eye correction

[davidknibb]

Got to the point where I need eye correction piece for my Nikon Fa (manual focus). I can no longer see when the screen gives a clear focus.
My reading glasses are +3 diopter - so does that mean that the correction piece I need for my camera is also +3 diopters ? I phoned a couple of camera shops - one had no idea what I was talking about - and the other said that they thought thatthe actual eypeices are not 0 diopters - but -1, so I'd need a +4 - but they didn't really know.

So does any one here know how to relate the strength of reading glasses to the requirments for a camera correction eyepiece ?

Thanks

David

[Roger_Provins]

A long time ago when I was battling with this subject I coped the following from a web source, I've lost the source so I can't credit it.

However here it is...

"Nikon SLR cameras (without built-in adjustable eyepiece correction) have a base dioptre value of minus one. This is why you won't find an accessory Nikon eyepiece dioptre valued at minus one. Minus one is considered the optimum starting point for the majority of SLR users with normal vision. The combination of the camera's viewfinder components and a clear (standard) eyepiece form a virtual image of a subject on the camera's focusing screen that is the approximate equivalent of a viewing distance of one meter.

Each Nikon eyepiece dioptre incorporates a numerical value, represented by a minus value (near-sighted) or a plus value (far-sighted) number, enabling you to select the appropriate dioptre for your vision and your camera model. The eyepiece's dioptre value is, when combined with the viewfinder's minus one value, the end-result value. No combination of the camera's base value of minus one and a given accessory dioptre's value is required to arrive at the final desired value. In other words, if you require a diopter of plus 3, simply add a plus 3 diopter to your camera.

Neutral correction eyepieces do not replace the supplied standard eyepiece. The use of a neutral correction eyepiece will change the dioptre value of the camera from minus one to zero.

To determine which Nikon dioptre value is best suited for you, visit your ophthalmologist, optometrist or dispensing optician. Ask them to determine your dioptre from (your corrective prescription) when viewing an object at distance of approximately one meter. Base your selection on this dioptre value."

Any help?

[davidknibb]

Thanks a lot - most useful.

So thatmeans I want a +3 correction piece.

Ta

David