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Old 07-12-2018, 06:26 PM
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gregbradley
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Quote:
Originally Posted by Stefan Buda View Post
Greg,

I think my image from a few years back is reliable enough to be used as a reference for figuring out what is real and what is just due to wignetting: http://www.iceinspace.com.au/forum/s...=146721&page=2
Yes I remember that image - its a stunner. I have another set of wider images taken with a Sigma 35mm F1.4 Art and its showing this when I push the ridiculous hell out of it. Its 30 minutes exposure at F1.4.
Yes I get the vignetting is causing an issue. Complicating it is the fact that the recent V2.0 firmware update seems to have caused a vignetting issue with one lens at least. Later in the weekend I turned off all lens corrections in camera as I didn't trust it.

It really wasn't a serious attempt, more a survey of what framing, how much exposure, what focal length would be best.

The 35mm for a full frame camera seems about perfect.

Quote:
Originally Posted by strongmanmike View Post
No doubt you have captured some of the outer LMC halo features and even the vertical stream, very faintly, Greg but they have been adulterated by the lack of calibration and exposure.

Mike
Yes I'll take some flats for sure next time but I probably will use the FLI camera rather than my Sony to go really deep. It'll be easier.

Quote:
Originally Posted by alocky View Post
Hi Greg, it’s a nice high resolution picture indeed, although as others have said flats will help bring out the asymmetrical shell around the lmc. You have definitely captured it, but because of the uncorrected vignetting I’m sure you’re seeing a combination of the halo and the illumination drop off. Here’s a similarly deep image that has been calibrated and is inverted to show off the cirrus. Taken in remote WA with no light pollution whatsoever, and you can see the halo isn’t circular.

https://www.astrobin.com/309256/

Cheers,
Andrew.
Thanks Andrew,

Yes I agree. I had processing version of this and it looks like yours but the processing was too harsh so I didn't publish it. This version was "soft" in comparison!!

I am planning to do a full on attempt now I have done the preliminary surveying.

Greg.
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  #22  
Old 08-12-2018, 06:03 AM
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silv (Annette)
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Hi Greg,
I had a look during daylight at the "large" version. No pattern. Now it's dark and the "loosely woven fabric" is back, again, depending on the angle and some form of averted viewing.
But since no one else sees it it can't rally exist, can it. In any case, you wrote you'll be using a different camera for the real LMC halo project.

Galaxy halos play a role in a new article about dark energy and matter. Qyite astounding. Here's the article in 17 tweets by the author https://twitter.com/Astro_Jamie/stat...02359325151233

the real thing: https://arxiv.org/pdf/1712.07962.pdf

And Oxford's proud press release: https://www.eurekalert.org/pub_relea...-bbt120318.php

Intriguing. Hope you'll get heaps of fine weather to work on your project.
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