Mars - 2 Dec 2022

[geoflewis]

Well after a couple of weeks of nothing much I had an unexpected and extremely fortuitous session with Mars last night. My wife and I were due to be celebrating our daughter's birthday with her family yesterday, but in the morning her husband tested +ve for Covid, so we came home. Then around 10pm I looked outside to see that the earlier fog was clearing, so I opened up the observatory and pointed the rig at Mars. I probably had the best seeing this apparition, so ran several SER videos, including adding the Baader barlow for amplification, allow the rig to operate at ~F21. The seeing was mostly stable, but was still a bit in/out, plus fog was patchy affecting the brighness of capture, eventually shutting me down. Anyway, here are 3 images, each comprising the best 30% of 3x6 min SERs. De-rotation was just the stack from each SER, not the SER itself.

Mars is now 100% phase being less than 1 week prior to it's opposition. It's good to see a bit more surface detail finally coming through. Mare Cimmerium, with finger of Sinus Gomer pointing towards the bright region of Elysium, is rotating away from the Central Meridian. The polar hood has shrunk a lot since I last imaged Mars.

 

Edited December 2, 2022 by geoflewis

[neil phillips]

lovely detail coming through. What frame rate did you go for, exposure ect?

[geoflewis]

Thanks Neil, I was still at 5ms (200fps) - I totally forgot to change that, but with the better seeing, I think it was ok.

[neil phillips]

7 minutes ago, geoflewis said:

Thanks Neil, I was still at 5ms (200fps) - I totally forgot to change that, but with the better seeing, I think it was ok.

Most certainly is

[lukebl]

Fabulous images.

I just wondered if derotation has any great effect with Mars, given that it rotates so slowly compared to, say, Jupiter?

[Kon]

Excellent Mars and good to see you managed a clear night. Hardly any edge rind as well. Lovely colour balance too.

I hope you are keeping covid under wraps.

[geoflewis]

Here's an annotated version of the 3 Mars images. Also if you want to have a try at seeing Mars in 3D just use either of the left 2 or right 2 images as stereo images and try to bring them together with your eyes. I use my hands to block the image, so that I look at the left hand one with my right eye and right hand one with the left eye.

[JeremyS]

Splendid 👍🏻

[geoflewis]

1 hour ago, lukebl said:

Fabulous images.

I just wondered if derotation has any great effect with Mars, given that it rotates so slowly compared to, say, Jupiter?

Thanks Luke. The effect of Mars rotation is much less significant than for Jupiter, but it is noticible over anything more than a few minutes and each of those 3 images has ~20 mins elapsed time, so would definitely smear without de-rotation. See my previous post with the annotated images for more information.

Edited December 2, 2022 by geoflewis

[geoflewis]

22 minutes ago, Kon said:

Excellent Mars and good to see you managed a clear night. Hardly any edge rind as well. Lovely colour balance too.

I hope you are keeping covid under wraps.

Thanks Kostas, yes, I think the bigger image size at F21 helps with the edge rind a lot. I captured some data at F13 before adding the barlow and the edge rind is much worse, as are the images overall, so yet more to the optimal sampling discussion. So far so good as far as Covid is concerned, so hopefully we have got away with it, but it's still early days.....🤞

[geoflewis]

5 minutes ago, JeremyS said:

Splendid 👍🏻

Thanks Jeremy

[Kon]

41 minutes ago, geoflewis said:

Thanks Kostas, yes, I think the bigger image size at F21 helps with the edge rind a lot. I captured some data at F13 before adding the barlow and the edge rind is much worse, as are the images overall, so yet more to the optimal sampling discussion. So far so good as far as Covid is concerned, so hopefully we have got away with it, but it's still early days.....🤞

Glad you have 'escaped it'.

Love the 3d on the images! Brings a new dimension to them. 

The correct sampling is really helping it a lot. Very good example.

[Elp]

1 hour ago, geoflewis said:

seeing Mars in 3D

Surprised it actually works quite well.

Great detail in those images.

[geoflewis]

15 minutes ago, Elp said:

Surprised it actually works quite well.

Great detail in those images.

Thanks, yes, the 3D works quite well with stereo images that are close in elapsed time.

[Space Cowboy]

Super images Geof! Really seeing definition in that surface detail.

[geoflewis]

53 minutes ago, Space Cowboy said:

Super images Geof! Really seeing definition in that surface detail.

Thanks Stuart, I finally had some decent seeing to work with.

[neil phillips]

21 hours ago, lukebl said:

Fabulous images.

I just wondered if derotation has any great effect with Mars, given that it rotates so slowly compared to, say, Jupiter?

It does when you capture for 12 minuets 

[neil phillips]

Just a great result Geof. Nice fine detail

[lukebl]

31 minutes ago, neil phillips said:

It does when you capture for 12 minuets 

Is that really necessary? I’d have thought a couple of minutes at 200fps would be sufficient. Law of diminishing returns and whatnot. I’ll have to try it if I ever get a clear night.

[neil phillips]

59 minutes ago, lukebl said:

Is that really necessary? I’d have thought a couple of minutes at 200fps would be sufficient. Law of diminishing returns and whatnot. I’ll have to try it if I ever get a clear night.

Not even close. More capture time allows a shorter exposure a higher frame rate. (because of SNR) Which helps beat seeing. It also enables via a large stack rate. Much stronger sharpening on programs like Astro surface. Which will 100% reveal more detail. Then any minimalist technique. Under poor seeing recently i managed to get a level of detail using this technique that looked like it was taken in reasonable seeing. The technique also alluded others detail wise on the same night. The result was easy to see its superiority. For the reasons outlined the law of diminishing returns is misleading.

Edited December 3, 2022 by neil phillips

[yelsac]

43 minutes ago, neil phillips said:

Not even close. More capture time allows a shorter exposure a higher frame rate. (because of SNR) Which helps beat seeing. It also enables via a large stack rate. Much stronger sharpening on programs like Astro surface. Which will 100% reveal more detail. Then any minimalist technique. Under poor seeing recently i managed to get a level of detail using this technique that looked like it was taken in reasonable seeing. The technique also alluded others detail wise on the same night. The result was easy to see its superiority. For the reasons outlined the law of diminishing returns is misleading.

Sorry to jump in, so does astro surface just replace registax in your processing?

[neil phillips]

55 minutes ago, yelsac said:

Sorry to jump in, so does astro surface just replace registax in your processing?

Compliments Yelsac. Not totally replace

[geoflewis]

15 minutes ago, neil phillips said:

Compliments Yelsac. Not totally replace

I think I need to take a look at Astro Surface…..🤔

[Space Cowboy]

Just wondered Geof, how tightly do you crop your captures before stacking? I notice there is a yellow hue on your limb. I had a similar effect on a Mars video capture I'd cropped too tightly in pipp. It may be coincidence but thought I'd mention it.

[geoflewis]

2 hours ago, Space Cowboy said:

Just wondered Geof, how tightly do you crop your captures before stacking? I notice there is a yellow hue on your limb. I had a similar effect on a Mars video capture I'd cropped too tightly in pipp. It may be coincidence but thought I'd mention it.

That’s an interesting question Stuart, could you amplify your thinking please? I haven’t cropped before stacking, just took the SER straight into AS3!, but I do set a pretty tight ROI in FireCapture. Why do you think that a tight crop, or ROI might give a yellow limb hue?