OM-PC Focusing Screen Transplant

[Dean Cho]

I have two 2-13 and one 2-4 Lumi-micron focusing screens for my OM-4T cameras. They are terrific, very bright, easy to focus screens and I really wanted another one for my OM-4 camera, but they are almost impossible to get these days, even on a well known auction site.

I had heard that OM-PC cameras also have Lumi-micron focusing screens that are essentially the same as a 2-13 screen. So I bought a OM-PC camera parts body off of EBy for $13.00. After getting the camera, I found out that it was fully working and actually took some nice pics with it, although it had a battery drain problem. After some handwringing about killing a functional camera, I finally harvested the OM-PC's focusing screen and compared it to a 2-13 screen. THEY ARE NOT THE SAME, WITH THE 2-13 SCREEN BEING NOTICEABLY MORE CLEAR BEING EXAMINED SIDE BY SIDE OUTSIDE OF THE CAMERAS.

However, after installing the OM-PC screen into my OM-4, I can say it is a definite improvement over the standard 1-13 screen, being somewhat brighter and more contrasty. The brightness level of the OM-PC screen is somewhere between that of a 1-13 and 2-13 screen. You do have to be careful in installing the screen, as it lacks the tab of a 1-13 or 2-13 screen so that you can easily and mistakenly install it upside down which will throw your focusing off. The screen has to be installed frosted side up.

 

[nikku]

Dean, good info. I happened to run across a 2-4 screen on KEH and snapped it up. I intend on using it in my OM-2n since it won't interfere with the automatic metering, but I'm a little hesitant to file down the tab myself. I thought about getting an OM-PC for a while for the express purpose of getting another screen, but like you I don't like the idea of ruining a perfectly good camera just for one part. The fact that it's not quite the same as the 2-series screen makes me feel a little better about my decision to spend a little more on an actual screen.

Incidentally, my OM-1n has a 1-4n screen in it currently, and while nice, I actually prefer the 1-4 screen because it has a "rougher" microprism pattern that is easier (to me) to focus.

 

[Trius]

Dean: Did you have 1-series screen in your OM-4? That seems strange, and I think it would give incorrect readings and incorrect manual exposures.

I have thought of buying an OM-PC for the express purpose of harvesting the screen for use in an OM-1 or OM-2. I would send both bodies to John, have him do the transplant and adjust the meter in the OM-1 or OM-2, and keep the rest of the PC for his parts bins. I'd even use an OM-2SP for that.

 

[Dean Cho]

Dean: Did you have 1-series screen in your OM-4? That seems strange, and I think it would give incorrect readings and incorrect manual exposures.

The 1-13 screen came standard on the OM-4 and OM-4T. The 2-13 screen was only standard on the OM-3Ti. The focusing screen used on an OM-3, OM-3Ti, OM-4, or OM-4T has no effect on the exposure readings, as the exposure reading is taken from the metering cell in the mirror box, as opposed to metering occurring in the prism area like the OM-1 or OM-2 (for manual metering). That's why you can use the 2 series screens without modifying the camera's meter on an OM-3, OM-3Ti, OM-4 or OM-4T, but need to adjust exposure in an OM-1 or OM-2 to use the 2 Series screens.

Judging from the brightness difference, some adjustment in an OM-1 or OM-2 will also be necessary if an OM-PC screen is used.

 

[Dean Cho]

Incidentally, my OM-1n has a 1-4n screen in it currently, and while nice, I actually prefer the 1-4 screen because it has a "rougher" microprism pattern that is easier (to me) to focus.

I have a 1-4N screen and have used the older 1-4 screen as well. Both are very good screens where you focus off of the matte area (no microprism or split image). I like the 1-4N better in an OM-4 or OM-4T, because there is a circle in the middle that matches the spot metering area of these cameras. In an OM-1n or OM-2n, I like the older 1-4 screen because the matte area is ground slightly rougher and therefore is slightly easier to focus.

 

[nikku]

I have a 1-4N screen and have used the older 1-4 screen as well. Both are very good screens where you focus off of the matte area (no microprism or split image). I like the 1-4N better in an OM-4 or OM-4T, because there is a circle in the middle that matches the spot metering area of these cameras. In an OM-1n or OM-2n, I like the older 1-4 screen because the matte area is ground slightly rougher and therefore is slightly easier to focus.

Have you used the 2-4 screen? How fine is the microprism pattern on that screen? Comparable to the 1-4 or 1-4N?

 

[Dean Cho]

Have you used the 2-4 screen? How fine is the microprism pattern on that screen? Comparable to the 1-4 or 1-4N?

I have used the 2-4 screen. The matte field is ground pretty fine -- more fine than either the 1-4 or 1-4N screens, which presumably is necessary to achieve its level of brightness. That said, I find it focuses at least as easily as (if not better than) either the 1-4 or 1-4N screens for most lenses and under most lighting conditions.

 

[Trius]

The 1-13 screen came standard on the OM-4 and OM-4T. The 2-13 screen was only standard on the OM-3Ti. The focusing screen used on an OM-3, OM-3Ti, OM-4, or OM-4T has no effect on the exposure readings, as the exposure reading is taken from the metering cell in the mirror box, as opposed to metering occurring in the prism area like the OM-1 or OM-2 (for manual metering). That's why you can use the 2 series screens without modifying the camera's meter on an OM-3, OM-3Ti, OM-4 or OM-4T, but need to adjust exposure in an OM-1 or OM-2 to use the 2 Series screens.

I was talking about manual exposures with an OM-4/OM-3, but probably forgot the mirror is partially silvered, permitting metering even when the mirror is down. My bad.