Greetings friends! As I hide in @XRaySpex rubbish bin since landing in beautiful Brisbane, I have come across something interesting. Since my last post on Spectrometric Color Calibration I have been playing around with other filter settings. In my first post, I provided a data set to alter the SPCC to better align with the SeeStar S50 (SS) internal filter, as well as a preexisting filter in SPCC that is close. Now, I have noticed that there is a SS specific filter setting in SPCC. I have been using this as I process images, both my own and shared, over the past few days. Then I started playing around with the other filter sets and found some sublte but amazing differences. The following images are of partially processed Caldwell 92 kindly provided by our friend XRaySpex. To the best of my knowledge, this is a mosaic of 10 second subs with the internal filter engaged. So far in the process of each of the following images, all that has been done is:

SCNR
Small Dynamic Crop
Dynamic Background Extraction-Division
Dynamic Background Extraction-Subtraction
BlurExterminator-Correct only
FWHMEccentricity PSF measurment for BlurExterminator
Full BlurExterminator
Full NoiseExterminator
SetiAstro Statistical Stretch (Target Median 0.20, Curves 0.10)
Resampled at 200%

First is the SeeStar SPCC filter setting

Everything is well defined. Lots of detail. Good transition between colors. The faint nebulosity at the top is easily seen.

Next is L Enhance Extreme

I think the colors are a bit more vibrant, a little more definition between the gradients, and the dark areas are more pronounced. The nebulosity at the top is not as defined as the SeeStar in my opinion, but has a richer color.

Next is the L Enhance Ultimate

Nebulosity at the top to me appears a bit bolder and richer in color than the Extreme. Overall, the nebula core seems a bit muted, but good contrast between dark structures. This filter option may be useful when dealing with other targets with lots of dark structures or perhaps reflection nebulae

Next we have the BaaderUHC-S

I feel this one has good balance overall. Brights are bright, darks are dark, colors are rich and balanced. This filter preset may be a good starting point for post processing using color masks, curves, NarrowBandNormilization and so on.

And finally we have the Antila Triband

Another rich starting point for post processing.

In closing, the SeesStar specific filter set does a good job, but don't let that limit you. Don't be afraid to try different things. Experiment with different filter settings on different objects. This is just one example. Other deep sky objects with different filter pre-sets may yield striking results!

As always, Per Aspera, Ad Astra my friends!

Spectrometric color what?....Part 2