Lens focal length and magnification

[timmyquest]

Does the focal length have anything to do with the amount of magnification?

Will all 300mm lenses show the same image on the same camera?

[Belmondo]

Yes.

Yes.*

*Actually, no. It will be the same on all cameras of the same format, however a 300mm lens on a medium format camera will not give the same magnification as on a 35mm camera. The 10D/Drebel uses 35mm lenses, so the magnification is the same, but the sensor is smaller than a 35mm frame, so it creates an effective magnification.

[timmyquest]

belmondo wrote:
Yes.

Yes.*

*Actually, no. It will be the same on all cameras of the same format, however a 300mm lens on a medium format camera will not give the same magnification as on a 35mm camera. The 10D/Drebel uses 35mm lenses, so the magnification is the same, but the sensor is smaller than a 35mm frame, so it creates an effective magnification.

Yeah i knew that about the digital vs the 35mm ( i think that issue is non existant on the 1D?)

Thats really all i wanted to know, i was pretty sure it was true, thanks.