More Nikon diopter drama.

[paulfish4570]

I hope so, Keith. My FE2 viewfinder is revelatory (thanks to an RFF'er) ...

 

[jonmanjiro]

How'd you go Keith?

 

[Keith]

How'd you go Keith?

Hi Jon ... I'm currently waiting for a zero diopter to arrive from your part of the world. Nate was good enough to PM me to let me know he had one he didn't need ... here any day now hopefully!

 

[peterm1]

"The figure that Nikon put on their diopters actually reperesents the over all dioptric value you get in the viewfinder when it's combined with the native -1 of the prism ... so a neutral or zero diopter actually has a real world value of +1 and a diopter marked +1 is in reality +2!"

I don't want to hijack this thread but can I take the opportunity to ask a question please - does anyone know about Leica diopter eyepieces? Specifically do they number their diopter lenses the same as it is said here that Nikon does. That is with the combined value of the adjustment lens plus the normal eyepiece lens. You see I believe that the Leica normal viewfinder lens for its M cameras is something like -0.5. I went to a pharmacy and tried reading glasses and found that the reading glasses that for me worked best when looking through a Leica M finder is a +1.0. This gave a workably sharp view.

If Leica number their adjustment lenses the same as the eyeglasses (i.e. with its own diopter value) then of course I need to buy a +1.0. adjustment lens from Leica. But if they label it the same way Nikon is said to, then I should get a +1.5 lens to have the same effect.

I realize the above is kinda confusing if you have not worked it through in your mind - but the logic does work. Problem is, I have no idea if Leica use the Nikon way of numbering their adjustment lenses or not.........................Any ideas?

 

[Mister E]

Hi Jon ... I'm currently waiting for a zero diopter to arrive from your part of the world. Nate was good enough to PM me to let me know he had one he didn't need ... here any day now hopefully!

I sent it a day or maybe two after you sent me your address. It should be there anytime!

 

[john_s]

.......the opportunity to ask a question please - does anyone know about Leica diopter eyepieces? Specifically do they number their diopter lenses the same as it is said here that Nikon does.

It's simple. The Leica diopter is, on its own, the diopter value marked on it. I use -1.5, and it's a -1.5 piece of glass.

My optical prescription is -1.75 for infinity (driving etc) and I have found that slightly weaker than that is better than slightly stronger (since they don't make -1.75). Also, you are supposed to choose the value that enables you to see clearly at around one metre, not infinity. For me, that would be -0.75, but I have chosen -1.5 by (expensive) trial and error.

 

[ampguy]

hmm, I'm near-sighted, so this may not apply, but for Nikons, and Leicas I just use the neg value equal to my rx.

I'm always on the lookout for -2 and -3 Leica M diopters, or that elusive MS Mag 1.15x with variable diopter correction for M eyepiece.

 

[Frankie]

I was amused by various posts in this thread. I say that not in a mean way...I am an aging yuppy myself.


What I can contribute is the following:

Diopter = Reciprocal of focal distance [in metres].​

For a 1m focal distance, the reciprocal is 1/1 = 1.​

Now if you want to focus to say 6~8" or 0.15~0.2m, the reciprocal is +5~6 diopter. [1/0.15 or 1/0.2]. I need a +2 to read newspaper.

Those diopter values are inclusive of whatever eyewear you are already using. In my case none...20/20 at infinity after laser surgery.

There is a market for screw-in adjustable diopter attachment. Let's see, Nikon, Cosina, Epson and Zeiss Ikon uses 19mm thread, Leica uses 12mm [?], who else?

I said often that digicam arms length photography does not work. My arms are far shorter than infinity and close up "critical" viewing will require a +6...serious glass unavailable in drug stores.

Don't manufacturers know that us aging yuppies have money to buy toys?

 

[Frankie]

I was amused by various posts in this thread. I say that not in a mean way...I am an aging yuppy myself.

What I can contribute is the following:

Diopter = Reciprocal of focal distance [in metres].

For a 1m focal distance, the reciprocal is also 1/1 = 1.
​

Now if you want to focus to say 6~8" or 0.15~0.2m, the reciprocal is +5~6 diopter. [1/0.15 or 1/0.2]. I need a +2 to read newspaper.

Those diopter values are inclusive of whatever eyewear you are already using. In my case none...20/20 at infinity after laser surgery.

There is a market for screw-in adjustable diopter attachment. Let's see, Nikon, Cosina, Epson and Zeiss Ikon uses 19mm thread, Leica uses 12mm [?], who else?

I said often that digicam arms length photography does not work. My arms are far shorter than infinity and close up "critical" viewing will require a +6...serious glass unavailable in drug stores.

Don't manufacturers know that us aging yuppies have money to buy toys?

 

[ampguy]

Frankie

Frankie

In my experience, when you're looking at a chimp screen, you need whatever glasses or eye aids you need to see clearly at that distance.

So if your LCD screen is 12" away, you need your glasses to be able to focus on that screen, regardless if that screen is viewing a close-up of a bug, or infinity.

With a RF, you need to see what you are photographing, which is often out there and at infinity, and rarely less than 2-3m.

Again, this is my experience, yours may differ. I have nearsightedness (slight myopic) for distance, with no corrections needed for close up (e.g. insides, reading, computer use).

I was amused by various posts in this thread. I say that not in a mean way...I am an aging yuppy myself.

What I can contribute is the following:

Diopter = Reciprocal of focal distance [in metres].

For a 1m focal distance, the reciprocal is also 1/1 = 1.
​

Now if you want to focus to say 6~8" or 0.15~0.2m, the reciprocal is +5~6 diopter. [1/0.15 or 1/0.2]. I need a +2 to read newspaper.

Those diopter values are inclusive of whatever eyewear you are already using. In my case none...20/20 at infinity after laser surgery.

There is a market for screw-in adjustable diopter attachment. Let's see, Nikon, Cosina, Epson and Zeiss Ikon uses 19mm thread, Leica uses 12mm [?], who else?

I said often that digicam arms length photography does not work. My arms are far shorter than infinity and close up "critical" viewing will require a +6...serious glass unavailable in drug stores.

Don't manufacturers know that us aging yuppies have money to buy toys?

 

[john_s]

.........There is a market for screw-in adjustable diopter attachment. Let's see, Nikon, Cosina, Epson and Zeiss Ikon uses 19mm thread, Leica uses 12mm [?], who else?.........

There are two common Nikon threads, a smaller one for the FM etc and a larger one for later cameras.

 

[peterm1]

It's simple. The Leica diopter is, on its own, the diopter value marked on it. I use -1.5, and it's a -1.5 piece of glass.

My optical prescription is -1.75 for infinity (driving etc) and I have found that slightly weaker than that is better than slightly stronger (since they don't make -1.75). Also, you are supposed to choose the value that enables you to see clearly at around one metre, not infinity. For me, that would be -0.75, but I have chosen -1.5 by (expensive) trial and error.

Thank you for that answer. It helps.

I do understand that I need the adjustment to allow me to see at a shorter distance than infinity (although I had thought someone had previously told me 2 meters not 1 for Leica, but speaking personally I have no idea so am quite happy to go with what you say.) I just know that I am long sighted. To read at normal reading distance I need eyeglasses that are +2.75 for my right eye (+1.75 for my left) but as I prefer to use my right eye for my Leica M8 (it avoids nose smears on the LCD amongst other things) its the right eye adjustment that matters to me.

As I said earlier, the non prescription pharmacy shop reading glasses that work best with my right eye are +1.0. I could persist with using a pair of cheap non prescription lenses but that prevents me from seeing the full field of view so is not ideal for that reason and still takes quite a while for me to focus then compose.

 

[Keith]

YES!


The zero diopter just arrived in the mail from Nate in Japan and I'm delighted to say I now have a sharp viewfinder image ... not to mention a camera (FM3A) that has gone up in my estimation considerably.

I've been holding off getting a portrait lens (105mm) for my Nikon bodies until this was sorted ... it's reasuring to know that there was light (and clarity) at the end of the viewfinder after all!

Thankyou sincerely Nate ... I hope you and all the generous souls like you have a great Xmas and New Year.

 

[Nikon Bob]

Now that is good news.

Bob

 

[paulfish4570]

way to go keith; our right eyes see that same ...

 

[john_s]

....I do understand that I need the adjustment to allow me to see at a shorter distance than infinity (although I had thought someone had previously told me 2 meters not 1 for Leica, but speaking personally I have no idea so am quite happy to go with what you say.).......

This would explain the anomaly that I referred to above, i.e. the "1 metre" rule would suggest that I need -0.75, but I actually need something stronger.

To explain, I need -1.75 for infinity. Therefore, I would need only -0.75 for 1 metre. But I would theoretically need -1.25 for 2 metre. So the theory is getting closer to the reality.

My infinity prescription has not altered since I was a teenager. Just about any minus diopter was fine. Now I'm 63 it's quite critical. I have one of Megaperls adjustable magnifier/diopter units (x1.15) and I can fine tune my diopter to optimise accurate focusing and I can tell the difference between the optimum setting for close portrait and a different setting for several metres away. I usually don't make the adjustment since it's a nuisance but I can see the difference. It's not the worst thing about getting old though.

 

[Frankie]

In my experience, when you're looking at a chimp screen, you need whatever glasses or eye aids you need to see clearly at that distance.

So if your LCD screen is 12" away, you need your glasses to be able to focus on that screen, regardless if that screen is viewing a close-up of a bug, or infinity.

With a RF, you need to see what you are photographing, which is often out there and at infinity, and rarely less than 2-3m.

Again, this is my experience, yours may differ. I have nearsightedness (slight myopic) for distance, with no corrections needed for close up (e.g. insides, reading, computer use).

I agree with you completely.

I don't need diopter correction when viewing at infinity. I can see an RF patch or a Nikon "apparent" distance well enough, if I use a split-image type focusing screen. But, for a dinky LCD usually with poor resolution, I prefer to see at ~8", and would need +5 reading glasses...generally unavailable in drug stores.

 

[ampguy]

right

right

I'm possibly just a few years away from needing closer (+) glasses, so at that time, I'm going to be doing "transitions" or "bi-focals" as they were called back in the day.

I expect my gear preferences at that time to possibly change radically.

Anyone else use bi-focals, or transitions type glasses yet with RF's and/or EVIL based systems yet?

I agree with you completely.

I don't need diopter correction when viewing at infinity. I can see an RF patch or a Nikon "apparent" distance well enough, if I use a split-image type focusing screen. But, for a dinky LCD usually with poor resolution, I prefer to see at ~8", and would need +5 reading glasses...generally unavailable in drug stores.