NGC3324 Gabriella Mistral and NGC3293 Gem Cluster

[tim.anderson]

Compiled from 78 exposures with an ASI2600MC Pro and a Skywatcher Esprit 100mm refractor on a ZWO AM5 mount. Processed with PixInsight and Photoshop. Larger size at:

https://www.astrobin.com/full/dj45p0/0/?mod=&real=

[ahmed_haider]

Nicely done! I like the framing you've done. And your star colors are great.....can you please add some basic editing flow if you find the time.

[tim.anderson]

Hi Ahmed

In PixInsight:
1. Blink test on the full set of your subframes to remove any dodgy ones.
2. Debayer all surviving subs (all my cameras use the RGGB Bayer filter pattern, but yours may not).
3. Calibrate all debayered subs with ImageCalibration against the appropriate matching master dark (I have never understood flat and bias frames, so I get on without them).
4. Register all calibrated subs using the ImageRegistration>StarAlignment routine with default settings.
5. Integrate all registered subs with ImageIntegration using default settings.
6. Run AutomaticBackgroundExtractor to remove gradients and other gunk (make sure you tell the process to subtract the extracted background - by default, it does nothing to the original image).
7. Also not a bad idea to run ColourCalibration to suppress some of the background graininess if you have too few subs for your target, but a better solution is to grab more subs
8. Save as 32-bit TIFF

Then in Photoshop:
1. Quick export to .PNG format (only because Photoshop does a lousy job with 32-bit files, at least in my opinion, and .PNG retains most of the editability of .TIFF)
2. Use Adjustments>Levels and Adjustments>Curves to get a pleasing colour balance. You should do this per-channel - R, G and B separately (this is entirely your judgement, I can't help you with that. Well, I might be able to but you would have to pay me in Swiss francs or some other rapidly exchangeable currency)
3. Use Adjustments>HueAndSaturation to tweak the colour balance (mainly reds/yellows and cyans/blues/magentas. I avoid changing the greens, just a personal bias against the ghastly gruens).
4. Use Adjustments>BrightnessAndContrast to make the colours pop a bit more and to increase the contrast to hide background defects - but don't be too aggressive with the settings or else the results will look urk.
5. I use the HealingBrush tool to remove any hot pixels that have appeared in my camera since I created my darks library. I really should generate new master darks, but it is such a mind-numbingly boring procedure that I intend to wait until the Rapture arrives and saves me from the effort.
6. Crop, resize and reformat the image to suit the rendering engines where I intend to publish (IceInSpace, Astrobin, tipua.com, and cwas.org.au (my astro club)). You might be surprised to see how different your image appears on various websites. There is no such thing as a standard JPEG rendering.

Remember that this workflow is aimed at sites that have file type and size limitations, and coarse rendering methods. I do things very differently if I am aiming for the fine-art market and other snooty locations.

Hope that helps

Tim