Wednesday, February 20, 2008

20080220 M42

Seeing was no good at around 3/10 (rough estimate), transparency 6-7/10, with poor polar alignment indoor, I couldn't get longer than around 12s exposure per frame, even at around this point, some frames are bad and needed to be discarded.

Remarks on 20080221: when processing those AVIs, I found that a couple of color shots were captured in Y800 which means all the color information is lost, since I've chosen hardware debayering, next time I shall use RGB24 no matter for monochromatic camera or color camera, since it removes any risk of lossing data, and at the same time, it's more friendly to Registax V3 which I've to use for V4 does not support field derotation.

C5 at f/6.3, DMK31AF03.AS on a roughly aligned LXD55:-

Short exposure done at 2.4s each at 750 gain, longer exposure at 11.6s each at 800 gain.

2235 (GMT+8), this is the longer epxosure mentioned above, the shorter exposure one is not posted:-

Next was by the same setup, but with a DBK 21AF04.AS:-

Short exposure at 9.2s at 800 gain, longer exposure at 11.6s each at 800 gain.

2245 (GMT+8), again, this is the longer exposure one, the shorter one is ommited:-

Then, I switched to my Borg 45ED II, again using the Hirsch f/6.3 reducer (Exact configuration: Borg 45ED II + JMI NGF-S + 2" extension tube + 2"->SCT adapter + Hirsch reducer + SCT visual back + DMK 31AF03.AS), and the effective focal ratio should be like f/4.6, taken with DMK 31AF03.AS, this time the exposure could be longer at 16.4s exposure at 500 gain due to the short focal length:-

Next is 23.2s at 500 gain (600 gain will get plain white screen):-

Next is 27.6s at 600 gain with DBK 21AF04.AS:-

Equipment used: C5, Hirsch f/6.3 SCT reducer, Borg 45ED II, DMK 31AF03.AS, DBK 21AF04.AS, LXD55.

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