Bronica GS1 prism finder questions

Paul Manuell · May 11, 2019

I'm seriously considering buying one of these cameras but have a couple of questions about the prism finders. I've already gone the Google search route but not found the answers I'm looking for. Ok, first off, does the standard AE prism finder have all the usual multi exposure modes, ie., spot, central and multi/evaluative? I only ask because I've read conflicting answers; some saying all, some saying spot only, others saying multi/evaluative.

Second question concerns the rotary prism finder. I've read that this is necessary if you use the camera in vertical or portrait mode (which I do a lot of), but why? Why can't you just use the standard AE prism in that mode? As you look 'through' the camera with a viewfinder attached, rather than down into it with the standard viewing screen, why does tilting the camera 90 degrees stop you being able to do so? Also with the rotary finder, my question in paragraph 1 above applies too.

Thanks for any help

abruzzi · May 11, 2019

From the looks of it the AE prism has only a single metering pattern. Check out page 20 which has a diagram of the metering pattern:

http://www.cameramanuals.org/bronica/bronica_gs-1_ae_prism_g.pdf

I don’t know if there were over versions of the AE finder. I don’t have a GS-1, but the ETRSi. That model had three different AE prisms, and at least the last one had a spot mode, but I don’t see that in he manual for the GS-1 prism.

I don’t know why you wouldn’t use the AE prism in portrait mode, it should work fine. What it challenging is trying the use the waist level finder in portrait mode. The WLF shows the image reversed left to right, which makes portrait very hard, but any of the prism finders will show the image upright and correct left to right, so should work fine—like any 35mm SLR—in portrait.

Paul Manuell · May 11, 2019

abruzzi said:
From the looks of it the AE prism has only a single metering pattern. Check out page 20 which has a diagram of the metering pattern:

http://www.cameramanuals.org/bronica/bronica_gs-1_ae_prism_g.pdf

I don’t know if there were over versions of the AE finder. I don’t have a GS-1, but the ETRSi. That model had three different AE prisms, and at least the last one had a spot mode, but I don’t see that in he manual for the GS-1 prism.

I don’t know why you wouldn’t use the AE prism in portrait mode, it should work fine. What it challenging is trying the use the waist level finder in portrait mode. The WLF shows the image reversed left to right, which makes portrait very hard, but any of the prism finders will show the image upright and correct left to right, so should work fine—like any 35mm SLR—in portrait.

Thanks for your reply. If only spot metering mode, I may give this camera system a miss. Spot metering's fine for something like portraits, but not so good for landscapes. And you seem to agree, that using the non rotary prism finder with the camera in vertical mode should be fine.

abruzzi · May 11, 2019

I think its more of a center weighted averaging meter. I have the AEIII for my ETRSi, and I prefer to just use a handheld light meter, though in body can be awful convenient at times. I've considered adding a GS1 to my collection, but for now I like the small size of the ETRSi.

Your other 6x7 SLR options are the RB67/RZ67, the Pentax 6x7/67/67II, and maybe some others I don't know. I'm not very familiar with the Mamiya, but the Pentax 67II has 6 segment matrix metering in its AE finder.

petrk · May 11, 2019

The AF finder has center metering, not a spot. As I know the rotary finder has both center and spot metering. The AF finder meter had interesting covering, you will find that it has two senzors that combine their mesurements. Both finders are modern for their time and I find the AF finder very good.
Regarding the rotary finder, there are discussions here on Photrio, which is better the GS-1 or Mamiya RB/RZ. Main advantage of Mamiya is in their rotary backs that makes portrait shooting very convenient. Now here the rotary prism on GS-1 somehow substitutes the disadvantage of not having the rotary back. So you can find sayings that you cannot shoot portrait with GS-1 without a rotary finder, this comes from people who use their RB/RZ in studio on tripod with waist level finder for portraiture. They do not need to bend and crouch their body behind the camera to look through a prism camera when the model is sitting and a camera is low and the back is in vertical orientation. They can look to a (waist level) finder from above. With GS-1, you can mimmick the same with the rotary finder. Thats all.

macfred · May 11, 2019

AE Prism Finder G : Aperture priority TTL-AE plus manual shooting. Provides aperture priority center-weighted average readings in 1/8 stop shutter speeds, which makes it an essential element for field and action shooting.
Using the AE Prism Finder G, laterally bright, clear images are obtained.

AE Rotary Prism Finder G : Built-in exposure meter, takesits power from the camerabody. When angle is changed from horizontal to vertical, the image can be seen from aboveby turning the eyepiece. The exposure measurement mechanism gives aperture priority TTL fully automatic operation. Average exposure or spotexposure measurements can be selected, plus manual shooting.

source: https://www.bhphotovideo.com/FrameW.../SourceBookProPhoto/Section01MediumFormat.pdf page 25

Paul Manuell · May 11, 2019

abruzzi said:
I think its more of a center weighted averaging meter. I have the AEIII for my ETRSi, and I prefer to just use a handheld light meter, though in body can be awful convenient at times. I've considered adding a GS1 to my collection, but for now I like the small size of the ETRSi.

Your other 6x7 SLR options are the RB67/RZ67, the Pentax 6x7/67/67II, and maybe some others I don't know. I'm not very familiar with the Mamiya, but the Pentax 67II has 6 segment matrix metering in its AE finder.

Ah, so a bit of a compromise between spot and evaluative/matrix then.
And ref. the other 6x7s; have never been interested in the Mamiyas, but the Pentax 67II is my dream camera. Have you seen the price of them, though? For the price of the body alone I could get a GS1 and 2 or 3 lenses.

Paul Manuell · May 11, 2019

petrk said:
The AF finder has center metering, not a spot. As I know the rotary finder has both center and spot metering. The AF finder meter had interesting covering, you will find that it has two senzors that combine their mesurements. Both finders are modern for their time and I find the AF finder very good.
Regarding the rotary finder, there are discussions here on Photrio, which is better the GS-1 or Mamiya RB/RZ. Main advantage of Mamiya is in their rotary backs that makes portrait shooting very convenient. Now here the rotary prism on GS-1 somehow substitutes the disadvantage of not having the rotary back. So you can find sayings that you cannot shoot portrait with GS-1 without a rotary finder, this comes from people who use their RB/RZ in studio on tripod with waist level finder for portraiture. They do not need to bend and crouch their body behind the camera to look through a prism camera when the model is sitting and a camera is low and the back is in vertical orientation. They can look to a (waist level) finder from above. With GS-1, you can mimmick the same with the rotary finder. Thats all.

which
Ah, that makes perfect sense now; with the standard AE prism you can't look down into it with the camera in portrait orientation, like you can with the rotary finder and the wlf, but can still use it like the viewfinder on any SLR by looking 'through' the body. Thank you for confirming what I thought but wasn't sure of.

itsdoable · May 11, 2019

The AE finder G was only made with a center weighted meter. You can shoot portrait or landscape like any eye level finder, but it helps to have the speed grip.

If you want a spot meter, you have to use the Rotary Prism Finder, which has both center weighted and spot. The Rotary finder is a waist level finder, and in conjunction with the Revolving Tripod Adapter G, allows you to simulate a rotating back from a tripod - switching from portrait to landscape without changing the camera position, and maintain a waist level finder.

Paul Manuell · May 11, 2019

itsdoable said:
The AE finder G was only made with a center weighted meter. You can shoot portrait or landscape like any eye level finder, but it helps to have the speed grip.

If you want a spot meter, you have to use the Rotary Prism Finder, which has both center weighted and spot. The Rotary finder is a waist level finder, and in conjunction with the Revolving Tripod Adapter G, allows you to simulate a rotating back from a tripod - switching from portrait to landscape without changing the camera position, and maintain a waist level finder.

It's ok, for general use centreweighted is more useful than spot, but it seems strange that what was probably a professional camera when launched doesn't have all 3 metering options.

LiamG · May 11, 2019

I used the GS-1 with the normal (unmetered) prism for some time- I would say that although it is possible to use the camera in portrait orientation with the prism finder, it is extremely awkward to hold the body in this orientation. I would suggest that the grip is essential if that's something you think you'd commonly do. The Pentax 67 is far easier to use in this regard, and it's what I switched to from the GS-1. That said, the Pentax 90mm/2.8 has nothing on the Bronica 100mm/3.5, which I found to be a far sharper lens. If I was to use it again, I'd probably go for the WLF to make it slightly lighter.

itsdoable · May 11, 2019

Paul Manuell said:
It's ok, for general use centreweighted is more useful than spot, but it seems strange that what was probably a professional camera when launched doesn't have all 3 metering options.

The GS1 was introduced in 1982 with an AE meter.

The 1st Matrix Meter appeared in 1983 with the Nikon FA (then call the AMP - Automatic Multi-Pattern meter), which was "good", but not great.

Back then Professionals generally preferred to use the AE lock, and/or spot meter to get the exposure. Or a hand held meter if time permitted, as that was more accurate.

Paul Manuell · May 12, 2019

LiamG said:
I used the GS-1 with the normal (unmetered) prism for some time- I would say that although it is possible to use the camera in portrait orientation with the prism finder, it is extremely awkward to hold the body in this orientation. I would suggest that the grip is essential if that's something you think you'd commonly do. The Pentax 67 is far easier to use in this regard, and it's what I switched to from the GS-1. That said, the Pentax 90mm/2.8 has nothing on the Bronica 100mm/3.5, which I found to be a far sharper lens. If I was to use it again, I'd probably go for the WLF to make it slightly lighter.

It's fine, ref. being awkward to hand hold in portrait orientation, I always use a tripod for shoots.

Paul Manuell · May 12, 2019

itsdoable said:
The GS1 was introduced in 1982 with an AE meter.

The 1st Matrix Meter appeared in 1983 with the Nikon FA (then call the AMP - Automatic Multi-Pattern meter), which was "good", but not great.

Back then Professionals generally preferred to use the AE lock, and/or spot meter to get the exposure. Or a hand held meter if time permitted, as that was more accurate.

Oh, I never realized this, I just assumed matrix/overall/evaluative etc. was the default metering mode of all cameras that had meters, and that spot and centre weighted were later additions. Makes sense now then, why the Bronica doesn't have it.

btaylor · May 12, 2019

I like my GS-1 a lot. It is smaller and easier to handle than the Mamiya RZ67. The bag to carry my RZ system is half again bigger than for the Bronica. The GS-1 AE prism has a very accurate meter in my experience, it’s done very well with slide film for me. The rotating prism is even bigger than the finder G. The rotating tripod adapter is very hard to find and will set you back at least $100, I’ve been unwilling to spent that for such a simple device! I use a ball head and flip it 90 degrees for portrait mode. The Speed Grip I think is essential, it makes handling the camera feel natural and secure and the film advance in the grip is a great feature. As mentioned above, the optics for this Bronica are second to none, and the lenses are very inexpensive these days for examples in mint condition.

Bronica GS1 prism finder questions

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