Wanderlust 4x5 P&S

[Simon Liddiard]

Please can someone help me with my newb viewfinder struggles?

I would have thought that one should use a 90mm viewfinder for a 90mm lens, however I see a 21mm viewfinder is recommended for the Travelwide 45 because "21mm on 35mm corresponds to the vertical FOV of 90mm on 4x5".

I know angle of view can be expressed in vertical, horizontal and diagonal planes, but why pick vertical and not horizontal?

[Ben Syverson]

Hi everyone! Welcome, Zuiko!

Chauncey, the distance is indeed set at infinity, and we'll ship the camera with shims so that you can fine tune the focus .

We've contacted a few retailers but will contact a few more—good idea! Unfortunately there's not much they can do for us at this point except tweet or share the link, but every little bit helps!

[Ben Syverson]

Please can someone help me with my newb viewfinder struggles?

I would have thought that one should use a 90mm viewfinder for a 90mm lens, however I see a 21mm viewfinder is recommended for the Travelwide 45 because "21mm on 35mm corresponds to the vertical FOV of 90mm on 4x5".

I know angle of view can be expressed in vertical, horizontal and diagonal planes, but why pick vertical and not horizontal?

Hi Simon,

I made that decision because I'm more often trying to figure out if vertical elements are in or out of the frame, versus horizontal elements. For example, I wanted the brightline to help me see if I could fit the top of a building or the top of someone's head. But it's more or less arbitrary which axis you choose.

Hope this helps!

[Simon Liddiard]

Thank you Ben. So I could choose a 90mm viewfinder, but unless it was designed for 4x5 the aspect ratio would be different, e.g. 1.5:1 for 35mm and 1.25:1 for 4x5.

Presumably this could be resolved by masking or am I barking up the wrong tree here?

[Corran]

It's not the aspect ratio you need to worry about but the FoV. A VF for a 90mm on 35mm film is a short tele, not a wide-angle, and would have the FoV of a 300-360mm lens on 4x5.

[Corran]

Perhaps a photo will be worth all the explanations one could write. I just whipped this up using a photo I was working on (that was shot with a 90mm) showing basically what a 21mm vs. a 25mm viewfinder will be (approximately) compared to the image. Of course I haven't taken into account parallax and such.

This arises from the differences in aspect ratio of the 35mm format:

[drew.saunders]

Please can someone help me with my newb viewfinder struggles?

I would have thought that one should use a 90mm viewfinder for a 90mm lens, however I see a 21mm viewfinder is recommended for the Travelwide 45 because "21mm on 35mm corresponds to the vertical FOV of 90mm on 4x5".

I know angle of view can be expressed in vertical, horizontal and diagonal planes, but why pick vertical and not horizontal?

A 90mm lens for 96x120mm film (4x5 in most holders, some vary by a wee bit) has the following angles of view in degrees: horizontal: 67, vertical: 56, diagonal: 81
A 21mm lens for 24x36mm film has the following angles of view in degrees: horizontal: 81, vertical: 59, diagonal: 91
A 28mm lens for 24x36 gets you, in degrees: h: 65, v: 46, d: 75

That's part of the problem comparing 4:5 ratio film to 2:3 ratio film, you have to pick whether vertical, horizontal or diagonal is the best to compare. If you could get a 4:5 mask for your 21mm viewfinder, that would probably be the best.

[Ben Syverson]

Thank you Ben. So I could choose a 90mm viewfinder, but unless it was designed for 4x5 the aspect ratio would be different, e.g. 1.5:1 for 35mm and 1.25:1 for 4x5.

Presumably this could be resolved by masking or am I barking up the wrong tree here?

Hmm, the nice thing about a brightline finder is that you can see beyond the lines, so personally I wouldn't mask it. Ultimately with a point and shoot camera, the viewfinder is just giving you a general idea (ie, the framelines are not outrageously accurate). That lack of accuracy actually helps me relax and just shoot!

[Simon Liddiard]

Ah right, of course! Angle of view / field of view as specified by the manufacturer https://www.schneideroptics.com/info.../6,8-90mm.html

So if the angle of view of the Angulon 90/6.8 is 81 degrees circular which is then constrained by the dimensions of 4x5 (horiz, vert or diag)

[Tin Can]

What he said!

Ah right, of course! Angle of view / field of view as specified by the manufacturer https://www.schneideroptics.com/info.../6,8-90mm.html

So if the angle of view of the Angulon 90/6.8 is 81 degrees circular which is then constrained by the dimensions of 4x5 (horiz, vert or diag)