The KatzEye™ focusing screen for the Canon 20D is a laser matte with a split prism circle and a microprism collar, very similar to the one you would find in many classic SLRs. It is a direct replacement with no modifications required to the camera at all. The split prism with microprism ring is a great combination for focusing in a variety of situations. The screen will have NO effect on the functioning of the autofocus sensors of the camera and the AF point indicators will continue to function as normal.
The KatzEye™ focusing screen for the Canon 20D has no effect on existing viewfinder information. All active viewfinder information, including the focusing points will still function normally. Metering Information
The KatzEye™ focusing screen for the Canon 20D has only a slight effect on light metering. In evaluative or centerweighted modes, it can be expected to be within 1/3 f-stop in most conditions. In the partial mode, it will increase exposure from 1/3 to 1 stop, depending on lens and aperture, but it is well within the range of exposure compensation available on the camera. For maximum metering accuracy, it is recommended to use centerweighted average metering mode or evaluative mode with an off-center focusing point selected when shooting with lenses slower than f3.5. In the event that partial metering mode or evaluative mode with center point selected must be used with a slow lens, it is advisable to set an appropriate exposure compensation by reading the histogram of a test shot. The “Plus” Prism
The KatzEye™ focusing screen for the Canon 20D 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.
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, a detailed installation guide, with plenty of high resolution photos, is available for download here.
If you don’t feel confident installing the KatzEye screen, your local camera shop should be able to complete the installation for you. Since the KatzEye screen is a direct replacement for the original, any competent shop should be able to handle the installation and the original screen can be reinstalled at any time, should you so desire. If you want us to install it at KatzEye Optics, we would be more perform the installation for you. 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.
Like all screens made by KatzEye Optics, the 20D screen can be OptiBrite brightness enhanced for the ultimate appearance. Click here for more information about the OptiBrite treatment.
All KatzEye™ focusing screens are available with optional guide patterns to aid in proper composition. We have a variety of standard patterns of grid lines and crop guides available or we can provide a custom pattern to your design. Click here for more information about our composition aid patterns.
All KatzEye™ focusing screens are custom made to order and are usually not available to ship the day the order is placed. As of 05/22/2013 production is running normally and most orders will be shipped in 4-6 business days from the date they were placed.