Magnification from a DSLR

[samir_ansari]

Hi Everyone,

I was just wondering what the canon 450D magnification (in terms of an eyepiece mm equivelant) was?

Also does anybody know what is it for a toucam 740K?

Thanks!

Samir

[dmahon]

Have a play with:

http://www.12dstring.me.uk/fov.htm

and

http://www.12dstring.me.uk/foveyepiece.php

and you should be able to get a good idea.

[Mick UK]

Both will give you around the equivalent of a 6mm eye piece.

[samir_ansari]

marvellous, thanks Mick and dmahon!

I thought the 450D would have less magnification for some reason, maybe its just that the image size is bigger that the target would naturally appear smaller.

[SteveL]

For imaging, there is no real right answer for magnification in a system, only a field of view or resolution per pixel.

When you look through an eyepiece, its easy to determine how large (in area and size) a specific object will be because everyones eyes are the same. M31 will always be the same angular size in everyones eyes for a specific setup.

For imaging, that doesnt really hold true. Your webcam or DSLR will capture a specific field of view. When you display that image, any "magnification" value is irrelevant. If you display it on a screen, how big is the screen itself? Or if you print it out on paper, then is that A4 or A3?

The image you have taken has the same field of view on screen or on paper, but you cannot really attach any magnification value to an image, as it only works for visual observing.

[Cornelius Varley]

Both will give you around the equivalent of a 6mm eye piece.

The sensor in a DSLR is alot bigger than a webcam's so the FOV is greater and therefore the apparent magnification is less.

Peter