[Aavso-photometry] Differential photometry for dummies

[Michael Koppelman]

Most people would say you should not align or combine the images.  
Like Tom said, just do photometry on the individual images and then  
combine those mathematically. The exception is if the object is so  
dim that useful measures are not obtained from individual images. In  
that case, you could align and combine, but you should make sure your  
alignment routine is "flux conserving".

M.


On Jun 16, 2007, at 11:33 PM, R. Brian Potter wrote:

> 3) Align individual images after dark subtraction
> 4) Median combine images to create a single processed image of the  
> field