Here are Mars images from January 15 in average seeing.
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Posted 17 January 2021 - 09:07 AM
Nice result Paul!
Looks to me that the seeing was better than average. Mars is getting so small now that perhaps a red longpass with a cut-on in the 610 to 680 range may regularly out preform the 742LP.
I had been using an Edmund 650LP as my IR early in the apparition last year, but stopped taking IR video back in August as it rarely bested my R results. I still used the 650LP as a focusing aid though in some conditions, as it is a 3mm thick fused silica filter that's parfocal with my Chroma/Astrodon filters.
BTW--- by early November I switched my R to a Chroma R-Bessell that has a wider 140nm bandpass than that of the normal Chroma R of 100nm, with a virtually identical CWL--- technically the Bessell design is 1nm shorter in CWL. I don't notice any resolution difference, just less noise and a bit better contrast. Wished that I had done that months earlier. I should mention that my old R had actually been an Astrodon Gen2 i-series R, but it's bandpass is essentially the same as the Chroma R.
Posted 17 January 2021 - 09:13 AM
Very fine image, Paul!
There are still lots of dark features on Mars with its delightful and continuing gibbous phase.
Very best regards from Aubrey.
(Who was once in Arizona)
Posted 17 January 2021 - 10:40 AM
Nice result Paul!
I agree, the 742 is basically giving me a mostly blobby image. The detail in the Chroma Red filter is much sharper. The red filter even out performs the 680nm I have. I should try the 610nm and see how it works.
Posted 19 January 2021 - 01:11 AM
Great images! With slightly warmer temperatures, the seeing tonight here in north Texas was fantastic (and comfortable). Mars was very high in the sky and it's the best I've seen it in a while (10" Dob with 6mm and then Barlow).
Question. I was able to get a fairly sharp ball focus on Mars (1/8" diameter at one foot distance), but it seemed all whitish to me. I couldn't see any surface color variations.
What would you recommend as a filter to bring out the surface color variations of Mars?
Posted 19 January 2021 - 07:53 AM
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