40D Focus Screens

feiron wrote in post #4389323
how will the EF-S make the focusin easier though? The only effect I could see was the darkened viewfinder

ChucklesKY wrote in post #4389937
Hmmmmm, according to the 40D manual the EF-S screen is dark if the lens used is slower than f/2.8 and it is recommended if most of your focusing is done manually. The Katz Eye Optics screens have all kinds of exposure compensation depending on what f-stop you're shooting. Sometimes it may be up and sometimes it may be down depending on what aperature setting and what method of metering. Also, "spot metering is not recommended when using a split prism focusing screen except with very fast prime lenses." On second thought, I think I may just stick with the OEM screen for now.

It disturbs me when I post most of the replies to my own thread!

With the EF-S screen the circle of mini-prisms "snap" into focus when focus is achieved and "snap" out of focus when you move away from sharp focus. It takes a little practice to see the effect, and you really need a fast lens for this to be optimal.

I went with the OEM screens because you can set the camera to compensate for the specific type of screen used in your custom functions and be done with it. I didn't want to have to fool with figuring out exposure compensation for non-Canon screens.

Mark

Mark_Cohran wrote in post #4389964
With the EF-S screen the circle of mini-prisms "snap" into focus when focus is achieved and "snap" out of focus when you move away from sharp focus. It takes a little practice to see the effect, and you really need a fast lens for this to be optimal.

I'm assuming that you're talking about manual focusing? (about the "snap"). I barely manual focus since most of my photos are portraits. I guess I won't really benefit from the EF-S

feiron wrote in post #4390030
I'm assuming that you're talking about manual focusing? (about the "snap"). I barely manual focus since most of my photos are portraits. I guess I won't really benefit from the EF-S

Yes, manual focus. It's primarily designed to assist with manual focus and FTM touch-up of AF focus.

Not having a split prism is by far my single most missed camera feature from my old slr.

And not that anyones asking, but here's my conspiracy theory on why Canon doesn't include it in current prosumer bodies:
it would be way too easy to see how often and by how much the auto-focus is off.
It may be my eyes, but I just can't tell if it's a bit off in my 20D viewfinder. Maybe it's easier with the 40D as it's brighter? And would you really need liveview for fine focussing if you had that little split ring?
I can't believe it is a physical/mechanical limitation preventing it, but maybe.
That's my theory anyways. Now ask me about the grassy knoll...

Having said that, I sure wish a split prism was available as an OEM factory install upgrade option ($100?), assuming as an OEM install it wouldn't mess with the metering.
Greg

I replaced my 40D's screen with the Ef-D screen. This is the grid screen. I shoot mostly soccer events and landscapes and I find the grid really helps with alignment. It took all of 2 minutes to swap out.

cheers,
Michael

If you had a 40D wouldn't you have to replace it with...

Split prism screens are available for the 1D series cameras (as OEM from Canon). I have one in my 1D and I love it. Be aware, though, that in low light or with lenses with smaller maximum apertures you can get a partial blackout of the prism.

Mark

carianoff wrote in post #4391178
If you had a 40D wouldn't you have to replace it with...

[GIFS ARE NOT RENDERED IN QUOTES]

...so you could have those same focal box thingers? If you were to get something like...

[GIFS ARE NOT RENDERED IN QUOTES]

would the light up boxes of the camera still light up in the same spot. Im not realy sure how this works, does it affect anything other than the viewfinder image?

I'm not sure how the 40D works, but the 20D has a focusing screen (it's completely matte) and an SI screen (which has the AF boxes that light up). SI stands for Super Impose, which is what that second screen is. It looks like glass, and has the etchings that you see in the viewfinder. It's located between the prism and the focusing screen.

I know this first hand because I scratched up my focusing screen AND my SI plate

I don't know how it works, but I have rule of thirds gridlines and focus points indicators with my Katz Eye. It's already saved several shots from being OOF. I use rangefinder cameras most of the time, and don't really like the whole SLR thing. The Katz Eye screen lets me be comfortable with an SLR, and benefit from the creamy goodness of the 40D

Hermeto wrote in post #4389477
Here is another one, Haoda focusing screen:

http://home.kc.rr.com/​educ/screen/index.html

http://tech.groups.yah​oo.com/group/screen4DS​LR/

Note that it appears that the Haoda screen is not available for the 40D. The Katz Eye, on the other hand, is.

feiron wrote in post #4389323
how will the EF-S make the focusin easier though? The only effect I could see was the darkened viewfinder

The EF-S screen has the effect of amplifying the blurriness of out of focus areas of the image, so it makes it easier to detect when your subject is out of focus. This effect isn't terribly apparent on a slower lens (e.g., f/4.0, f/5.6, etc.) but is quite apparent with a faster lens (e.g., f/2.0).

The downside of the EF-S is that it is quite a bit dimmer than the standard screen with slower lenses.


For those of you who want the custom grid of the Katz Eye but don't want the split prism (since it has an effect on spot metering), it's possible to special order a custom screen from them without the split prism and microprism collar. I did precisely this because I wanted something at least as bright as the standard screen (getting this requires their "OptiBrite" treatment) but with better focus precision and a rule-of-thirds grid. It works somewhat better than the standard screen in terms of precision (but not by a whole lot), and I really like the grid. I use it with the EF-A setting on my camera and haven't noticed much in the way of metering error from it (then again, one could probably argue that I'm not very good at metering. ). The only real disadvantage is that you pay quite a premium for it relative to the Canon screens, so if the Canon screens suit your needs then there's little point in going with anything else.

brightscreen.com is another good brand to look at.

carianoff wrote in post #4391178
If you had a 40D wouldn't you have to replace it with...

...so you could have those same focal box thingers? If you were to get something like...

would the light up boxes of the camera still light up in the same spot. Im not realy sure how this works, does it affect anything other than the viewfinder image?

The focus points aren't on the focus screen and are there regardless of what screen you use.

Ron

Cool, now for the other magic question. Do you void any warranty(s) by doing this? Or is it considered like just another accessory?

carianoff wrote in post #4393727
Cool, now for the other magic question. Do you void any warranty(s) by doing this?

I would doubt it, particularly if you use a Canon screen.

Ron

Changing out a screen that's designed to be changed by the user certainly wouldn't void the warranty, even if you used a third party focus screen.

Mark