Ganymede Shadow transit - 26th October 2022 11pm

[Stu]

I’ve posted these up elsewhere but thought it worth repeating in this forum with some additional details for reference.

I missed the GRS transit unfortunately, but was able to see the double shadow transit at around 11pm.

These were taken with a Tak FC76Q ie 76mm, f12.75, 969mm focal length. The eyepiece was a Leica Zoom at max setting (8.9mm) giving x108. I used my iPhone 11 Pro with the x2 camera, and I handheld this up against the eyepiece eye guard which I extended so the camera was correctly positioned.

I use ProCam 8 to capture lunar and planetary images as I just find it works very well. If you tap on the object you can adjust focus easily and it gives a red outline/highlight at best focus. Exposure is also well controlled using  ISO and shutter speed. Obviously faster is better to reduce shake and freeze the seeing, so it’s a balance.

I tend to take quite a few images at a variety of settings, most important is to keep the brightness down so as not to saturate the detail on the surface. Seeing also varies, so the results from images taken very close to each other can vary a lot. Just look for the sharpest ones.

I also set it up to record both jpg and RAW files. The RAWs process much better even on a phone.

For processing I use PS Express. This has a wide range of adjustments, and I use a combination of exposure, contrast, clarity, dehaze, sharpness and both noise controls to get the best results. It’s all a matter of trial and error to see what works best.

Initially I processed an image which didn’t show the moons, but had good surface detail. Then I did one with good moons but little surface detail, and then created a composite image using Snapseed. This looked reasonable, but then I found another image which showed both surface detail and the moons, and I this this one is best overall.

Obviously using a phone mount may produce steadier results, and you could even take a video to stack for far better clarity, but first and foremost I’m an observer, so, despite owning four phone mount, I normally handhold at the eyepiece to allow me to continue observing as much as possible.

I’ve chucked a load of images in here for reference.

This one was a lower exposure, which showed good surface detail (note that I wasn’t able to capture the Europa shadow, too small I guess)

This one is longer exposure to show the moons.

This was my first attempt at a composite using Snapseed.

Second attempt.

 

Original image showing surface detail, shadow plus moons.

Processed and cropped image, probably my favourite.

Highlighting the two bands and zones visible below the SEB, much clearer in the scope last night. Not bad for 76mm!

Finally one of my failures! 🤪

Hopes my ramblings are of some use and interest.

Stu

[JeremyS]

Very good @Stu. Also good to hear you have a replacement phone after it’s predecessor’s dunking. Are you going to tests Apple’s water resistance claims on the new one?

[maw lod qan]

Very nice Stu!

And I like you posting a failure. Makes me think of Yoda and Luke sitting together when he says something along the line "the best teachers, our failures they are!"

[Stu]

14 minutes ago, JeremyS said:

Very good @Stu. Also good to hear you have a replacement phone after it’s predecessor’s dunking. Are you going to tests Apple’s water resistance claims on the new one?

Having dunked two this year, with identical results, I can safely say they are NOT water proof/resistant in any way shape or form! I think they would cope with taking pictures of rain, from safely inside a dry house, but that is about their limit!! 😬😬

[Stu]

8 minutes ago, maw lod qan said:

Very nice Stu!

And I like you posting a failure. Makes me think of Yoda and Luke sitting together when he says something along the line "the best teachers, our failures they are!"

I have many failures (and failings, if you ask Mrs Stu 🤣), and as you say, it’s good to share those too!

[Stu]

On the subject of Mrs Stu, I actually persuaded her to come and look at Jupiter last night, and she did manage to see bands, moons….and the Ganymede shadow 👍👍. She was almost impressed! Well actually she did say she was impressed with the view through such a little scope! I’ll make a Tak fan out of her yet! 🤣

[JeremyS]

+1 for Mrs Stu 👍🏻

[maw lod qan]

Yes, tickles me pink when I can convince SWMBO to have a look!