StarTools

Ok. when applying a mask for wide field images do you just apply a full mask? Star Mask? Do you define ROI?

Thanks

torsinadoc wrote:Ok. when applying a mask for wide field images do you just apply a full mask? Star Mask? Do you define ROI?

Thanks

Hi,

I'm not entirely sure I understand the question...

The usage of a mask has very little to do with the characterstics of the data (wide field, narrow field or otherwise).
Masks are used to selectively process an image. The effect a mask has is therefore highly dependent on the module you're using a mask with.

Similarly, a Region of Interest (ROI) has, again, very little to do with the characterstics of the data (wide field, narrow field or otherwise).
In the AutoDev module a Region Of Interest (ROI) is used to specify exactly that - the region that is most 'interesting' and therefore requires AutoDev's special attention to bring out as much detail as possible. What is deemed 'most intersting' has of course very little to do with whether an image is a wide field or narrow field.

I guess a better question would be when processing a wide field (like Milky Way) would you use any mask? I would think since it is a star field without any particular roi I would use either? Or would I choose nebulositty/Milky Way as the roi?

Btw my iMac seems to work well as long as image is correct size

torsinadoc wrote:I guess a better question would be when processing a wide field (like Milky Way) would you use any mask? I would think since it is a star field without any particular roi I would use either? Or would I choose nebulositty/Milky Way as the roi?

Sure! You could just use the entire image as the ROI (default) for the Milky Way if you feel every part of the image is equally important. Some people like to optimise the dynamic range for the HII regions (such as M8, M42, etc.) so that any detail in these is readily visible. Of course the latter can also be achieved with local dynamic range optimisation (e.g. HDR module).

As for the mask, again, it totally depends on the module what sort of mask you create and use. If you want to manipulate the stars (ex. Magic module), then you create a star mask. If you want to protect the stars (ex. Wavelet Sharpen module) then you create an inverse star mask. If you want to apply deconvolution, you mask out overexposed parts of the image. If you have dust donuts in your image you mask them out before using Wipe, etc.