Lagoon Trifid Mosaic in HDR

[avandonk]

After dodging clouds both thick and thin before the fog again, I managed to get enough data for this image.

Large image 3.8MB
http://members.optusnet.com.au/~trlee8/lagtr_100mos.jpg

Canon 5DH, 100ED, lpr filter.
2x(5x(1m, 2m, 4m, 8m)) at 200 ISO without ICNR. I managed to keep the fridge constant at -12C so used four darks for each exposure level.

The usual HDR method.

I am still not happy as I could have gone a lot deeper ie 16min exposures but the fog beat me. But at least there was a window in the cloud to test the fridge at constant temperature.

Bert

[Lester]

Well done Bert, another cracker image.

[h0ughy (David)]

bugger that robbers dog!!!! nice image Bert

[leon]

A truly fine image Bert, haven't seen much from you of late, nice work.

Leon

[jase (Jason)]

Great composition Bert. The mosaic has enabled you to frame the field well. It does look a little dark to me. There isn't any clipping and mid tones appear ok. Perhaps the data could be stretched a little more? What focal ratio are you operating the 100ED at? I believe natively its F/9. This would yield 1.8 arcsec/pixel on the 5D. Do you believe the mildly square stars is sampling related or post processing? I'm expecting you've got a reducer in the optical train considering the FoV. Your colours are there, just need to bring them out a little. Well done.

[tornado33]

Just viewed the full sized version, even the brightest part of the Lagoon, the "hourglass" isnt overexposed. A huge dynamic range is covered. Well done Bert.
Scott

[Tamtarn]

Nice to see you back imaging again Bert. The weather hasn't been too kind to us in Melbourne recently.

This is a great image. You have certainly brought out lots of outer nebulosity.

[avandonk]

Thanks all for the comments. It is difficult to be objective about any image you produce yourself especially when you have been up all night. I have taken the comments on board and produced this new improved image. I am not really happy wth the raw data because of the clouds interference.

Jase the 100ED is fitted with an Astro Physics 2.7 inch focuser and an AP 0.75 FR/FF so it is actually f/6.75 at 675mm FL. I have optimised the FR/FF to sensor distance to get the flattest field and this turns out to be at a focal reduction of 0.75. So the FOV is 2.59x3.14 degrees approximately.

You are correct Scott it is tricky getting everything to show in widefields due to the huge variation in dynamic range. This HDR method seems to work quite well. I am still trying to improve it.

Large full resolution image 4.2MB
http://members.optusnet.com.au/~trlee8/lagtr_100mos.jpg

Melboune weather has been almost continuously cloudy lately. Good for some rain at least.

Bert

[jase (Jason)]

Great work Bert. The image is showing some great form. Certainly not as dark as the last post. I concur with you - Its hard to start processing an image the next day if you've been up all night. Typically, all I do the next day is check the calibrated subs to see if they show potential. A suggestion on HDR - why not crop the individual targets of interest to get the full dynamic range, then integrated them back onto the image.

[avandonk]

I had some HA and O3 data of this region so I merged it with the colour in ImagesPlus.

Large image 1.6MB
http://members.optusnet.com.au/~trlee8/col+ha+o3.jpg

Bert


Colour ____________________Colour+HA+O3

[strongmanmike (Michael)]

This is a great image Bert.

If you could tone the lipstick red down a little and add some blue perhaps, it may look better..? Of course you may like it just the way it is

I haven't done a Lagoon + Trifid yet myself..on the must do list I think

Mike

[jase (Jason)]

Each iteration just keeps getting better Bert. Well done.

[Alchemy (Clive)]

i like the last one ... its got a bit more punch. but thats just me.

[avandonk]

Here is a better version. Same data a bit better gradient control and colour balance.

3.5MB
http://members.optusnet.com.au/~trle...tr_100mos3.jpg

Bert

[Phil]

Stunning stuff.
Phil