Out of curiosity... Lens equivalent.

[peter k.]

I have a 350mm lens on a 4x5 Speed Graphic.. and was out shooting today, and also had a 35mm Canon AE-1, with a 400mm lens on it, and comparing them.
Out of curiosity, searching the net, I came up that it would be about 120mm, in 35mm.
No big deal, but wondered, give or take, if this is this about right?

 

[wiltw]

I follow the Sinar suggestion to use the vertical frame dimension for 'equivalent FL' calculations, as that neutralizes completely diagonal differences inherent to different aspect ratio frame sizes.

350mm / 95mm = 3.72x
So 24mm * 3.72x = 88mm

 

[jcc]

Toyo gives equivalent focal lengths in their website. http://www.toyoview.com/LensSelection/lensselect.html