Neptune and Triton with SAC 4.2

[[1ponders]]

Managed to get three short avies tonight before the cloud moved back in. This is the last of the three using a barlow. Trialed the SAC 4.2 with the Meade DSI IR filter.

Seeing about 7/10, transparency 6/10. Considerable humidity in the air and very light fine cloud

Best 50/100 frames. 2sec exp at 80% gain. Meade 8" sct with 2X barlow. Initial processing in Registax, curves, levels and re-size x 200% in PS

I reduced the image back to natural size in the second one. I think I prefer it for detail
Quite happy with it for a trial run.

[iceman]

Nice colour Paul! Not sure why the second one is still pixelated though?

[Dennis]

Hi Paul

Good one! Wow, check put that pixilation - mate you're working right on the edge. Imagine what Nyquist would have said about this under-sampling?

Cheers

Dennis

[[1ponders]]

Not sure why either Mike. Here is an unadulterated screen dump of the avi in Registax. The natural size of the capture area is 1280 x 1024 and the capture was using ROI. That shouldn't have made that much difference though. It could have also been something in the processing as well. Fingers crossed for a fine night tonight and I'll give it another shot.

[iceman]

gee it's dim. Looks like my Neptune raw frames with the red filter.

[[1ponders]]

I once tried to read a paper on Nyquist theory, Dennis. It now props up a short table leg :scared: Over my head like a circus tent. Maybe I should give it another go :lol:

[[1ponders]]

I'll post one of my unbarlowed runs to compare.

[[1ponders]]

He it is with no barlow, 125/180 frames. Fairly heavy on the curves and levels but light on wavelets.

[[1ponders]]

I'm not sure what is happening with the pixelation, it may have something to do with the amount of gain I was using. Unfortunately I didn't manage to get Uranus which would have required less exposure and gain, to compare.

Here is a screen dump of some extreme processing, I was trying to get an idea of what was going on. I've really pushed the wavelets, contrast, gamma, curves, and levels on some of them.

btw these images are 90 deg clockwise from my first image. They haven't been orientated for the time of night. Triton is at the top to the left of Neptune in some of these

[[1ponders]]

Ok I think I've got the pixelation worked out. It's a combination of things. Strong gamma and high contrast and brightness in Registax. Then after applying curves and levels in PS I applied a despeckle filter as I didn't like the job noiseware did on the image. This really cranked up the pixelation

[[1ponders]]

I've done a quick reprocess with no Reg processing except for stacking and then applied two rounds of strong highlight curves and then greyscaled. Lots of noise, I need to consider taking darks with this setup at exposures this long.

[John K]

Awsome images! Well done.

Have not tried it, but dont think it's visible with my SPC900 and 12.5" and 5 x Powermate?

[iceman]

John I was able to capture it with my 10" dob and 3x barlow, so you'd probably be able to get it at the longest exposure the ToUcam can support (5fps, 1/25s), but gain would have to be way up high.

You'd probably also want to use a 2x or 3x barlow, rather than the 5x.

[John K]

.....interesting Mike,

I don't have anything else other than a 5 x Powermate, but will try it with just eyepiece projection to increase the image scale and report back (sorry, did not mean to sidetrack from this thread!)

[[1ponders]]

Not sidetracked at all John. Any input to help improve all our capture techniques are more than welcome. I'm considering eyepiece projection tonight if it clears. That will give me greater range of image scale to choose from :thumbsup:

[EzyStyles]

crazyy. that just crazy. the size of nepture and you even got one of its moon. well done paul.