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Sculptor Galaxy, Orion Nebula, Horsehead


Martin Meredith

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Here's some shots from last night, none of which need much in the way of an introduction...

First, NGC  253 in Sculptor, one of the brightest non-Messier galaxies at mag 7.2. This is 8 x 15s and the detail coming out suggests seeing was pretty good last night. Ignore the mislabelling as M33.

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Next, M42. This is in 1s subs. I tried to stop it stacking after just a few but it was belting away and by the time it stopped it had taken 22 seconds worth. The aim was to prevent overexposure of the Theta Orionis region using arcsinh compression of LodestarLive.

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Finally, the Horsehead. Although a reasonable image could be had in one minute (first shot), in this case I think the result of letting it stack through the entire observing session in the second shot (30x15) really paid off in terms of seeing the background nebulosity and the wisps of brighter material in the 'head' itself. That is the beauty for me of live stacking of shortish subs: less waiting, more observing, and the gradual emergence of fainter details.

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post-11492-0-84835600-1447682296.png

Cheers

Martin

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Thanks Michael and Laudropb. Steve, these are from the X2 mono camera. All processing is done live in LL and consists of choosing whether to compress the brightness linearly or via one of two compression functions (I generally use one of the nonlinear modes), and then setting the brightness, contrast and black and white levels. I find that once I have them set up for the first object I tend not to shift them much if at all for subsequent objects. I also collect darks at the start of the session using LL and they get applied automatically. That's it I think. The images you see are saved directly from LL with no further processing.

Martin

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Amazing detail in those captures, who would have thought the humble Lodestar was capable of so much detail!

Just out of interest how do you manage to keep your sensor free of dust and resulting dark blobs (bunnies?). I clean my sensor before every session using the paint on / peel off solution specially designed for sensors. Seems to work superbly for about 10 seconds before another blob rudely deposits itself.  :laugh:

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Thanks Charl, Hiten and Rob. Yes, the SNR is decidedly improved with the longer total exposure and really helps with the fainter nebulosity. I kind of feel bad about posting these long stacks but then it does represent the live experience so I think, why not?

Rob, I used to have the dirtiest sensors on the forum… but I now use Baader's Optical Wonder fluid, applied with a cotton bud. I only clean it about once every couple of months when I spot a dust shadow. Having the camera more or less permanently attached to the filter wheel seems to help too as it is almost never exposed to the environment (the shots above were thru the C filter).

We're having a good run of clear/still weather here so the scope is already out cooling. Last night was actually more about finding some of the early-numbered Hicksons and so is tonight, I hope. Those objects above were just irresistible targets along the way….

Martin

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Thanks Charl, Hiten and Rob. Yes, the SNR is decidedly improved with the longer total exposure and really helps with the fainter nebulosity. I kind of feel bad about posting these long stacks but then it does represent the live experience so I think, why not?

Rob, I used to have the dirtiest sensors on the forum… but I now use Baader's Optical Wonder fluid, applied with a cotton bud. I only clean it about once every couple of months when I spot a dust shadow. Having the camera more or less permanently attached to the filter wheel seems to help too as it is almost never exposed to the environment (the shots above were thru the C filter).

We're having a good run of clear/still weather here so the scope is already out cooling. Last night was actually more about finding some of the early-numbered Hicksons and so is tonight, I hope. Those objects above were just irresistible targets along the way….

Martin

Thanks for the info Martin. Sounds like while i keep swapping reducers and scopes I will probably introduce some dust to the sensor. one day I may stop fiddling.... :)

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Fantastic work Martin - Sculptor is a definite target for me next tie I get out.

This is what EAA/Video Astronomy is all about - quick results with more detail emerging during the viewing session, just like visual when you spend more and more time at the eyepiece.

Clear Skies

Paul

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