Originally posted by GezinhoKiko
reply to post by Pinke
but surely they can match the colours on the rover (ie the flag, nasa badge, jpl logo) to visually be what the colours are on earth which in turn
reveals Mars' true colour.......yes??? or no???
Isn't that simple sadly.
I know NASA have released some images that they say are very close to the correct shades, buuuuuuut ....
Even in mega controlled environments with professionals, people still make mistakes, or factors influence things so colorists are still needed in
movies for example.
The rover had I think (from memory) nine cameras or some such on it. All of them were for different purposes. Some were even just black and white.
Calibrating two cameras of even slightly different hardware (and purposes) to show the exact same shades is actually pretty hard - all kinds of things
can change a shade here and there. Over long periods of time with shifting sky cover, too ... you can actually take two shots within 10 minutes of
each other and end up with a different result on annoying days.
The hand lens imager was used to get close ups of soil, and could also be used to look at the rover. It was focused to infiinity to allow land scape
The mast cams had a wheel with filters on it, and could pick up near infrared etc ... for various purposes. You can read about it a bit
. The two mast cams were also set to different focal lengths. They also had ND
filter or neutral density filters. You can look up comparisons of shots and without neutral density filters on googles.
Basic example here.
I suppose the end conclusion is that a lot of pictures were taken for a lot of different purposes, and a lot of them (especially those using various
filters) were to gauge things like minerals, look at the sun, or investigate soil samples. There are also a lot of other factors such as
dust and weather
so its not always just a case of
knowing exact shades.
The explanations and documents have been available ... but I guess NASA prefers to leave more fluffy easy to understand writings on their main web
It's one of my sources of frustration when dealing with NASA sometimes! Surely they know that persons just look at the photo and don't exactly do
piles of research. A little note saying, 'we are doing X or Y in this photo' would be nice! I know the information is out there, but it can be a pain
to dig up sometimes.
They've always been a little bit like that though!
Edit: It won't be today but if I stumble on the NASA piccies that are meant to be close I'll maybe U2U link but they shouldn't be mega hard to find.
Persons obviously have differing opinions though.
edit on 24-1-2013 by Pinke because: Edit