6x4.5 format to 35mm equivalent?

[stradibarrius]

I know in 6x7 the 35 mm equal is roughly 1/2 the focal length.
How is it calculated in 645?

 

[Sirius Glass]

A normal lens for 6x4.5 = sqrt(60^^2+45^^2) = 75mm

Steve

 

[Joachim_I]

Just take the ratio of the format diagonales: 70/43 = 1.63. Divide by this number to get the 35mm equilvalent of a 645 lens.

Steve: 645 is actually more like 56mm x 41.5mm. Therefore I used 70mm for the diagonal.

 

[Mike1234]

I believe 645 is 42x56mm and the diagonal is 70mm. 135 is 24x36mm with a 43mm diagonal. 70/43 is 1.63 so 1.63x is your multiplier to go from 135 to 645. The inverse of 1.63 is .613 so that's your mulitplier to go from 645 to 135.

 

[Christopher Walrath]

Wirelessly posted (BBBold: BlackBerry9000/4.6.0.297 Profile/MIDP-2.0 Configuration/CLDC-1.1 VendorID/102 UP.Link/6.3.0.0.0)

I had an 80mm Sekor C for my M645j that was close in FOV to my Rokkor 50mm MD on my XG-M. There ya go. Kinda like converting miles to km's when comparing 35mm to fsd. 1.6 or .62, depending on which way you go.

 

[Q.G.]

This page starts with 6x6's equivalents, but read on a bit and you'll find 6x4.5's equivalents.

 

[stradibarrius]

Thanks O.G. that is good info!