Viewfinder Markings The standard KatzEye™ screen for the Canon 550D/600D/650D does not have the focus area rectangles marked like the original screen. In addition, the red dots in the viewfinder will not light when the AF points are activated. For those users that wish to have the focus area rectangles marked, this available as an option. If you want the AF area rectangles, please be sure to select the appropriate option below when adding the screen to your cart. Please be aware though, that even with the rectangles marked, the red dots will still not light. All other viewfinder information displays function as intended. The lack of the indicator dots and/or rectangles has no effect on the camera’s ability to autofocus. In addition, the LCD on the back will allow you to select your focusing point and the green light in the viewfinder will blink for focus confirmation.
Metering Information The KatzEye™ focusing screen for the Canon 550D/600D/650D has little to no effect on light metering in Evaluative or Center Weighted metering modes. However, because of the presence of the prism, Partial and Spot metering modes are slightly affected, depending on the lens in use. Suggested exposure compensation values for each of the metering modes are as follows:
| Aperture | Evaluative | Center Weighted | Partial | Spot |
| 1.4 | 0 | 0 | 0 | 0 |
| 2.0 | 0 | 0 | 0 | 0 |
| 2.8 | 0 | 0 | 0 | 0 |
| 4.0 | 0 | 0 | -0.6(S), -1(O) | -1.6(S), -2(O) |
| 5.6 | 0(S), -0.3(O) | -0.3(S), -0.6(O) | -1.6(S), -2(O) | -4.0(S), -4.3(O) |
(S) = Without OptiBrite Treatment
(O) = With OptiBrite Treatment
0 = No exposure compensation required.
NR = This combination is not recommended. Use an alternate light metering mode or manual exposure settings.
Note: These exposure compensation suggestions are a recommended starting point only and actual results may vary depending on conditions. Users are advised to take a test photo and check the histogram before beginning any critical work. Apertures indicated in the above chart are the lens maximum aperture as indicated on the lens body and are not affected by the actual aperture chosen for a given photo.
Metering test results presented are based on testing of the 550D model. While results are expected to be similar for the 600D and 650D, users of these camera models are strongly encouraged to take a test shot and check the histogram before beginning any critical shooting.
The “Plus” Prism The KatzEye™ focusing screen for the Canon 550D/600D/650D 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, a detailed installation guide, with plenty of high resolution photos, is available for download here.
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 are happy to complete this service 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.
Brightness Enhancement
Like all screens made by KatzEye Optics, the Canon 550D/600D/650D screen can be OptiBrite brightness enhanced for the ultimate appearance. The OptiBrite treatment has little to no additional affect on light metering in the Canon 550D/600D/650D beyond the effect caused by the prisms (described under Metering Information). Click here for more information about the OptiBrite treatment.
