OK, so I guess it's just my eyesight. I redid the diopter, it didn't change. I repeated the pure "eyeballing it" watching the diagonal split MF, then I did MF with a half-press of the shutter red-box/confirmation beep watching the split, then I did AF.
The pure eyeballing it MF is way off as B4, the MF with half-press red-box/confirmation beep is just a smidge back-focus and the all AF is great.
So, I guess I need to always half-press the shutter for MF to make sure I'm in the ballpark.
Does this sound right to anyone? I'd appreaciate any comment, from anyone...or I'll just go to bed which is what my body is ready to do anyway...
Where did you install the shim? It looks like you might have placed it on top of the focussing screen. It should be placed on the screen carrier and then the screen on top of it.
I have the same one as Leah (with diag split). Tried it without the shim - no cigar. With the shim it is spot on. I also got the same one for the 1DM2 and that works spot on without the shim. The 1D shim is extremely thin and seems to curve and placing it in the carrier is quite difficult.
The AF sensors are behind the main mirror so I do not believe they rely on proper screen placement for the AF to work properly. (Please correct me if I'm wrong.) It's got to be a shim issue. Based on your sample photos, the screen needs to move away from the lens, IOW, up closer to the prism than it is now. This can only be done by placing the shim on the flip down screen tray thereby forcing the screen to sit closer to the prism/eyepiece assembly (which is the same thing as moving it further away from the lens.)
How do micro prisms work anyway? My EC-A drops off the clift at f4 no matter what length lens is on the camera or how much light is in the frame. Literally, it's worse than nothing at f4.5 and above and I have to focus from the matte portion of the screen (but if I am doing this it generally means there is lots of light and so it isn't a problem).
p.6 #10 · Microprism-only Brightscreen on Canon 5D
Leah, don't know if you have already done this but it is quite easy to screw up on focus once or twice in a series of manually focused shots. So in case you are not basing your conclusions on a consistent finding in a series of 5 shots or so, but simply a one off when you did your best to manually focus you may want to repeat everything and make sure you shoot a minimum of 5 frames and toss out any obvious outlier. A bit of eye spasm and fatigue and you can quite easily trip the shutter when the focus is not spot on where you want it.
p.6 #11 · Microprism-only Brightscreen on Canon 5D
...and by the way the target you used is a pretty good one, although I find that it is better to have focus lines above and below the target focus point as well.
The central area on this target is white apart from the focus line, so in the event of front or back focus you have to look at the margins to see what degree of focus error there is. It seems to me that you don't want lens distortion or softness at the edge of the frame to be coming into play so I created a target in Excel based on this target that I am using and find it more informative. People can PM me if they want me to send them the file - no sense doing the same work twice.
The other thing is that it is quite easy if you just print the target on a piece of paper and lay it on a flat surface to have hard to interpret results simply because the paper buckles somewhat and the target doesn't sit perfectly flat. I made a simple plywood assembly angled at 45 degrees and spray mounted the target to this base. I'm now quite confident that the results I get actually reflect what is going on in the focusing chain rather than anything else.
p.6 #12 · Microprism-only Brightscreen on Canon 5D
David has a point, I hope everyone that is performing the ruler focus test is using the screen or the split/prism and not tilting the camera down to focus with the split and then tilt back as it would change the plane of focus some - on any system.
Got my shims yesterday and was just about to fit them, hopes are high.
p.6 #16 · Microprism-only Brightscreen on Canon 5D
Umm, thanks, I guess... but I know how to use one, I was wondering about the optical theory behind how they produce that "shimmery" effect.
jjlphoto wrote:
When the image is "shimmery" is is OOF. When it is crystal clear, it is dead-on.
Jan 27, 2006 at 09:49 AM
jjlphoto Offline • • • • • [X]
p.6 #17 · Microprism-only Brightscreen on Canon 5D
I read an article on Rezzmasters last year and I'll be darned if I can find it. Can't even find Google hits as I don't know how to spell it. Buy I know it has something to do with how these work. It's one of those 100 year old principles.
p.6 #18 · Microprism-only Brightscreen on Canon 5D
I got the shim yesterday. Had high expectations, but it didnt help. I installed the brightscreen and the shim several times (the right way) but after 50 pictures I can only conclude that it is not usable. With the standard Canon screen I get much better results. Always sharp or almost sharp.
A pity because I really liked the look through the viewfinder.
I will write a message to Brightscreen; hope they take it back. I have the screen 5 weeks already, but I wanted to be sure. I paid about $60 for internat. shipping if I remember well, and $70 for import tax/vat...
p.6 #19 · Microprism-only Brightscreen on Canon 5D
Tried the shim and it didn't help the back-focus problem. I don't think the problem can be blamed on body variation since the 2 canon screens (standard and Ee) I have work fine.
p.6 #20 · Microprism-only Brightscreen on Canon 5D
I give up. I can not get MF to be in focus where I want it. It's always in front. I fiddled with the position of the screen itself. I tried it with and without the shim and fiddled with it's position. I tried setting CFn-00 to the Ee-S screen, didn't help. I did mirror lock up and remote release. I tried adding a bit of home made shim to the shim. Shim in back of the screen. Reset the Diopter.
I put my old screen in and I can get MF just fine. I have just lost my whole day testing this and I'm toast. I am now going to go do what my cat has been doing this whole time and maybe eat something....
