Well, Jed and I just hit upon something. The truth to all the loupes (ok, let's just say "most" to be safe ;p )

We probably hear/read that a 4x loupe on a 35mm slide gives magnification equivalent to a 4R print. Likewise, a 8x loupe gives the equivalent of an 8RC.

The reason behind that is simple. A slide is roughly 1 x 1.5", so 4x on both side gives 4x6", and 8x on both sides gives 8x12". Logical right?

No! Loupe magnification is usually based on magnification of

**area**, not a single dimension (i.e. not linear magnification). A 4x loupe on a 35mm (36x24mm) slide therefore gives an image size of only 72mm x 48mm, which is 4 times the area of a 35mm slide. Similarly, a 8x loupe will give 144 x 96mm.

Do this experiment. Put 4 slides in 2 by 2 layout. Does it equal the size of a 4R print? No right?

If you looked through a 4x or 8x loupe, you would have found that it isn't quite the same size as a 4R or 8R print. For the same reason, the image through an 8x loupe does not look twice the size as a 4x. It's only 1.4x more.

So here it is, the myth debunked. Feel free to post if you don't agree. :rbounce:

Regards

CK