does megapixel count when imaging DSO

[Daniel-K]

just a thought how does a 6mp dslr compare to a 18mp dslr when what we image is so small anyway?

[Freddie]

Assuming everything else is the same, you will get more of the FOV on the chip.

[gkec]

Assuming everything else is the same, you will get more of the FOV on the chip.

That assumes that the 18mp chip is physically larger. Larger number of pixels mean smaller pixels which reduces the dynamic range of the pixels. This can limit the exposure time especially in low signal to noise situations. However if this is not a problem you would get more resolution with a higher pixels count depending on the telescope limits.

[Gina]

You'll need much longer exposures with the 18mpx due to the smaller pixels. The sensor size is likely to be much the same unless the 18mpx is a full-frame camera.

[ollypenrice]

Who says what we image is small? Many of us need to do mosaics to cover vast swathes of sky. Nine panels...

http://ollypenrice.smugmug.com/Other/Best-of-Les-Granges/i-SgJHrdL/0/L/HEARTLEY%20HEART%20FINAL-L.jpg

Even the Andromeda galaxy in a very short FL scope needed two panels;

Millions of pixels may (or may not) be wonderful for daytime photography but in AP having the right sized pixels for your focal length is more important. Lots of small noisy insensitive pixels that try to resolve detail below what the atmosphere will allow is a total waste of time.

Olly

http://ollypenrice.smugmug.com/Other/Best-of-Les-Granges/22435624_WLMPTM#!i=1793668870&k=R4v6bFN

[Chris]

The 1100D is a good compromise at 12mp, I really like the old 350D's (as you know Dan ) at 8mp pixels the pixels are large enough for good dynamic range and short exposure times, but not so many pixels that it eats computer memory:) they are very light cameras as well, the second lightest Canon after the 1000D. Shame theres a wuestion mark over the software for Win 7:(?

[Freddie]

That assumes that the 18mp chip is physically larger. Larger number of pixels mean smaller pixels which reduces the dynamic range of the pixels. This can limit the exposure time especially in low signal to noise situations. However if this is not a problem you would get more resolution with a higher pixels count depending on the telescope limits.

It would have to be larger is everything else was the same !!

[Chris]

Also wouldn't resolution be limited by seeing conditions as much as anything else?

[Daniel-K]

im going for the 1100D going out to get one tomorrow

[gkec]

It would have to be larger is everything else was the same !!

But they are not. The sensor size is usually the same regardless of pixel count. It is a pity it isn't true as larger sensors would have larger field of view. I worked on one of the first megapixel sensors and it was about an inch square. It was great for imaging. Cost about a million pounds though.

And yes resolution is usually governed by seeing unfortunately.