Beemermark
Veteran
I have a Bronica ETRS with a AEII finder. I like it alot except the standard diopter is -1.5. That means I can see it great with my +2 reading glasses but can't see it at all with my normal far vision. However, I'm confused by what diopter I should buy. Is it -1.5 + 2, or just +2, or even -1.5-2??? Help.
peterm1
Veteran
Couple of ways of dealing with it in a practical sense.
One thing I did was to take my camera to a chemist store or a news agent where they sell cheap reading glasses each with fixed diopters. These range from minus 2 to plus 3 or something like this.
I than tried several of these while looking through the viewfinder. The one that gave the sharpest vision was the diopter I needed to buy for my camera.
Another way if you have a helpful optometrist is to ask them to do much the same. I asked mine when I was in having my eyes checked and she told me to bring my camera in one day and check using her equipment. She had a whole tray of lenses with many more diopters than you can ever get in cheap reading glasses (I presume they have smaller variations between each diopter) and she was happy to hold them up in turn to my eye while I peered through the camera viewfinder till I found the one that worked best.
In any event I thinkOptometrists can calculate what the diopter should be based on the strength of your reading glasses, the "native" diopter of the camera and the theoretical viewing distance you see when peering through the finder.
If you are truly happy with the vision afforded by your reading glasses when looking thru your finder and those glasses are +2 then thats the diopter you should buy. Just be aware that +1.75 or +2.25 might be what you really need (but if you cant buy eye piece diopteradjustments in those finer settings its a bit academic in any event).
BTW work out first which eye you use if your eyes differ like mine do.
One thing I did was to take my camera to a chemist store or a news agent where they sell cheap reading glasses each with fixed diopters. These range from minus 2 to plus 3 or something like this.
I than tried several of these while looking through the viewfinder. The one that gave the sharpest vision was the diopter I needed to buy for my camera.
Another way if you have a helpful optometrist is to ask them to do much the same. I asked mine when I was in having my eyes checked and she told me to bring my camera in one day and check using her equipment. She had a whole tray of lenses with many more diopters than you can ever get in cheap reading glasses (I presume they have smaller variations between each diopter) and she was happy to hold them up in turn to my eye while I peered through the camera viewfinder till I found the one that worked best.
In any event I thinkOptometrists can calculate what the diopter should be based on the strength of your reading glasses, the "native" diopter of the camera and the theoretical viewing distance you see when peering through the finder.
If you are truly happy with the vision afforded by your reading glasses when looking thru your finder and those glasses are +2 then thats the diopter you should buy. Just be aware that +1.75 or +2.25 might be what you really need (but if you cant buy eye piece diopteradjustments in those finer settings its a bit academic in any event).
BTW work out first which eye you use if your eyes differ like mine do.
Rob-F
Likes Leicas
When you are able to see with your +2 reading glasses, is the standard -1.5 diopter mounted? If so, I suspect that the present -1.5 diopter should be replaced with a +0.5, since that is the algebraic sum of -1.5 + 2.
That said, Peter M's suggestion is the safest: try before you buy. There is more to it than meets the eye, no pun intended.
Another thing: minus 1.5 sounds awfully strong for a standard diopter. Are you sure that's the standard one, or something someone else left in it? I would be tempted to check that with Bronica before doing anything else. You might be trying to correct someone else's correction!
That said, Peter M's suggestion is the safest: try before you buy. There is more to it than meets the eye, no pun intended.
Another thing: minus 1.5 sounds awfully strong for a standard diopter. Are you sure that's the standard one, or something someone else left in it? I would be tempted to check that with Bronica before doing anything else. You might be trying to correct someone else's correction!
Beemermark
Veteran
Yes, the factory standard diopter is minus 1.5. Since my reading glasses are +2 and I am viewing thru the installed diopter the +0.5 sounds correct. The confusing part is the Bronica offered diopters range from -4.5 to +1.5, with the +1.5. being hard to find.
sevo
Fokutorendaburando
You'll have to figure out their nomenclature - if they sell their dioptres with true numbering, you'd want +2 for a effect similar to your reading glasses. But if they number by cumulative strength, that would be +3.5, more than you bargained for, and you'd need +0.5.
Of course, that assumes that you want the effect you now have with the reading glasses when looking through the finder with no glasses at all. If you want to be able to see through the finder with far vision glasses (often more comfortable than taking off your glasses whenever you look into the finder), you will additionally have to subtract your far strength.
Of course, that assumes that you want the effect you now have with the reading glasses when looking through the finder with no glasses at all. If you want to be able to see through the finder with far vision glasses (often more comfortable than taking off your glasses whenever you look into the finder), you will additionally have to subtract your far strength.
sevo
Fokutorendaburando
Given that we are not talking about a waist level finder (where the dioptre, if you need one, will replace the finder loupe): Is it really installed or the inherent dioptric strength of the finder itself?
That is, can you remove the currently installed eyepiece protection glass and does that have a non-zero strength? In that case, you presumably have a camera previously owned by a myopic person, and you should start your tests from scratch without that correction dioptre. Usually, it will be the strength of the finder itself, and the protective glass has zero strength.
Beemermark
Veteran
Again, the standard eyepiece in the Bronica AE II prism viewfinder is a minus 1.5 diopter. If I go to a different diopter I replace the minus 1.5 diopter with the new strength.
So if my +2.0 reading glasses looking thru the standard eyepiece of minus 1.5 diopter, what strength do I need when I replace the standard eyepiece?
Bronica never made an eyepiece that was greater than +1.5. And that bothers me. I've removed the standard -1.5 diopter eyepiece and no matter what the amount of magnification I use, everything is a blur.
Should I be looking for a -3.5 diopter? Bronica made diopters (eyepieces) from -4.5 to +1.5.
So if my +2.0 reading glasses looking thru the standard eyepiece of minus 1.5 diopter, what strength do I need when I replace the standard eyepiece?
Bronica never made an eyepiece that was greater than +1.5. And that bothers me. I've removed the standard -1.5 diopter eyepiece and no matter what the amount of magnification I use, everything is a blur.
Should I be looking for a -3.5 diopter? Bronica made diopters (eyepieces) from -4.5 to +1.5.
Rob-F
Likes Leicas
Sevo's point is that the power marked on the eyepiece may not refer to the eyepiece itself, but to the eyepiece + prism; thus, the final, or effective, power with the eyepiece in place. For example, a Nikon finder has a native power of -1 diopter, even with no eyepiece in place. So the standard eyepiece, which is window glass, gives an effective power of minus 1. The reason is that the Nikon finder presents the image at a virtual distance of one meter. A minus one diopter power is consistent with the image being presented at that distance, for most of us.
Now to apply this to your (non-Nikon) camera: if the standard eyepiece is -1.5 diopter, that means the virtual image in the finder is at a distance of 66.67 centimeters. So the minus 1.5 diopter eyepiece will allow a normal eye (or one corrected with eyeglasses) to focus correctly in the finder.
Next, what eyeglass prescription do you need for normal distance vision? Do you require any correction, or do you have normal distance vision? Or do you wear glasses to see at a distance? That's the place to start. I think you may be overthinking this by bringing your reading glasses into it. You shouldn't be using them with your camera to begin with. You should either look into the finder through your distance prescription (if you have one); or simply with your normal, uncorrected eye.
I hope this helps. Let us know.
Now to apply this to your (non-Nikon) camera: if the standard eyepiece is -1.5 diopter, that means the virtual image in the finder is at a distance of 66.67 centimeters. So the minus 1.5 diopter eyepiece will allow a normal eye (or one corrected with eyeglasses) to focus correctly in the finder.
Next, what eyeglass prescription do you need for normal distance vision? Do you require any correction, or do you have normal distance vision? Or do you wear glasses to see at a distance? That's the place to start. I think you may be overthinking this by bringing your reading glasses into it. You shouldn't be using them with your camera to begin with. You should either look into the finder through your distance prescription (if you have one); or simply with your normal, uncorrected eye.
I hope this helps. Let us know.
Beemermark
Veteran
I do not wear glasses for distance, like most people over the age of 40 I need glasses to read a book.
With the normal eyepiece (with a -1.5 diopter lens) I need to use my reading glasses (+2.0) to focus. I do not want to use my reading glasses when out and about. Out of maybe a hundred cameras (every Nikon, Olympus, Canon, RF &SLR) I've never had this problem before.
john_s
Well-known
I'm not familiar with your camera, but I need -1.5 to view through most cameras. Some camera have diopters which simply add to the existing camera, e.g. Leica RF. On some, the standard eyepiece lens is removed and replaced with one that includes the correction, but the strength that's written on the eyepiece diopter might not be the actual strength of that piece of glass, but rather a combination of its correction and the standard system, e.g. Nikon SLRs.
My Rollei SL66 prism has a removeable eyepiece glass, the standard value is about +9 diopter. If I want correction for my eyes, I need to replace it with one that's
+9-1.5=+7.5
This is a pain because it's not an off the shelf lens. (In this case the standard lenses from telescope suppliers etc are far too thick). I'm still trying.
Incidentally, the lens is so strong because it's to enable a person with normal sight to see the screen that's a few inches from their eye.
My Rollei SL66 prism has a removeable eyepiece glass, the standard value is about +9 diopter. If I want correction for my eyes, I need to replace it with one that's
+9-1.5=+7.5
This is a pain because it's not an off the shelf lens. (In this case the standard lenses from telescope suppliers etc are far too thick). I'm still trying.
Incidentally, the lens is so strong because it's to enable a person with normal sight to see the screen that's a few inches from their eye.
sevo
Fokutorendaburando
So if you remove the eyepiece, the finder shows the image at infinity? And you do not need glasses for infinity vision? If both are true, which is possible given that +2 compensates -1.5 to +0.5 (which should cause only a slight blur, or even none if you are slightly hyperopic, as it is not that much past infinity), you need a blank no-correction (0dpt) eyepiece! That would be easy to test by trying without eyepiece - if the above assumption is right, it should be even more comfortable to view than with eyepiece and glasses.
If the eyepiece is inscribed -1.5 and you haven't actually tested the individual eyepiece and finder strengths, and do not have a similar problem with Nikons (whose finders have a native strength of -1), another, perhaps slightly more likely, possibility would be that the camera has a native strength somewhere closer than infinity, probably about -1.0, and a previous myopic owner added another -1.5 in the shape of a correction eyepiece to a total of -2.5, which +2 would bring down to -0.5 (i.e. 2m distance), which certainly will be in your accommodation range. In that case, you'd be in the same state (of 1m apparent viewing distance) as on the Nikons with a zero-power eyepiece in place of the current -1.5, and would be corrected to infinity with a +1 (assuming -1 to be the native strength of the finder) eyepiece.
Rob-F
Likes Leicas
I think we are back to where we started:
1. It appears likely that you need a +0.5 diopter to replace the -1.5. Because your +2 added to the existing -1.5 equals +0.5.
2. However, we don't know if -1.5 is the eyepiece power, or the sum of the eyepiece power and the finder's native power.
3. You should really take the camera to an optometrist and have the eyepiece measured by itself.
4. Then get an eyepiece +2 diopters stronger than the existing one. If you can't order it, have the optometrist make one.
1. It appears likely that you need a +0.5 diopter to replace the -1.5. Because your +2 added to the existing -1.5 equals +0.5.
2. However, we don't know if -1.5 is the eyepiece power, or the sum of the eyepiece power and the finder's native power.
3. You should really take the camera to an optometrist and have the eyepiece measured by itself.
4. Then get an eyepiece +2 diopters stronger than the existing one. If you can't order it, have the optometrist make one.
Ernst Dinkla
Well-known
Try the cheap acrylic glasses without the diopter attached, keep the glasses as close to the camera as possible. Buy the glasses that do the job. Remove the glass of the diopter and insert a segment of one of the glasses center. Keep the other in reserve.
Done that for an Iskra rangefinder but used the glass of one of my old spectacles.
Ernst
Done that for an Iskra rangefinder but used the glass of one of my old spectacles.
Ernst
Beemermark
Veteran
Yup, that's what I tried last night. The results are that no amount of + magnification does it. So I think I need to go negative. Seems counter-intuitive.
Unfortunately I do not have any friends that are optometrists that are going to devote time for free to play around with their tools of the trade.
sevo
Fokutorendaburando
Well, if it should be a finder not designed to be usable by people with normal vision without a eyepiece it might be - I haven't ever heard of such a prism finder with a native positive (past infinity) value, but needing a strong positive lens is the default state for hoods/waist level finders, and it is not entirely impossible that some prisms mimic their operation. But the whole discussion is somewhat futile until you give us a description that allows us to determine the individual dioptres of the finder and eyepiece each...
Rob-F
Likes Leicas
I looked at the Bronica manual online.
The standard magnifier for the magnifying hood is minus 1.5 diopters, all right.
But your AEII is a prism, not the standard hood.
Some points:
a. Does the AEII also use the minus 1.5 diopter lens?
b. Is the lens on your AEII marked with a power?
c. If not, I suspect it is not the power it is supposed to be.
d. I suspect you are on the right track in thinking you need a lens with negative power.
e. I think you just need to order a standard eyepiece. I believe the camera is discontinued, so parts may not be available through Bronica. You may have to do an eBay search, or put out an APB to all camera stores. Until you find one, use your reading glasses.
The standard magnifier for the magnifying hood is minus 1.5 diopters, all right.
But your AEII is a prism, not the standard hood.
Some points:
a. Does the AEII also use the minus 1.5 diopter lens?
b. Is the lens on your AEII marked with a power?
c. If not, I suspect it is not the power it is supposed to be.
d. I suspect you are on the right track in thinking you need a lens with negative power.
e. I think you just need to order a standard eyepiece. I believe the camera is discontinued, so parts may not be available through Bronica. You may have to do an eBay search, or put out an APB to all camera stores. Until you find one, use your reading glasses.
Rob-F
Likes Leicas
I suggest watching KEH and waiting for the right part to show up:
http://www.keh.com/Camera/format-Me...ssories?s=1&bcode=ET&ccode=14&cc=80960&r=WG&f
http://www.keh.com/Camera/format-Me...ssories?s=1&bcode=ET&ccode=14&cc=80960&r=WG&f
john_s
Well-known
When you remove the eyepiece glass, just looking through it on its own, is it just flat glass, minus or positive?
Beemermark
Veteran
I sort of feel like I'm repeating myself, but one last time -
(1) The AE II eyepiece (when removed) is labeled -1.5
(2) The AE standard eyepiece (per the manual) is -1.5
(3) A combination of the -1.5 eyepiece AND my +2.0 strength reading glasses allows me to focus clearly with my normal 20/20 distance vision. Without my reading glasses things are a little blurry (just like trying to read a book without my reading glasses).
(4) I need reading glasses to read, i.e. to focus clearly at items closer than 3 feet
(5) Replacement eyepieces (diopters) are available from -4.5 to +1.5. They replace the existing -1.5 eyepiece
(6) If I remove the eyepiece everything is nothing but a blob of light. If I add +2, +3 or + 4 it remains a blob.
I was really hoping someone had a Bronica ETRS or SQ (which is the same) that could enlightened me.
(1) The AE II eyepiece (when removed) is labeled -1.5
(2) The AE standard eyepiece (per the manual) is -1.5
(3) A combination of the -1.5 eyepiece AND my +2.0 strength reading glasses allows me to focus clearly with my normal 20/20 distance vision. Without my reading glasses things are a little blurry (just like trying to read a book without my reading glasses).
(4) I need reading glasses to read, i.e. to focus clearly at items closer than 3 feet
(5) Replacement eyepieces (diopters) are available from -4.5 to +1.5. They replace the existing -1.5 eyepiece
(6) If I remove the eyepiece everything is nothing but a blob of light. If I add +2, +3 or + 4 it remains a blob.
I was really hoping someone had a Bronica ETRS or SQ (which is the same) that could enlightened me.
john_s
Well-known
So the eyepiece that is marked -1.5, when removed: is it plane glass, or is it a positive piece of glass or is it a negative piece of glass?
My guess is that it's strongly positive, and not a -1.5 piece of glass. In that case, it's probably like the situation I describe in post 10 above.