Cardboard viewfinder?

[fabulousrice]

I am shocked at the price of some folding viewfinders for my Bronica ETRS - up to $300?
Which makes me think that they're either made of gold, or of brittle plastic, or that some digital users have found a use for them and are buying them - that's almost more expensive than my camera body + lens + backs!

However, it's a simple enough object that it could be built at home with simple cardboard, and it would be easy to make it fold open (like these bankers boxes or pop-up books!).

Has anyone ever made a pattern to build one that they could share?

 

[Jay Schrotenboer]

Sadly I have no pattern for you, but I would imagine it would not be to hard to make. I do have the folding viewfinder for an ETRSi that I could give some measurements from if that would help. At those prices I should think about selling mine to fund a better head for my enlarger. As I do not have the winding leaver, just the speed grip, it does me no good anyway.

 

[Sirius Glass]

I am confused. Exactly how are you going to make a viewfinder with a prism and a light meter out of folded cardboard?

 

[MattKing]

I'm guessing the OP is speaking of the relatively rarely used waist level finder.
They tend to be expensive because they are rare. If you have ever tried to use a waist level finder in portrait orientation with a 645 camera, you would know why very few were sold.

 

[reddesert]

If you want a wind knob for the Bronica ETR, someone has put a design for 3D printing on thingiverse: https://www.thingiverse.com/thing:4392317

Making a rectangular, rigid WLF hood that sort of works isn't hard, making one that blocks all stray light and folds up and is still durable is a little harder.

We've been around the question of "where did all the waist level finders and wind knobs go" a few times, and some regulars believe that many of these cameras (especially Bronica and Mamiya 645) were originally sold with prisms and wind grips or motor drives, so there were fewer WLFs to begin with.

I bought a Mamiya 645 WLF for peanuts on ebay a few years ago and now they are ridiculously expensive, so I also think there is a fashion / demand element. Some prisms have coating damage, the WLF is light and is sort of an icon of medium format SLRs (whether it is practical or not), so demand may have gone up.

 

[Sirius Glass]

I'm guessing the OP is speaking of the relatively rarely used waist level finder.
They tend to be expensive because they are rare. If you have ever tried to use a waist level finder in portrait orientation with a 645 camera, you would know why very few were sold.

Yet another reason to no shoot 645. Shoot 6x6 or bust!

 

[Sirius Glass]

If you want a wind knob for the Bronica ETR, someone has put a design for 3D printing on thingiverse: https://www.thingiverse.com/thing:4392317

Making a rectangular, rigid WLF hood that sort of works isn't hard, making one that blocks all stray light and folds up and is still durable is a little harder.

We've been around the question of "where did all the waist level finders and wind knobs go" a few times, and some regulars believe that many of these cameras (especially Bronica and Mamiya 645) were originally sold with prisms and wind grips or motor drives, so there were fewer WLFs to begin with.

I bought a Mamiya 645 WLF for peanuts on ebay a few years ago and now they are ridiculously expensive, so I also think there is a fashion / demand element. Some prisms have coating damage, the WLF is light and is sort of an icon of medium format SLRs (whether it is practical or not), so demand may have gone up.

There must be good reasons that so many users got rid of the waist level finders

 

[Jay Schrotenboer]

Yet another reason to no shoot 645. Shoot 6x6 or bust!

I actually shoot both, quite often preferring 645 as I can frame for the print better (possibly a “me” thing). With 6x6 I sometimes have gone to far to print my subject to my liking. It is likely that ETRSi’s and their kin were mostly bought with prism finders so even if they came with a waist level finder it probably got “put somewhere safe” or just thrown in the junk drawer as the owner never intended to use it. It does work exceptionally well with the prism and speed grip so I am very happy with the camera.

 

[MattKing]

The last time I got a lot of use from the WLF with my Mamiya 645 Pro was when I used it at our (normally) annual collector car show that the streets get shut down for.
The body, a 55mm lens and a WLF is a wonderfully compact kit, and the "waist level view" of the world works well with collector cars.

 

[Sirius Glass]

I actually shoot both, quite often preferring 645 as I can frame for the print better (possibly a “me” thing). With 6x6 I sometimes have gone to far to print my subject to my liking. It is likely that ETRSi’s and their kin were mostly bought with prism finders so even if they came with a waist level finder it probably got “put somewhere safe” or just thrown in the junk drawer as the owner never intended to use it. It does work exceptionally well with the prism and speed grip so I am very happy with the camera.

My WLF for the Hasselblad never even made it to my home on the camera body. It has sat quietly for years hoping to be called back into service.

 

[Jay Schrotenboer]

My WLF for the Hasselblad never even made it to my home on the camera body. It has sat quietly for years hoping to be called back into service.

It is likely I was the first person to put my WLF on my camera as it reportedly came from a wedding photographer who had to quit because of health problems with his wife (this is what I was told). I doubt he felt the need for it, and unlike me was unlikely a twenty year old kid that was fascinated with the camera. But this is all a bit off topic so let me at least attempt to be useful to the OP with some pictures of my WLF. Maybe they will offer some inspiration

 

[Mick Fagan]

Using a WLF is not an exclusive medium format camera thing, for decades now I have always carried my WLF for my F3 bodies. Inspiration can happen at the strangest of times and places.

We were in Iceland on a near two month trip when I was otherwise engaged, when I noticed an opportunity to photograph something that is extremely rare in my own country. Not only was the subject rare to me, but as presented it made for a superb B&W picture; in my mind that is.

So once I made up my mind I cobbled together the appropriate parts, tripod, camera, 24mm lens, followed by the WLF. I than made myself comfy on the supplied seating and exposed a couple of frames. ½ a second at f/8 from memory using Neopan 400 film at 320 ASA.

 

[wiltw]

I'm guessing the OP is speaking of the relatively rarely used waist level finder.
They tend to be expensive because they are rare. If you have ever tried to use a waist level finder in portrait orientation with a 645 camera, you would know why very few were sold.

^. The finder was not included automatically with the body+back, per the 1990 Price List description of content. Extra cost item, the WLF was originally only $135, so it is the rarity of the item in today's market is what accounts for its price.
The body was originally $1300, and today you pay $300-500 for body, back, metering finder and lens! So the WLF price today is crazy, in comparison.

keep in mind that if you make one up of cardboard, or even if 3D-printed, you will lack the benefit of a flip-up magnifier to assist with focus precision

I just found one available for $160 + $40 shipping from Japan, BTW.
https://www.ebay.com/itm/265475919084?hash=item3dcf990cec:g:9NEAAOSwSplhzSHU

 

[Luckless]

even if 3D-printed, you will lack the benefit of a flip-up magnifier to assist with focus precision

Why would a 3d printed one have to lack a flip up magnifier? Or even one made from cardboard/stock? Find a suitable lens to build your popup hood around. Or get fancy and find two different strength ones to build around, and get more functionality out of a pop-up than most pop-ups have.


I don't have a Bronica ETRS to draft a precise pattern off of, but mocking a pattern up with heavy cardstock till you have parts moving the way you want, and then coating in resin is an easy path to building one to a reasonably useful level of durability.

 

[DMJ]

If you have access to a 3D printer you could adapt this: https://www.thingiverse.com/thing:4807731
I 3D printed one (https://www.thingiverse.com/thing:4924892) for my sq-a. The chimney can be made out of core board or 3d printed and glued to the locking part.

 

[wiltw]

Why would a 3d printed one have to lack a flip up magnifier? Or even one made from cardboard/stock? Find a suitable lens to build your popup hood around. Or get fancy and find two different strength ones to build around, and get more functionality out of a pop-up than most pop-ups have.


I don't have a Bronica ETRS to draft a precise pattern off of, but mocking a pattern up with heavy cardstock till you have parts moving the way you want, and then coating in resin is an easy path to building one to a reasonably useful level of durability.

3-D printed solution does not eliminate the possibility of a flip up magnifier. But YOU have to figure out the diopter value of the lens which matches the design elevation at which Bronica designed their magnifier to be.

 

[reddesert]

The lens isn't too complicated, for a medium format WLF the magnifying lens is typically about 70mm focal length (I've roughly measured a few) and is around 60mm above the ground glass. The lens is typically a positive meniscus, mounted convex side down, but a plano convex or convex lens would do. The exact numbers aren't critical, but IIRC the focal length is usually a little longer than the distance between the lens and ground glass, making the image easier for your eye to focus on.

Making a hood and magnifier that withstands repeated flipping up and down is probably the hard part. There are a couple of rudimentary designs on Thingiverse, just search waist level finder, for ex:
https://www.thingiverse.com/thing:2886488 (not sure this was ever completed)
https://www.thingiverse.com/thing:5137420 (pictures of an actual printed example)
https://www.thingiverse.com/thing:4587197 (rigid chimney hood, not folding)

 

[Don_ih]

I find it impossible to focus a Bronica ETR using the wlf. It's almost as bad as trying to focus an Exacta (or Exa) with one. If I had to make one, I think I'd just make a rigid box with a magnifier on the top. There's no need tor it to fold if you only need it for a rare occasion.

 

[wiltw]

The lens isn't too complicated, for a medium format WLF the magnifying lens is typically about 70mm focal length (I've roughly measured a few) and is around 60mm above the ground glass. The lens is typically a positive meniscus, mounted convex side down, but a plano convex or convex lens would do. The exact numbers aren't critical, but IIRC the focal length is usually a little longer than the distance between the lens and ground glass, making the image easier for your eye to focus on.

Making a hood and magnifier that withstands repeated flipping up and down is probably the hard part. There are a couple of rudimentary designs on Thingiverse, just search waist level finder, for ex:
https://www.thingiverse.com/thing:2886488 (not sure this was ever completed)
https://www.thingiverse.com/thing:5137420 (pictures of an actual printed example)
https://www.thingiverse.com/thing:4587197 (rigid chimney hood, not folding)

But keep in mind there are DIFFERENT VALUE diopter strenghts, one specific diopter is standard for the camera, others were availble to make the WLF suited to the eyesight of a user who is more near- or far-sighted than the person with 20/20 and young flexible lenses in the eyeballs!
'diopter value' = changes to FL of that lens...

1 dioptre = 1 m−1​

 

[grat]

When I was considering this project (I found one at an exorbitant, but acceptable, price), I noticed that replacement diopter lenses (and original strength) were available. So as long as you get a diopter lens for your model, and set it the right height, you should be OK.

I reached the point of deciding I could use the base linked above, and print a cover, along with the magnifier plate, but I'd cut the side panels out of some thin ABS sheeting, and model the whole thing closer to the Mamiya C series WLF (three panels), than the Bronica's folding design.

As I said, though, I found a WLF eventually, so I gave up on printing / constructing one.

 

[reddesert]

But keep in mind there are DIFFERENT VALUE diopter strenghts, one specific diopter is standard for the camera, others were availble to make the WLF suited to the eyesight of a user who is more near- or far-sighted than the person with 20/20 and young flexible lenses in the eyeballs!
'diopter value' = changes to FL of that lens...

1 dioptre = 1 m−1​

Generally, replacement diopters are necessary for prism finders and users who need corrective vision. I'm less familiar with diopters being added on to waist level finder magnifiers. I assume that someone who is planning on making their own WLF will also figure out how to adapt the magnifier to their vision.

Some tedious optical notes:
The apparent distance of the image in a prism finder is usually set up to be about 1 meter. If the user has difficulty focusing at this distance, they'll need to add diopters to the prism, whose value is given in inverse meters as you said (so a +3 diopter has focal length 0.33 meters).

Lenses in magnifying glasses and loupes are usually referenced to a standard distance of 0.25 m, about 10 inches. I guess the idea is that a young person with good eyes can focus at 10 inches (when I was young, I could focus closer, but I sure can't anymore). So a lens with 3.5x magnification has a focal length of 250mm /3.5 = 71mm. This is about what you would find in a medium format WLF, which typically have 3.5-4x magnifiers. In diopter terms this would be a +14 diopter, which is crazy strong, not a stock item. Because it's serving a different function - close-up magnification, not correcting moderate-distance vision. Adding an ordinary diopter (+/- 3 or whatever) to this "+14 diopter" magnifier lens wouldn't change its magnification by much.

 

[wiltw]

From the 1990 Bronica Price List, the WLF has 7 different strength lenses, 3 to either side of the '0' value. Similarly two other finders each have 7 lenses suited for mounting on those finders.

the standard eyepiece setting of '0' is actually a non-zero diopter, selected by Bronica to set the apparent viewing distance of the focusing screen and status numbers (in the metering finder) to about 30-36". (Different manufacturers choose different apparent distances, and I cannot tell you what Bronica chose.)

 

[eli griggs]

If your camera does no lift the focusing screen, black matboard will work just fine, and using a super black, which has the UV absorbing feature will give you a workable WL Finder, and you can cut it to a length from the ground glass screen that gives you an ideal hight above the camera, for your vision.

Make several and remember you can make a better fitting eye to finder profile by no getting stuck in thinking the top must be a set of 90° angles, so find what's comfortable to your face

If you do, do this, post pics.

Good Luck!

 

[eli griggs]

A nice set-up and wlf are very useful, if you are motivated to actually move through prone to overhead viewpoints.

I have a F that I would like a wlf for, especially if I get a second f body some time in the future, but my main 35mm shooting is done with Canon F1n and F1N_ae bodies and though I do no have a wlf for either card stock can serve.

I do have a F1n duel position "sports finder" and a slip over black box of super black matboard, held in place with gaffers tape, can substitute just as well.

Cheers,
Eli

Using a WLF is not an exclusive medium format camera thing, for decades now I have always carried my WLF for my F3 bodies. Inspiration can happen at the strangest of times and places.

We were in Iceland on a near two month trip when I was otherwise engaged, when I noticed an opportunity to photograph something that is extremely rare in my own country. Not only was the subject rare to me, but as presented it made for a superb B&W picture; in my mind that is.

So once I made up my mind I cobbled together the appropriate parts, tripod, camera, 24mm lens, followed by the WLF. I than made myself comfy on the supplied seating and exposed a couple of frames. ½ a second at f/8 from memory using Neopan 400 film at 320 ASA.

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