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iceman
01-09-2006, 12:44 PM
Hi all.

Here's an image of Uranus from last night. I got some images of the moon earlier, but a 2deg difference in temperature was killing me. I left the fan running and went back inside for a couple of hours until Neptune and Uranus were high enough.

I didn't get anything for Neptune (the subject of another story), but managed to get 3 avi's of Uranus at around 10:30pm before I gave up.

The transparency was shocking, and I had to use near maximum gain with the DMK, even with only a 2x barlow. This image was captured at 7.5fps and an exposure of 1/8s (0.13s). I captured ~450 frames in each channel (approx 1 minute each), and stacked 100 frames in each channel and processed mild wavelets in registax.

No further processing was done except to combine the channels in AstraImage. Any further sharpening introduced artifacts such as a darker area in the centre.

I'm happy that this image is a nice round disc, but would've preferred some more image scale - I couldn't go any higher as the image got too dim. I need to use a longer exposure, and my platform isn't accurate enough for that.

Thanks for looking.

Robert_T
01-09-2006, 01:16 PM
Nice one all the same Mike. I reckon there is some mottling here that looks like "real" feature mottling in some of the images I've seen on the net, though I guess could easily be artifacts (how do you get the disk edges so sharp by the way?). If you get a night of cracking seeing and do a few shots over a couple hours could check to see if the mottling is moving the direction the planet's spin would have it...:D

Lester
01-09-2006, 02:15 PM
Hi Mike,

if it was easy we would all be doing it. That is a very nice start.

Dennis
01-09-2006, 02:54 PM
Hi Mike

Well, it was certainly worth the pain and effort - that is an excellent image. Unlike a lot that I have seen recently, the Uranian disc looks very natural and you have resisted the temptation to "pump it up", which generally introduces processing artifacts rather than real features.

Cheers

Dennis

davidpretorius
01-09-2006, 04:08 PM
well done mike!! i am also very very interested in what that the lines are going thru the middle of the planet from 10oclock to 4oclock.

this weekend should be a bit of fun, chasing uranus and drawing up the peltier cooling system for you. and then saturn will be just around the corner!!

John K
01-09-2006, 04:37 PM
great work mike, it's a small and difficult object!