Mercury in RGB & IR 15/9

[Dave882]

Wanted to have another go at Mercury this week as it’s orbiting furthest from the sun and positioned as best it’ll get for afternoon viewing. Even though seeing conditions were not fantastic, it was finally a clearish afternoon on Wednesday.

I read that IR might reveal some more detail so armed with my new Optolong IR685 filter took a few vids.

The result showed quite a bit of extra contrast for IR vs slightly better resolution with the rgb. Even though I set up much earlier than last time I was frustrated by a single high cloud in the wrong spot (that I swear doubled back at least twice) so ended up closer to the horizon than I wanted.

Even so I reckon it’s a better result from previous attempts. Compared with Winjupos ephemerides i reckon that I’ve got a lighter region that coincides with 347.5W 33.9S which after a bit of research showed to be the Debussy Crater - a rayed impact crater. (Cmon just let me have it guys!!) And another region in northern hemisphere that I haven’t identified.

I tried combining the layers in Gimp but not that effective. When I can work on it a bit more I’ll post an image.

Might have one more shot at this if the conditions are good in next week.

By the way- this IR filter was useless for Venus just in case you were wondering.

10” LX50
ASI290mm mini for IR
ASI224mc FOR rgb
captured with ASIAIR Pro
1.8x Barlow
ZWO ADC (for rgb only)

RGB 20210915 1754
129sec , 12700 frames @98fps
320x240 - RAW8
2ms exposures rgb @ 300gain
AS!3 - 20% of

IR685 20210915 1650
122sec , 17400 Frames @ 141fps
320x240 - RAW8
3ms exposures rgb @ 300gain
AS!3 - 20% of

Registax6 for wavelet processing
GIMP to tidy & combine images

[multiweb]

Nice. Nailed it! :thumbsup::thumbsup::thumbsup: Did you find the ADC helped?

[Dave882]

Honestly really hard to tell what impact the adc has on final result as the seeing changes so drastically from minute to minute. But the view on the screen does appear to show less colour dispersion and a bit tighter image with adc. But again - very subjective opinion. Obviously the adc is pointless when shooting in just Ir or uv.

[Stonius]

Kicking goals! Nice work!

[Derek Klepp]

Great results.

[Dave882]

Thanks Derek / Markus for your comments! I also realise I didn’t post the combined rgb/ir image. Wasn’t exactly what I was hoping for but guess it’s a starting point…

Cheers
Dave

[multiweb]

Nice colors. :thumbsup: I should be out playing again tomorrow night hopefully. Can't wait to give it another crack.

[Dave882]

Thanks Marc. The colours I just left unaltered- the ones that as!3 spit out. I used lap4 when processing this one and got the orange hue (did not use uv-Ir block filter). Previously used laplace7 and with Bayer override it was greyscale (but this one had the uv-Ir in place).

I’ve been doing some reprocessing using different ap numbers, Laplace , drizzle settings just to see what difference it makes but haven’t quite found a combination that works repeatably.

[multiweb]

Did you find using drizzling integration to make a difference? I couldn't see much difference and was wondering if it mattered given the data is already oversampled.

[Dave882]

Done a couple stacks with d15 d30 and no drizzle. I actually found that it was better without drizzle for Mercury and Venus. But 1.5 drizzle better result for Saturn and Jupiter. Only a couple trials done so can’t guarantee this is true for every image

[multiweb]

I'm glad it's just not me then. :lol: It is also my experience to get noticeably better result on Saturn and Jupiter with drizzle15 but bugger all on Venus or Mercury. I also never got any improvement doing a double stack pass. I am not sure if it is because of my lack of aperture so I cannot confirm but I am aware that some seasoned planetary imagers with 16"+ aperture benefit from it.

[Dave882]

That’s interesting actually. I think I just do the double stack by habit but never tested it.
I’ve been doing some tests with align points too. For the bigger planets I thought that more align points would yield better result but after a few tests I get better results with 200ish points vs 1000ish points (using the grid). More detail and less noise. Have you ever tested this variable?

[multiweb]

I have blinked between with and without and I can't see any difference. The fact it takes so long to do sold me early in the piece. I thought the extra time wasn't worth the result. :shrug:

I try to place the APs manually and on features that are sharp and have a defined edge like bands on Jupiter or rings on Saturn. I also stick an AP on any moon in the field. I was also advised not to put APs too close to the limb of the planets.