by DavidLeodis » Sat Mar 15, 2014 11:34 pm
Chris Peterson wrote:DavidLeodis wrote:I would like to know if Hydrogen-alpha, OIII and SII filters can be used to obtain image data even in daylight
I assume that Red, Green and Blue filters have to be used in darkness.
No. The objects that emit at these wavelengths are very dim, which is why narrowband imaging typically requires such long exposures. You can image pretty well under moonlight or light pollution, but the daytime sky is just too bright, even in a band just a nanometer wide.
Thanks Chris for that very helpful reply, which is appreciated. I had wondered, if like radio astronomy, that the filters may be usable in daylight as well as darkness.
[quote="Chris Peterson"][quote="DavidLeodis"]I would like to know if Hydrogen-alpha, OIII and SII filters can be used to obtain image data even in daylight :?: I assume that Red, Green and Blue filters have to be used in darkness.[/quote]
No. The objects that emit at these wavelengths are very dim, which is why narrowband imaging typically requires such long exposures. You can image pretty well under moonlight or light pollution, but the daytime sky is just too bright, even in a band just a nanometer wide.[/quote]
Thanks Chris for that very helpful reply, which is appreciated. I had wondered, if like radio astronomy, that the filters may be usable in daylight as well as darkness. :)