is this internal reflections?

[Daniel-K]

just having a go at processing some data gathererd the other night and when stretching this big halo is showing is this a reflection?

scope used was ED80 with a REDUCER/FLATTNER non matching WO

thanks

Dan

[michael.h.f.wilkinson]

Looks more like a vignetting issue (or flats not matching the precise imaging conditions)

[Uplooker]

I would concur with Michael

Ian

[Naemeth]

I agree too. You can see that the edges are blacker than the centre in this sort of pattern

Dark ( Lighter ---- Centre of Image ---- Lighter ) Dark

[Daniel-K]

ok i must take flats

[ollypenrice]

ok i must take flats

You must indeed! They really are incredibly important, especially on a large chip and on targets with lots of faint signal. You need flats to separate the faint signal from the vignetting and dust bunnies.

Lots of nice browns lie around the Iris...

Olly

[Earl]

Flats are really essential, but more so is knowing how to calibrate them correctly.

[Daniel-K]

Flats are really essential, but more so is knowing how to calibrate them correctly.

would you like to collaborate on calibrate them correctly

[Earl]

would you like to collaborate on calibrate them correctly

Simples

Run PI Calibration Script

[Earl]

Check out Harry Page's tutorials he does a section on Flats, its for a OSC camera however it does explain a few things

http://www.harrysastroshed.com/AA4flat.html