NINA's histogram

[chubster1302]

Im trying to do my flats in NINA by taking exposures and looking at the histogram on the statistics window but the histogram on there is completely different to the one in camera raw. For instance these were taken at a 1/10s and i was expecting the histogram in NINA to show it blown, but no. So I checked in CR and as expected it was massively over exposed. What gives ?

[Clarkey]

I think NINA just re-scales the graph to fit the exposure. If you look at the statistics it shows the max, min and mean as 16383 i.e. swamped. What is the problem with the standard NINA flats wizard?

[chubster1302]

29 minutes ago, Clarkey said:

I think NINA just re-scales the graph to fit the exposure. If you look at the statistics it shows the max, min and mean as 16383 i.e. swamped. What is the problem with the standard NINA flats wizard?

Not had much luck with it to be honest but that s mainly because I don't really understand it. Will give it some more of my time 

[ONIKKINEN]

NINA is displaying a 16-bit histogram here for some reason, whereas your image is presumably taken with a 14-bit camera. The max value in a 14-bit camera is 16384, or 16383 if we include 0 as one of the values so fully saturated.

You need to go to the Options->Equipment-> and under the Camera tab set your Bit depth to the correct value which would be 14. This should make the flats wizard work too if there was a problem with determining a nice exposure because of the incorrect assumed bit depth of the camera.

[chubster1302]

2 hours ago, ONIKKINEN said:

NINA is displaying a 16-bit histogram here for some reason, whereas your image is presumably taken with a 14-bit camera. The max value in a 14-bit camera is 16384, or 16383 if we include 0 as one of the values so fully saturated.

You need to go to the Options->Equipment-> and under the Camera tab set your Bit depth to the correct value which would be 14. This should make the flats wizard work too if there was a problem with determining a nice exposure because of the incorrect assumed bit depth of the camera.

Ok, thanks, it was set to 16 so Ive changed that. So will that make the Histogram "look" the same as the Camera Raw one, or does NINAs histogram work completely differently to every other histogram? CR tells me im well over exposed NNA's says Im well under exposed (when looking at the histograms) 😖

[ONIKKINEN]

1 hour ago, chubster1302 said:

Ok, thanks, it was set to 16 so Ive changed that. So will that make the Histogram "look" the same as the Camera Raw one, or does NINAs histogram work completely differently to every other histogram? CR tells me im well over exposed NNA's says Im well under exposed (when looking at the histograms) 😖

Yes it should scale the histogram correctly now. You should be looking at a roughly 8000 median value for a mid level exposure at 14-bit.