PDA

View Full Version : diopter needed


pete
01-30-2005, 11:26
just bought a new pair of glasses, and brought the r-d1 with me for the exam. i would like a diopter, and did not know how to decide which one, so after the exam i asked if i could look thru the one(s) he thought might be right(holding them up to the r-d1 finder). the -.5 works well for me...only thing wrong is that i cannot find one...

can anyone help?

thanks in advance

pete

ps .....love this camera

rover
01-30-2005, 12:54
Pete, I believe the Nikon diopters for the FM3a will fit the r-d1.

pete
01-30-2005, 15:25
rover, i think they will too, but i cannot find a -.5.

rover
01-30-2005, 16:26
You may want to check the specs of the camera. I just looked in the info for the FM3a and the standard eyepiece has a correction of -1. The R-D1 may already be corrected for your sight with the standard eyepiece. I recall reading the reason this was the case with some cameras but cannot recall what it is.

pete
01-31-2005, 04:32
i could see clearer with the -.5 in front of the finder than without it. i doubt there is any builtin correction in the rd-1. also i tried it with the lens (over the eyepiece) on and off, and it was the same both ways.

Huck Finn
01-31-2005, 07:29
Pete, the diopters for the Nikon FM3A will work on the Epson RD-1, as Rover has stated. Nikon does not make a -0.5 diopter in this series. If you choose to use one of these diopters anyway to adjust your viewfinder to the best fit for you, be careful. As Rover stated, the FM3A has a built-in correction of -1.0, so to achieve -2.0, a correction of only -1.0 is needed to the camera's built-in viewfinder. Therefore, the Nikon diopter for this camera that is labeled "-2.0" is a correction of only -1.0 because the other -1.0 is already built into the viewfinder. The correction number for the diopter, in other words, indicates the final correction of viewfinder & diopter combined, not the actual correction factor of the diopter.

Assuming that you are correct & that the Epson RD-1 has no built-in correction, if you want to use a diopter, the closest adjustment would be the Nikon diopter for the FM3a, labeled "-2.0" (part # 2935) since there is no -0.5 diopter made for this camera. However, I would not assume that the RD-1 does not have a built-in adjustment just because it looked the same with & without the eyepiece. The standard correction factor is normally built into the viewfinder itself, not into the eyepiece & the standard eyepiece is neutral. Therefore, using a -0.5 at the eye doctor's office in front of the camera viewfinder may actually have been achieving a total adjustment of -1.5 if the RD-1's viewfinder is corrected. The "-2.0" Nikon diopter would again be the closest adjustment available if the built-in adjustment is -1.0. However, if Epson built in an adjustment of -0.5, the "-2.0" diopter would be exactly what you need.

It seems to me that your first task is to find out from Epson if the RD-1 viewfinder has any correction built in & if so, what it is.

Good luck.

pete
01-31-2005, 08:06
huck, thanks! i was aware of the -1 being built into the nikon camera. the -.5 correction i was using in front of the r-d1 works perfectly for me, and was determined by the prescription for my glasses. if i put my glasses on and look thru the viewfinder, they work as well. this would lead me to believe that there is no correction built into the camera.

with my glasses on its hard to see the complete 28mm frame; hence, my desire for a diopter.

i noticed that the removable eyepiece on the camera has threads on the eye side, making me think that i could get two to make the correction i need. don't know if this would prevent me from seeing the 28mm framelines as with glasses though.

do you know if the nikon diopters are stakable?

Huck Finn
01-31-2005, 08:21
Sorry, Pete, I don't. The eyepiece on my FM3A doesn't have those threads - unless they're under the piece of rubber than runs around the circumference of the eyepiece.

You may be able to get an answer by calling Nikon Customer Service (800-645-6687) or you can e-mail them from the Nikon website.

My key point was not that the FM3A has the -0.1 correction. It was that the diopter designation on for the eyepiece diopter lens describes the effect of the complete viewing system. So, to use another example, a diopter lens with the designation "0" is actually a +1.0 diopter lens. Those who wear glasses must bear in mind the need to subtract one diopter from the prescription value of the eyeglasses when ordering diopter correction lenses - or as in your case, using a diopter in the eye doctor's office that states the true adjustment value.

Good luck with your search.

Huck

jlw
01-31-2005, 09:04
just bought a new pair of glasses, and brought the r-d1 with me for the exam. i would like a diopter, and did not know how to decide which one, so after the exam i asked if i could look thru the one(s) he thought might be right(holding them up to the r-d1 finder). the -.5 works well for me...only thing wrong is that i cannot find one...

can anyone help?

thanks in advance

pete

ps .....love this camera

Your optician seems pretty camera-friendly, so what about asking him/her for some ideas? I wonder if a lens could be ground to your prescription and fitted into the mounting ring of an FM3a diopter corrector.

That way you wouldn't have to worry about the amount of minus diopter (if any) built into the R-D1's finder, since you already know what correction you need in the eyepiece (-0.5).

I've never tried having this done, but I've HEARD that it can be done. And if it can, I'd like to know about it, because I'd also love to have a "prescription" R-D1 eyepiece!

pete
01-31-2005, 09:39
jlw, i wiil ask when i go to pick up my new glasses. will let you know. i guess if it can be done, it could go into the existing eyepiece.