Re: Image Luminosity vs magnification

From: Martin Brown (|||newspam|||_at_nezumi.demon.co.uk)
Date: 08/27/04 

Date: Fri, 27 Aug 2004 14:31:27 +0100

In message <1093598175.922815@athnrd02>, Ioannis <morpheus@olympus.mons>
writes
>How does brightness/luminosity vary with magnification?
>
>Does it drop linearly as mag increases? For example, assuming same
>aperture two images at magnifications 10x and 20x will have a ratio of
>1/2 in brightness?
>
>All assuming visual observations, of course.

You get the same answer for photography too. The image gets dimmer with
the square of the magnification factor.

So at 2x magnification the image is twice the linear size and therefore
4x the area - with the same amount of light is spread over that region.

Regards, 

-- 
Martin Brown

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