The Katz Eye™ 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’d 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.
Viewfinder Markings The Katz Eye™ 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 Katz Eye™ 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 Katz Eye™ focusing screen for the Canon 20D is available exclusively in the Katz Eye™ “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 Katz Eye™ “Plus”. More information about the Katz Eye™ “Plus” can be found here.
Installation
The Katz Eye™ 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 and the link will be included with your purchase.
Should you wish to preview the procedure, one of our customers, Doug Kerr, was kind enough to write a set of instructions based on his own experience, which are available here.
If you don’t feel confident installing the Katz Eye screen, your local camera shop should be able to complete the installation for you. Since the Katz Eye 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 Katz Eye 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 Katz Eye™ Optics costs $65, plus the cost of return shipping of your camera.
Brightness Enhancement
Like all screens made by Katz Eye Optics, the 20D screen can be OptiBrite brightness enhanced for the ultimate appearance. Click here for more information about the OptiBrite treatment.
Grid/Crop Lines
All Katz Eye™ focusing screens are available with grid patterns or crop lines. We have a variety of standard patterns available or we can provide a custom pattern to your design. Click here for more information about our grid/crop line patterns.
All Katz Eye™ focusing screens are custom made to order and are usually not available to ship the day the order is placed. As of 07/09/2008 production is backlogged due to very heavy order volume and most orders are being completed in approximately 2 weeks from the date the order is placed.
