tutorial MASK's in AA6 ?

[Forum_2018]

Hello,

Is there a tutorial how to work with masks in Astroart 6 ? It is not clear to me and in the manual is just a explaination of the menu's and what you see. a turorial or youtube with an example should be fine. at the moment i can't find any youtube where this give more clarity and what is the power of the masks.

[Forum_2018]

Hello, no but the procedure (for image processing) is the same of photo retouch software.
Masks permit to apply a strong filter on some parts of the image and a weak filters on the others (or no effect at all).

For example last week I was correcting coma on a wide field image: I wanted a full correction on the egdes of the image, no correction in the center, and a transition in between. To do that:

1) Select a circular mask in the middle of the image.
2) Invert the mask.
3) Smooth the mask.

Now the Compress Stars filter will do the job, compressing more in the edges:

[Forum_2018]

Thanks Fabio,

I want to use that for comet-imaging & processing. I have 1 image stacked (sigma) on the comet and 1 image stacked (sigma) on the stars. So i have a comet-image without startrails. I want to selct, via mask only the comet, do some processing and paste this in the star-stacked image. But i don't know how i can manage this with this feature of AA6. As i could understand, only filter can be used with the masks, not brightness/contrast/histogram Stretch ?

thanks for your time.
Erik

[Forum_2018]

Hi, I think that using masks you can obtain the desired result working directly on the image. I suggest the filter "Histogram stretch" (the preview will be on the whole image, but the filter do actually work on the masked region). If you like, feel free to send by email the image.

[Forum_2018]

Hi Fabio,

I could manage this now, thanks to Fabio's tips !

What i did now with AA6:
1. stack comet images on comet with sigma= 1.5

2. stack the same set of images on the stars with sigma=1.5

3. with the mask-function i draw with the paint-tool (about 60 pix in diameter) the comet with tail as the mask and then i used 'smooth' of the mask tool window

4. now i 'copy' the mask of the comet and 'paste' this as 'into image' and position on the image which was stacked on the stars.

5. finally result can you find here.

I repeated this steps here, some other starting comet-imagers are interested as well?

@ Fabio, thanks again

[Brocke]

Hi,

thanks Fabio and Eric for your explanations on this task.

Helps me a lot.

cs, Dirk