97% waxing moon, mosaics, #25 red & IR cut filters

[turfpit]

Captured 25th Feb 2020 around 19:30 - 20:30. Moon 97% illuminated, elevation around 50°. 1 hour of imaging gathered ~88gb of data. Celestron AVX mount, Celestron C8 SCT, Altair 183M camera & Skyris 618m camera. Processing with Autostakkert!3 (best 5% of frames stacked) & GIMP mosaics stitched with Microsoft Image Composite Editor. Information from Virtual Moon Atlas.

To counter the brightness a Wratten #25 red filter and IR Cut filter were used together.


Altair 183M, each panel 1920x1200, MONO8, gain 400/4999, 2,000 frames @35fps. Mosiac annotated for interest.

183M_6-panel-mosaic.jpg (369.68 KiB) Viewed 737 times

Skyris 618m, each panel 640x480, MONO16, gain 303/1000, 7200 frames @ 120fps.

618m_6-panel-mosaic.png (754.13 KiB) Viewed 737 times

Skyris 618m, 640x480, MONO16, gain 303/1000, 7200 frames @ 120fps. Pythagoras is the the crater at the centre of the rim.

Pythagoras.png (204.66 KiB) Viewed 737 times

Skyris 618m, 640x480, MONO16, gain 303/1000, 7200 frames @ 120fps. Rimae Darwin - the fissure can be seen from the centre of the image travelling downwards.

Rimae_Darwin.png (187.5 KiB) Viewed 737 times

A note on histograms. For a lunar image with some black the histogram will look like this - classic 'whale' shape with right hand side around 60%.

histogram.JPG (53.38 KiB) Viewed 737 times

For a full surface lunar image the histogram will look like this - a 'hump' with a gap at the left hand side, the right hand side being around 60%.

histogram-surface.JPG (38.16 KiB) Viewed 737 times

Dave

[timh]

Very nice indeed! The Rimae Darwin especially.

Must admit that I had considered the moon to be ' done ' and now as just something of a nuisance that restricts observations elsewhere to narrow band only but your close in mosaics are full of interest. Like a flyover. Something to have a go at down the road.

I think that the seeing has been quite steady these last couple of moonlit nights ? Getting FWHM values down to 2.5 arc sec which is a record for me.

TimH

[turfpit]

Thanks Tim.

Rimae Darwin is a feature that is not visible at capture time but is only revealed after stacking & processing.

before_and_after.JPG (67.12 KiB) Viewed 718 times

I have found the moon to be an interesting object. Because of the constantly changing illumination, 2 images of the same location taken 10 minutes apart can reveal different features. There are shadows of carter walls on crater floors and craters within craters to be captured. Plus the illumination is different for waxing and waning phases. I consider this my best effort to date https://www.astrobin.com/full/uj3ns8/B/?nc=user.

The near full moon has always been a challenge to reveal features but I think the combination of filters I now use - IR685, Wratten #25 red & UV/IR cut - have helped to tame the brightness.

Dave

[timh]

That astrobin image of the Clavius crater area with the AR865 filter is astonishing. Well done.
Tim

[turfpit]

Thanks Tim.