Want to Buy Viewfinder suitable for a 38mm lens on 6x6 (medium format)

Hello, fellows!

I need a viewfinder — one of those that go on the flash/accessory shoe of the camera — that is suitable for a 38mm lens on a 6x6 camera. I've heard it's the same angle of view as a 21mm on 35mm (around 91 degrees diagonal), but maybe I need one that's just a bit wider (20mm?) and mask it for the square format.

Cheers,
Flavio

Is it a 38mm Biogon on a swc ? Horizontally that lens is closer to a 24mm

fdonadio said:

Hello, fellows!

I need a viewfinder — one of those that go on the flash/accessory shoe of the camera — that is suitable for a 38mm lens on a 6x6 camera. I've heard it's the same angle of view as a 21mm on 35mm (around 91 degrees diagonal), but maybe I need one that's just a bit wider (20mm?) and mask it for the square format.

Cheers,
Flavio

Click to expand...

The discussion of 'equivalant AOV' between formats is typically flawed by the fact that formats vary in terms of their aspect ratios, so the diagonal measure varies as a multiplier * the short dimension of the frame

If we use the SHORT dimension (SD) of the frame, 24mm for 135 and 56mm for 6x6,

• the 38mm lens is 0.67 * SD(6x6),
• and 16mm lens = 0.67 of SD(135)

Same VERTICAL AOV for both formats = same vertical view captured within the frame from same camera position.

fatso said:

Is it a 38mm Biogon on a swc ?

Click to expand...

It’s an Ilex Super Paragon 38mm f/4.5, a “clone” of the Biogon. I am making myself what I call a “poor-man’s SWC” with a custom made body that will use Hasselblad standard backs.

wiltw said:

The discussion of 'equivalant AOV' between formats is typically flawed

Click to expand...

Yes, that’s why I talked about getting a wider finder and mask it. I guess knowing the actual angle of view of the finder is the best bet. So, I need 91 degrees of view (diagonal).

fdonadio said:

Yes, that’s why I talked about getting a wider finder and mask it. I guess knowing the actual angle of view of the finder is the best bet. So, I need 91 degrees of view (diagonal).

Click to expand...

And I previously wrote that 38mm on 6x6 is like using 16mm on 135 format, in terms of vertical AOV captured in the frame. You would have to mask down the 38mm AOV finder if you wanted it to show you a narrower AOV captured on 135, such as masking down the viewfinder to see the narrow (comparatively) AOV seen by 24mm or 28mm lens on 135.