Wednesday, January 24, 2007

20070124 Earthshine, Occultation

Borg 45ED II with NGF-S on LXD55, DMK 31AF03 at prime focus, they're sorted according to the time:-

2011 (HKT), this is the mug shot style exposure (1/38s), to show what we would see with our eyes:-


2013 (HKT), this is to increase the exposure to see background stars, notice that there's a bright star close by, just finished occultation apparently, it's pity bad that I missed the event, you could see the original video below as well:-


2013 (HKT), the video which is processed and stacked by Registax, this one is compressed and you can see the moon receding from that star, it shows that the moon travels faster than the background sky:-


2016 (HKT), to increase the exposure further (~2s) to pick up even more background star, but the bright side of the moon become overwhelming bright to saturate neighbour pixels so that the star in the above picture disappeared by the excessive glare; we can see a little bit of the dark side of the lunar disc, by Earthshine:-


2015 (HKT), further pushing the exposure (4s) to show the dark side of the lunar disc by Earthshine:-



Thin cloud floating around, seeing moderately to poor.

Finally, we did some visual observation. With a 40mm Pentax SMC XL, the wide field of view is immensing, with a lot of sky background, contrast is great, the image is sharp but pretty small at ~8x only. No false color is detected even at the limb, color fidelity is the strongest thing for this eyepiece.

We pumped up the power with a 7mm Ortho, still in that 2" diagonal, the moon filled up the field of view very nicely, still have some dark space around. Image stay very sharp, just slightly dim, and no false color too. I shared the view with my wife and she's more impressed than I did, she didn't expect that it could be so sharp and clear even with just so small a scope! Like before, she usually spend more time at the eyepiece than I do.

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