Help please! ADU Value in pixinsight

[cloudbuster]

Hi All

I'm new to this forum, having had pi for about a year...but have only just started using it properly. i have an Atik313L.

please could someone kindly part with their PI knowledge? im not too good around pi, and have just started ccd imaging. i just dont know how to view the ADU value of my flats.

hoping u can help

cheers

bob

[Juan Conejero]

Hi Bob,

Welcome to PixInsight Forum. On the bottom of PI's main window, you'll see a little blue arrow that allows you to change readout options. Click the arrow and select "Integer Range > 16-bit" from the popup menu. Now when you move the cursor or click on an image in readout mode (the default mode), you'll get pixel values directly as ADU counts.

See the attached screenshot.

[cloudbuster]

hi juan....thanks very much, but i still cant see a value....what is readout mode? im trying to see if my flats have an adu value of around 20,000.

sorry to be a pain!

bob

[cloudbuster]

k:0,3419

hi again juan.
the above readout changes as i move the cursor over the image. if so, are my values too high?
also, im mistaken...its an atik 314L that i have!

cheers

bob

[Juan Conejero]

Hi Bob,

"Readout mode" refers to a working mode for interaction with images. In this mode. you can read pixel coordinates and values while you move the cursor over an image, or click on an image and hold the button while you drag the mouse to get a readout preview. See the attached screenshots.

if you want to obtain a robust estimate of the average value of one of your flats, you can use the Statistics tool (available on the Process Explorer window, default Favorites category). On Statistics, you can select the 16-bit range to get ADU values. The mean, median and maximum values will tell you how your flats are numerically.

[cloudbuster]

thanks juan

will check that out a little later when i get home.

greatly appreciated

bob

[Juan Conejero]

k:0.3419

That is about a 34% of the available dynamic range (or if you prefer thinking in ADU, about 22000 counts). I think it's okay, but I think most people would prefer something closer to the 50% range (around 32000 counts). But I am the guy behind keyboards, algorithms and mountains of source code like the K2 (both in terms of height and danger), so I can be wrong. I'm sure other users with high imaging skills will advice you better.

[Geoff]

Hi Bob
What capture program are you using? Usually these will display a histogram of your image as you take it. From the value of the peak you can get a good idea of the ADU value.
Geoff

[cloudbuster]

thanks geoff...and thanks again juan
going into 'statistics' has done the trick!

cheers...til next time

bob