Putting aside the question of FLR, here is the thing; I don't trust AF :-) Maybe I have trust issues. And maybe I havn't been using it long enough, and maybe in time, I'll get to know when it's reliable (actually, many times I do trust it, because it's obvious what it's doing if you focus on the side of a barn at 100' ) But, I also think a lot of other people around here don't trust it entirely, and I can prove that they don't.
How many times have you read somebody comenting, finding fault with a "ruler" type focus test saying that "You can't trust the test the way you've done it because the AF point might not be what you think it is, set up a flat vertical target in the middle of the inclined ruler, so you can be sure of what you are focusing on." That's a good criticism of the kind of ruler tests that omit a vertical target... and it reveals that in a very typical real world shot, say photoing objects on a table receding from you at about 45degrees, that you don't really know where the AF point is focussing.... it's the same situation... you can't have it both ways If I piont my center AF at the center of a ruler, and someone tells me, "The AF might be being fooled where to focus." that indicates to me that I better not completely rely on that confirmation beep if there is inclined texture near the AF point in a real world shot.
I look forward to having a split prism focusing screen so I can watch my split prism jump into clarity when my AF is working, and maybe in a little time I'll really get to know when AF is likely to fooled and when it is reliable.
nutek wrote:
Correct me if I'm wrong - but what is all these hype with all these focus screens with split/micro-prisms?
1) If you're using MF, then you're defeating the purpose of using an AF-camera, and all the associated AF-goodies that came along with it.
2) The prism is only available in the center - are you going to resort to using the Focus+Lock+Recompose method for focussing on off-center subjects again? What are your 3, 7, 9 or 45 point AF points used for then?
3) If you're going to use your side AF points anyway, then what's the purpose of having a micro/split prism at the center?
Most MF cameras have split/micro prism screens simply because multiple-point AF wasn't around in those days. Also most people did not print big, or view 100% like we do in digital nowadays, so the margin for error in focussing was considerably larger, and could cover the focussing 'error' due to the FLR (focus-lock-recompose) dance.
Ask yourself: am I going to shoot dead-center subjects all the time? Why do I need this micro/split prism screen on your AF camera? What kinds of subjects am I shooting that I require a micro/split-prism focussing screen? If you can verbalize out loud with a good reason why you need a micro/split prism, go ahead and buy and install one. Otherwise, I would suggest learning how to use your AF properly - focussing technology is much better than our eyes nowadays. ...Show more →
Huh?
Interchangeable focusing screens have been part of the high-end EOS AF system since the beginning, and still are. Canon offers them in many different configurations.
Your question should be "Why not?" for the 20D instead of "Why?"
Interchangeable focusing screens have been part of the high-end EOS AF system since the beginning, and still are. Canon offers them in many different configurations.
Your question should be "Why not?" for the 20D instead of "Why?"
DT
If you know what you are doing, then go ahead and get one.
If you don't know what you are doing, then don't get one.
That is the point I'm trying to say.
"Why not?" for the 20D? I don't know... Perhaps Canon should really introduce focussing screens for the 20D - they'll earn loads of $$$, but it'll be no surprise then to see more pictures turning out more blur just because people 'mis-use' or misunderstand the use of the focussing screen.
If I piont my center AF at the center of a ruler, and someone tells me, "The AF might be being fooled where to focus." that indicates to me that I better not completely rely on that confirmation beep if there is inclined texture near the AF point in a real world shot.