched, but I'm guessing that they serve different purposes.
For example the rover has several "safety cameras" which purpose is to
detect and avoid collisions against obstacles when the rover moves. These
seem to be B&W, and I suppose that's enough for that purpose (and are probably
more reliable because the technology is simpler and more robust).

Perhaps some of the regular cameras are also B&W for the same reason: Maybe
they are less likely to break or malfunction in other ways. Maybe they have
a higher contrast, maybe they can capture a larger range of light amplitudes,
I don't know.

-- 
                                                          - Warp

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Also, colour camera have a resolution of 1/2 in each dimension when
compared to a B&W: the colour is achieved by masking some detectors with
coloured filter.

Do you want a 2MPixel colours pictures, or a 8MPixel B&W ?
(now, the number of pixels is probably far greater on such expedition.
Yet 10MPixel or 40MPixel ?)

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On 10/08/2012 8:17 PM, Stephen wrote:
>
> Don't ask me, ask NASA. :-P

FYI http://www.bbc.co.uk/news/science-environment-19201742

-- 
Regards
     Stephen

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On 8/10/2012 11:28, Stephen wrote:
> Bandwidth, old chap.

Actually, precision and robustness. It's better to have one camera take 
three different pictures with three filters than to build a camera that 
takes three pictures at once.

-- 
Darren New, San Diego CA, USA (PST)
   "Oh no! We're out of code juice!"
   "Don't panic. There's beans and filters
    in the cabinet."

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Am 10.08.2012 20:28, schrieb Stephen:

>> kidding aside, why in 2012 we still need to look at B&W photographs
>> from outer
>> space?
>>
>>
> Bandwidth, old chap.


More likely payload weight. That thing has plenty of cameras on board - 
many of them designed for special purposes for which resolution is more 
important than color. This particular one, for instance, is intended for 
navigation purposes - most likely a wide-angle camera; but the 
scientists have enough panorama color shots from the Mars surface 
already, so they went for the lighter alternative, and only have color 
on some other camera designed for close-up shots (as close as 2 cm or 
so; it can focus at infinity as well though). We'll see full-res shots 
from that camera in due time.

Remember, this is not a sightseeing trip - it's scientific exploration.

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On 11/08/2012 4:56 PM, clipka wrote:
> Remember, this is not a sightseeing trip - it's scientific exploration.

I did not even imply that but it was in my mind. It was at the start of 
this phase of the mission and I suspect that there is more need for the 
bandwith than sending postcards home. :-)

-- 
Regards
     Stephen

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Am 11.08.2012 18:01, schrieb Stephen:
> On 11/08/2012 4:56 PM, clipka wrote:
>> Remember, this is not a sightseeing trip - it's scientific exploration.
>
> I did not even imply that but it was in my mind. It was at the start of
> this phase of the mission and I suspect that there is more need for the
> bandwith than sending postcards home. :-)

Testing all the systems is probably the current top priority ATM, so 
aside from some hi-res postcards from each camera, they'll also want a 
nice greeting from each and every sensor, actuator and any other gizmo 
onboard, yes.

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"nemesis" <nam### [at] gmailcom> wrote:
> "gregjohn" <pte### [at] yahoocom> wrote:
> > Typical case here:
> > http://www.nasa.gov/mission_pages/msl/multimedia/pia16013.html
>
> they faked it at arizona desert!
>
> kidding aside, why in 2012 we still need to look at B&W photographs from outer
> space?

It's a ... a ... a ...  Monochromatic World.

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