Mars - Sunday morning in good seeing

[iceman]

Hi all

The seeing was good on Sunday morning, helped by very stable overnight temperatures (14°C) allowing my mirror to cool (passively, with a fan) to within 0.2° of ambient.

Mars is still very low at max 31° altitude, but it's just high enough to still capture some decent detail in good conditions, as shown by Anthony's amazing image from last week.

At this CM, Syrtis Major is the main vertical dark albedo feature just to the left of the middle, and Hellas is the bright area up near the South pole. The dark regions rotating into view from the right are Sinus Sabeaus and Pandorae Fretum.

Captured with my 12" newt on EQ6, DMK21AF04 + 5x powermate + Astronomik RGB filters. Best 300 frames from each channel were stacked. The red channel was used as Luminance.

Thanks for looking.

[h0ughy]

the image on the left seems pretty darn good, I can see the chang in the seeing with the later shot

[acropolite]

The right image looks to have more detail to me:confuse3: Both are very fine images Mike.:thumbsup:

[RB]

Both great images but I really like the left one, it's got lovely rich colours.

[Outbackmanyep]

Fantastic!
How does the DMK camera compare to the old ToUcam you used Mike?

[iceman]

Thanks guys


The DMK is in a different league to the ToUcam. It's 3-4 times the price, but it's definitely the next logical step (depending on budget) once you've exhausted what you can do with the ToUcam.

The DMK is better because of:
1) Fast framerates
2) No compression
3) Full resolution in each colour channel (mono camera, when used with RGB filters (as opposed to the 1-shot colour ToUcam ))
4) Better sensitivity
5) Lower noise

[Rodstar]

Lovely images, Mike. It is nifty to see the rotation of the disk over the period of about 30 minutes. Have you considered doing a moving Mars, like you have done in the past with Jupiter?

[iceman]

Thanks Rod, yes for sure - an animation is on the cards in the future.. However Mars rotates much slower (2.5 times slower) than Jupiter, so it will take a longer period of good seeing to get a good quality animation.

[Ingo]

wow. excellent! :eyepop:

[Ric]

Fantastic images Mike, the levels of detail are superb.

Cheers.

[matt]

Nice work, Mike.

The image on the right is the better of the two (IMO)...thanks to the seeing and slightly improved altitude.

You didn't say how long or how many frames you captured in each channel?

What's the maximum you can capture for in each channel before rotational smearing becomes an issue?

Good work:thumbsup:

[iceman]

Thanks guys.
Matt - I captured for 2 minutes in Red and 1 minute in Green and Blue. Red and Green @ 30fps, Blue @ 15fps.

For Mars, you can easily capture for 5 minutes without problems with rotational blurring. And probably even longer. Like Jupiter, it's only going to give you a slight red and blue fringe on the limbs if you go too long overall.

Because we're working with mono cameras, as long as the individual colour channel is around 2 minutes, then if registax stacks a frame at the start and end of that 2 minutes, they'll be fine. Over the whole RGB capture period, you might have gone for 6 minutes, but each individual channel will show no rotational blurring - when you combine the channels into a colour image, you would choose to align on the central features, leavnig a slight blue/red fringe on the limbs if you captured too long.

Like Anthony has said with his Jupiters, he captures for 1 minute in each colour channel - and at the long focal length he uses, Jupiter definitely rotates from the start of the red channel to the end of the blue channel, but each individual colour channel is sharp. It's better to have more frames to stack to make the middle (interesting) parts of the image smoother and more detailed, than to worry too much about 1 or 2 pixels of fringe colour.

Thanks

[matt]

Thanks, Mike.

That's handy info.

My new filter wheel should arrive in the next few days. I'm looking forward to finally having a go at RGB imaging.

I'll keep the trusty ol' ToUcam in my bag of tricks for the time being.

If I get a night of really good seeing, I'll grab AVIs with both cameras...just in case:whistle:

My plan is to get some solid DMK practice on Mars...ahead of the next Jupiter season.

Thanks again for the info.