WBPP2.1 Star Alignment vs the process Star Alignment

Roger Smith

Hi Adam,

In WBPP2.1 Star Alignment it offers in the Image Registration pop up box to do Distortion Correction.

In the separate process Star Alignment, this is greyed out; I guess unless you have a .csv distortion correction file. See attached.

Kindly (our HK word for please) comment on this.

Previously, in April/May I ran WBPP (2.0?) on the same raw frames (at 460mm FL) and clicked distortion correction in Image Registration popup. I had good registration and as I recall no distortions. I am sure I would have noticed, and I doubt NSG script would work if distorted. I deleted that data and have been reprocessing with WBPP2.1.2.

With WBPP2.1.2 (same data), and with distortion correction enabled, I definitely have distortion (not rotations) in multiple registered images. Same reference image both times.

Now I am wanting to go back to the WBPP2.1.2 debayered images and run Star Alignment for comparison. But no distortion correction seems available. 

I do not want to go through the extra scripts steps you did in your Cosmic Canvas video NGC3981 Register Luminance because WBPP2.0 worked well. I am wondering if WBPP2.1.2 is handling registration differently for some reason or I made some mistake with ver 2.1.2. 

Do you have any suggestion what I should check, or do again?

Thanks,

   Roger

Roger Smith

Hi Adam,

Above I incorrectly wrote:   

"Previously, in April/May I ran WBPP (2.0?) on the same raw frames (at 460mm FL) and clicked distortion correction in Image Registration popup. I had good registration and as I recall no distortions. I am sure I would have noticed, and I doubt NSG script would work if distorted. I deleted that data and have been reprocessing with WBPP2.1.2."

++++++++++++

The above is wrong. I found the WBPP2.0 script I used in May and I did not register the images with WBPP, but used Star Alignment separately.  

Just now I took my debayered (but not registered) WBPP2.1.2 images and ran Star Alignment separately with defaults. All images are registered nicely with no distortions.

So I do not understand why WBPP2.1.2 would make the registration / distortion worse. The settings I used in WBPP2.1.2 giving the distorted images is in the above message's attachment.

So my only question is do you know any reason why WBPP (any version) would not handle registration as well as Star Alignment?

Roger