Astro image colours

[smiddit]

I haven't purchased my scope yet but I know when you look through the EP you don't see any colours in nebula, galaxies etc as the distances are just too great, but my question is if you were to travel to these galaxies, nebula etc would it actually look like it does in these amazing astro images you see on this site?

You'll have to excuse the beginners question as I'm new here.

Thanks in advance, Brian.

[Merlin66]

No not really...I think it would be a wasted journey of many light years:(

The usual images you see are taken with a collection of narrowband filters in different wavelengths - Hydrogen Alpha (Ha), Oxygen (OIII) etc and our eyes are not really sensitive to these regions of the spectrum.

Grey on grey is what I'd think you'd see...maybe a slight touch of green in the brighter emission nebulae.

[jgs001]

Brian, it's not the distances, as such, it's related to how the eye works.

The eye changes a lot when you become dark adapted. The cones, colour sensitive parts of the eye, shutdown, and the rods, monochrome but far more sensitive activate. This is why you won't see the colours that the images capture. There's also some chemical changes, but that's getting too deep into the biology of it all, and beyond my meagre knowledge.

I think you see some green on the brighter Neb (as Ken said) because the eye is more sensitive to green light, the reason why cameras use two green sensors in each pixel with one red and one blue alongside.

I think, if you have a large enough telescope to gather sufficient light from the objects to activate the cones, you'd see the colours, but... given that in a lot of cases, we're having to capture a long exposure to actually capture the nebula/galaxy colours in the first place, I think it would have to be a really really big aperture scope.

[smiddit]

Show's how much I know!!

Thank's for the info and the clarity. It's a pity it doesn't actually look like the photos, kind of nice to imagine it's that beautiful up there.

Thanks, Brian.