Mandy D

Very pertinent advice, there. I never think about this, but I recall bringing my camera and lenses in from the Land Rover in Switzerland one time when it was -24 °C outside and my lenses fogged up on the inside as well as outside and took an hour or more in a warm place to clear! Thankfully, we do not heat the hallway where my telescopes are generally stored, so I may be OK. I don't have room to store my OTAs tilted, but might do it overnight after bringing them in, just in case.

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.

I don't know if you found this, already, but I'll post it for anyone else who may come across this thread and wish to build their own. https://www.aluflex.com/Filer/PDF-Dokument/MB_Building_Kit_System.pdf Page 96 shows the angle brackets. From the weight given, you want part no. 0.0.602.36.

Artemis I captured part of the same region that you have, above and from a slightly different angle to how we see it from Earth. The image, used in the article linked below, was the opposite way up, so I have rotated it and reproduced it here. The credit and copyright is NASA. I thought it would make a nice comparison and illustrate how high quality your images are. It would have been nice if NASA's image had been colour.

I should probably have said to take the battery out for safety before heating, but common sense should dictate that anyway!

Dry it in a warm environment, about 40 deg C, for a few days. Airing cupboard, above a radiator, etc. If you feel competent, strip it and dry parts separately. I obtained an A0 plotter that had been stored outside without cover for six months, stripped it and dried everything in my domestic oven on the lowest setting for a few hours, put it back together and it ran perfectly. I've had it for 20 years. Whatever you do, don't run it until you are certain it is 100% dried out. Water will not harm it when it is not running.

No Citroens were harmed in the manufacture of those racks!

I was very lucky and had clear skies from 17:44 when I was leaving work and started observing the approach of Mars to the Moon and took my first photos of the evening with a 50 mm prime lens on the D800, right through to second contact. It was hardly going to give me anything like an award winning photo at that focal length, but it did produce an image in which both Mars and the Moon were clearly visible and you could measure the separation between them, so useful data, I guess. At home, I had to cook dinner, then watched a movie before venturing back outside, this time with a 300 mm lens on the D800. Much better! It was 20:30 by the time I grabbed the next images and Mars was still too far separated from the Moon to fit on the sensor with 600 mm of focal length, which was the plan for later. I really wanted to get the RC6 out with a 2x focal extender to give me 2740 mm, but my back was not going to allow, so tripod and camera lenses it was! I also had no plans at this point to stay up all night. But, as some of you already know that is exactly what happened. It was definitely worth it! I was outside for 5 minutes every hour from 22:30 until the last half hour before first contact when I did not go back in until Mars had disappeared behind the Moon. It was quite magical to watch. Every hour throughout the night I processed images and posted one in here to record progress and for those who were not fortunate enough to have cloud free skies like I had. My first two photos of the night are shown here for the first time. The first image is cropped from the original 7360 x 4912 to just 1200 x 800. There is a link to the rest of my sequence, below. I'll probably add these images to my thread later for completeness.

That reminds me, I need one of those for my devil's oven!

I get a 404.

Awww, that's a shame, you missed a real treat. Hopefully you will get to see the Uranus one in the new year.

Here is my photo of first contact between Mars and the Moon.

Thank you! It was not so bad, as I was only outside for 5 minutes every hour until the last mad half hour. If I'm doing stuff, the cold doesn't bother me too much.

04:57 - re-worked image of first contact, with Mars brightened and the Moon sharpened.

Thank you! It is nice when your work is appreciated, especially after all the trials and tribulations involved in achieving the end result. The cold was not much of a problem, as I only spent 5 minutes outside each hour, until the last half hour, when it was manic. Biggest issue was shredding my ankle on brambles in the dark! Have you posted any images?

@Les Ewan Thank you! It was a fun night and I am now just a bit tired. Conditions down here were pretty perfect until 25 minutes before first contact, when the seeing became hazy due to clouds forming on my western horizon. So, the last photos were rather blurry, but at least we did not completely lose Mars, well not until last contact, of course!

04:33 - This is cropped from the last good image I got. After this time, things started to get hazy, but here Mars is still a good distance from the Moon and nice and sharp. The crop is approximately 1/3 linear of the full frame. nikon D800, 300 mm f/4 prime lens with x2 teleconverter (so f/8), 1/640, ISO-400. Processing in GIMP to increase contrast & saturation and sharpen.

The clock on my D800 is 1 min 07 sec fast, so correcting for that, I believe I have a time for first contact of 04:56:37 (± whatever) - this comes from two consecutive photos, one showing the full disc and the next showing Mars begining to go behind the Moon, both with the exact same time, so within that one second period. Disappearance time I got was 04:57:41. I'm out of focus on the Moon at this point or have some haze in the sky so don't have a clean edge, but there appears to be a definite reddish smudge where Mars should be. Looking at an image taken at 04:57:37, the edge of Mars is most definitely still visible. Checking my last imaging session, everything was reasonably sharp at the begining, but gets gradually more blurred as time progresses, so I think it must be atmospherics. There were some dense, visible clouds below the Moon, but I thought the Moon was in clear sky at the time; apparently not. Oh well! I'm about 30 km north of Derby city centre and a smidge to the east.

Wow! This looks to be an incredible homemade AZ mount. I was looking for ideas on line to build my own just last week, but never came across this. Everything else I saw was rubbish by comparison. In the end I ordered the Skytee 2 from RVO. If I ever want to build one, I think yours an excellent starting point. I wonder if a worm and wheel could be found to give it slow motion control on both axes, which could also serve as a brake. It looks like you should be able to bolt the wheel to the side of the bearing. Thank you for posting this.

04:58 - Mars touching lunar limb

04:52 - Mars very close to lunar limb. Invisible to naked eye.

04:42 - Mars within a quarter of a Moon diameter

04:33 - Mars within half a Moon diameter.

03:35 - Mars now appears just over one lunar diameter away from our Moon.