Ngc 4755

[WingnutR32 (Sam)]

I am still trying to get my setup working right with so many changes in one go.

New equipment:
- SkyWatcher AZ EQ6 GT mount
- MicroTouch Focuser with motorised control
- FocusMax
- ACP Planner
- ACP v7 (RC1)

As you can see, I changed an awful lot at once and now have a huge headache each night making sure things go 'semi' right.

The result over the last two nights was a 'semi' okay NGC 4755 - Jewel Box Cluster.

Luminance = 16 x 120s 1x1
RGB = 6 x 120s 2x2

I lost a lot of data due to struggling with pointing repeatability through ACP/EQMOD. My pointing accuracy is over 25 arcmin rather than less than 3 arcmin.

In terms of the actual photo result, I think 120 seconds may be a little too long exposure as the central stars just started to bloat. 90 seconds may yield a better result.

[WingnutR32 (Sam)]

Reprocessed to get rid of the 'skyglow' / 'colour cast'..

[Larryp (Laurie)]

Looks great!

[alpal]

Quite good but there is a cloud around the target which I've never seen before.

pointing repeatability through ACP/EQMOD

You only need a one star alignment with Synscan if that star is
close to your target & in this case B Crux is right there.

[WingnutR32 (Sam)]

Not using Synscan alpal.. EQMOD..

There was a lot of high cloud wisps around so maybe its that.

[LewisM]

Just back off on the gradient removal a little - I think it pushed it past green removal and into a red addition a little too much. If you use any of the standalone filters (like the Deep Space HLVG gradient tool, you can use the standard Photoshop Fade function.

If you are using another program, then I have no idea

[WingnutR32 (Sam)]

Using StarTools - It has an aggressiveness slider, so I can pull that back a bit quite easily.

[cybereye (Mario)]

I like the second version - it has an almost 3D feel!

Cheers,
Mario

[WingnutR32 (Sam)]

Thanks for all the comments, guys..

I have attached some screen caps after certain steps of processing:

1 - First stack and global stretch
2 - Crop, redo global stretch
3 - Wipe gradient/colour cast
4 - Life, adjust to taste, but I try to neutralize the background a bit
5 - Boost star colour a little
6 - Final image post noise reduction

[multiweb (Marc)]

I really like the field and the resolution. Only one comment. Your red channel seems clipped or saturated in the highlights. You can see it the ringing around the orange stars in the cluster, Other than that, top shot.

[WingnutR32 (Sam)]

Thanks Marc, I could see the clipping in the red but with the little data I had and the random pointing errors, my red was the worst of the bunch.

Cheers for pointing it out though, I can make sure to pay more attention when I increase the colour saturation for induced clipping.