Leo Triplet (reprise)

[NoelC]

Another re-process of Leo Triplet data from Feb. different data to my previous one.

About 10 subs each LRGB 200S Atik One 6 taken under APT.
Managed (finally) to assemble the colour components in APP using their colour composition tool (I am struggling processing this stuff so much...). Colour balance managed using APP's star colour tool (Black body & Extinction model). Stretched in APP using standard stretch, disappointing result so turned saturation up full. Cropped stretched and fiddled with in Photoshop Elements.

I shot a whole load more L subs after the meridian flip, but cannot work out how to use them - any advice?  Tried calibrating them then batch flipping, but suspect that didn't work as colour disappeared and hot pixels started burning through everywhere, processed as two batches, and couldn't assemble due to differing size, cropped to correct size, but couldn't assemble due to registration being different. Flipped cal'd subs, processed as two sessions - and added 2 luminance to RGB - no colour (obviously) ...
All advice gratefully received.

[ApophisAstros]

Like it , nice one Noel,
With regard to meridian flip , when i did it i stacked the 2 sets of Luminances separately and rotated one and aligned them in PS.
Roger

[Roy]

Super image, I wish I'd taken it!

Roy

[NoelC]

Thanks for your comments Roy and Roger.
May give PS a go Roger, but the problem I had with 2XL was the colour got washed out.

[The Thing]

Hi Noel,

If you stack in Deep Sky Stacker 4.n  it will register and rotate both orientations with no effort on your part. If you have different flats, darks, bias frames then stick each set in a different Group tab with their subs. Save the result as 32 bit no adjustments Tif or Fit. Then post-process in whatever you are using.

HTH

Duncan

[The Thing]

Ah, you are using filter sets. I think you need to do each filter separately in DSS and combine the channels afterwards.

[NoelC]

Thanks Duncan
I'll give DSS a wiz - but will it calibrate prior to flipping? (or else the reference frames will be out of sync).

Yes I'm using filters, the problem I have had is that separate stacks come out as subtly different sizes (due to stacking) which means they cannot be combined by the tools on offer (only combined by eye in PS or Gimp).  Which then leaves me the problem of colour balancing by eye, which is tricky when I'm partially colour blind (red/green) - hence my preference for using a tool to combine.

[Carole]

Are you using the same camera and
scope for both lots.  If so they should be the same size
after stacking.  Unless you have binned some and not others.

I never found DSS could cope with flipping but it will rotation so long as
it is not a huge rotation. It is possible the later versions may
cope with these but l have't updated DSS as l hardlt use it these days.

If you binned some and not others then l have found the beast tool for this
is Registar.

Carole

[NoelC]

Thanks Carole
Yes its the same camera, the same session, same target etc. I flipped the rig as APT was showing it was overdue for a flip, and continued taking Luminance assuming I could stack them...  However, when stacking them as separate exposures the sizes come out different.  I guess this is due to dithering and slightly greater registration differences, it's only a few pixels, but AstroArt and APP refuse to combine them as they are different sizes.

Not used Registar; will take  a look.
Thanks
Noel

[Carole]

Does APT put a border along one side, l can't remember.
If so that might be causing it.
You should't need to fork out for Registar in these circumstances.

Try stacking each side of the flip separately then flip one and then try
stacking the stacks. 

As a last resort just try registering the two sides on DSS and then
stack them manually in PS using 50% for the top layer.

Carole

[The Thing]

In DSS set the stacking mode to standard so you get the dodgy edges as well, otherwise DSS will trim the subs for each filter to suit itself and the results won't be able to match as  you have found. You could try re-running DSS using the result files to stack the filters using Intersection mode. This will give you a cropped image which you could use as a reference to line up and crop the individual filter results as channels/layers in PS.

BTW APT doesn't add any strange borders on my ZWO ASI294 FITs files.

[Roy]

Carole,
APT has no effect on the image, it merely controls the camera and other equipment's operation.
Roy

[ApophisAstros]

In APT if you Dither then there will be a border effect , need to crop it out in processing.
Roger

[Carole]

Does APT put a border along one side, l can't remember.

APT has no effect on the image, it merely controls the camera and other equipment's operation.

I think it might have been the QHY8L camera data that I used in the past I might have been thinking about that used to produce a border.

Am now back from my holiday and able to use the desktop instead if fiddling with my smartphone and roaming.  So excuse previous typos.

Carole

[NoelC]

Thank you for all the advice.
Roger; your right, I used dither which accounts for the size changes.

Busy cleaning up machines to provide disk space (just got 10GB off my obo pc!).
Will get back to images shortly.

Noel