SCP Wide Field from Hiro

[avandonk]

Hiro has been at it again.

Original thread here
http://www.cloudynights.com/ubbthreads/showflat.php?Cat=0&Number=3889587&page=0&view=collapsed&sb=5&o=all&fpart=1&vc=1&PHPSESSID=

I made a HDR from his two JPG's.

Here 14MB

http://d1355990.i49.quadrahosting.com.au/2010_06/Hiro_SCP.jpg

Makes me want to move to a dark sky site!

Bert

[iceman]

Incredible!

[Phil Hart]

wow. mike's right.. that is incredible. :eyepop:

i started a mosaic of a similar field awhile back but never got very far. will have to try again, but maybe with a wider lens!

i've heard about but don't recall seeing images of all that 'stuff' around the SCP and between the magellenic clouds. i assume hiro's '5Dmk2-sp2 by Seo san' is some kind of modified 5D2?

and we have a dark sky waiting for you when you want to visit LMDSS at heathcote!

Phil

[avandonk]

If you look at the original thread you will find Hiro's longest exposure was 28 minutes!!!! at 1600 ISO at f/5.6 with a 24mm lens. He is realy picking up the dim stuff as he is using a modded Canon 5D MII.

The longest I can expose for with even an LPR filter is about eight minutes at f/5.6 at 1600 ISO due to light pollution.

The dim stuff is real and I suspect if you overlay HA or radio images from monatomic Hydrogen the stuff between the Magellanic clouds would closely match in intensity and extent. The unresolved dim stars gravitationally drawn with the monatomic Hydrogen gas are also 'visible' as the greenish areas.

Bert

[JD2439975]

Holy cow that's a massive chunk of sky! :eyepop:

That's the first time the LMC has ever looked like a "real" galaxy.

Nicely captured Hiro & masterfully processed Bert, what an eye opener. :thumbsup:

[tornado33]

Thats stunning. Was a pleasure to download with my new 12 megabit net connection.

Looks like theres lots of galactic cirrus about. Ive never seen such a deep widefield image like that before.
Scott

[malp]

Wow, a few stars in there, wonderful.

[Garyh]

Beautiful! and so deep.
Must be real dark at that location to get exposures so long!

[luigi]

A beautiful image, great work, it looks stunning!

[strongmanmike]

Can't say I have seen an image with this perspective before...very eye opening shot Bert. Has Hiro done one with the two magellanic clouds more centered? That would also be worth seeing too.

Top shot

Mike

[leon]

Sorry I have to say this but it is not a very appealing image at all, :shrug: maybe I'm looking at the pretty picture side of things, :shrug: but honestly it dose not turn me on at all.:sadeyes:


Leon :thumbsup:

[strongmanmike]

I think you may be looking at it from "too much" of an aesthetics view point Leon, try disregarding that side of it for a bit and see past the "pretty" bit and see the amazing collection of stars and faint dust and the overall wide and unusual perspective. :)

Mike

[DavidTrap]

It's certainly an impressive expanse.

Why is the monatomic hydrogen in this long exposure showing up in the green part of the spectrum. Normally hydrogen is seen towards the red end of the spectrum - Hydrogen Alpha line. If this area of hydrogen were so faint, why would it now preferentially show up as green, rather than red?

I had a look at the original 15Mb images he posted. There is some red haziness around the LMC & SMC which I thought would be the hydrogen?

Could the green be an artefact from the HDR process?

DT

[Bassnut]

Ditto :shrug:

[jase]

Pure gold. More please.

Whilst exquisite in its own right, it also makes for a remarkable reference image. Well done and a huge thanks for sharing Bert.

[avandonk]

The very dim unresolved stars show up as a faint green with HDR and DSLR's as DSLR's have twice as many green pixels as red or blue. If it was light pollution it would be far more uniform. I will dig up a radio image of monatomic Hydrogen and superimpose it. When galaxies interact gravitationally both stars and Hydrogen and dust etc are all drawn out together.

Here is an image of the LMC taken by Hiro with a 105mm lens at f/5.6 that I enhanced to show the dim stuff. 13MB

http://d1355990.i49.quadrahosting.com.au/2010_06/LMC_col_easyHDR.jpg


Original thread here

http://www.cloudynights.com/ubbthreads/showflat.php/Cat/0/Number/3875143/page/3/view/collapsed/sb/5/o/all/fpart/1


It is obvious from this image that the LMC used to be a barred spiral galaxy. It has been 'Auntie Jacked' ie had its arms ripped off gravitationally. This has also caused the intense star formation we see today.


Bert

[avandonk]

Yes Jase it does show what we are missing. Hiro goes to great lengths to take his equipment to dark sky sites. These images were taken In WA in Australia. He has collected data at 10,000 ft on THE mountain in Hawaii in the shadow of the observatories there.

THe LMC and SMC were low when these images were taken. I can only imagine what would be possible when they are near or at the zenith.

Bert

[DavidTrap]

Do you have any references to support your statements?

Surely if the dominant colour from hydrogen is towards the red end of the spectrum, wouldn't a prolonged exposure give greater pixel well filling for those pixels under the red filter of the bayer chip, which would then give a greater red colour to the processed pixel? If you were dealing with unprocessed FITS files, I would seem plausible that the greater number of green pixels would have an impact?

The data you are applying the HDR algorithm is from compressed JPEGS of a stack of colour converted images from a Bayer chip. There are a number of mathematical processes that this data has undergone, which could result in an artefact - hence my original question.

I'm not trying to take away from the beauty of this image, but am wondering if you are trying to read to much into this potentially compromised data?

DT

[avandonk]

Just observation David. Here is a sequence of 15s, 30s, 60s and 120s 300% crops of these exposure stacks as an animated gif. Watch the dim stars as they 'appear'. 1MB

http://d1355990.i49.quadrahosting.com.au/2010_06/stars.gif

These stars are resolved. When they are not they show up as a faint green background. Light pollution is far more uniform.

Neutral (non ionised) Hydrogen gas does not show up at HA if it is not excited by nearby stars. I was just assuming that the faint unresolved star streams from the LMC would be roughly where the intergalactic Hydrogen is that only show up in radio images. The green regions are real. This is the only explanation I could think of.

Below is the latest map of the neutral H at radio wavelengths.

From here
http://www.sciencedaily.com/releases/2010/01/100104151921.htm

Bert

[Garyh]

That faint stuff is real, Can`t think of his name (IIS member) but there was a real deep LMC imaged from Chile showing a distinct halo etc around the LMC. I tried for a deep widefield once and started to get some showing but the weather didn`t agree! Have to try that again!

[DavidTrap]

Thanks for clearing that up Bert. Your original post seemed to imply your statements were based on something more concrete.

I couldn't find anything about the spectrum of monoatomic hydrogen on a quick Google search.

I still have my concerns about the robustness of the data after having gone through multiple mathematical processes, including compression algorithms.

Regards
David T

[avandonk]

Sorry for the confusion Dave. It is difficult to get across complicated explanations for things you have lived with for a long time. One always makes the mistake that others have the same knowledge as yourself.

Bert

[multiweb]

That's a superb milkyway shot. I really like how you brought up all those red Hii areas. Great colors. :thumbsup:

[PeterM]

WOW factor is 10/10. Stunning.
PeterM.

[mexhunter]

Hi Bert:
Simply exquisite.
Many greetings
Cesar