Who Likes a Prism on Their Medium Format Reflex Camera?

[SMD]

Never with TLR. They are tall and wobbly, the prism makes them even more top heavy.
On cube format SLR depends.

 

[SMD]

In France we have square biscuits I think called Nantais. Once framed etc I pop one on the WLF of my m645 to avoid stray light, then eat it after shutter release
It doesn't help the L- R issue but I feel less hungry.

Stray light from the WLF? Is this a particular problem with the m645 (plain m500 and m1000s)? Never heard that to be the case with any other camera. Would explain why the WLF for this camera is so expensive. Usually the prism is more expensive, not so for the Mamiya. Could it be it was a failure and therefore only few WLF were made?

 

[MattKing]

Very few WLF were made for the Mamiya 645 series because using a WLF on them makes taking photos with a portrait orientation very challenging - particularly if trying to use them handheld.
The cameras were aimed at the professional wedding and portrait market, and portrait orientation results were important for users.

 

[SMD]

using a WLF on them makes taking photos with a portrait orientation very challenging - particularly if trying to use them handheld.
The cameras were aimed at the professional wedding and portrait market, and portrait orientation results were important for users.

I read this explanation before but always had my doubts. My thinking is, for a camera specialised to that market it has too many characteristics that are exactly the opposite what that market needs.
- No interchangeable back? (They even made the M645J without roll insert and called it a student version.)
- Why not portrait orientation transport of film if that was the purpose? If Pentax managed, Mamiya could also do it. Instead they later offered an accesory that tilts the tripod mounted camera 90 degrees.
Even considering that they wanted to offer a lighter and cheaper alternative to the RB67 (or the also electronic RZ67), I consider it cuts too many corners for a wedding or pro studio camera.
Well... we will never know. I wish those WLF would be cheaper though.

 

[MattKing]

I was selling the Mamiya 645 cameras when they were current. The marketing emphasis was clear! And almost all the packages sold to the professionals that bought them from me and others were packaged with prism finders or the prism-like mirror based finders that were also available later.
And yes, they were buying them for wedding work!
The earlier models were relatively soon replaced by the Super, Pro and Pro-Tl, which did offer interchangeable backs.
I only did a bit of wedding work with my 645 Super (since replaced with a 645 Pro), but if used with any of the motor winder or left hand accessory grips, portrait orientation work is easy. And when working on a tripod, the rotary adapter works well - the smaller old one - or just use the head on the tripod.
Of all the pro photographers I knew who were doing wedding work back then, only one used an RB67 on location, and he was old! He had downsized from a Speed Graphic on locations, and an 8x10 view camera in the studio.
He ended up using a Koni-Omega for the handheld work, and the RB67 on the tripod.
These cameras and lenses were not found in camera stores that catered mostly to amateurs. They were targeted - very successfully - to the working professionals.
The greater number of negatives per roll were a real advantage when compared with Hasselblads. What was even more important was that the 6x4.5 aspect ratio increased efficiency greatly when it came time to prepare proofs or machine enlargements for customers - square prints were not widely liked by customers.
As far as why the film transport was oriented the way it was/is, I expect that resulted in simpler engineering when the winding lever/winder is to be on the side of the camera.

 

[SMD]

Thank you for the insight.
Was the film insert (instead of a real exchangeable back, I refer here only to the M500 and M1000) not a problem for pro work?

 

[MattKing]

Thank you for the insight.
Was the film insert (instead of a real exchangeable back, I refer here only to the M500 and M1000) not a problem for pro work?

They were both a positive and a negative.
They are/were very quick and easy to load. They are/were small and light and they rarely need service - at least not as frequently as the insert + back combination.
And relatively speaking, they are/were inexpensive.
It was relatively easy to load three or four ahead of time. And of course for wedding work many of them were 220 inserts, loaded with 30 frames at a time.
Their only real downside is that they don't permit mid-roll switching - something that one would rarely do in the midst of a wedding or portrait session. I think the only time I wanted to do a switch mid-roll was the few times I wanted to mix in some black and white.
I actually shot most of my weddings using a Mamiya C330 - not even an insert to speed loading!
But that meant I had to spend much more time in the film era's version of post processing - individually masking (with machine printer masks) each and every negative I wanted to have album prints or individual enlargements made for my customers. Without putting that time in, my profit margin was greatly reduced, because I would either have to take my chances on the lab guessing right on cropping, or pay much more money for custom enlargements.
And yes, I used the prism finder on the C330. When equipped with the left hand grip, it is very nicely balanced. Works great on the tripod too.
In case you missed my earlier post with a photo - see it here: https://www.photrio.com/forum/threa...ium-format-reflex-camera.208436/#post-2819569

 

[Alan Edward Klein]

I use the waist level, chimney, and prism on my RB67 almost equally, depending on what I'm photographing. The only TLR I own (with a focusing screen, obviously not counting the Duaflex family or the Brownie Bullseye etc.) never had a prism option: Kodak Reflex II.

Donald, what decides using a waist level or chimney?

 

[Alan Edward Klein]

I use a eye-level viewfinder on my Mamiya RB67. I find the reverse view in the waist-level finder difficult to use. It constantly aims the wrong way when adjusting the composition. However, I do keep it in my case for low shots. Also, my eye level finder has a separate magnifier attachment to nail focus. It articulates up and down to switch from normal to magnification view for easy use.

 

[Alan Edward Klein]

Sometimes I use a prism on my Mamiya C330.
View attachment 376097
But many times I prefer the waist level finder on it.
With my Mamiya 645 Pro, the prism finder is in use 95% of the time, because using the waist level finder on that camera means subjects that call for a portrait orientation are just too much of a pain to do.
With the RB67 I used to have, the waist level finder is wonderful - although the chimney finder has its uses.

What are they?

 

[MattKing]

The chimney finder is very light, well shielded against exterior light flare, has a built in variable diopter and if you have a metering version - preferably the PDN model with a silicon cell - it makes it easy to adjust exposure to take into account bellows extension exposure variation.
Unfortunately, it's light-weight bulk takes a lot of space in a camera bag - although certainly much less than a prism finder.
Unfortunately for Alan and others who are bothered by it, it presents with the same right-level reversal as the WLF.

 

[Alan Edward Klein]

The chimney finder is very light, well shielded against exterior light flare, has a built in variable diopter and if you have a metering version - preferably the PDN model with a silicon cell - it makes it easy to adjust exposure to take into account bellows extension exposure variation.
Unfortunately, it's light-weight bulk takes a lot of space in a camera bag - although certainly much less than a prism finder.
Unfortunately for Alan and others who are bothered by it, it presents with the same right-level reversal as the WLF.

My chimney finder doesn;t have a light meter and yes it takes up a lot of room in the bag. So I leave it at home. But my waist level folds up and takes little room. So I take that with me. But the eye level finder is attached to the RB67 camera all the time in the bag. Its magnifier attachment is in the bag as well ready when needed.

 

[Donald Qualls]

Donald, what decides using a waist level or chimney?

For me, it's where/how I'm working. If I'm carrying the camera on its strap I'm likely to use the WLF because I can steady the body on the strap like I'd do with a TLR. If I'm on a tripod, it'll likely be the chimney, because I can see the ground glass better with the small magnification and adjustable eyepiece focus.

 

[Dr. no]

Next

In France we have square biscuits I think called Nantais. Once framed etc I pop one on the WLF of my m645 to avoid stray light, then eat it after shutter release
It doesn't help the L- R issue but I feel less hungry.

Isn't Nantes the home of Lu? I miss those...

 

[Cheveuxroux]

On my RZ 67; sometimes.
Doesn't matter if on location or indoors.
On my Kiev 88s: never

 

[Arthurwg]

Always use one with my Hasselblads. Aside from focus and framing, I find that pressing the eyepiece to my brow helps to steady the camera when hand-holding,

 

[lecarp]

Photos of people that are taken from a lower point of view tend to accentuate the size of hips and stomachs, and tend to make heads and faces appear smaller.
Not a good formula for photographs of brides!
Not to mention photographs of mothers of the brides!

Like looking down into a crystal ball and seeing the future, Is that what your saying Matt?

 

[Taylor Nankervis]

Both my Pentax 67s have working-order TTL prisms on them. I never use them, preferring instead the unfailing accuracy of a Sekonic L758D multispot/incident meter, as all of my work is produced on E6 film stock where there is no room for the foibles or misfires of old TTL meters. And so, the big black things stuck on the top of these cameras are left there and occasionally get removed to clear away accumulated dust beneath the prisms. They come up quite nicely with a polish, too.

 

[Ben Hutcherson]

I use nothing but a prism on my Pentax 67, whether handheld or on a tripod. I have the metered prism, which makes for a really nice handling package handheld.

Hasselblads I have several 45º prisms(NC-2, old style metered, PM45) and find them useful on a tripod but at the end of the day prefer waist level finders. I often bring the WLF up to semi-eye-level to look through the loupe, and find I can actually see most of the screen that way too. I often will go ahead and shoot while still in that position.

As much as that one may sound akward, it's not that different from using a chimney finder(I need to dig my Hassy one out of storage), and it actually puts the camera at about the same position as a 45º prism but I find it somewhat more comfortable.

I actually quite like the result too of using what I'd call the "chin level" position. I'm a taller guy(6'2"), and this brings the camera eye level with a lot of under 6ft people. With the WLF, I can lower a bit more, more like to neck height, and it gives me still a slightly lower perspective than shooting at eye level. I will not go to full waist level for photos of adults as I don't find it a very flattering perspective-at most I'll go maybe chest level(although waist level is handy for kids, and as a parent of a 2 year old, it works great provided I can actually manage to track focus properly...).

I've not owned a 645 camera for several years-I sold my Pentax 645 and Bronica ETRS both off in ~2019. With the Pentax I didn't have a choice on whether or not to use a prism(or IIRC it was actually a mirror, but for purposes of this disucssion there's not really a difference other than it being lighter). I think I only used the WLF on my ETRS once or twice, and used the 90º prism the rest of the time. Verticals are way too awkward for me with a WLF-a lot of the reason too why i prefer the prism on my Pentax 67.

While we're at it, I actually had a metered prism(I think 90º? don't hold me to it) for my RB67. That was a chunk of glass-I think almost as heavy as the body from what I remember. I rarely used that, especially considering that the solution to rectangular format verticals is kind of a big part of the RB67 design.

 

[Donald Qualls]

While we're at it, I actually had a metered prism(I think 90º? don't hold me to it) for my RB67. That was a chunk of glass-I think almost as heavy as the body from what I remember. I rarely used that, especially considering that the solution to rectangular format verticals is kind of a big part of the RB67 design.

There have been two different versions of the RB67 prism -- one was an actual solid glass prism; the other was a "hollow prism" using first surface mirrors where the internally reflective prism surfaces would be. The latter was MUCH lighter, of course. The one I have is the solid glass one; they're significantly less expensive these days.

 

[reddesert]

Stray light from the WLF? Is this a particular problem with the m645 (plain m500 and m1000s)? Never heard that to be the case with any other camera. Would explain why the WLF for this camera is so expensive. Usually the prism is more expensive, not so for the Mamiya. Could it be it was a failure and therefore only few WLF were made?

(Replying to an old post) I don't really think worrying about stray light from the WLF is important in the Mamiya M645 or most other cameras of that ilk. Unless the sun is shining straight down into the WLF and the seals around the mirror are degraded.

The Mamiya M645 was definitely aimed at the professional market as Matt said, and the prism offered speed of operation. They made a lot of the original models with fixed backs, which is why there are still so many around. The WLF was, I imagine, just not in very much demand. It was cheaper than the prisms when the systems were new. Before the film revival of the last several years, you could still get a WLF for a medium format SLR for not much - I bought a WLF for the M645 probably at least 8 years ago for around $20 on ebay (Sorry, not a boast, just a marker of changing tastes). WLFs have become more in-fashion for whatever reason, plus some of the older M645 prisms suffer from reflective coating damage due to the interior foam, which might drive up the prices of intact prisms and WLFs.

 

[loccdor]

True that. I'd be using a WLF on my Mamiya 645 if it didn't cost more than the camera itself. The prism on the other hand was 30 bucks.

What I like about WLFs is you can tension the camera by the neck strap while taking your shot, leading to less shake, and they also make the cameras more portable. They are bothersome if your subject is moving, though.

 

[Ben Hutcherson]

There have been two different versions of the RB67 prism -- one was an actual solid glass prism; the other was a "hollow prism" using first surface mirrors where the internally reflective prism surfaces would be. The latter was MUCH lighter, of course. The one I have is the solid glass one; they're significantly less expensive these days.

I'm pretty sure mine was the glass version, as it weighed a ton.

I've always called mirror prisms "Porroprisms", or at least that's the term I've seen used for them. As a general rule, they are less expensive to make and also much lighter, although they tend to not be as bright or as clear as a proper solid glass prism. For a long time(maybe still) makers were using them on their low end AF 35mm SLRs and DSLRs(think like Canon Rebel series, Nikon N55 and D40, etc) for both of those reasons. They're not actually bad on those cameras especially since AF cameras tend to favor very bright screens(terrible for AF, but great if you're trusting the camera to focus correctly for you and especially if you're using a slow zoom). On MF, they can be a worthwhile compromise since especially in the larger formats proper prisms do get chunky.

I'll mention too, though, I THINK the Hassy PM45 is glass and not a mirror, but it also feels a lot lighter to me than the NC2.

 

[Donald Qualls]

I've always called mirror prisms "Porroprisms"

A Porro prism is a more compact prism for a binocular, compared to the classic "roof prism". If you have a binocular with the objectives wider than the oculars, it's a roof prism; if they're in line, it's either a prism-less "field glass" or a Porro prism. The prisms used in SLRs are "pentaprisms" due to the pentagonal shape that gives the five reflections (one folded) that do the work of making the reversed ground glass image look upright and right-reading in the eyepiece.

Mirror prisms will be less bright, but it's usually not enough to matter. The aluminized or dichroic mirror surface reflects 98% or so (to the power of five reflections) =about 90% , while total internal reflection (that makes a prism work without silvering) is 100% minus the glass absorption and entry/exit loss of a couple percent -- typically around 96% at the eyepiece, assuming both surfaces are coated. They also have the disadvantage that the mirrors can become misaligned with rough handling, leading to a split or decentered eyepiece image.

Honestly, on a camera as heavy as the RB67, I'm not sure another pound or so for the glass prism vs. a mirror prism makes a lot of difference. It's not a backpacker's camera anyway...

 

[reddesert]

Technically, a Porro prism like you find in a

A Porro prism is a more compact prism for a binocular, compared to the classic "roof prism". If you have a binocular with the objectives wider than the oculars, it's a roof prism; if they're in line, it's either a prism-less "field glass" or a Porro prism. The prisms used in SLRs are "pentaprisms" due to the pentagonal shape that gives the five reflections (one folded) that do the work of making the reversed ground glass image look upright and right-reading in the eyepiece.

I don't know if I agree with this rule of thumb about offset binoculars, I think a lot of binoculars with offset objectives use two Porro prisms per side. See https://en.wikipedia.org/wiki/Porro_prism

Technically, a prism is a solid chunk of glass. A camera finder that uses mirrors instead can be a Porro finder (Mamiya TLR) or a penta-mirror (inexpensive SLRs like the Rebel or N55 mentioned earlier). But neither is a prism, and calling them Porro prisms or mirror prisms will lead to confusion.

Mirror finders are generally thought to be less bright, the Porro finder for the Mamiya TLR is known for this. In theory it shouldn't be enough to really notice, but perhaps in practice, imperfect coatings or years of degradation and dust on the coatings makes it enough to notice. For a very large finder like the RB67 the weight tradeoff may be worth it.