The viewfinder's meter presentation is a digitized analog display. The camera shows the shutter-speed, but oddly enough, not the aperture. This lack of aperture setting in the viewfinder has always been the most criticized design decision in the entire OM series. Whatever technical reason prevented the aperture setting from being displayed must have been serious enough to warrant foregoing the necessary interconnects required to provide it. For years, not ever having an aperture reading didn't seem to bother me, but once experienced, it is difficult to go without. I would now agree with the critics that this is a most unfortunate omission.  As a "street photography" camera, this is a non-issue, but when working through the viewfinder, in low-light conditions, or on a tripod, this makes it less than ideal. But to put this into perspective, very few non-35mm cameras had aperture or shutter-speed display in the viewfinder. I consider this design an irritation, but not a show-stopper.  Having used the OM system since 1986 I never really considered it an issue as I was used to it.

The viewfinder's exposure metering scale is oriented to favor adjusting the aperture dial. If you need to move the meter to the left, you turn the aperture ring to the left. If you need to move the meter to the right, you turn the aperture ring to the right. Unfortunately, the shutter-speed ring moves opposite of the meter, but this was necessary to maintain the relationship between aperture and shutter-speed rings.

The exposure meter of the OM-3Ti is normally center-weight averaging. The sensor for the meter is within the mirror box itself and measures the light reflecting off of a sub-mirror hidden behind the semi-silvered main mirror. As such, the metering is unaffected by light entering the viewfinder nor is it affected by any changes to the focus screen which is user-swappable. The metering is a digitized "match-needle" style analog display. This style of display is simplistic and changes to exposure are sensed and does not require "reading" the display. This means the eye does not need to look away from the focus screen.  Again, I feel that this is a design aspect of the OM series similar to the Leica M-series which changes the user emphasis from operating the camera to capturing the "decisive moment".

View through the viewfinder with meter in center-weight averaging mode. The "+" and "-" are each 4 stops from middle-tone.

If the exposure meter is normally center-weight averaging, how then does it do multi-spot metering and does anybody actually use it?  There are only four controls for the metering system in the OM-3Ti:  Spot-meter, Hi-light, Shadow and Clear.

Every time you press the spot-meter button it takes a meter reading of the center of the frame (outlined by a circle on the focus screen). This then marks a dot above the "analog" bar-scale which moves when you adjust exposure. Each time you press the button, another dot is placed on the scale--up to eight readings are stored in memory with a FIFO (first in, first out) replacement. The primary bar-scale will average these spot readings together.  The display contains markings for one, two and three stops over and under. For those people who understand the "Zone System", it is just a matter of adjusting your exposure to place these spot-meter "dots" on the scale within the exposure range of the film loaded in the camera. In fact, multi-spot enabled OM bodies are frequently named the best light-meters for Zone-System metering for large-format photography.

View through the viewfinder in multi-spot metering mode. Note--the highest value in this exampe is 1 and 2/3 stop above middle tone, and the shadow spot is 1 stop below middle tone. Adjusting the shutter speed or aperture moves the dots and the bar-scale.

For example, I can take a spot reading of a highlight, a midtone and a shadow. Three dots will appear on the display. If I'm using a film with six stop exposure range, I'll make sure that all three dots appear within the +/- 3 stop marks. Of course, I can bias my exposure to place a highlight or shadow anywhere I want on the scale.  Digital cameras are capable of producing a histogram of an image. The multi-spot scale, with the "dots" is a poor-man's variation of the histogram where we are able to define our bright areas and dark areas of a scene and like a histogram we are able to move these points around to place them within the acceptance range of the film. “Expose To The Right” is actually “Expose To The Left” on this metering scale.

The Hi-Light and Shadow buttons are quite unique to the OM-3 and OM-4 series bodies. Take a spot-meter reading of a high value and press the Hi-Light button. This tells the camera to bias the meter display by offsetting the display by -2 stops. This will place the highlight at the maximum which most films will maintain detail (approximately Zone VIII-IX). If you press the Shadow button instead, the meter display will bias +2 2/3 stops which places the selected point at approximately Zone I-II. For several years I owned an OM-4 and then an OM-4T and never used the Hi-Light and Shadow buttons. In the past two months I've started experimenting using them and have come to really appreciate their simplicity and power. They really do work, and they can quickly satisfy the needs of black and white photography where you are concerned with preservation of a highlight or shadow. The old method of "expose for the shadows, develop for the highlights" is a perfect application of the Shadow button.