m8 built in -0.5 diopter

[pekem]

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Well that is it then, thank you.

[Guest tummydoc]

Well-said Howard! I had completely neglected the fact that the de-magnification (particularly in other than the M3) contributes to a lessening of the effect of distance on apparent sharpness to someone with less-than-perfect eyesight. Then again de-magnifying also contributes to a lessening of focussing precision There is no free lunch, as I'm forced to remind myself each time a sales rep offers to treat me

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The Leica Q3 is available for pre-order at B&H Photo Video and Adorama

[ho_co]

There is no free lunch, as I'm forced to remind myself each time a sales rep offers to treat me

<grin>

[ArtZ]

Hi all!

 

This an amusing thread.

 

Well, this my conclusion: If you're older than 40 and you suffer of presbyopia or you wear lenses, M8 is not a camera for you. In other words, M8 is not suitable for 90% of users here... We're as old as the hills! :D

 

Obviously, I'm just joking.

 

My two cents:

 

I suffer of presbyopia (+0,75) and I agree with most of the comments here. I've been buying +1 diopter corrections (3 in two months) because I keep on losing them on the 1.25x magnifier (they get unscrew after a while). I bought another one two weeks ago but this time I tried the +1 D and +1.5 D (for the first time because if, logically, +1 D correction should be good for me). I felt more confortable with the +1.5... so I got an appointment this morning with my optician thinking that I should also/probably correct my glasses. He told me that my presbyopia is still +0.75...

 

Fortunately, I've bought the Megapearls magnifiers. 1.15x is now permanently screwed to the M8, I have set it for my sight and I feel very happy with that.

 

Cheers!

 

PS: Tonight at 8:00 PM I'll have my bowl of soup and turned in at 9:00 PM

.

[Guest tummydoc]

I've been buying +1 diopter corrections (3 in two months) because I keep on losing them on the 1.25x magnifier (they get unscrew after a while).

 

A rather costly way to solve the problem. A less-costly way is the application with a toothpick of the tiniest drop of clear fingernail varnish to the threads and quickly attach the diopter before it dries.

[ArtZ]

A rather costly way to solve the problem. A less-costly way is the application with a toothpick of the tiniest drop of clear fingernail varnish to the threads and quickly attach the diopter before it dries.

 

tummydoc,

 

Actually I did it with the first diopter (a drop of nail varnish) and when I wanted to remove the diopter, a part of the magnifier come out with it. I didn't realized until I saw the magnifier lenses (and a ring to separate both lenses) on my table. It was a pain in the a*** to fit it.

[Guest tummydoc]

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I apologise, I had completely forgotten about the dispicable insufficiency of the magnifier's assembly. One would be well-advised to disassemble and reassemble it with a drop of thread-locking agent, whether or not one intends affixing a diopter.

[Maggie_O]

I am no optician but I cant see how the Leica diopter of -0.5 can be at reading distance. My vision at about 6 feet is excellent so the standard -0.5 works best for me.

 

Jeff

 

That's good news for me, as my reading glasses are between 1.25 and 1.5, so the standard VF should work for me.

 

Edit: X-posted too soon- OH NO!!! I won't be able to focus my new camera?!?!??

[wlaidlaw]

I apologise, I had completely forgotten about the dispicable insufficiency of the magnifier's assembly. One would be well-advised to disassemble and reassemble it with a drop of thread-locking agent, whether or not one intends affixing a diopter.

 

Vinay,

 

I have a problem with doing this. Thread locker by design, creeps (there is a specific word for this but it escapes me at the moment) and I can just see it getting on the one of lenses of my GBP199 magnifier and then being unable to undo it because the thread is now locked. You would also have to use very low strength thread locker. Nail varnish might be safer as a droplet of acetone will immediately soften it and it is more viscous to start with.

 

Wilson

[pekem]

Howard said:

"You use whatever is your medium-to-far distance correction if you wear glasses. It _is_ simple, though a little of what everyone says is correct."

 

Thank you Howard. Leica UK have just confirmed to me that you are indeed correct.

[pklein]

This thread came at a very good time for me. I just was at the optometrist yesterday. I'm at that time of life when my vision is changing every 9 months or so.

 

I told him about the viewfinder -0.5 correction and 2 meter virtual distance. And how my new glasses were OK for focusing, but the trial contact lens was not. And I brought a Leica body with me. The optometrist held a several of his test lenses between my eye and the camera, asked me to focus my camera on his eye chart. Tried four different lenses, asking me in pairs, which is better, this one, or that one?

 

He changed the contact prescription slightly, and now I can focus easily again.

 

This is important for me, because I can only use my glasses with 50mm and longer lenses on a film M, or 35mm on the M8. I either have to use contacts or constantly take my glasses off to use a 35mm (film) or 28mm (M8).

 

--Peter

 

"Free the Presbyopic Six!"

"I can't read this sign, either."

(from a recent ad for an optical company, showing Baby Boomers demonstrating and holding signs in front of a courthouse, as in the 60s.)

[ho_co]

Howard said:

"You use whatever is your medium-to-far distance correction if you wear glasses. It _is_ simple, though a little of what everyone says is correct."

 

Thank you Howard. Leica UK have just confirmed to me that you are indeed correct.

 

Thanks for the thanks!

 

But I may lose my curmudgeonly credentials if I start giving good advice...

 

--HC

[lars_bergquist]

Seems this dioptries thing needs some cleaning up. This is just a different way of denoting the refraction ('strength') of an optical system:

 

Dioptries = 1m : focal length in metres

 

so that a lens, an eyepiece etc. which brings rays from infinity to a focus of 2m has a strength of (+) 1 : 2 = +.5 dioptries. Conversely, a lens of +2 dioptries has a focal length of .5m. (Lenses of negative power, i.e. spreading lenses, have minus dioptries.)

 

Most SLR cameras have used finder eyepieces of c. +1 diopter, so that the apparent viewing distance was about 1 metre. Leica M has always used +.5, so that the apparent viewing distance to the frame lines and the RF patch (which is not by definition the same thing as that to the subject) is 2 metres.

 

I am badly presbyopic, actually oversighted so that I cannot see even the horizon sharply, but I use the M without any problems. How? Progressive specs. You will learn very quickly to place, by instinct, the finder eyepiece so that you see the RF patch sharply through the appropriate area of your spectacle lens. It doesn't slow me down the least.

 

This is also the cure for astigmatism. You can in theory order an empty correction lens mount from Leica and have your own optician mount an appropriate cylindrical lens in it. But this would work only with the camera in one orientation. Rotate it ninety degrees and you will be even worse off than with no correction! But if your specs correct for astigmatism, then you are OK because even though you rotate the camera, your specs will keep their normal orientation vis-a-vis your eyes.

 

The old man from the Age of Frame Finders

[wlaidlaw]

Seems this dioptries thing needs some cleaning up. This is just a different way of denoting the refraction ('strength') of an optical system:

 

Dioptries = 1m : focal length in metres

 

so that a lens, an eyepiece etc. which brings rays from infinity to a focus of 2m has a strength of (+) 1 : 2 = +.5 dioptries. Conversely, a lens of +2 dioptries has a focal length of .5m. (Lenses of negative power, i.e. spreading lenses, have minus dioptries.)

 

Most SLR cameras have used finder eyepieces of c. +1 diopter, so that the apparent viewing distance was about 1 metre. Leica M has always used +.5, so that the apparent viewing distance to the frame lines and the RF patch (which is not by definition the same thing as that to the subject) is 2 metres.

 

I am badly presbyopic, actually oversighted so that I cannot see even the horizon sharply, but I use the M without any problems. How? Progressive specs. You will learn very quickly to place, by instinct, the finder eyepiece so that you see the RF patch sharply through the appropriate area of your spectacle lens. It doesn't slow me down the least.

 

This is also the cure for astigmatism. You can in theory order an empty correction lens mount from Leica and have your own optician mount an appropriate cylindrical lens in it. But this would work only with the camera in one orientation. Rotate it ninety degrees and you will be even worse off than with no correction! But if your specs correct for astigmatism, then you are OK because even though you rotate the camera, your specs will keep their normal orientation vis-a-vis your eyes.

 

The old man from the Age of Frame Finders

 

Lars,

 

I use Varifocal spectacles and whereas I agree that you can nod your head up and down like a chicken to find the correct part of the spectacle lens, which gives you best vision, you have the distinct downside of often getting a doubled image. As you are already trying to get a double image to overlap in the RF patch, this can often be a considerable distraction. I would much prefer to to use the M8 without glasses and I can manage up to about 35mm lens f2. Longer or wider open, I need my glasses and or the magnifier for additional focus accuracy.

 

Wilson

[Guest tummydoc]

Lars, your account is 100% accurate. People who need only single-vision correction or only mild correction both near and far can often get by quite well with a single diopter correction, leading to a body of anecdotes that go to support false assertions. Someone who for example requires a -3 or stronger correction for distance, as well as a +1,5 or greater 'add' for reading distance, will not be able to see subjects in the viewfinder or rangefinder (even if they can see the patch outlines sharply) clearly using a single corrective diopter. Of course someone will no doubt ring in with their personal contradictory anecdote, just as often when I'm admonishing someone to cease smoking I'm regaled with a story of their great-uncle who smoked 6 packs a day and lived to be 110

[gravastar]

My eyes have very limited accommodation and although I can get by with a single correction lens for far subject distances it's useless for anything nearer than about 12 feet unless I change to a stronger correction.

 

Except for very wide angles I've found the best compromise is to use a magnifier with adjustable correction. Most often I use a longer focal length for close up portraits and the solution suits me well. The effective rangefinder base length is multiplied by the magnification factor, helping focus accuracy. I'm all for the M8 having an adjustable correction.

 

I have a similar problem with the 21/14/28 finder. The correction needed changes with focal length setting and subject distance ....

 

Bob.

[lars_bergquist]

Lars,

 

I use Varifocal spectacles and whereas I agree that you can nod your head up and down like a chicken to find the correct part of the spectacle lens, which gives you best vision, you have the distinct downside of often getting a doubled image. As you are already trying to get a double image to overlap in the RF patch, this can often be a considerable distraction. I would much prefer to to use the M8 without glasses and I can manage up to about 35mm lens f2. Longer or wider open, I need my glasses and or the magnifier for additional focus accuracy.

 

Wilson

 

Strange, I do not have this double image problem. Also, I prefer shooting with the specs I normally use. Having to do the infamous 'specs on – specs off' drill is no way to do action photography. One could just as well use a SLR.

 

The old man from the Age of Frame Finders

[wlaidlaw]

Strange, I do not have this double image problem.

 

The old man from the Age of Frame Finders

 

It is of course because I am using Zeiss Varifocals without 6 bit coding, which are therefore incompatible with a Leica camera.

 

Wilson