Nikon Photomic-T Finder

Introduction

The Photomic-T Finder is an eyelevel viewfinder incorporating a CdS exposure meter, designed to function as a "Through-The-Lens" (TTL) system exposure meter. When mounted on the Nikon F camera, it couples with the camera's shutter speed dial and the lens's aperture diaphragm. The meter's indicator needle is visible both on the top exterior of the camera and within the viewfinder field.

This system simplifies exposure calculations, eliminating the need to consider exposure factors for various shooting conditions such as close-up photography or photomicrography.

Characteristics

• Type: Through-The-Lens system
• Measuring range of average brightness: 0.5-16000 cd / m² (with F1.4 lens)
• Aperture scale: F/1.4-F/22
• Shutter speed scale: 2 sec. (with B setting) to 1/1000 sec.
• Film speed scale: ASA 25 - 6400
• Adjustable range of max. aperture of lens: F/1.2 - F/4.5
• Batteries: 2 x 1.35V Mercury batteries (e.g., Mallory PX-13, Eveready E625)
• Weight: 230 g

Mounting the Finder

1. Set the camera's shutter speed dial to any speed except 'T'.
2. Set the lens's aperture ring to F/5.6.
3. Move the slider at the bottom of the Finder so that '5.6' appears in the aperture window on the back of the Finder.
4. Mount the Finder onto the camera top. Press it into position until a click is heard.

Note: For mounting on earlier Nikon F cameras (up to serial No. 6700000), consult your dealer.

To detach the Finder, press the lock button on the back of the camera.

Coupling and Lens Exchange

To couple the Finder to the camera and lens:

1. Rotate the shutter speed selector of the Finder until the small pin on the camera's shutter speed dial fits into the groove on the selector. The selector will turn with the dial.
2. Ensure the slider is coupled to the prong on the lens's aperture ring.

Exchanging the Lens:

1. Set the aperture ring to f/16.
2. Move the slider at the bottom of the Finder to the rightmost position.
3. Attach the lens to the camera via the bayonet fitting.
4. Engage the prong on the aperture ring with the slider.

Exposure Measurement

Full-Aperture Measurement

When the lens is coupled to the Finder via the prong, exposure can be determined with the lens aperture fully open. This allows for the brightest possible viewfinder image for focusing and composing, especially with 'Auto' lenses.

Stop-Down Measurement

For lenses without a coupling prong, or when coupling is prevented by an intermediate attachment (like an extension ring or bellows), exposure must be set with the aperture stopped down to the value actually being used. This method requires specific procedures, especially with certain lenses and finder screens.

Order of Using the Finder

1. Set the film speed (ASA) to match the maximum aperture of the lens.
2. Press the side button on the Finder to switch on the meter.
3. Look through the Finder eyepiece to focus and compose the picture.
4. Adjust the shutter speed selector and/or the lens aperture ring until the pointer needle inside the viewfinder aligns with the indicator. The needle is also visible in the external top window.

Setting Film Speed to Max. Lens Aperture

Ensure the film speed (ASA) is set to correspond with the maximum aperture (F-number) of the lens. Use the Film Speed (ASA) dial on top of the shutter speed selector. Align the film speed number with the maximum F-number engraved on the lens's edge. For example, ASA 100 can be set to F/1.4 or F/2.8 depending on the lens.

Intermediate dots on the film speed and max. aperture scales correspond to specific F-numbers and shutter speeds, aiding in precise settings.

Determining the Exposure

Depress the side button so the top button pops up, revealing a red band. Rotate the shutter speed selector and/or the lens aperture ring until the pointer needle inside the viewfinder centers. The needle's movement corresponds to the rotation of the selector and aperture ring. The meter pointer is also visible externally.

The camera is now ready for taking the picture.

Important Notes

• After use, depress the top button to retract the side button, preventing unnecessary battery drain.
• The shutter speed selector clicks at each marked setting. If the needle doesn't center precisely at a click, adjust the lens aperture ring slightly to compensate.
• When the needle centers at the 'B-2' setting, the correct exposure time is 2 seconds. Use a tripod for this duration. 'T' (Time) exposure is not possible with the Photomic-T Finder; use the 'B-2' setting with a cable release instead.

Using Filters or Close-Up Attachments

A key advantage of the Photomic-T Finder is that exposure factors for filters or close-up attachments do not need to be considered. The exposure decrease caused by these accessories affects both the meter and the film equally, ensuring correct exposure without manual alteration. Similarly, adjustments for lens extension in close-up photography can be disregarded.

Important: Set the exposure after focusing. Do not remove a filter after setting exposure with it attached.

Bright or Dark Scenes

The Photomic-T Finder measures the average brightness across the entire viewfinder image. If a significantly brighter or darker element occupies a large portion of the frame (e.g., bright sky, snow, dark wall), the meter reading may be inaccurate.

To ensure accurate measurement, adjust the camera's position or move closer to the subject so that the intended subject fills a larger part of the viewfinder.

Meter Coupling Range

In extremely bright or dark scenes, the meter needle might stop or move erratically, indicating the scene's brightness is outside the meter's coupling range. For example, with ASA 100 film and an F/1.4 lens, brightness levels beyond F/22 at 1/500 sec. or below F/1.4 at 1 sec. may be out of range.

If the needle movement is discontinuous within the range, try resetting the shutter speed to 1/15 or 1/60 sec. and re-measuring. The minimum coupling brightness varies with the lens's maximum aperture; a wider aperture lens will have a narrower low-light coupling range.

Influence by Finder Screen

Different finder screens can affect meter readings. To compensate, adjust the film speed setting based on the number printed in bold on the table provided, corresponding to the lens type used. For lenses with small maximum apertures, if this adjustment exceeds the maximum aperture limit, reduce the exposure determined by the meter by the number of steps indicated in red in the table.

For example, using a 300mm F/4.5 lens with an H2 finder screen requires a 1-step adjustment. If the meter indicates 1/125 sec. at F/8, change to 1/250 sec. at F/8 or adjust the aperture between F/8 and F/11.

Lens Compatibility and Finder Screen Adjustments

The following table details adjustments needed for various lenses and finder screen types:

Note: Finder screen 'C' should not be used for exposure measurement with the Photomic-T Finder.

Light Entering the Eyepiece

The Photomic-T Finder is designed to minimize light entering from behind the eyepiece. However, in specific situations, using an eyecup is recommended:

• When using the 'stop-down' method with a very small aperture.
• When measuring a dark subject from a bright location (e.g., shade to sun).
• When viewing the external meter window, cover the eyepiece with your hand.

Stop-Down Measurement Procedure

For lenses without a coupling prong, or when coupling is intentionally disengaged:

1. Set the film speed (ASA) to the red dot (F/1.2 position).
2. Move the slider at the bottom of the Finder to the position just before the limit.
3. Determine exposure using the 'stop-down' method (as described on page 11) with the lens aperture set to the value being used.

Note: Finder screens G or H series cannot be used with this method. Refer to specific instructions for Micro-Nikkor lenses.

Micro-Nikkor-Auto 55mm f/3.5

When using the Micro-Nikkor-Auto 55mm f/3.5:

1. Engage the coupling prong on the lens aperture ring with the Finder's slider.
2. Set the film speed (ASA) to the maximum aperture (F/3.5).
3. After determining exposure, reset the diaphragm a half-stop smaller for reproduction ratios of 1:9 to 1:4, and one stop smaller for 1:4 to 1:2.
4. The 'stop-down' method can also be used, with caution to prevent light from entering the eyepiece.
5. For magnifications between 1:2 and 1:1 using an M-ring, set the film speed (ASA) to the red dot and use the 'stop-down' method.

Battery Replacement

The Photomic-T Finder uses mercury batteries, which typically last over a year with proper use. To replace them:

1. Unscrew the lid of the battery chamber.
2. Insert new batteries with the positive (+) side facing outward.
3. Screw the lid back on, ensuring the internal positive (+) mark contacts the battery.

Recommended Batteries: Mallory PX-13, RM-625R; Eveready E625; G.E. No. 625; National M-1D; Toshiba TH-ME (except type Y).

Battery Precautions

• Avoid exposing the meter to bright light at low temperatures (below 0°C) for extended periods, as this may cause errors or temporary malfunction. The meter will normalize as the temperature rises. In cold weather, limit continuous button depression to 3 minutes.
• Battery power drops suddenly when depleted, indicated by the needle ceasing to move.
• Do not dispose of used batteries in fire or heat them.
• Never short-circuit the battery terminals.
• Do not attempt to disassemble or recharge the batteries.
• If the camera will be unused for a long time, remove the batteries from the Finder.