Today, I want to share an image of one of the most interesting and also most frustrating lunar features to image - the Vallis Alpes in the Montes Alpes. Since I saw an amazing image of the Vallis Alpes in the german astronomy magazine Sterne & Weltraum (transl. Stars & Space) in the late 1980s, I wanted to take a similar photo. My first attempts on analog film and with a hi8 camcorder in the early 1990s using my first 2" Bresser achromat & C8 showed no signs of the Vallis. My next attempt in 2013 with my first dedicated planetary camera DMK 21AU608.AS, gifted by my extraordinary girlfriend after my PhD defense, showed some hints of the Vallis - maybe - or not. After almost 35 years, I'm quite happy, that I was finally able to capture the Vallis in 2023 with the C14. However, there is still room for improvement - better seeing and illumination ...

The SER movie is significantly affected by high-frequency turbulence. However, the 4 ms exposure time and stacking only 5 % - 10 % of the best subs still reveals the Vallis.

The data was captured on the morning of Sep 6th 2023 in Northern Germany. According to the star test using Capella before the planetary and lunar imaging session, I think the seeing was fair-good (~ 6-7 on the Pickering Scale). Processing of the IR/G data is based on the tutorials Processing Lunar images with Photoshop by Damian Peach and Imaging the Moon: Capture and Process, Stack, Sharpen by Refreshing Views.

If you want to process the data yourself, I uploaded the raw stack straight out of AS!3 here.

06.09.2023 (04:13 UT)

Celestron C14 Edge HD @ f=6650 mm (F/28), res = 0.09"/px
+ Celestron CGE Pro mount
+ Celestron EF
+ ZWO ASI 290 MM
+ Baader 2x VIP Barlow
+ ZWO EFW
+ Astronomik G filter
+ Tempest Cooler
+ Omegon Dew Heater
+ Astrozap Dew Shield for C 14

Very short imaging train: I simply screwed the Baader VIP Barlow into the nose piece of the ZWO EFW. However, the small pixel size of the ZWO ASI 290 MM leads to a pixel scale of 0.09"/px at a reasonable f-ratio of f/28.

G: 5000 frame  SER movie
1x1 bin

recorded with Firecapture

Moon 59° above the horizon
Seeing: Pickering 6-7 (fair - good)

Postprocessing

G

Autostakkert!3:
- Stacking 500 of 5000 frames
- Image Stabilization: Surface, Improved Tracking, Cropped
- Quality Estimator: Laplace, Noise Robust 5, Local
- Reference Frame: Autosize
- Minimum AP size = 104, Min Bright = 20, Multi-Scale

Registax:
- histogram correction to increase the brightness of the underexposed image
- wavelet sharpening using Wavelet filter Gaussian, step increment = 0, no linked wavelets:
layer 2 - 100, denoise & sharpen

Photoshop CS2:
- image crop
- level corrections to clip the black levels of the shadows
- unsharp mask (amount: 21%, radius: 1.9 px)
- sharpen
- slight noise reduction

Schwentinental (Germany)

-CS Daniel