Viewfinder Markings

The KatzEye™ focusing screen for the Nikon D300/D300s has NO effect on existing viewfinder information. All viewfinder markings, including focusing points and on-demand grid lines will still function normally.

Metering Information

The KatzEye™ focusing screen for the Nikon D300/D300s shows only a very minimal effect on light metering. In our testing, the KatzEye™ screen tested within factory tolerance in nearly all situations. The only exception is when using spot metering mode with lenses having a maximum aperture smaller than f2.8 (higher numerical f-stop). With lenses slower than f2.8, it is advisable to use either centerweighted average metering or matrix metering to preserve accurate meter response. In the event that spot metering mode must be used with a slow lens, it is advisable to set an appropriate exposure compensation by reading the histogram of a test shot. Detailed test results for each of the three metering modes are as follows:

• Matrix Metering Mode: Our testing showed matrix metering mode to be within factory tolerance for all lenses having a maximum aperture of f5.6 or larger (lower f number).
• Center Weighted Average (CWA) Metering Mode: Our testing showed CWA metering mode to be within factory tolerance for all lenses having a maximum aperture of f5.6 or larger (lower f number).
• Spot Metering Mode: Our testing showed spot metering mode to be within factory tolerance for all lenses having a maximum aperture of f2.8 or larger (lower f number). Lenses having a maximum aperture smaller than f2.8 (lager f number) will show a shift toward increased exposure. The shift will be greater for lenses with smaller maximum apertures. When using spot metering mode, it is strongly advised to first take a test shot, check the histogram, and adjust exposure compensation as required. Starting points for exposure compensation are as follows: f3.5 lens: -1EV, f4.0 lens: -1 1/3EV, f5.6 lens: -2 1/3EV.

The “Plus” Prism

The KatzEye™ focusing screen for the Nikon D300/D300s is available exclusively in the KatzEye™ “Plus” version . The “Plus” version has a unique prism design which delays the prism ‘blackout’ phenomenon until well after f11. Ordinary split prisms will black out by about f5.6, rendering them difficult to use with slower zoom lenses, teleconverters, or in extreme macro photography... but not the KatzEye™ “Plus”. More information about the KatzEye™ “Plus” can be found here.

Installation

The KatzEye™ screen is a direct replacement for the original and no modifications to the camera are required. The installation requires no special tools or skills, but it does require working in tight spaces. If you are not confident in your vision or dexterity, professional installation might be advisable. For those users installing the screen themselves or for those taking the camera to a local shop, complete installation instructions, with plenty of photos, are available for download here. We will also include an installation tool to assist in the manipulation of the screen retaining wire, but the installer should still expect to provide their own tweezers, gloves, lens tissue, and other common items.

If you do not wish to perform the installation yourself and you do not have a trusted local shop, we’d be happy to install your new focusing screen for you here at KatzEye™ Optics. Please see the Installation Service page to order installation with your focusing screen. Installation service at KatzEye™ Optics costs $65, plus the cost of return shipping of your camera.

Brightness Enhancement

The original Nikon D300 and D300s screens are optimized for automatic focusing. As such, they are very bright, but give a very poor indication of DOF and have very little ‘snap’ (indication of when focus is achieved). The KatzEye™ screen is optimized for manual focus applications and has a much improved matte surface. The matte surface on the KatzEye™ screen is designed to give excellent DOF indication and a very sharp ‘snap’. However, because of this, the standard KatzEye™ screen for the D300/D300s is slightly darker than the original Nikon screen, particularly at smaller apertures. If viewfinder brightness is a concern for you, consider the optional OptiBrite enhancement. With the OpitBrite treatment, the brightness of the KatzEye™ screen is comparable or slightly brighter than the standard Nikon screen. The OptiBrite treatment affects only the matte portion of the screen; it had no effect on the prism and the OptiBrite treatment will have no significant effect on light metering in the D300 or D300s. Click here for more information about the OptiBrite treatment.

Composition Aids

Although the Nikon D300 and D300s have very nice on-demand grid lines which remain functional with the KatzEye™ focusing screen, additional patterns can be added to the focusing screen if you require different composition aids. We can meet your needs with a variety of standard patterns of grid lines and crop guides or we can provide a custom pattern to your design. Please be aware that composition aid patterns added to the KatzEye™ focusing screen will be permanent and will not turn off like the in-camera grid lines. Click here for more information about our grid line and crop guide options.