Interesting- for those that don't already know

from the DP Review EOS 300D forum:

 

Folks

I have actually replaced my focusing screen with another containing a

split prism and micro-prisms. I took my 300d in to a good camera

repair facility in Cape Town, and asked them if could could be done.

After hearing the usual disclaimers about Canon's warranty, the guy

showed me how easy it is to remove the focusing screen. I did this,

and used the existing focusing screen as a template to cut smaller a

focusing screen from an old, dead Pentax K1000. I put it in, and

viola!, it works!! I will make up a series of instructions and photos

to explain to everybody how it is done. This will go onto my website

http://www.sdeklerk.com . On this site is a comparison between the

Sigma 70-300 DL and the 70-300 APO. There were some issues worth

mentioning:

 

1. The mod is completely reversible, leaving not trace to Canon's

technicians that you were there, should a warranty claim arise.

(Phew!) When unclipping the screen, 3 thing come out of the body, The

retaining clip, the focusing screen and a brass spacer shim. I just

put the new screen and the retaining clip back.

2. The metering and autofocus still works, this is proven by about

1000 shots I have taken since the mod.

3. You cannot see the red focus dots anymore, just vey dimly. Which

are is selected can now only be seen on the back LCD.

4. The viewfinder is darker with the K1000 screen. In twilight it is

very difficult to do manual focus on a dark spot, you have to find a

light point or something. In such conditions the original

5. I have not got the calibration right 100% (although autofocus is

calibrated spot on). It could be overcome however, because the edges

of the screen needs to be filed down so that the height at which it

seats matches properly. This could be seen from the original 300D

focusing screen (carefully stored away). I have started filing it

down, and it gets better at every filing session.

 

I got 6 screens from the camera repair shop. The fist one got

destroyed as a result of my experiments, the second is scratched and

filed past the correct calibration point, and the third is in the

camera, also somewhat soiled. I will still complete it's calibration,

after which I will measure it's dimensions and tolerances do make

myself a nice one from the next screen, one with composition lines

and a nice central area of micro and split prisms.

I will keep you folks posted.

 

Regards

 

Stephan de Klerk

Cape Town, South Africa

Kind of related question... Can somebody tell me where can I get a focusing screen for Elan II? The repair ficility (Ritz Camera) asks about $150 for replacing the screen; I believe I can do it myself, if I can get one.

look for a dead elan II on ebay (should be less than $20) sold for spares.

If not ebay, try all the local camera repair shops. I know a lot of areas tend not to list them, so I recommend asking at a few pawn shops since most have their cameras checked by them.

Call Canon USA. They can connect you with their parts dealer. I've bought several parts from them and service was fast. You don't have to know the part number, just tell 'em the camera model number and item and they'll figure it out.

 

Concerning the focusing screen mod, Canon makes 3 or 4 different MF screens (various combos of microprisms and spilts for the EOS 1 series). Once you have your cutting technique down, the Canon screens are much brighter than the old K1000 screens. Also, there are pro outfits that specialize in screen mods if you don't want to do it yourself.

If the mod screen is makes the viewfinder darker, doesn't this throw metering off since the meter is up there?

Paul makes an interesting point.Older focusing screen are frankly pretty dim,i wonder how that works out?

<BR>In general stephen CONGRATULATIONS for doing this and proving it so easy!!

<BR>I've known for some time that allmost all eos screens are removable and did plan one day to cut down some other screen to fit my 300D.I'm just gald someone did it and proved that it is easy.

<BR>I imagine (from some experience) that calibration will be unessesary *IF* the original screen and the replacement both sit flush-with no built in raised sections around the edge for example.Testing/calibration would be a doddle with digital thankfully.

<P>As an aside...my brother modified his 3000/rebelG screen for grid lines with a razor.He was abit clumsy so one line is crooked but a razor works very well,giving nice thin crip lines

yeah it does effect the metering somewhat, I'm not sure how much. I would guess the only workaround for that is either another hack or a handheld meter. That's the cost of experimenting though. Weigh the pros and cons of each and decide on what is acceptable for each individual.

Why would the screen affect AF at all?

same thing as trying to use autofocus in some low light situations, as with mine on some occassions, it can't see enough to autofocus.

The light falling on the AF sensor does not pass through the focusing screen though. Focusing screen will not make a difference to AF no matter what. You can take it out and AF will still work.

Really? I'm confused. I thought that until the mirror flipped up, the only path that light can take after going through the lens is through the focusing screen. I was under the impression that the AF sensors were in one of the roof prism's (or pentamirror's) upper sides.

 

Where else can the camera meter (and focus on) a scene coming through the lens before the mirror flips up, unless the camera contains a pellicle mirror?