Narrowband Pelican

[roundycat]

A total of nine and three quarter hours exposure which breaks down to 285:150:150 in S2HaO3. All subs were fifteen minutes and a couple were thrown away owing to excess noise in the sky background at 3:15 in the morning. 150 minutes of O3 is not enough, another 100 would be good but it looks like the clear sky for June has gone. Misty here now and rain forecast.

Pre processed in Maxim, bias subtraction, flat field and hot pixel filter. Some clone repairs to get rid of the worst excesses of the aviation world. Pretty normal PS post processing but the green (Ha) channel needing lowering and the blue (O3) had a mid range boost prior to selective colour to get closer to the Hubble palette.

Dennis

[Tim]

Very nice Dennis, the S2 detail has come through very strongly and I like the highlights in the O3 layer too. The colours look pretty good too. Bit of a shame about the star haloes, the newer incarnations of the Ha filters are much better at preventing those reflection artifacts.

When you say "sky background noise", was that with the S2 filter? I was suprised at how much background light comes through an S2 filter, which makes it very tricky to gather enough data on these summer targets, you've done well to get as much as you have, and the time spent shows clearly in the quality, great pic!

Cheers

Tim

[roundycat]

Tim, the interesting thing about the star halos is they come from S2 and O3, very little evidence of it in Ha. A different mix, HaS2O3 shows this clearly.

From memory the S2 was the noisy one, sky flats through it did not need as much exposure as I thought would be the case.

Dennis

[ollypenrice]

It is a great image, Dennis. The lighting is subtle, giving a very strong sense of three dimensionality and transparency in the nebula. I think it is important not to let nebuale become solid-looking. Yes, I like it a lot.

Olly

[George]

A total of nine and three quarter hours exposure which breaks down to 285:150:150 in S2HaO3. All subs were fifteen minutes and a couple were thrown away owing to excess noise in the sky background at 3:15 in the morning. 150 minutes of O3 is not enough, another 100 would be good but it looks like the clear sky for June has gone. Misty here now and rain forecast.

Dennis

Wow that's a lot of time to get in on a single target at this time of the year Dennis

Its a beautiful image, almost 3D

[roundycat]

thanks guys. I was lucky with this one George, I did it all over three nights - 2nd, 3rd and 4th of June. I guess that's my ration until August.

Dennis

[zhgutas]

Superb shot Dennis!.. Exciting colour palette as well

Marius

[Beyond_Vision]

Dennis a very nice image showing up the structure very well. Worth all the time spent spent.

Regards

Kevin

[cloudbuster]

wot a gem of a pic....great colours!

[narrowbandpaul]

my only critique would be that the image looks a bit over processed. There are haloes around the stars, which suggests too much sharpening. Perhaps the background is a bit too light also.

other than that its very good, and you got a good colour balance

paul

[roundycat]

thanks for the comments Paul, always welcome.

My pictures often tend to look a bit over processed - there is probably a good reason for that!

The star halos are caused by the extreme stretch needed for the red and blue channels which are S2 and O3. Apparently Astronomik filters are known to be a bit of a problem in this respect. The stars were not sharpened, the nebula was sharpened using high pass at around 15 pix with the stars on a separate layer.

In another version that I played around with I shrunk the R and B channel stars using Filter - Minimum, 1 pix and fade 60%. The bigger halos were treated separately and responded well.

As for the light background, the upper part of it is quite dark and the lower half was actually treated to a gradient darkening as it was even lighter than you see it. All the data still exists for another foray into processing it when I can stand to look at it again.

Dennis

[narrowbandpaul]

yeah I know that the O3 and S2 need lots of stretching but when i do it with less data than yourself i never get halos....maybe it is the astronomics themselves....