new camera dark frame ok ?

[iwols]

hi just took some darks with my new cmos camera (imx 571 sensor) stretched in PI but doesnt look as good as my old ccd atik 414ex camera,any thoughts please or am i looking into it too much 

 

the new altair camera

old atik 414ex

 

 

probably a better image on these downloads to see

 

 

https://www.dropbox.com/scl/fi/w1img39jxxdm02q2p811q/altair-astro-dark-test.png?rlkey=6b58prwrbebzpllumsgkz2n5f&dl=0

 

https://www.dropbox.com/scl/fi/71bt0f171odr9x6ko0ixw/atik-414ex-dark.png?rlkey=7nns8d8m1mniu32x5f7xybrhx&dl=0

Edited September 12, 2023 by iwols

[symmetal]

Your downloads are the same as the images posted. 😉

The PI STF function will stretch the image until the brightest pixels are near white. If your image has a more noisy sensor like your atik then less stretching is applied by STF until the brightest pixels are near white. Your IMX571 sensor has lower noise so more stretching must be applied to achieve the same level of white pixels. This makes the IMX571 image look more noisy.

To compare them the same stretch must be applied to each, so use the HistogramTransformation to stretch the Atik image until the noise is quite evident. Then apply the same HistogramTransformation stretch to the IMX571 image and you'll see it is much less noisy. 🙂

Alan

[iwols]

thanks