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Topics - joelkuiper

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Wish List / Sensible presets for subframe selector
« on: 2019 January 31 13:03:10 »
Now this might be somewhat outside the philosophy of Pixinsight, but I often find myself sorting and copy+pasting values from the (amazing!) new subframe selector into the tool provided here to get some reasonable expressions. It would save me a ton of time if it were possible to express variables in the formulas (like min/max FWHM from the measured output) so I can save the generic formula, or even better yet ... have some of these expression preloaded as selectable defaults.

Gallery / NGC 691 & Friends (a not often seen pair)
« on: 2017 November 10 04:57:31 »


Using PhotoMetricColorCalibration. The framing is a bit off I think, but there seems to be some nice red shifted galaxies in the background, that might be worth exploring with a NIR filter.

Bonus, M110


I have an odd problem, my flats seem to be overcorrecting and I can't seem to fix it. They are Sky Flats (morning twilight) taken on the same day as the lights.

However, when I apply them they seem to somehow overcorrect the data.
I aimed for an ADU of 30k, but they're closer to 40k. Might be slightly overexposed, but not tremendously I think?

Flat (XISF, dropbox)
Light (XIFS, dropbox)

Any thoughts on whats wrong with my flats, and how to avoid this problem in the future (or ideally, somehow "fix" the flat?). I tried subtracting a fixed value from the flats (e.g. a pedestal) but I couldn't seem to get it right.

Note that this problem is /much/ worse with narrowband data, even though the flats were also shot with that filter.

SII Flat
SII Light

Full stack of flats (~700MB, very large!). And, also master bias for good measure. For NB data it seems that working without flats is preferred over using them in this setup, but I'm stumped as to why.


Gallery / Some of my exclusively PI edited frames
« on: 2017 October 03 04:58:54 »

Deer lick group
Bubble Nebula HaRGB
Bubble Nebula in SHO
NGC 6951 with IFN
Pelican Nebula (IC 5070) in SHO

Been only doing this for a year and half now … and boy it's tricky. But I love Pixinsight and would love to learn more of the features available! 


Drizzle integration requires well dithered undersampled images, but methods exist for recovering (perceptual) sharpness using blind (multi frame) deconvolution. These would be an absolutely amazing feature for PI, especially since lucky imaging setups with CMOS cameras (e.g. moving beyond the classical dozen or so frames into the realm of thousands) become more common.

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