Do different focussing screens affect metering?

[adamadam]

I'm always using spot metering in my 1V.

Was wondering if I put another screen in there ( would like the Ec-S (but apparently it's not compatible with the 1V), so thinking of getting the Ec-L for manual focussing), would the metering be affected?

kthxbai

[catchlights]

depends on the design where the metering sensor is placed, if the sensor is place inside the viewfinder, so light have to pass thru the focusing screen to reach the sensor, of course it will affect the metering.

if you sensor is place under the reflex mirror, the light does not pass thru the viewfinder to reach the sensor, it will not affect the metering.

[adamadam]

I think the AE sensor on the EOS slr is inside the viewfinder, so based on that and your answer, it will affect metering.

Do you or anyone here have any experience with how much the metering is affected?

Thank you

oh oh, and also, if I use AF, will the red squares indicating which focusing point I am using still light up?
I don't think AF will be affected by the screen - as the AF sensor is placed under the mirror, but are the red AF point indicators a property of the focusing screen?

[Dream Merchant]

Adam, look at your Cfns.

For the 1V, there should be two options: '0 and '1'. Your LCD screen should actually tell you which setting to use for any screens other than the factory supplied focusing screen. Usually, for 1 series cameras, '0' is factory standard, and '1' is for other screens' but it ciould be the other way around as well. A quick check should tell you what you need to know.

On 1 ser cams, you should still be able to see all the little red squares regardless of what focusing screen you use, or even if you take out your focusin screen completely as the red squares are etched on another screen other than the focusing screen. Take your focusing screen out and tap the shutter button. Do you see the red squares? Of course, switch the camera on first.

[catchlights]

sorry, I not sure about Canon camera, DM can help you on this.

[Dream Merchant]

Another thing, for Canon 1 ser, the spot metering will be lnked to a specific AF point (either the center one by default, or any AF point you select).

When using split screens like the cross or split image, or any central microprism device which is essentially multiple split-images, you have to choose an AF point that is NOT in the center of that cross/split/microprism for accurate spot metering readings.

The prisms used in such focusing aids/devices may throw the accuracy of your spot metering off if the selected AF point coincides with the prisms.

[adamadam]

Thank you very much DM!

I used to have the PDF version of the manual which mentioned something about the custom functions, but couldn't find that tonight, but I shall search for it again for more detail. Thanks! It makes sense about the spot metering, because I usually use the centre metering point, but I should use the points other than the centre (or have it linked to the focusing point that is not in the centre).

Thanks!

[longkangman]

according to manual

"•The Ec-A, Ec-B, Ec-I, and Ec-L focusing screens have a prism at the center. A
correct exposure reading cannot be obtained with evaluative metering or spot
metering based on the prism at the center. Use centerweighted averaging
metering or off-center spot metering with these focusing screens. "

HTH

[adamadam]

Originally Posted by longkangman according to manual "•The Ec-A, Ec-B, Ec-I, and Ec-L focusing screens have a prism at the center. A correct exposure reading cannot be obtained with evaluative metering or spot metering based on the prism at the center. Use centerweighted averaging metering or off-center spot metering with these focusing screens. " HTH

Thank you very much!!!!!!!!!!