Ngc3628

[Bolts_Tweed]

This is a quicky of the hamburger in the Leo Trio (although I reckon its more like the dogbone). Insufficient data but clouded now - might add to it later

Astrophysics 130EDT, ST8300, Astrodon E Series

Mark Bolton

[DavidTrap]

Silky smooth Mark,

What were the length of your subs, etc, etc, etc??

Ta
David T

[Bolts_Tweed]

gday David

The Lum was HDR processed with exp. of. 45sec, 90 sec, 3min, 5 min and 8 min - about 10 of each. Colour was 6 min subs.

Selectively smoothed the areas away from the dust lane

Mark

[Lester]

Very nice hamburger.

[DavidTrap]

Thanks for the details Mark,

How did you HDR process - run the subs through the usual processes, stack them in batches and then put the resulting images through an HDR program or align in photoshop and selectively mask??

What do you mean by selectively smoothing??

Just trying to learn from those with more skills than myself...

Ta
DT

[gregbradley]

Nice image Mark. Below the galaxy at the bottom right is a tidal stream.
You can just see it in your image. That could be enhanced to bring it up and is worth it.

I imaged this myself over 2 nights but its too low and dim and the resulting image wasn't good enough so I didn't publish it. Yours is better.

I may be just this laptop's monitor which seems to highlight background noise but I can see some green background noise in your image (is this my monitor?)

Did you use flats, the noise seems to follow a vignetting pattern? Nice score with getting an AP130.

Photoshop CS5 has a more automated HDR routine by the way.

Greg.

[Bolts_Tweed]

Thx Guys

David - I used Easy HDR to add the stacked subs of each exposure stack. I have only just started doing this - I used to layer mask and manually perform the HDR. Selective smoothing - I found the HDR procedure introduces a bit of noise - especially in areas with low signal (like the outer edge of the galaxy) so my ptrefered method of selective smoothing is to run Carbonis space noise (or deep space noise ) reduction as a layer on top and then layer mask it and paint through the areas with objectional noise. It is just the same as selective sharpening or multi layer deconvolution blending to mask through sharper areas (I used MLDB on the dust lane) - check Ken Crawfords web site for more info on that.

Greg - Yeah looking at it this morning i can see the green tinge - it is a result of tired eyes and the observatory computer I think (gotta blame something). This is exactly the reason I try and get them on IIS - You cant buy this type of feedback. I just ran HLVG (thx Marc) and it is ok. Yeah I saw the tidal stream in Ken Crawfords image (in fact that was the inspiration for the image) - It is just there in the 8 minute subs. I'll have a play at home and see if I can enhance it just a bit.

Re flats, darks etc - ok I am going to offend the purists here :P. I've never found the need for em :eyepop:. Well ok darks - I used to take a dark library at temperature but I started using SBIG Auto Dark in Series method - ie it tarks at dark at the start of a run of subs and auto extracts it before saving the sub. Provided I take enough subs it works fine and the subs are already calibrated ready for stacking. Flats well - in this iamge obviously they could have been used (green - interesting it was mainly in this cahnnel- i'll have investigate) however any slight gradient I get I remove in processing on a duplicate image, match the ADU of the background with the original and layer mask through the affected corners in the original (to avoid clipping of the central object). If I have an image with nebulosity to the edge (like the 3567 image I took recently) obviously I take flats or if I ma not happy with this method described above I will take them but things with a birght object like a galaxy in the centre I usually process out any vignetting. So plats about 40% of the time.

Thx for the feedback guys. I attached the image with the green removed but if I can tease out a bit more of the tidal stream during the week I might post a repro

Mark.

[Bolts_Tweed]

I just checked the repost and I can still see a slight green tinge in the corner - Interesting I cant see it in PS - OK - it needs flats:)
I also notice that the star colours are muted on the posted image compared to the jpg in PS - its not worth adjusting the colours for a posting I've matched this computer to the printer so wwhat I see on the screen is what I get on the printer so I'll leave it as it is

Mark

[multiweb]

Great shot Mark. Very sharp. Nice colors too. :thumbsup:

[Bolts_Tweed]

Thanks Marc and thanks for the tip on HLVG - it works a treat

Mark Bolton