M27 Challenge

Hi All,

I had been waiting to get a night to take new data on this but time was running out , so I re-processed data from November 2019. Since I took this data I’ve found that DSS doesn’t stack it properly so I have re-stacked it manually and tinkered with it in Photoshop to come up with this.

You can see the star that is causing the nebula at dead centre. This was taken using RGB filters only, 1 hour each in 4 minute subs.

Then along came a clear night (finally). So rather than redo the image in RGB, I did it in Ha, O3, S2. Again 1 hour each but in 5 minute subs.

Stacked manually again and really processed hard to bring out the outer ring of blue.


For both images I used the RC 6 inch telescope with the Atik 314L+.


Reducing blue halos around stars on my M27 image

I received a criticism that there were too excessive blue/purple halos around the stars in my M27 image.

It has taken me ages to come up with a solution but here it is.

Starting with my previously processed image:

(i) Load image into Photoshop CS6.

(ii) Duplicate layer.

(iii) Add mask to duplicate layer. Use brush (137 pixel, airbrush soft round 50% flow) to cover nebula in mask on duplicate layer.

(iv) De-select bottom layer (without mask) so not visible.

(v) Go to duplicate layer (not mask) and open levels and raise lower limit on blue level until blue halo disappears.

(vi) Re-select bottom layer so visible again.

Voila! Blues gone but nebula still original colour!


Iris Nebula

I revisited an old target last night hoping to get more of the dark nebula round it. My initial target was M31, however the skies were very light polluted due to it being relatively low in the sky. Until I get my L-Pro filter, this beauty may have to wait.

As the night progressed and the nebula was getting closer to the zenith, i did encounter some guiding issues which resulted in some frames being dropped from the stack. But all good experience.

The managed to get 2hrs of images before the clouds rolled in and was just finishing my calibration frames when the drizzle started. I have never packed away so quickly in my life!!

Here is the Iris Nebula.