Sharpless 2-240 in HaRGB

[RickS (Rick)]

SH2-240 is a very large (approx 3x3 degrees) and dim supernova remnant on the Taurus/Auriga border.

We captured 63 hours of Ha data on this object back in late 2014/early 2015 at SRO (California) as a 3x3 mosaic with a FSQ106ED and QSI683 camera (2x2 binning). Unfortunately, we were too late to capture enough RGB to make a full colour image so I have been sitting on the data for a while. Then, in late 2016/early 2017 we captured 19 hours of Ha/R/G/B with a Rokinon 135mm f/2 lens at DSW (New Mexico) which included the original field of view. This is my first attempt to combine the data using the Rokinon wide field as a base. My next project is to make a high res version based on the SRO data with the DSW star colours.

DSW data capture details...

Scope: Rokinon 135mm f/2
Mount: Paramount ME
Camera: QSI583
Filters: Astrodon E-series Gen II LRGB, 5nm Ha
Image scale: 8.6 arcsec/pixel (drizzle to 4.3 arcsec/pixel)
Exposures: 24x300s R, 21x300s G, 27x300s B, 78x600s H (19 hours)

SRO data capture details...

Scope: FSQ-106ED
Mount: Paramount ME
Camera: QSI683
Filters: Astrodon 5nm Ha
Guiding: QSI OAG + Lodestar
Image scale: 4.19 arcsec/pixel
Exposures (3x3 mosaic):
A1: 16x1800s Ha
A2: 16x1800s Ha
A3: 13x1800s Ha
A4: 15x1800s Ha
A5: 07x1800s Ha
A6: 10x1800s Ha
A7: 19x1800s Ha
A8: 19x1800s Ha
A9: 11x1800s Ha

All image processing done in PixInsight. I'm still not sure if the result is just too red I'm having some colour management issues that are proving difficult to diagnose.

Higher res version at Astrobin: http://www.astrobin.com/full/284525/0/

Thanks for looking and for any constructive comments.

Cheers,
Rick.

[h0ughy (David)]

[alpal]

That's nice Rick,
I wonder why there is no step in the red channel on the histogram?
The Green & Blue look normal.

ie.
the Red starts at a level of 52
The Green & Blue start at 0 as they should & slowly climb upwards.
How did you stretch the data?

cheers
Allan

[Placidus (Mike and Trish)]

That is magnificent. Wonderful.

[Atmos (Colin)]

Very nice Rick! One object that has always fascinated me... It's HUGE!

[RickS (Rick)]

Originally Posted by h0ughy

Thanks, Dave

Originally Posted by alpal

That's nice Rick,
I wonder why there is no step in the red channel on the histogram?
The Green & Blue look normal.

ie.
the Red starts at a level of 52
The Green & Blue start at 0 as they should & slowly climb upwards.
How did you stretch the data?

cheers
Allan

Not sure where that came from, Allan. It ended up being quite a complex process and a lot of tweaking happened. I suspect it was the NB/RGB combination but I'll step through the history and find out.

Originally Posted by Placidus

That is magnificent. Wonderful.

Thank you, M&T!

[RickS (Rick)]

Originally Posted by Atmos

Very nice Rick! One object that has always fascinated me... It's HUGE!

Thanks, Colin. It certainly is a monster! About the same size as the Veil but much dimmer.

[strongmanmike (Michael)]

Great piece of work Rick and a lot of it by the sounds of it It's a magnificent object. Nice use of different data sets and mosaicing, a great view and I think this object looks good in red.

I can't wait to have my FSQ...waiting, waiting...

I think I have seen this nebula on television before too?

MIke

[glend (Glen)]

Just great Rick. I admire your perservance in building over years. Great dedication. Your storage capacity must be significant to support retention of all that (and other) data.

[gregbradley]

That's a stunner Rick. Gorgeous.

Greg.

[willik (Willik)]

That is a top shot a beut image Rick

[Andy01 (Andy)]

Well done Rick!

Valiant and mighty data gathering and processing effort there Rick, big ups for patience & persistance.

Stunning object and high on my bucketlist to try to image one day.

I wonder though, when comparing it to other images of this on Astrobin, if it's appearing to lose detail because it's oversaturated & lacking contrast?

Just my 2c worth but I'm thinking (can't believe I'm saying this) a bit of tweaking would yield an even better result.

Disclaimer: Your image looks dramatically different when downloaded & viewed on my calibrated Hi Res monitor in Photoshop -which confirms my suspicions about Astrobin rendering images correctly.

[Camelopardalis (Dunk)]

Outstanding Rick the detail in the full-res version is (almost) unbelievable. Love all the faint faint nebulosity around the sides...must be really faint given the exposure time

[RickS (Rick)]

Originally Posted by strongmanmike

Great piece of work Rick and a lot of it by the sounds of it It's a magnificent object. Nice use of different data sets and mosaicing, a great view and I think this object looks good in red.

I can't wait to have my FSQ...waiting, waiting...

I think I have seen this nebula on television before too?

Thanks, Mike! Very topical video #LastnightinSweden

Originally Posted by glend

Just great Rick. I admire your perservance in building over years. Great dedication. Your storage capacity must be significant to support retention of all that (and other) data.

Thanks, Glen. I keep all the lights and master calibration frames. It does take up a bit of space but you never know when they'll come in handy.

Originally Posted by gregbradley

That's a stunner Rick. Gorgeous.

Ta, Greg!

Originally Posted by willik

That is a top shot a beut image Rick

Thanks, Martin.

Originally Posted by Andy01

Well done Rick!

Valiant and mighty data gathering and processing effort there Rick, big ups for patience & persistance.

Stunning object and high on my bucketlist to try to image one day.

I wonder though, when comparing it to other images of this on Astrobin, if it's appearing to lose detail because it's oversaturated & lacking contrast?

Just my 2c worth but I'm thinking (can't believe I'm saying this) a bit of tweaking would yield an even better result.

Disclaimer: Your image looks dramatically different when downloaded & viewed on my calibrated Hi Res monitor in Photoshop -which confirms my suspicions about Astrobin rendering images correctly.

Thanks, Andy. Yes, there is definitely something not right with Astrobin rendering. It used to strip ICC profiles but that's been fixed for a while. The problem could be browser related too. Colour management on the web is a bit of a crap shoot.

Originally Posted by Camelopardalis

Outstanding Rick the detail in the full-res version is (almost) unbelievable. Love all the faint faint nebulosity around the sides...must be really faint given the exposure time

Thanks, Dunk. Oh, it's faint all right

[ozstronomer (Geoff)]

Beautiful image Rick, great result.

Geoff

[Spookyer (Brett)]

Rick that is quite and epic effort, well done.

Brett

[RickS (Rick)]

Originally Posted by ozstronomer

Beautiful image Rick, great result.

Thanks, Geoff!

Originally Posted by Spookyer

Rick that is quite and epic effort, well done.

Thanks, Brett. Not quite my longest integration time, but extra difficulty points for the 135mm/530mm focal length disparity

[batema (Mark)]

Absolutely stunning Rick. Beautiful.

Mark

[RickS (Rick)]

Originally Posted by alpal

I wonder why there is no step in the red channel on the histogram?
The Green & Blue look normal.

ie.
the Red starts at a level of 52
The Green & Blue start at 0 as they should & slowly climb upwards.
How did you stretch the data?

Allan: the red histogram is normal until I combine the luminance with the colour data and then the bottom of the red histogram kicks up a little. The area affected is just some speckles of background at the top left edge. Fixing the data makes no visible difference so I'm not going to worry about it

Originally Posted by batema

Absolutely stunning Rick. Beautiful.

Thanks, Mark.

[alpal]

Originally Posted by RickS

Allan: the red histogram is normal until I combine the luminance with the colour data and then the bottom of the red histogram kicks up a little. The area affected is just some speckles of background at the top left edge. Fixing the data makes no visible difference so I'm not going to worry about it

Fair enough Rick,
It just looked strange on the histogram.
Normally on pictures you always leave a bit of room at the bottom end.
That also helps when converting to LAB mode if you need to adjust the tones with 4 colours to work with.

cheers
Allan