Tarantula NGC2070 - looking for feedback

[cometcatcher (Kevin)]

Not sure about the colours on that one. Black point clipping too is hiding some nebula.

[Amaranthus (Barry)]

Agreed. But there was a lot of colour information in the image, so the choice of colours to focus on enhancing was somewhat arbitrary... so I figured I'd try something a little 'different'. The colours are real in the sense that they are in the image - just not necessarily dominant.

[Amaranthus (Barry)]

Here is a link to the original FTS (after stacking), if you're interested:

DELETED (114 MB zip file of a 32-bit FTS)

It was made by EWA combining in DSS of two stacks - 150 x 10 sec subs and 50 x 30 sec subs, to create the final HDR image. It needs edge cropping as a first step.

[rmuhlack (Richard)]

Hi Barry i've had a quick play with your eta fits data using pixinsight.

some field rotation in there due to the alt-az mount, so i've cropped it more tightly around the keyhole. in low signal areas it's a little blotchy, which may be due to your sub frame calibration procedure and/or the temperature of the sub frames vs the temp of the darks.

i've tried to colour balance to something more "mainstream". Quite a bit of detail there considering the sub duration and overall integration time.

[Amaranthus (Barry)]

Thanks Richard, yes, I did a bit of tweaking with just the core of the Keyhole myself last night, in StarTools, and came up with something similar, see attached. It is the larger vista that presents the colour issues.

The darks are matched well, and I calibrated with flats and bias. The problem, I think, is the subs quality due to the mount (and short exposure). Soon I'll be up and running with my AZ-EQ6 and the game will be afoot!

[Amaranthus (Barry)]

Here is another version, with a bit more work in ST. I think it's looking decent!
Full image here: http://www.astrobin.com/98885/C/

[raymo]

great job Barry.
raymo

[irwjager (Ivo)]

Hi Barry,

Nice to see continuous improvements.
I had a quick look at the data you posted and there is still something strange going on. Calibration might be the culprit - detail has been introduced that isn't real (the blotches that Richard is talking about). There is also a most peculiuar color gradient that seems to radiate outwards. I'm suspecting the flat frames are not suitable or not applied appropriately (just guess ).

[cometcatcher (Kevin)]

I noticed the blotchy artifacts too but I can't quite put my finger on what's causing them. Could it be from the Nex?

[Amaranthus (Barry)]

I think the NEX is fine - chip is clean and the sensor is an excellent one. Wayne Anderson has gotten some great results from this camera, and it takes beautiful terrestrial shots.

As Ivo notes, it may be coming from my less-than-perfect flats (I was experimenting with using the garage light to take them, but looking at them, they seem vignetted due to uneven illumination. I might try it again, sans the flats, as there were few dust bunnies I could see anyway. Will post a new version soon where I leave out the flats and use only the highest quality subs, and see if that improves things (even with a loss of faint detail)

[Amaranthus (Barry)]

Here is a link to the a new FTS (after stacking):

https://dl.dropboxusercontent.com/u/...014_10subs.zip (40 MB zip file of a 32-bit FTS)

10 x 30 sec subs (i.e., 5 min total integration) with darks and bias but no flats. These were the best of the subs, stacked using 'Average', and I also used a custom area to remove the worst of the field rotation.

Does it look improved in terms of its blotchiness or gradient?

[Amaranthus (Barry)]

Here is an example of a processed image from the above FTS file, and here is the StarTools log:

-----------------------------------------------------------
StarTools 1.3.5.285
Sun Jun 01 16:39:53 2014
-----------------------------------------------------------
--- Auto Develop
Parameter [Ignore Fine Detail <] set to [2.1 pixels]
Parameter [Outside ROI Influence] set to [15 %]
--- Bin
Parameter [Scale] set to [(scale/noise reduction 35.38%)/(798.89%)/(+3.00 bits)]
--- Crop
Parameter [X1] set to [1135 pixels]
Parameter [Y1] set to [783 pixels]
Parameter [X2] set to [29 pixels (-1161)]
Parameter [Y2] set to [24 pixels (-797)]
File saved [C:\ASTROGRAPHS\Eta_Car_Amar_21May20 14_10subs.tiff].
--- Wipe
Parameter [Mode] set to [Correct Color & Brightness]
Parameter [UNKNOWN] set to [No]
Parameter [Precision] set to [512 x 512 pixels]
Parameter [Dark Anomaly Filter] set to [10 pixels]
Parameter [Drop Off Point] set to [100 %]
Parameter [Corner Aggressiveness] set to [100 %]
Parameter [Aggressiveness] set to [75 %]
--- Auto Develop
Parameter [Ignore Fine Detail <] set to [Off]
Parameter [Outside ROI Influence] set to [15 %]
--- Deconvolution
Parameter [Image Type] set to [Deep Space]
Parameter [Mask Behavior] set to [De-ring Mask Gaps, Hide Result]
Parameter [Radius] set to [2.0 pixels]
Parameter [Iterations] set to [50]
Parameter [Regularization] set to [1.00 (optimal noise and detail)]
Parameter [Mask Fuzz] set to [8.0 pixels]
--- Contrast
Parameter [Expose Dark Areas] set to [No]
Parameter [Compensate Gamma] set to [Yes]
Parameter [Precision] set to [512 x 512 pixels]
Parameter [Dark Anomaly Filter] set to [10 pixels]
Parameter [Aggressiveness] set to [75 %]
Parameter [Dark Anomaly Headroom] set to [15 %]
--- HDR
Parameter [Small Detail Precision] set to [Max]
Parameter [Channels] set to [Brightness & Color]
Parameter [Algorithm] set to [Optimize Soft]
Parameter [Dark/Bright Response] set to [1.00]
Parameter [Detail Size Range] set to [20 pixels]
Parameter [Noise Suppression] set to [5 %]
--- Wavelet Sharpen
Parameter [Intelligent Enhance] set to [Yes]
Parameter [Scale 1] set to [100 %]
Parameter [Scale 2] set to [100 %]
Parameter [Scale 3] set to [100 %]
Parameter [Scale 4] set to [100 %]
Parameter [Scale 5] set to [100 %]
Parameter [Mask Fuzz] set to [8.0 pixels]
Parameter [Amount] set to [175 %]
Parameter [Small Detail Bias] set to [75 %]
--- Life
Parameter [Detail Preservation] set to [Min Distance to 1/2 Unity]
Parameter [Compositing Algorithm] set to [Power of Inverse]
Parameter [Inherit Brightness, Color] set to [Color]
Parameter [Output Glow Only] set to [No]
Parameter [Airy Disk Sampling] set to [128 x 128 pixels]
Parameter [Airy Disk Radius] set to [8 pixels]
Parameter [Glow Threshold] set to [12 %]
Parameter [Detail Preservation Radius] set to [20.0 pixels]
Parameter [Saturation] set to [100 %]
Parameter [Strength] set to [100 %]
Parameter [Mask Fuzz] set to [1.0 pixels]
--- Color
Parameter [Cap Green] set to [To Yellow]
Parameter [Bias Slider Mode] set to [Sliders Reduce Color Bias]
Parameter [Style] set to [Scientific (Color Constancy)]
Parameter [LRGB Method Emulation] set to [RGB Ratio, CIELab Luminance Retention]
Parameter [Dark Saturation] set to [1.50]
Parameter [Bright Saturation] set to [Full]
Parameter [Saturation Amount] set to [250 %]
Parameter [Blue Bias Reduce] set to [2.66]
Parameter [Green Bias Reduce] set to [2.98]
Parameter [Red Bias Reduce] set to [1.00]
Parameter [Mask Fuzz] set to [1.0 pixels]
--- Wavelet De-Noise
Parameter [Scale 1] set to [90 %]
Parameter [Scale 2] set to [90 %]
Parameter [Scale 3] set to [90 %]
Parameter [Scale 4] set to [90 %]
Parameter [Scale 5] set to [50 %]
Parameter [Mask Fuzz] set to [1.0 pixels]
Parameter [Scale Correlation] set to [3]
Parameter [Color Detail Loss] set to [12 %]
Parameter [Brightness Detail Loss] set to [12 %]
Parameter [Redistribution Kernel] set to [2.5 pixels]
Parameter [Read Noise Compensation] set to [1.80 %]
Parameter [Smoothness] set to [75 %]

[rmuhlack (Richard)]

a definite improvement in both blotchiness and gradient (IMO)

[cometcatcher (Kevin)]

Yep, Ivo called it. It was the flats causing the blotchy.