ASI178MC and sharpcap/firecapture MONO/RAW and hardware bin2

easybob95

Hello,

i am a new ASI178MC user and i have some questions about capture mode and BIN2.

In sharpcap, i have strange results with MONO and RAW mode capture. I mean i have B&W result with MONO and i have colored images with RAW.

How can i have B&W result with a color sensor ? What is the way used to have B&W image ?

Using RAW mode, i thought i should have not debayered image ?

Concerning BIN2 :

Hardware binning does not enhanced image brigthness. What does hardware binning bring to me ?

Mainy thanks for the highlights.

Alain

riklaunim

Sony sensors in ASI cameras do not support hardware binning, only software. When you do plain bin2 on a color sensor then the color data is destroyed and outputted as "mono" (2 green, 1 red and 1 blue pixels combined into one). It should affect brightness.

Rarely some sensors did had color binning in the past (4 green into 2 green, 2 red into 1 red, 2 blue into 1 blue).

easybob95

Hello Piotr,

according Sam, IMX178 support hardware binning. I don't know much about that.

Concerning software binning, i first thought as you said (bin2 gives mono image) but when i select bin2 with sharpcap and firecapture, i have color pictures if i use debayer option and if not, i have the bayer matrix in the picture. Quite strange and i don't really understand. If Sam could explain me this, it would be interesting for me to know what kind of picture i get with bin2.

For RAW8 and RAW16, it's ok.

For MONO8 with sharpcap, i don't understand what kind of picture i get. It's a mono picture but i would like to know how mono is built.

An other point : i know RN is higher when gain is low but i can see i have very clean pictures with very low gain (no noise) and the noise increase very quickly when i raise gain. I suppose gain is not really a linear scale ? The noise comes rather quickly and is rather high when i have for example a gain which is set at 300 (scale 0 to 1000). Is it normal ?

Alain

riklaunim

If the image scale goes 4x down with that binning then it's doing that color binning.

With high gain you will see noise, but if you lower it it won't be apparent until you stretch the histogram to the same level. If you lower the gain and increase the exposure to get the same histogram fill then the read noise may be bit higher, but you have much higher SNR of the frame (longer exposure) and that is usually better ;)

easybob95

Thanks for your answer Piotr.

As it seems ZWO won't reply to my questions, i will try to ask directly sharpcap and firecapture owners in order to have some informations about BIN2.

Have a nice day.

Alain

Sam@ZWO

mono8 means mono instead of RAW

it is converted to grey scale by software

so you can use this mode to shoot lunar or solar and don't need to debayer it and save harddisk space

Sam@ZWO

178 hardware bin is color bin

same does color and mono version

so we would suggest use software binning

easybob95

Hello Sam

many thanks for your reply.

I will make some tests with software binning. But from what i can remember, software binning gives me color image.

Have a nice day.

Alain