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Full Version: focus screen for Canon 5D
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I want to do manual focus, however no compromises on metering, or using the camera AF points, which one would offer this

The Ee series is for the 5D. Manual focus with small aperture lenses, the focus in your 5D is just fine. For bigger aperture lenses (think f2.8 and bigger), the Ee-S is the one to install. The camera has a setting to let the metering adjust to the different brightness of this focus screen.

I went down that road once too.

 

Had my 5D and I was using mostly m42 lenses on it. Was thinking of getting a screen optimized for faster lenses and a split circle in the middle but then I realized that the image on my stock screen was WAY OFF compared to what I was getting at the end. I was either going to shim the screen somehow or find another way.

 

The best solution I came up with was using adapters with EMF chips on each lens. You can calibrate those lenses for AF microadjustment (Also focal length and max aperture info). Your screen will still be off but you'll be able to rely on the blinking red AF assist lights inside the viewfinder, which is much more accurate than the screen once calibrated on the EMF chip.

The 5D has no AFM. Normally, the screen is not way off. And the Ee screens have the right thickness.

Quote:The 5D has no AFM. Normally, the screen is not way off. And the Ee screens have the right thickness.
EMF chips for 5D have AFM of their own, I was using them on a 5D as well. I found trusting the red beep better than trusting the focus screen. 
I use the Eg-S in my 6D and find the focus screen pretty precise. The beep is not red, just beep Wink... and not very accurate depending on the lens.

I also used the laser mattes (-S screens) on any of the Canon bodies with interchangeable lenses I own(ed) - they always worked great, much more accurate for MF than any other focusing screens.

 

Officially they take away a bit more light, but I always found that to be so minimal as to have no effect, not for me anyway.

 

Kind regards, Wim

Obican:  This is why I never switched screens.  I've read too many stories of they screens having to be shimmed, and I just figured it was too much trouble to go through if I wasn't going to be sure of the result.  Here is a thought though:  I don't know what "Way off is, but don't forget the diopter adjustment may be able to compensate for that?  I think that screen is for your eyes only and will not effect the cameras AF which is located below the flange.  If so, -2 to +2 covers a pretty broad range.  Please correct me if I'm wrong.  I accidental popped something out of the screen area of an EOS film camera.  But it still had no problem AF-ing.


@ brightcolors - Here is an interesting fact.  The famous Dandelion chips and the notorious Chinese chips are offered with programmable capability.  And the claim is that they allow MFA on a camera like a 60D that does not have in camera MFA (micro focus adjustment).  The question, naturally is how?  That question in turn leads to how do cameras like the 70D do it? 


We know the camera does the AF-ing.  We know the camera stores the AF MFA information based on a unique lens identifier.  So, I guess the camera simply remembers what you tell it.  So, the big news is now you can MFA manual focus lenses, and strangely enough you can use MFA even with cameras that do not make this feature available.


I have to admit:

- I question how good legacy glass really is.

- I suspect a lot of times the problem is me.

- If legacy glass is so inferior, than why did Canon disable AFC for manual lenses and require Chips on some cameras or the camera will pretend there is now lens there. Is a modern top lens maker afraid it can't compete with 30-50 year old lenses.  If they believe that they need to up there game!

The basic error is: The focus screen could be well placed for all lenses.

 

If every lens needs a different AFMA value, you would also need for every lens a different shimmed focus screen. No matter, if it's the AF module which is focusing indirectly or the matte-screen, which is also at the end of a mirror.

 

On Nikon, I have or had AFMA ranges between -15 ... +10. So, if they cannot manufacture their lenses to tighter tolerances, what is the point of a focus screen? Estimating or guessing sharpness? And if they cannot manufacture lenses without focus drift, there's only a very specific distance being exactly right.

Joju, I may understand what you are saying.  My fear for a while has been that they will use the feedback from the lens to make different Micro Focus Adjustments based on, not just the lens, but the F-stop, and the distance of the in focus area from the field plain.

 

One of the things that erks me is that the camera does not communicate object distance and record it in EXIF.  You may ask why should it?  Well, because it can.  In the Magic Lantern hack one of the things you can have displayed in real time is the distance of the in focus area from the image plane,

 

But anyway, along with other tools for live view focus determination when focused on a suitable target, you have a means by which the camera could do many different adjustments for the same lens so that even though the camera may be PD focusing at f/2.8 it determines you are shooting at f/8 so adjusts the focus for that lens at that focus distance at that F-stop. 

 

This is something of a mixed blessing because for the first time you have a real shot a very good focus.  Plus, the would be no need for you do any work beyond set up a suitable target and let the camera compare and adjust until CF and PDF are in complete agreement across the entire F-stop range.  Possible at a set number of different distances between MFD and Hyperfocus distance.

 

So in this scenario manual focus will still be possible to some extent with a lot more effort, but after which time you could rely on the AFC (auto focus confirmation) for a good result.  But I suppose the real news is that faster lens designs would be possible...

 

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We never covered optical magnifier viewers.  They are hard to use with glasses, but if you don't wear glasses you can get much improved focus results. 
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