RZ67 Diopter Help

xvelids

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Hey guys - quick question about diopters here! Been having some focus problems with my RZ67 with a -1.5 diopter in the flip up magnifier despite stopping down to a F4 or F4 ~ 5.6 Split. Tried both wearing glasses and without wearing glasses and modifying my shooting technique a little, but the images still seem soft.

My prescription is as follows:

Right (OD) - SPH -0.5; CYL -1.0; Axis 95 degrees.

Left (OS) -SPH 0.75; CYL -1.0; Axis 95 degrees.

Pupillary Distance

Right (OD) - Monocular - 31.5

Left (OS) - Monocular - 33.0

I am looking to figure out whether or not the -1.5 diopter is the right/wrong diopter for my eyesight! Hope to hear back from y'all, thanks!
 

voceumana

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How old are you? I'm not being "smart"--it's a real question. If you are approaching the age where supplemental magnification is needed for close focus, then you'll need a different diopter for the camera.

Your prescription indicates some myopia (nearsightedness) but not extreme, and some astigmatism, again, not extreme but just a little greater correction than for your myopia. How recent is your prescription? How is focusing your eyes on an object at about 1 meter/40 inches? If that's a little difficult, then you need a different diopter in your camera..

You can ask your optometrist or ophthalmologist what supplemental lens he or she suggests for 1 meter. Most cameras seem to set the visual focus distance at about 1 meter. Usually you need about +1 to +1.5 diopter in addiiton to your distance correction; +1 at the beginning of presbyopia (eyes getting older).

I have a much stronger prescription than you, and extreme astigmatism--I always choose a focusing screen with a split image because it really helps me achieve precise focus.
 

toyoboyo

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I had the same issue with the Mamiya. I'd recommend trying the Magnifying Hood and seeing if you can adjust the diopter there.
 

macfred

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There were followig diopters for the focusing hood and for the prism finders (from the RB67 Pro SD System Chart).

I guess with the help of your optometrist you should be able to find the right one. If you can't find the right RB67 Connection Lens maybe the optometrist can fit another lens into the frame.
 

k.hendrik

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This is the expensive route; AE prism finder FE701 plus the magnifier FD701. magnification 2.4: diopter correction range; -6 ~ +4. It works for my old & weary eyes.
 

john_s

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I think that -1.5 is too strong a correction. There is a rule of thumb for off the shelf spherical-only viewfinder correction lenses that suggests Spherical+halfCylindrical. It's not a complete solution.
This would suggest -1.0 for your right eye.
In my experience, with eyesight similar to yours, that less correction is better than more if the exact value is not available. As one ages, this becomes more critical because the eye loses accommodation.

However, the viewfinder diopter is an alternative to eyeglasses and you should be able to focus critically accurately with your eyeglasses (and without corrective diopter of course). If I'm reading your post properly, you can't see the image in the viewfinder perfectly sharply focused. Can anyone else see satisfactorily through the viewfinder? Maybe there's a problem with the camera, maybe focus screen upside down?
 

john_s

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The ideal solution for a camera that does not need to be turned 90 degrees to go from portrait to landscape etc is a fully corrected diopter spherical and cylindrical. In my country I have not found any optical person who will do that. At my advanced age my spherical is getting slowly smaller (good) but cylindrical slightly worse (bad).
 

wiltw

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Keep in mind that most folks get a prescription for DISTANCE vision...20' printed target with differing rows of letter sizes...but what YOU need for your camera (particlarly with a prism finder) is consideration of the fact that the focus screen is designed to be at a certain VIRTUAL distance (about 30" to 1m depending upon manufacturer.)..IOW seeing your focus screen is like reading a book or newspaper, and that prescription is a 'more positive diopter' than the diopter for distance.
For example, my distant correction for both eyes is -4.25 diopter. I can adjust my vision for reading a book simply with a pair of +1.50 readers from the corner drugstore.

You provided us no information about your READING Rx, so any comment is a guess about how YOUR eyes.

The other 'unknown' is how Mamiya represents its correction lenses. If the standard lens is -0.5 diopter, some manufacturers list a 1.0 diopter difference lens
  • as "+1.0" (relative value to standard)
  • while others would list "+0.5" actual diopter value...1 diopter different from standard -0.5 lens!
 
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toyoboyo

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-1.5 is standard I believe. A -2.5 is only a -1.0 correction. If you have the option, try seeing what diopter you set a SLR at. I'm at -3 with glasses.
 

wiltw

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Jonathan F said:
-1.5 is standard I believe. A -2.5 is only a -1.0 correction. If you have the option, try seeing what diopter you set a SLR at. I'm at -3 with glasses.
Click to expand...

I believe going to -2.5 diopter lens is in the wrong direction!...I would choose a 1.0 offset in the other direction, to -0.5!

Note that you NEVER find reading glasses in the drugstore with Negative diopter values, they all go from +1.0 to +3.0

Minus 1.5 diopter plus offset of 1.0 equals Minus 0.5 diopter

In fact, the OP should take his camera to a drugstore, put on a +1.0 pair of reading glasses and look into his viewfinder to note the degree of benefit from the standard magnifier lens alone.
 
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voceumana

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Just try a low power magnifying glass in addition to your distance lenses and see if that works better--that's a positive diopter change and at least you'll know the direction.
 

wiltw

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voceumana said:
Just try a low power magnifying glass in addition to your distance lenses and see if that works better--that's a positive diopter change and at least you'll know the direction.
Click to expand...

Not truly useful... a 5X magnifier is 20 Diopter! A quick trip to a drugstore quantifies the diopter offset needed by the OP
...+1.0, +1.5, +2.0, +2.25 etc.
 
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john_s

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Ideally being in a shop with a range of diopters and trial and error has worked best for me. I have several makes of cameras and I have a diopter for all but one of them. They are the best diopter values available. However they are not all the same values because the camera viewfinders are all different. IMO asking an optometrist for a recommendation based on eyeglass prescription is often not going to work because of this.

I would like to see the OP seeing focus sharply with eyeglasses first: maybe prescription reading glasses set up for around 1m best focus. The optometrist could set this up in 5 minutes. Then maybe diopters could be tried. If he/she can't see with eyeglasses at the moment there are too many variables.
 

john_s

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macfred said:
I wanted to focus without my glasses. I took my Rolleiflex with the WLF to the optometrist and he installed a new lens in the WLF for little money.
Click to expand...

You are lucky to be in a country with technicians who are as versatile as this. Here at the end of the Earth it seems that there is a level of standardization in such professions. They are efficient in standard optometrist's activities, but don't seem able to source anything else. I have tried hard over the years. The nearest I got was an expert in telescopes but I needed something smaller that what he did, so could not help. However the eyes are ageing, so less correction is needed!

(This was for something similar, the lens on a Rolleiflex SL66 prism finder. It's quite a strong +ve lens, I just needed one a bit weaker.)
 

k.hendrik

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macfred said:
I wanted to focus without my glasses. I took my Rolleiflex with the WLF to the optometrist and he installed a new lens in the WLF for little money.
Click to expand...
That was in Germany or The Netherlands ?? I'm in need for something similar for my Grey Baby.
 
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