Techniques I've always wondered about

[jonbarr87]

Before I start, please bear in mind that I have NO experience with astrophotography...

1- Would you get an equally impressive final image if you merely copied one photo "x" amount of times and then stacked it as opposed to taking "x" amount of images and stacking them?

2- Say you had a single frame with a 12 mp DSLR... would you get a roughly similar quality image if you were to take a 1 mp webcam and snap/combine 12 frames? Seeing as then technically you would have the same number of pixels in the image. Or would the resolution still be far lower?

If this doesnt make sense I apologise... It does in my head and that's the important part lol

[SteveL]

A1) No... the reason for taking lots of images is so that the stacking program can anazlyze them. During the processing, it will reduce/remove the noise (and the noise is random in each image), and at the same time enhance the signal (and the signal will be the in the same place in each image), and create a single image where the noise has been reduced and the signal enhanced. Taking a single image and stacking it wont allow this process to work

A2) Do you mean 1 single image with a 12Mp DSLR, versus a 12 single shot mosaic of the same area taken with a 1Mp webcam? Well, for one, most webcams are AFAIK only 256 colour (or even 256 shades of grey if they are mono), whereas a 12Mp DSLr will be at least 12bit and probably 16bit colour depth. I`d say for the overall area, the DSLR will win. The problem is that DSLRs are good at taking long expsure images (DSO imaging), and the webcams are good at taking a lot of short images very quickly (planetary/lunar/solar imaging), so each camera has its strong points and its weak points. You need to choose the right tool for the right job.

[jonbarr87]

I guess I mean more just the concept.... Like if you had a webcam that somehow had a sensor that was equivalent to the dslr... If you had the same exposure time/overall number of pixels in the image would it create similar results or are composite images always slightly less "resolved/sensitive"?