M42

[Ouroboros]

The Great Nebula in Orion and a reminder that winter’s on the way.  Back in January this year I captured 3 hours worth of OSC data with my ASI2600MC on my SW Evostar ED80. I forgot to process it at the time and have just done so. I’m quite pleased with it although I know images of M42 are ten a penny but it was fun to do. Processed only in Pixinsight. Darks, flats and dark flats. This is the first time I’ve used EZDenoise, which worked well I think. The centre was very saturated and I thought fatally so.  Fortunately a bit of HDR Multiscale Transform pulled a lot out. Comments welcome.  Thanks for looking.  

[Ags]

That's superb - I personally think M42 is hard to make good-looking, but you have definitely succeeded!

[teoria_del_big_bang]

Agree it is a great rendition. so many, including mine, look very generic but that has something different about it, well done 🙂 

Steve

[ollypenrice]

Good reds and blues and good brown dust. I really think this is one target on which you do need to use the high dynamic range technique of blending short exposures for the Trapezium. However, the Trapezium could still be brought under more control, I think, if you could boost the colour saturation for the over-exposed region, because one consequence of too much signal is burning out of colour. If you could pull the colour into the Trapezium it would boost the image, I think.

Olly.

Edit: Just done quickly on a screen grab.

 

 

Edited October 22, 2022 by ollypenrice

[Ouroboros]

2 hours ago, Ags said:

That's superb - I personally think M42 is hard to make good-looking, but you have definitely succeeded!

Thanks. It surprised me how it looked immediately after pre processing it. I think it’s got something to do with the way the camera has picked up the background dust.  My previous attempts with a DSLR have only hinted at it.  

[Ouroboros]

1 hour ago, teoria_del_big_bang said:

Agree it is a great rendition. so many, including mine, look very generic but that has something different about it, well done 🙂 

Steve

Thanks. 

[Ouroboros]

1 hour ago, ollypenrice said:

Good reds and blues and good brown dust. I really think this is one target on which you do need to use the high dynamic range technique of blending short exposures for the Trapezium. However, the Trapezium could still be brought under more control, I think, if you could boost the colour saturation for the over-exposed region, because one consequence of too much signal is burning out of colour. If you could pull the colour into the Trapezium it would boost the image, I think.

Olly.

Edit: Just done quickly on a screen grab.

 

 

Yes, I see what you’re saying.  I’m always a bit uncertain about colour.  My preference is for subtle colouring rather than something too garish. But that’s just a personal thing.  I’d like to go for realistic, but I’ve no idea what it would look like by eye anyway. My approach is to use photometric calibration initially. That seems to get rid of most unpleasant colour casts, but tends in my opinion to leave the image a little under stated colour wise.  So towards the end of processing I tend to just increase saturation a notch or two without going over the top.

I see exactly what your saying, Olly, and I like what you have done there. I’m guessing you’re using Photoshop.  Now I know you can isolate an area, feather it, and then work on only that isolated part of the area. Lasso is it called? Anyway, I’m not sure that’s possible in Pixinsight. One can mask of course. But that doesn’t achieve the same effect. Maybe a more experience Pixinsighter might know. 

[ollypenrice]

9 hours ago, Ouroboros said:

Yes, I see what you’re saying.  I’m always a bit uncertain about colour.  My preference is for subtle colouring rather than something too garish. But that’s just a personal thing.  I’d like to go for realistic, but I’ve no idea what it would look like by eye anyway. My approach is to use photometric calibration initially. That seems to get rid of most unpleasant colour casts, but tends in my opinion to leave the image a little under stated colour wise.  So towards the end of processing I tend to just increase saturation a notch or two without going over the top.

I see exactly what your saying, Olly, and I like what you have done there. I’m guessing you’re using Photoshop.  Now I know you can isolate an area, feather it, and then work on only that isolated part of the area. Lasso is it called? Anyway, I’m not sure that’s possible in Pixinsight. One can mask of course. But that doesn’t achieve the same effect. Maybe a more experience Pixinsighter might know. 

I think it will be possible in PI, presumably by masking all but the over exposed areas and boosting colour saturation in what's left. It's esesntially the same in Photoshop.  Just working quickly on the screen grab I made a copy layer, boosted colour saturation on the bottom layer and erased the top selectively. I didn't intend to alter the colour palette overall but forgot I was in the wrong colour space on my PC. My point was just that brightening a region always reduces its colour intensity and vice versa, so whatever method you use, you'll need to up the colour in the bright bits. The proper thing to do in Ps would be to make a copy layer of the original, create a layer mask, copy the original onto it and give this mask a huge contrast boost and blur.  Such a mask would be transparent only on the bright regions so boosting the saturation on the top layer would increase the colour only on those regions.

Olly

Edited October 23, 2022 by ollypenrice
Clarification

[Ouroboros]

@ollypenrice  OK, sort of.  I’ll have to think about that. Thanks though.  The thing I’ve discovered about a learning curve is that there’s no top. 

[ollypenrice]

1 hour ago, Ouroboros said:

@ollypenrice  OK, sort of.  I’ll have to think about that. Thanks though.  The thing I’ve discovered about a learning curve is that there’s no top. 

That's why it remains interesting...

Olly

[AstroMuni]

On 22/10/2022 at 20:00, Ouroboros said:

The Great Nebula in Orion and a reminder that winter’s on the way.  

That looks awesome. You almost get a 3D effect where the pinks seem to sink deeper than the rest.

 

[Ouroboros]

51 minutes ago, AstroMuni said:

That looks awesome. You almost get a 3D effect where the pinks seem to sink deeper than the rest.

 

Thanks. Totally accidental on my part.  

[AstroMuni]

16 hours ago, Ouroboros said:

Thanks. Totally accidental on my part.  

You should submit it to the astro magazines for publishing!