Orion nebula core burning out

[neil groves]

I have around half hour of data for M42 which I feel I can make a nice image out of, I have 63 light frames at 30 secs each then I shot a frame at 3 secs for the core but I don't know how to blend it into the main image after

since when the image comes out of DSS it is a different size and my 3 sec image doesn't fit?

Neil.

[johnfosteruk]

Surely with all things in your optical train being equal they should be the same size unless dss is cropping them or something, but they should definitely be the same scale importantly.

as for blending, use the blown out longer exposure as a mask for the shorter exposure.

if you're using photoshop:

1. Align the images (You could use DSS if you don't have something like Registar or Maxim. Use one as the reference image and run through a stack process selecting the option to save calibrated copies of each sub)
2. Open them in Photoshop
3. Copy the short exposure to the clipboard
4. Paste the short exposure on top of the long exposure in a layer
5. Make a mask
6. Paste the long exposure into the mask
7. Open a new view of the image to see effects of manipulating the mask
8. Blur the mask
9. Adjust the density and contrast of the mask with curves
10. Tweak the color of the core to match the rest of the image

HTH

[wimvb]

There is a setting in dss which lets you set the geometry of the output image. Set this to be the same as the reference. Then use the same reference for the short exposure stack as for the long exposure stack. I can dig up a screen dump later tonight, am not at my computer right now.

Hope this isn't too cryptic.

[ollypenrice]

I would process the long subs into one image and the short subs into a different one.

Once you have them both, use this method:

http://www.astropix.com/HTML/J_DIGIT/LAYMASK.HTM

Olly

[wimvb]

Here's the setting in DSS I mentioned in an earlier reply. It shoulld produce a final image with the same geometry as the input light frames. This can then be stacked with the shorter sub(s).

[Jannis]

I would process the long and short exposures separately, then gently blend in the core.

I've found the hardest part to be aligning the images. So hard in fact i bought Registar, and i don't regret spending those $179 even one bit (especially as I'm aligning images taken with different cameras and scopes).