Weird stuff on Mars !!!

Linda wrote:
When you say that the FOV of the image is 31 x 31 mm I take that as meaning
at the plane of the
CCD image much like a SLR 35mm image. So what if my pictures are 5 x 8? I
still cannot make
any inference about the size of ojects in the picture. So, what does it
matter if the FOV is 31mm x 31mm?
This is 2 dimensions not 3 and perspective is at play. I really think you
don't know what you are talking about. If you did
you would just tell me what the size of those beads are based on your
"technical specifications".

You are either really thick headed *and* self righteous or you are just
another troll. My bet is on the latter. Shawn Grant as a girl. Ick!

--
Greg Crinklaw
Astronomical Software Developer
Cloudcroft, New Mexico, USA (33N, 106W, 2700m)

SkyTools Software for the Observer:
http://www.skyhound.com/cs.html

Skyhound Observing Pages:
http://www.skyhound.com/sh/skyhound.html

To reply remove spleen

On Sun, 08 Feb 2004 20:41:18 GMT, "Linda" wrote:

When you say that the FOV of the image is 31 x 31 mm I take that as meaning
at the plane of the
CCD image much like a SLR 35mm image. So what if my pictures are 5 x 8? I
still cannot make
any inference about the size of ojects in the picture. So, what does it
matter if the FOV is 31mm x 31mm?
This is 2 dimensions not 3 and perspective is at play. I really think you
don't know what you are talking about. If you did
you would just tell me what the size of those beads are based on your
"technical specifications".


Please understand, this is a microscope. There is no issue of perspective. The
fov is 31mm square. That means when you look at one of these images, you are
seeing 31mm across the sample- it doesn't matter how big you display or print
it. Because the sensor is 1024x1024 pixels, the image scale works out to
30um/pixel. That is all you need to figure out what size any object is. Taking
as an example the image at
http://marsrovers.jpl.nasa.gov/galle...0P2932M1M1.JPG
you can easily measure the globule at the very middle and see that it is 115
pixels in diameter. 115*30um = 3450um, or 3.45mm. You can see individual grains
of soil, and they are about 3-4 pixels across, so these particles must be around
100um.

_________________________________________________

Chris L Peterson
Cloudbait Observatory
http://www.cloudbait.com

On Sun, 08 Feb 2004 20:41:18 GMT, "Linda" wrote:

When you say that the FOV of the image is 31 x 31 mm I take that as meaning
at the plane of the
CCD image much like a SLR 35mm image. So what if my pictures are 5 x 8? I
still cannot make
any inference about the size of ojects in the picture. So, what does it
matter if the FOV is 31mm x 31mm?
This is 2 dimensions not 3 and perspective is at play. I really think you
don't know what you are talking about. If you did
you would just tell me what the size of those beads are based on your
"technical specifications".


Please understand, this is a microscope. There is no issue of perspective. The
fov is 31mm square. That means when you look at one of these images, you are
seeing 31mm across the sample- it doesn't matter how big you display or print
it. Because the sensor is 1024x1024 pixels, the image scale works out to
30um/pixel. That is all you need to figure out what size any object is. Taking
as an example the image at
http://marsrovers.jpl.nasa.gov/galle...0P2932M1M1.JPG
you can easily measure the globule at the very middle and see that it is 115
pixels in diameter. 115*30um = 3450um, or 3.45mm. You can see individual grains
of soil, and they are about 3-4 pixels across, so these particles must be around
100um.

_________________________________________________

Chris L Peterson
Cloudbait Observatory
http://www.cloudbait.com

Ï "Joe Knapp" Ýãñáøå óôï ìÞíõìá
om...


"Ioannis" wrote
[snip]
That's what my guess would be, too. I've seen similar glass-bead
spherules,
having resulted from meteor impact heat on the moon in one of my astro
books.

But those moon beads are tiny ( 300 microns) and black. These are ~5000
microns and appear to have a matte surface?

Yeah, it was just a guess. I don't know. Are such sizes prohibitive by
natural meteor impact processes? Perhaps the materials on Mars allow for
size differentiation?

Joe
--
Ioannis Galidakis
http://users.forthnet.gr/ath/jgal/
------------------------------------------
Eventually, _everything_ is understandable

Ï "Joe Knapp" Ýãñáøå óôï ìÞíõìá
om...


"Ioannis" wrote
[snip]
That's what my guess would be, too. I've seen similar glass-bead
spherules,
having resulted from meteor impact heat on the moon in one of my astro
books.

But those moon beads are tiny ( 300 microns) and black. These are ~5000
microns and appear to have a matte surface?

Yeah, it was just a guess. I don't know. Are such sizes prohibitive by
natural meteor impact processes? Perhaps the materials on Mars allow for
size differentiation?

Joe
--
Ioannis Galidakis
http://users.forthnet.gr/ath/jgal/
------------------------------------------
Eventually, _everything_ is understandable

=

Please understand, this is a microscope. There is no issue of perspective.
The
fov is 31mm square. That means when you look at one of these images, you
are
seeing 31mm across the sample- it doesn't matter how big you display or
print
it. Because the sensor is 1024x1024 pixels, the image scale works out to
30um/pixel. That is all you need to figure out what size any object is.
Taking
as an example the image at

http://marsrovers.jpl.nasa.gov/galle...0P2932M1M1.JPG
you can easily measure the globule at the very middle and see that it is
115
pixels in diameter. 115*30um = 3450um, or 3.45mm. You can see individual
grains
of soil, and they are about 3-4 pixels across, so these particles must be
around
100um.



Ok, it seems we are communicating now after a complete waste of other posts.
But, how does one count pixels?

=

Please understand, this is a microscope. There is no issue of perspective.
The
fov is 31mm square. That means when you look at one of these images, you
are
seeing 31mm across the sample- it doesn't matter how big you display or
print
it. Because the sensor is 1024x1024 pixels, the image scale works out to
30um/pixel. That is all you need to figure out what size any object is.
Taking
as an example the image at

http://marsrovers.jpl.nasa.gov/galle...0P2932M1M1.JPG
you can easily measure the globule at the very middle and see that it is
115
pixels in diameter. 115*30um = 3450um, or 3.45mm. You can see individual
grains
of soil, and they are about 3-4 pixels across, so these particles must be
around
100um.



Ok, it seems we are communicating now after a complete waste of other posts.
But, how does one count pixels?

Linda wrote:

Ok, it seems we are communicating now after a complete waste of other
posts. But, how does one count pixels?

One, two, three .... etc.

Linda wrote:

Ok, it seems we are communicating now after a complete waste of other
posts. But, how does one count pixels?

One, two, three .... etc.

On Sun, 08 Feb 2004 23:10:46 GMT, "Linda" wrote:

Ok, it seems we are communicating now after a complete waste of other posts.
But, how does one count pixels?

I do it in Photoshop, but most image editing programs have some kind of
measurement tool.

_________________________________________________

Chris L Peterson
Cloudbait Observatory
http://www.cloudbait.com