Non linear scaling function(s)

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roelb
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Non linear scaling function(s)

#1

Post by roelb »

Non linear histogram scaling functions would be interesting.
eg. to correct galaxy center blowing
Roel
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Re: Non linear scaling function(s)

#2

Post by admin »

Hi Roel,

it's always best to delay this sort of non-linear stuff until final processing to avoid data loss, but you can do it already for the display in SharpCap - two ways:

* Display gamma adjustment for general usage - http://docs.sharpcap.co.uk/2.9/#!2!Display%20Controls
* Live stacking gamma adjustment when stacking - http://docs.sharpcap.co.uk/2.9/#Histogram%20Tab

cheers,

Robin
roelb
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Re: Non linear scaling function(s)

#3

Post by roelb »

Thanks Robin, but up to now I wasn't able to correct very well the "blowout galaxy cores".
I tried also the gamma slider.

I also use Starlight Live software in conjunction with a Lodestar X2 Mono (CCD).
This software enables 2 non-linear scaling functions: ARCSINH and X^0.25, and works very well.
If you want more info I can submit some examples (linear compared to arcsinh).
Roel
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turfpit
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Re: Non linear scaling function(s)

#4

Post by turfpit »

Roel

Have a look at the last 2 bullet points at http://docs.sharpcap.co.uk/2.9/#Stretch ... ck%20Image for FITS Liberator and the tutorial link.

FITS Liberator offers the following comprehensive Scaling and stretch functions:
scaling.png
scaling.png (46.59 KiB) Viewed 2289 times
I have tried out all of the above functions on some of my deep sky images with some interesting results. The lessons learned have made me go back and experiment with different settings during capture.

Over the last few months, I have attended 4 astro-imaging workshops - 2 each by Gary Palmer and Damian Peach. Both of these drew a distinct line between data capture and data processing - they both grab data as one step and process it later as a second step.

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Re: Non linear scaling function(s)

#5

Post by admin »

Ah, ok, I have a Lodestar X2 now, so I will have a play with Starlight Live when I get some time and see what I can learn.

cheers,

Robin
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