Mars Moon Photobomb

[MarkRadice]

Still buzzing (if a little sleepy!) after the Mars occultation. Amazing to watch celestial dynamics in realtime.  A rather beautiful view despite the horrors of the 0400 alarm! A rather beautiful view this morning - despite the 0400 alarm clock! Not often you get to see Mars disappear behind the Moon - this is just before first contact.

Celestron C11 at f20 on an EQ6 with ASI224MC + IR filter

[MarkRadice]

I put together a short video here showing the set up and some of the raw footage: 

 

[Scooot]

Cracking images Mark. 

[Kon]

Excellent images! 

[geoflewis]

That's brilliant Mark. I love that you had the foresight to capture yourself capturing the event. Fantastic final still images too, you really got the focus dialled in.

Edited December 12, 2022 by geoflewis

[Rusted]

Excellent capture.

Just curious: Did you notice any difference in focus between the planet and lunar limb?

[Mandy D]

2 hours ago, Rusted said:

Excellent capture.

Just curious: Did you notice any difference in focus between the planet and lunar limb?

There should be none. Once you are focussed on something as distant as the Moon, the amount of focuser travel to reach the theoretical focus point for anything beyond, e.g. planets, galaxies, etc, will be infinitessimally small. Therefore, if focus on the Moon is as perfect as you can get it, then it will be for Mars. Thierry Legault discusses this in detail in his excellent book, Astrophotography.

[Rusted]

Thank you Mandy.

It is rarely one can have two such distant objects in the same field of view. Albeit one much closer than the other.
Particularly when subjected to high magnification from using a very long, effective focal length.
A shorter focal length would have a much deeper field of view. Notwithstanding the extreme distance to both objects.

Where two distant objects are in separate fields of view one would naturally tweak the focus just to check best focus.
Thereby losing the reference point from the first [sharply focused] object.

[Mandy D]

2 hours ago, Rusted said:

Thank you Mandy.

It is rarely one can have two such distant objects in the same field of view. Albeit one much closer than the other.
Particularly when subjected to high magnification from using a very long, effective focal length.
A shorter focal length would have a much deeper field of view. Notwithstanding the extreme distance to both objects.

Where two distant objects are in separate fields of view one would naturally tweak the focus just to check best focus.
Thereby losing the reference point from the first [sharply focused] object.

I accept what you say about focal ratio and depth of field, but at astronomical distances it becomes totally irrelevent. Referring to Thierry Legault, Astrophotography, pg 74, he states that for a focal length of 1000 mm the difference in focus position for the Moon and a star hundreds of light years away is of the order of one billionth of a millimetre! I don't know about you, but I am certain that I cannot make such a fine adjustment of focus, myself. 😉