p.12 #1 · Microprism-only Brightscreen on Canon 5D
Hi,
I'm interested in getting the BrightScreen p232 MICROPRISM SPOT CENTER screen for 5D. A question I have is that will using that screen affect the auto focusing? Can I still use all the AF points on 5D?
Btw, will this new screen affect metering?
Thanks
Apr 06, 2006 at 03:28 PM
jjlphoto Offline • • • • • [X]
p.12 #2 · Microprism-only Brightscreen on Canon 5D
Contact Jim Lakey at Brightscreen. He is quite knowledgeable about all the features of the Canon.
p.12 #4 · Microprism-only Brightscreen on Canon 5D
I use the p222 large microprism spot center screen on my 1DsII. The AF mechanism is under the mirror, so the screen does not affect it at all. Metering is behind the screen in the light path, so metering can be affected. I have found that up to aperture of f/4.5, metering is accurate. However, with smaller apertures, I find that I need to use -1 to -3 stop exposure compensation, depending on the aperture and metering mode. It definitely affects metering on the Canon 100-400mm f/4.5-5.6 zoom. I have not tried 3rd party lenses with stop-down metering yet. I have a feeling that if you stop down more than f/4, then manual metering would be more accurate than Av mode.
I wonder what makes you choose the thrid-party one instead of the original Canon one?
Thanks.
Apr 06, 2006 at 04:29 PM
jjlphoto Offline • • • • • [X]
p.12 #6 · Microprism-only Brightscreen on Canon 5D
The Brightscreen microprism is a whoipping 13mm diameter. That's more than 1/2 of the total height of the screen. Makes Canons seem kinda whimpy. Remember, if you are having to tilt the camera so the item you want sharp is within the focusing aid, that tilting in itself may make you misfocus.
p.12 #7 · Microprism-only Brightscreen on Canon 5D
Hey
Have any of you Canon 1DsMkII users found that with spot metering using the P222 13mm prism major exposure errors happen as a function of f stop?
I get accurate exposure wide open but as I stop down to 5.6 or greater there is major over-exposure. It is independent of lens used. No idea what would cause this except the spot is basically right in the center of the microprism.
No problems with evaluative metering and haven't tried averaging yet.
p.12 #8 · Microprism-only Brightscreen on Canon 5D
Same experience here, Woody. From my experience, I have to dial in anywhere from -1 to -3 EV from f/4.5 on down. Evaluative and other metering modes are affected as well. If you're going to stop down this much with non-EF lenses, it's best to use manual mode. For EF lenses like the 100-400IS, where max aperture is f/5.6 at the longer end, you have to experiment to see how much exposure compensation you need to dial in.
p.12 #9 · Microprism-only Brightscreen on Canon 5D
jjlphoto wrote:
Remember, if you are having to tilt the camera so the item you want sharp is within the focusing aid, that tilting in itself may make you misfocus.
My worries exactly. It's tough to off center focus with this screen if the area is outside the spot. I'm finding myself switching back and forth between focus screens way too often latelty. Not that it's difficult to do, just introduces to much exposure of elements (dust) to the body and screens (which aren't easy to keep spotless).
p.12 #10 · Microprism-only Brightscreen on Canon 5D
I was wondering if anyone uses Brightscreen products on their R9/DMR combo? or any other focusing screen products that deliver better results than the provided screen?
p.12 #11 · Microprism-only Brightscreen on Canon 5D
Should there be some kind of shims when fitting Canon screens on 5D? I don't recognize this from the instructions or from the camera itself. I am having problems with back focusing with the Ee-S screen.
p.12 #17 · Microprism-only Brightscreen on Canon 5D
Kit, Guy
I ordered the BS MP just wonder when they will ship. Hate to bug Jim. But would be nice to have for my Corsica shoot since I will be at f4 and 5.6
These old eyes need some help!
p.12 #18 · Microprism-only Brightscreen on Canon 5D
I am one of those Canon orders. I am generally happy with the service, but a little miffed that they took the payment immediately, but took so long so send. I had a shipment come in yesterday, and took a half day off from work to pick it up early, anticipating that it would be the Proscreen, or at least the 80 Lux. Turned out to be some printer ink cartridges and paper, as well as some old LFI editions :(
Btw, I noticed a couple of days ago that I can't get true infinity with my 90 Cron. I will try rotating my adapters around, but I may need to look at something better than the F/S adapters. It is very close, as I can focus at about 30-40m, but not on the horizon. I read somewhere that Leica uses 1000 (or was it 10000?) times the focal length as infinity. I think I read that Canon uses 100... Can anyone confirm these numbers?
p.12 #20 · Microprism-only Brightscreen on Canon 5D
why bother with multiple of FL for infinity? On optical bench should focus parallel rays to fp.
100 x seems bad. For wide open say 1.4 80mm, that is only 25ft!. This could lead to being at hyperfocal point, not infinity, if I remembr my optics right
