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Smart Histogram Brain Function Retention

Posted: Sun Feb 03, 2019 12:15 am
by GregL
There is quite a lot of material calculated when I use the Smart Histgram 'brain' function exposure estimate -- is this information saved anywhere or must I go through and screen capture each page? I have used the clipboard option with the sensor analysis and was disappointed that it only captured the text portion.

And if I decide that using a non-unity BIN setting for my camera is appropriate for conditions, does the smart exposure adjust its results or ?

Finally, I have noticed that even though I set a minimum exposure duration, the calculation appears to ignore it and recommend a large number of very much shorter exposures -- example: I tell it 30 seconds minimum and it comes back that I want 3.6 second exposures... 360 of them. (At 30mb a pop for 16 bit FIT files by the way). Why does it do this and is there any way to convince it otherwise?

Thanks,

greg
avalon observatory

Re: Smart Histogram Brain Function Retention

Posted: Sun Feb 03, 2019 7:44 pm
by admin
Hi Greg,

I'm surprised that the calculation is ignoring the minimum exposure value – can you send me a screenshot that shows this problem so I can try and set up the same situation myself and work out what is going wrong.

There is no need for you to worry too much about the information that is shown on the brain window. The most important figure that comes out of the brain calculations is the sky background brightness – everything else follows on from that. So, if you note down your sky background brightness and then reuse that at a later date you will get very similar results (they won't be identical because the drop-down of sky brightness figures only has a limited range of options).

I did design the brain calculation to cope with binning so I think it should adjust the recommendations appropriately if you use it while bidding a selected. I would recommend that you should run the sky brightness measurement while using the same binning that you intend to use, as I cannot remember if I made that measurement adjust for binning changes.

Cheers, Robin

Re: Smart Histogram Brain Function Retention

Posted: Sun Feb 03, 2019 9:36 pm
by GregL
Thanks, Robin.

Next time its not snowing... ;-(.

BTW -- is there any way to save the displays other than multiple screen captures? It really would be nice...

greg

Re: Smart Histogram Brain Function Retention

Posted: Mon Feb 04, 2019 6:48 pm
by admin
Hi Greg,

I find the snipping tool application that is built into Windows is excellent for capturing small areas or the whole screen and saving them.

Cheers, Robin

Re: Smart Histogram Brain Function Retention

Posted: Wed Nov 27, 2019 9:01 am
by Paolo2710
Hi i'm Paolo Banci from Italy.
In the smart histogram window, above is written e/pixel/s.
What should be entered if this value is not known?

Re: Smart Histogram Brain Function Retention

Posted: Wed Nov 27, 2019 8:14 pm
by admin
Hi,

Normally the best option is to let SharpCap measure your sky brightness. If you can't or don't want to do this then there is a calculator available here where you can enter an estimate of your light pollution levels and some details of the equipment you are using to calculate an approximate value.

https://tools.sharpcap.co.uk/

Hope this helps, Robin

Re: Smart Histogram Brain Function Retention

Posted: Wed Nov 27, 2019 8:20 pm
by Paolo2710
Should the measurement be done with the light pollution filter?

Re: Smart Histogram Brain Function Retention

Posted: Thu Nov 28, 2019 9:41 pm
by admin
Hi,

The sky brightness measurement should be done with any filter that you intend to use for imaging stop do not need to be done with any filter at all but it won't do any harm to use a filter except change the lengths of the exposures used during calibration and perhaps slow the procedure down a bit.

Cheers, Robin