Mars Monday AM

Finally got some nice seeing and was ready for it.
C9.25 + TV 4x + 1.6x. Toucam 740 with the NO-RAW mod;
mod seems to help, though there is still some ringing
at the limb. 15fps. 600 of 2250 frames with Registax.

Interesting to compare with Alan's beautiful image taken at
about same time; nearly every feature shows up in both.
I have sometimes been a skeptic of image processing, but
it is obvious there is considerable reality to these images.

I have been wondering if the ringing at the edge was partly
due to the large central obstruction in these SCTs. Perhaps
it is a manifestation of the bright first Airy ring?
Processing seems to pick-up on it and further accentuate it.
Comments?

Attached Image:

Hi John,

Very! detailed image, thanks for posting, as a helpful comment IMO the color appears to be a little to much on the yellow side.

Wes Higgins

John Biretta said:

I have been wondering if the ringing at the edge was partly
due to the large central obstruction in these SCTs. Perhaps
it is a manifestation of the bright first Airy ring?
Processing seems to pick-up on it and further accentuate it.
Comments?

I think the effect of CO would be to reduce the contrast in the image as in at the eyepiece - this artifact comes from too much contrast - usually applied in unsharp masking. If you experiment with this processing tool you can see the effect it has on the following edge of mars. The larger the pixel radius used the more dramatic the increase in contrast - the albedo features respond OK to using a larger pixel diameter because they are low in contrast to start with, but unfortunately the bright limb doesn't accept this as well.

Nicely done image!

Alan

VERY nice detail John! I think Alans response about low and high contrast features response to certain processing steps is quite correct, but I also think the ring is a real feature that is just overemphasized. The blue channel also shows it because I think its the edge-on atmosphere of Mars we are looking through which in the blue channel widens near the NPR. Sometimes this dark ring near the thin blue strip of atmosphere is also a dark albedo feature rotating into view. So my opinion is that its both real and overemphasized by the steps we need in processing the details of Mars.

--Mike

John, Nice shot of Mars! What do you mean by the "no-raw modification"? This is new to me and I have noticed several Mars posts recently mentioning it. I cannot find this option with my toucam 840 setting or registax. At this point, I need every possible option to get my images improved. Thanks!

Regards,
Steve

Excellent image John. Beautiful job. I don't think the CO has anything to do with the edge. The best images are being taken with scopes having COs (Maksutovs, Schmidt-Cass, Dall-K.,Mak-Newts and Newtonians). It is probably a processing artifact of some type.
Congratulations!

Jim Phillips