OVF eyesight correction

[Kiwimac]

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I used to have issues using cameras when I wore glasses. 
 

Modern cameras don’t seem to be made in high eye point versions so my composition suffered because I often couldn’t see the frame edges when wearing glasses. 
 

I started using contact lenses and would wear one in my right eye so I had good distance vision looking through the camera and nothing in my left eye so I could see the menus and rear screen etc. 
 

Since then, I had LASIK. The surgery was differential - my right eye has distance and my left close. The brain melds the two unconsciously and the effect is clear vision from about 8” to infinity. Excellent. 
 

Every camera I’ve used since has adjustable diopter in the VF. 
 

I use my right eye to look through cameras. I’ll be able to see my subjects well through an M camera OVF. 
 

My question is this: will I be able to see the RF patch well also?

[DenverSteve]

See the box or focus? No way to know really.  Ask your optician? 

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[Jeff S]

On 12/26/2022 at 3:33 PM, Kiwimac said:

My question is this: will I be able to see the RF patch well also?

The RF patch is set at to a virtual distance of 2m.  Provided you have no astigmatism, you should be fine.  Best way to know, of course, is to try for yourself. 
 

Jeff

[Kiwimac]

Sounds as though it should be fine. I can see very well at 2m through my right eye.

[CDodkin]

10 hours ago, Kiwimac said:

Sounds as though it should be fine. I can see very well at 2m through my right eye.

And you can of course add a fixed diopter to the viewfinder as needed. I wear reading glasses for close work, and found adding a +1.0 Diopter beneficial with the M10 viewfinder.

[jdlaing]

The focusing patch is not set to a virtual anything. 
The bright line frames are set so that what you see inside the framelines is accurate at a distance of 2 meters. This is the distance that what you frame an image using the bright line framelines is the most accurate. 
The rangefinder focusing patch is something completely different and is not set to anything virtual. It works with a coupled lens from somewhere around 0.7 of a meter to infinity. 

[Jeff S]

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6 hours ago, jdlaing said:

The focusing patch is not set to a virtual anything. 
The bright line frames are set so that what you see inside the framelines is accurate at a distance of 2 meters. This is the distance that what you frame an image using the bright line framelines is the most accurate. 
The rangefinder focusing patch is something completely different and is not set to anything virtual. It works with a coupled lens from somewhere around 0.7 of a meter to infinity. 

The frame lines for the M11, M10, M240 and M8.2 are optimized for 2m. The M9 frame lines are optimized for 1m. The original M8 had frame lines optimized for .7m.
 

The RF patch, as I should have called it, is indeed set to a virtual distance of 2m on all of these M models; hence the built in -.5 diopter.

If you think otherwise, maybe you should petition the mods to change the FAQ, as well as all the countless other discussions.

Jeff

[jdlaing]

Just because some statement keeps being parroted doesn’t make it true. 
 

Show me one thing from Leica that states the virtual distance of the rangefinder patch.

 

[Jeff S]

1 hour ago, jdlaing said:

Just because some statement keeps being parroted doesn’t make it true. 
 

Show me one thing from Leica that states the virtual distance of the rangefinder patch.

 

Well, my camera manual (M10-R in this case; p.143) confirms that the eyepiece is set for -.5 diopter.

Jeff

[Jeff S]

1 hour ago, Musky said:

See? This is why YMMV and IMO are so important to avoid … 

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Simply register for free here – We are always happy to welcome new members!

That applies to matters of personal taste.  Here we are discussing actual technical specifications, which are matters of fact, provided that they can be documented or proven.  

But we get your point…repeated ad nauseam by now.  Maybe the cartoon character is you. 🤪

Jeff

[Jeff S]

2 hours ago, jdlaing said:

Show me one thing from Leica that states the virtual distance of the rangefinder patch.

 

Also just consulted the manual for my M9 Monochrom.  On p.165…”eyepiece adjusted to -.5 diopter.”  Frame lines, as I wrote earlier are, however, optimized for 1m, not 2m.  This is documented on p.120… “ The size of the bright line frame is matched to the initial format of the Leica M Monochrom and thus corresponds to a sensor size of approximately 24x36mm at a distance setting of 1m.”

Jeff

[jdlaing]

9 hours ago, Jeff S said:

Well, my camera manual (M10-R in this case; p.143) confirms that the eyepiece is set for -.5 diopter.

Jeff

So what? The .5 diopter is to offset the difference for a person with 20/20 eyesight at 20 feet, which is the norm, focusing at .7 of a meter. The .5 diopter has nothing to do with some fantasy virtual focus patch distance.

[jdlaing]

8 hours ago, Jeff S said:

Also just consulted the manual for my M9 Monochrom.  On p.165…”eyepiece adjusted to -.5 diopter.”  Frame lines, as I wrote earlier are, however, optimized for 1m, not 2m.  This is documented on p.120… “ The size of the bright line frame is matched to the initial format of the Leica M Monochrom and thus corresponds to a sensor size of approximately 24x36mm at a distance setting of 1m.”

Jeff

Which has nothing whatsoever to,do with the rangefinder focus patch.

[Jeff S]

On 12/30/2022 at 2:29 PM, jdlaing said:

The bright line frames are set so that what you see inside the framelines is accurate at a distance of 2 meters. This is the distance that what you frame an image using the bright line framelines is the most accurate. 

 

Not so with the M9 (1m) or M8 (.7m) frame lines, neither of which are optimized for 2m.  The M9 Monochrom manual, as noted, is clear on this.
 

The RF patch is indeed a different issue, as we’ve both commented.  But everything  I’ve read here, including the FAQ (written by @Jaap), as well as comments from eye doc @Rick ,and others (I may recall@01af), have seemed to point to the -.5 diopter as directly related to the 2m RF patch virtual distance.  I’m not an optician, nor a Leica tech expert, so happy to be corrected by any of these folks.  

Jeff

Edited January 1, 2023 by Jeff S

[jaapv]

There are two things being confused here.

The markings in the viewfinder including the rangefinder patch are mirrored in by a semi-silvered prism as the viewfinder is a simple telescope. They create an overlay that is set at a virtual distance of 2 m for all M cameras. The diopter is set to -0.5 as that helps the eye accommodate from 2m to infinity. 
Then there is the framing of the framelines . Obviously the coverage is a constant, although they will shift to compensate for parallax. it However, the angle of view of a lens is not a constant. It varies with the focus distance, most narrow at infinity, most wide close-up. I am talking about lenses with classic focusing here, lenses with internal focusing may react differently. 
So the coverage of the frame lines can only be accurate at one focus distance, which varies from 0,7 m to 2 m depending on camera model  That is what is meant by the frame lines being optimized at a certain distance, which has nothing to do with the virtual distance of the overlay in the viewfinder which is determined by the construction of the rangefinder and its lenses and prisms  

 

[Jeff S]

These are the same two issues that I discussed: 1) 2m virtual RF patch distance  (i..e., the display); and 2) frame line distance optimization, which varies by M model as I listed.  

Thank you for confirming.

Jeff

[01af]

vor 14 Stunden schrieb jaapv:

They create an overlay that is set at a virtual distance of 2 m for all M cameras. The diopter is set to -0.5 as that helps the eye accommodate from 2 m to infinity.

To be clear: The setting of -0.5 dpt is what puts the viewfinder elements (framelines, focus patch, LED) at a virtual distance of 2 m.

[Jeff S]

1 hour ago, 01af said:

To be clear: The setting of -0.5 dpt is what puts the viewfinder elements (framelines, focus patch, LED) at a virtual distance of 2 m.

That’s what I posted earlier, thanks to your clarification many years ago, and why I cited the M manual regarding the -.5 diopter and the 2m RF patch virtual distance. 
 

@jdlaing doesn’t agree, instead derailing an otherwise simple discussion with the OP.  I appreciate your feedback… again.

Jeff

[jdlaing]

2 hours ago, 01af said:

To be clear: The setting of -0.5 dpt is what puts the viewfinder elements (framelines, focus patch, LED) at a virtual distance of 2 m.

Frame lines yes. Focus patch no. The focus patch is accurate from .7 meters to infinity. The focus patch is totally unrelated to frame lines. Doubt me? Send an email to Leica Germany.

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[01af]

vor 12 Minuten schrieb jdlaing:

Frame lines yes. Focus patch no.

Uh oh. You are still confusing two different things, as Jaap jaapv pointed out in post #16.