6 replies to this topic

[james7ca]

Taken on Thursday evening, July 11, 2024 using a Takahashi FC-100DZ four inch doublet refractor and a ZWO ASI678MC camera (more details are in the captions). Image capture with SharpCap, processing with AutoStakkert! (best 384 of 1500 frames), Registax (wavelet sharpening), and Photoshop 2024 (tweaks and labels).

 

This turned out better than I was expecting since I had to record the image at just a few minutes past sunset and even then I had intermittent low clouds that were crossing the moon. However, it's surprising how good the seeing can be when you have to shoot through clouds. However, the cloud cover varied during the entire sequence so I didn't get very many frames that were properly exposed.

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Edited by james7ca, 12 July 2024 - 07:21 AM.

[james7ca]

Here is a larger crop of the northern half of the moon (taken from the same data/image posted above).

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[james7ca]

And, here is the southern half (which required more compression to get under the 500KB limit on CN).

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[Stellar1]

Awesome capture! It seems this intermittent cloud cover was not an issue considering the quality of the final result, it doesn’t hurt you were using a supreme 4” refractor, as well.

[Tony_Gondola]

Very nice full disk image and processing. Is this full white light or were filters involved?

[james7ca]

Stellar1 and Tony, thanks for the comments and similarly to everyone else for the likes.

The main issue with the clouds is that they constantly varied in density so it was difficult to select an exposure time to balance the highlights to the shadows (I mostly had completely overexposed or underexposed frames). Other than that, the seeing looked better than I've gotten recently under completely clear skies. I spent over thirty minutes trying to get a good sequence and at the end I can remembering thinking to myself that I had "wasted" my time even trying to take these images.

As for filters, the ASI678MC is a one-shot-color camera but you have to use at least an IR cut filter since this sensor has extended IR sensitivity. So, I use a Baader Moon & Skyglow filter that works to block the IR/UV and cut some of the wavelengths that are associated with light pollution (the latter not necessary for the moon, but I also use this setup for DSO imaging). I've included this filter's spectral bandpass plot below (from baader-planetarium.com).

Also, I was wondering how this capture did on the Apollo 11 landing site and since that area was pretty close to the terminator below is a 1:1 scale reproduction from the above image data where I boosted the shadows to reveal Armstrong crater. But, I've definitely surpassed this under better lighting and seeing when using the FC-100DZ, as shown in an image __HERE__ on CN.

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Edited by james7ca, 12 July 2024 - 09:22 PM.

[Tony_Gondola]

Yes, a UV/IR cut filter is a must for this kind of work. I have also found that with  lesser quality refractors and achromats that a green or Ha filter can make a world of difference. BTW, great go on the older image of the 11 site.