How to make LF composing card with proper focal length?

[Pieter12]

At only $3.5K this is a gadget every film photographer should have in their pocket.

I'm not sure where you get that price from. Maybe a whole camera? The viewfinder is listed at 1820 euros, expensive as all new Linhof equipment is. But they come up on auction sites and used equipment dealers quite often. If you don't buy the newest one (and it is certainly not necessary), they can be more reasonably priced--in the $150-300 range.

 

[BrianShaw]

LOL.
Good luck with that!

How about 4x5 cm cut out of a 3x5 inch index card?

 

[Kino]

If you need help in determining the equivalences for your format and range of lenses, just ask here. One of us can give you the answers you seek, whether you choose to make a viewing card, multiple cards, or use an SLR. We’d need to know the format and the focal length of lenses you plan to use.

Ian,
Thanks for you're comprehensive response!
At the moment, I have the 207mm f7.7 Kodak lens for my 5x7. 4x5 and Whole Plate are yet to be determined.

 

[Kino]

I had the same desire to make a viewing card last year, and made a little Excel file to calculate the size and viewing distance for different lenses.

I've modified that file and made it available here in the attachment. You enter the lens focal length and the film format dimensions. With that information, you can either create a new card based on a desired card viewing distance, or find the appropriate viewing distance for a card you already have.

Very generous! Thank you and I will give this a try.

 

[Kino]

Thanks to everyone who chimed-in!

I didn't think it would generate this much interest!

 

[Alan Edward Klein]

An app similar to this is precisely how I had to determine the long frame dimension 24mm AOV on 135 format equivalence 4x5 format FL AOV

As an aside, I have long suspected the frame dimensions for 4x5 used by the app I used were suspect...and comparing my recent calculation (67mm) vs. your app calculations (79mm) reinforces my suspicions...I had long thought of 24mm on 135 is rather equivalent to 75mm on 4x5.
After using your linked app, I was able to determine that if you take the 135 format lens FL, and simply multiply it by the factor of 3.33x, one can directly compute the 4x5 lens FL that gives 'the same' long dimension of the frame AOV on 4x5 as contained within the 135 format long dimension of its frame!

• 24mm on 135 (74 degrees) is like 79mm on 4x5 long dimension
• 35mm on 135 (54 degrees) is like 117mm on 4x5 long dimension
• 50mm on 135 (40 degrees) is like 166mm on 4x5 long dimension

That's what I use. 3.3 or 1/3.3 for the long side which is the usual horizontal field of view for landscape pictures between 135 and 4x5. I ignore the diagonal because I don;t use that when composing a scene. For horizontal landscapes, the width is the view most people use. Many advisors give the diagonal factor between lenses, but who looks that way? You check the left and the right sides. The height pretty much falls where it falls. Of course, if you're doing a vertical shot, then another factor should be used.

 

[Alan Edward Klein]

I've used actual-size cutouts (4x5") in mat board, the Zone VI viewing filter and a hole cut out of a 3x5 index card. My index card was folded in half and kept in a shirt pocket. Pull it out, unfold, view: EZPZ.

All the above work just about equally well for framing purposes. Personally, I like my Zone VI viewing filter. The Wratten #90 filter it has helps (a little) with judging tonal convergences since it removes much of the color from the scene.

OP,

I'd go for a smaller than 4x5" hole in a piece of mat board. All you need is the right aspect ratio and the ability to move the opening closer and farther from your eye. A small viewing frame on a lanyard that you can keep in a shirt pocket is quite handy. Figure out what distance corresponds to which focal length by simply comparing to the ground-glass image for your lenses and tie a knot or make a mark on the lanyard.

I rarely have to change lenses from the one I choose this way; maybe once or twice in 10 set-ups, and then only to the next longer or shorter lens I'm carrying.

Best,

Doremus

Here' my Zone VI viewing filter and instructions. I think it's for my 6x7 medium format but I haven't used it in years.

 

[Pieter12]

Dunno if something like this might be of interest:

Golden Section Finder

Parsons & Charlesworth is a design studio founded in 2014 by Chicago-based British husband and wife team Tim Parsons and Jessica Charlesworth. After running independent practices they joined forces to pursue projects that explore the practical, rhetorical, poetic and speculative possibilities of...

parsonscharlesworth.com

 

[Ian C]

Per post #28

5” x 7” film holders mask the film to about 119 mm x 170 mm.

For a 207 mm lens, the angle of angle across the minor dimension and the equivalent 35 mm format lens that sees the same angle across its minor dimension are 32.1º, 41.7 mm.

Across the major dimension they are 44.6º, 43.8 mm

A viewing card for that lens and format requires an opening whose dimensions are in the ratio of 170/119. The viewing distance is

d = w/(2*tan(θ/2))

where w = the opening dimension (major or minor) and θ is the angle associated with that dimension.

If we use the major dimension of the format and its associated angle of view, then

d = 170 mm/(2*tan(44.6º/2)) = 207 mm viewing distance. [Thank you Sharktooth. You caught and reported my error in post #35. I've corrected it. Of course, the calculation for the viewing distance is unnecessary, in this case, since it' simply the same as the focal length of the lens.]

These give a viewing card of opening 170 mm x 119 mm with a viewing distance of 207 mm.

 

[Sharktooth]

Per post #28

5” x 7” film holders mask the film to about 119 mm x 170 mm.

For a 207 mm lens, the angle of angle across the minor dimension and the equivalent 35 mm format lens that sees the same angle across its minor dimension are 32.1º, 41.7 mm.

Across the major dimension they are 44.6º, 43.8 mm

A viewing card for that lens and format requires an opening whose dimensions are in the ratio of 170/119. The viewing distance is

d = w/(2*tan(θ/2))
44.6
where w = the opening dimension (major or minor) and θ is the angle associated with that dimension.

If we use the major dimension of the format and its associated angle of view, then

d = 170 mm/(2*tan(43.8º/2)) = 211.3 mm viewing distance.

These give a viewing card of opening 170 mm x 119 mm with a viewing distance of 211.3 mm.

Your formulas are correct, but you input the wrong value for θ. It should have been 44.6º, not 43.8. The 44.6º angle was your own correct calculation, but I have no idea what the 43.8 mm value represents. When the correct 44.6º angle is input in the formula, the viewing distance is 207mm.

This example actually demonstrates that you don't have to do any calculations if your card opening size is the same as the film image size. When that's the case, the card viewing distance is always the focal length of the lens.

If you're uncomfortable with the math, then just make your card opening size the same size as your film size. For any lens you mount, the card viewing distance will be the focal length of that lens.

 

[xkaes]

That's one of the reasons I made mine a 4x5" hole in an 8x10" gray card. My bellows only opens 360mm, but my arm reaches out to about 600mm -- which fortunately is my longest lens.

 

[grain elevator]

Gentlemen, you don't new the tan

Per post #28

5” x 7” film holders mask the film to about 119 mm x 170 mm.

For a 207 mm lens, the angle of angle across the minor dimension and the equivalent 35 mm format lens that sees the same angle across its minor dimension are 32.1º, 41.7 mm.

Across the major dimension they are 44.6º, 43.8 mm

A viewing card for that lens and format requires an opening whose dimensions are in the ratio of 170/119. The viewing distance is

d = w/(2*tan(θ/2))

where w = the opening dimension (major or minor) and θ is the angle associated with that dimension.

If we use the major dimension of the format and its associated angle of view, then

d = 170 mm/(2*tan(43.8º/2)) = 211.3 mm viewing distance.

These give a viewing card of opening 170 mm x 119 mm with a viewing distance of 211.3 mm.

Let me summarise this: you take the image dimensions and the fl to calculate the aov to calculate the fl?

 

[Ian C]

Thank you Sharktooth. You caught and reported my error in post #35. I've corrected it in post #34. Of course, the calculation for the viewing distance is unnecessary, in this case, since it's simply the same as the focal length of the lens.

 

[David Lindquist]

I'm not sure where you get that price from. Maybe a whole camera? The viewfinder is listed at 1820 euros, expensive as all new Linhof equipment is. But they come up on auction sites and used equipment dealers quite often. If you don't buy the newest one (and it is certainly not necessary), they can be more reasonably priced--in the $150-300 range.

Typical price for US reseller, e.g. B&H wants $3575 with 2-4 week delivery. Compare with Linhof & Studio at £1650 and they have it in stock.
You don't want to know what B&H wants for a new Master Technika Classic

I really like Linhof & Studio...

David

 

[KinoGrafx]

I use a little graflex finder that you would find on top of a speed or crown graphic. Fits in a pocket, you can get masks for most common focal lengths, and it’s easy to use and pretty accurate.