Sensor Analysis Multiple Readings - RAW8 & RAW12

[jaq1967]

Hello,

I Have the Altair Astro Hypercam 183C Pro. Their website recommends the following when working with 8bit or 12bit output:

Planetary imaging: Planets are quite dim especially at high power, so typically in planetary imaging you run with high gain – think of gain as “ISO”, You’ll want to use high gain to keep exposure duration short to freeze the distortion caused by the air. Using high gain increases noise though, so the noise is going to be much more than 1, so 8 bit is quite good enough.

Lunar imaging or white light solar imaging might be a bit different – you could probably run at low gain if the object is quite bright, in which case the noise level might be less than one pixel level, so maybe 12 bit will help you there.

For long exposures of deep-sky objtecs, noise builds up quite a lot, so you’d typically run at minimum gain to get rid of that noise. So in this low gain situation, 12 bit should help improve the image, and it should also increase the dynamic range between the dimmest and brightest features making the object appear more detailed to the eye.

Video astronomy (live stacking in SharpCap for example) seems to work best at fairly high gains, so 8 bit might be sufficient, but you can start to see more tonal range in 12 bit mode and seeing you aren’t going for high frame rates or recording vast amounts of data it can’t hurt.

So, for DSO, although it recommends 12bit, 8bit is possibly good enough.

The Question: When I run the Sensor Analysis in SharpCap Pro 3.2, and set it to test for RAW12, can I then re-test the sensor by running this test again for RAW8 and it will keep both results recorded, and depending on what I decide to shoot on a particular night (be it RAW8 or RAW12) and I check The Brain, it will automatically decide (depending on what I preset before checking The Brain) what SharpCap's recommendation is for this particular DSO night project?

I ask, because in the manual, under Senson Analysis, it states:

SharpCap stores the results of completed Sensor Analyses on your computer and will use them later to provide Smart Histogram functionality on analysed cameras. If you re-run the analysis then the previous saved version will be overwritten. Note that previously saved sensor data will not be shown when you re-select the Sensor Analysis tool. It can however be viewed in one of the tabs of The Smart Histogram Brain Window.

To gain full Smart Histogram functionality, you should analyse your camera at both it’s maximum bit depth (i.e. in RAW12/RAW16/MONO16 mode) and at a bit depth of 8 bits (i.e. in RAW8/MONO8 mode).

This. I assume, means it rewrites over the old data if you run the test (meaning you cannot shoot in either/or RAW settings) yet, in the same breath, you recommend running the test in both it's maximum bit rates (meaning you can) to gain full Smart Histogram functionality. I am confused.

Thanks in advance.

Jacques

[admin]

Hi,

SharpCap keeps both the sensor analysis results and those which one to use depending on the setting you have chosen for your camera at that time.

Cheers, Robin