SH2-308 The Dolphin Nebula

[gregbradley]

Originally Posted by Andy01

Sorry Greg, I agree it looks great at first, but when you dive into the high res the the stars look chunky.
The data is fantastically deep but because you've stretched the heck out of it it looks unnatural.
I encourage you to have another go - but tone map so you remove the stars first, Starnet++ is perfect for this - then stretch it as you have & the pop the stars back in.

Here is a great video tutorial by JP Metsavainio on how it's done.
https://www.youtube.com/watch?v=EQlGsM-S8vM

Sorry Andy I missed your post. I started watching the video. Quite good.
I did a repro and will post the alternate version which is fairly different really.

Greg.

[gregbradley]

Here is another version where the stars are preserved and a slighty different weighting on the Ha component:

https://pbase.com/gregbradley/image/170941951/large regular size

https://pbase.com/gregbradley/image/170941951/original large size

Greg.

[Atmos (Colin)]

Very deep image Greg! The new version definitely has better looking stars than the original

[Benjamin (Ben)]

Having just done a reprocess myself on this one, I tried a similar technique to what Andy suggested. I kept the stars in but used a star less mask to bring the Dolphin/Gourd from the background which left the stars alone. I didn’t get much time on it from the burbs but got a lot out of the data this way. Not sure that helps as I had a quite different FoV. Love love the wider field you here though and the depth of the OIII :-)

[gregbradley]

Originally Posted by Atmos

Very deep image Greg! The new version definitely has better looking stars than the original

Thanks Colin. I'l have to review my processing workflow and add in more star removal techniques.

Originally Posted by Benjamin

Having just done a reprocess myself on this one, I tried a similar technique to what Andy suggested. I kept the stars in but used a star less mask to bring the Dolphin/Gourd from the background which left the stars alone. I didn’t get much time on it from the burbs but got a lot out of the data this way. Not sure that helps as I had a quite different FoV. Love love the wider field you here though and the depth of the OIII :-)

Cheers Ben. Yes that is what I did in the repro.

Greg.

[Benjamin (Ben)]

Originally Posted by gregbradley

Cheers Ben. Yes that is what I did in the repro.
Greg.

My apologies, I think I get the reprocess now. The glow around the Dolphin is perhaps more of the [OIII]? Too used to my limited FoV!

[gregbradley]

Originally Posted by Benjamin

My apologies, I think I get the reprocess now. The glow around the Dolphin is perhaps more of the [OIII]? Too used to my limited FoV!

The pinky area is from the Ha and the blue is the O111.

Greg.

[Benjamin (Ben)]

Originally Posted by gregbradley

The pinky area is from the Ha and the blue is the O111.

Greg.

Very interesting. I had much more limited Ha and [OIII] so must have clipped it from the background. 👍🏻

[John K]

Great work Greg, the different images in the Cosmos never cease to amaze! Nicely captured.

John K.

[gregbradley]

Originally Posted by Benjamin

Very interesting. I had much more limited Ha and [OIII] so must have clipped it from the background. 👍🏻

I did try to contain these in the background as its easy to have an all lue background with this object. I checked other images of it on Astrobin and mine is more widefield than almost all of them but the ones that do show some of the background show it similarly.

Originally Posted by John K

Great work Greg, the different images in the Cosmos never cease to amaze! Nicely captured.

John K.

Yes I know what you mean. There is always something to image that is interesting.

Greg.

[TrevorW]

Excellent a joy to view

[gregbradley]

Originally Posted by TrevorW

Excellent a joy to view

Thanks very much Trevor. I am glad you liked it.

Greg.

[astronobob (Bob)]

10/10 Greg,, awesome !

[TrevorW]

Actually Greg your image compares very favorably to an APOD see


https://apod.nasa.gov/apod/ap200302.html


although I believe the finer nebulousness at the edge s of your image is more realistic than a definitive cut off point

[gregbradley]

Originally Posted by astronobob

10/10 Greg,, awesome !

Thanks Bob. I'll probably add to it next year when its around again.

Originally Posted by TrevorW

Actually Greg your image compares very favorably to an APOD see


https://apod.nasa.gov/apod/ap200302.html


although I believe the finer nebulousness at the edge s of your image is more realistic than a definitive cut off point

Thanks Trevor. There definitely is some background O111 and Ha, mostly O111.

Greg.

[pkinchington (Peter (Kanga))]

Wonderful!

[gregbradley]

Originally Posted by pkinchington

Wonderful!

Thanks Peter!

Greg.

[codemonkey (Lee)]

Great work, Greg. Love the colours, deep too!

[gregbradley]

Originally Posted by codemonkey

Great work, Greg. Love the colours, deep too!

Cheers Lee. I'll revisit it next year when it comes around again.

Greg.

[marc4darkskies (Marcus)]

I've looked at this several times since you posted it Greg and I have to say it's a pleasure seeing something different and something that's difficult to image. So on that score alone, well done! I actually prefer your original processing. It's quite compelling and I particularly like the structure visible in the fainter extents.

I'll be honest though and say that the reprocessed version seems to have obliterated the structure in those fainter extents. Colours notwithstanding, the reprocessed version would benefit greatly if you could restore that structural detail.

Cheers, Marcus