rachaelseven Offline Upload & Sell: Off
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I hope I'm not violating board rules, but since it's been asked about, I'll post the information regarding the 20D split prism focusing screen here and beg understanding from the monitors if I have crossed the line into commerical posting....
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General and Metering Information
The screen I have available 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 the Nikon FM3A and many other SLR's. They are a direct replacement with no modifications required to the camera at all. The split prism with microprism ring is a great combination and it doesn't seem to have any significant effect on metering with the 20D. In evaluative or centerweighted modes, it tested dead on. In the partial mode, it appeared to overexpose a bit, but it is well within the range of exposure compensation available on the camera. The focus indicator rectangles and original composition circle will show on top of the focusing aids of the new screen, so all AF information is retained. The screen will also have NO effect on the functioning of the autofocus sensors of the camera.
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Installation
Installation is not terribly difficult, but it does require care. Instructions for the 20D are not available, as Canon never officially released a replacement screen. But, someone wrote instructions for the 300D which are available at http://groups.yahoo.com/group/canondigicamhacking/files/How%20To%20Remove%20the%20Canon%20Digital%20Rebel%20Focusing%20Screen.pdf. The basic instructions for the 20D are the same as the 300D and the pictures in the posted instructions give a good idea of what's involved. There are only really two points that are slightly different: 1. if the shim is removed or dislodged, it has to be inserted a certain way. The top edge (furthest from the mirror) has to be put in first and then the other edge tipped down into place. 2. Because of the 2nd screen with the composition marks, it seems to be more difficult to get the installation dust free. Keep the environment very clean and use the air puffer liberally at each step. Beyond these two points, it's pretty much the same as the 300D installation described in the above mentioned PDF. If you don't feel confident installing it, your local camera shop should be able do it for less than $50. If you want me to install it, I can, though it's not my normal procedure. I charge $25 for the installation, plus actual cost for the return shipping.
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Optional Brightness Enhancement
Although the screens look good and they are fairly bright as they are, if you want the ultimate appearance I can have it treated to improve its brightness. I use a process called Hi-Lux which is provided by Maxwell Precision Optics. The treatment will increase the apparent brightness by about 2 stops or more and is particularly useful for slower lenses or low light. Without the treatment, the screen does appear slightly "rougher" than the original, but not much. This actually allows for easier manual focusing using the matte portion of the screen. With Hi-Lux treatment, the screen looks pretty similar to the original, though it still retains most of its improved focus ability. And of course, the prism areas are still there for precision focusing. The extra brightness is difficult to quantify exactly. It tends to increase with smaller aperture. At f1.4, for example, you can barely see the line between the two halves of a screen that’s been half-treated for demonstration purposes – I would say maybe ½ to 1 stop equivalent. But, as the aperture gets smaller, the improvement gets greater. By f6.3, I’d say it’s good for a full 2 stops. By f16, it might be equivalent to 3 stops or more. It’s definitely a pleasant change. For the record though, Hi-Lux will do nothing to resolve the fact that half the prism blacks out around f6.3 or so – that’s just a limitation of optics related to the angle of incoming light. If you want the Hi-Lux treatment, it will cost an additional $50USD.
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Logistics
The 20D split prism focusing screen costs $110USD, which includes USPS Priority Mail shipping in the USA. International or alternate shipping methods are charged at actual cost. As I mentioned, Hi-Lux treatment adds an additional $50USD, if you desire it. I take payments through PayPal www.paypal.com to the account [email protected]. You can use your choice of credit cards or any other method they accept. When you place your order, please be sure to tell me what you've ordered and include a complete shipping address with phone number.
I make the screens to order, so it will take 7-10 days to process your order. Hi-Lux treatment adds an additional 10 -14 days or so, as I have to send the screens to Maxwell and back for the process.
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If you have any other questions, feel free to email me at [email protected]. I'll get a proper website up within the next few weeks, I promise. I had no idea the demand would be so great for these and right now, I'm just struggling to keep up with orders. Thanks so much for your interest.
Take care,
Rachael Katz
Katz Eye Optics
www.keoptics.com
Edited by rachaelseven on May 05, 2005 at 08:34 AM GMT
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