What is a split-screen focus screen (EC-L)

[schmoelzel]

Since I have acquired a few manual focus lenses lately, I have read info concerning new focus screens for the 1-series viewfinders. What exactly does a split-screen do to the normal focus screen of the camera? Any info is much appreciated!

[mdr]

This is a quote from a website:

3mm diameter split-image spot, for precise pinpoint focusing on subjects with distinct contours, use the central split-image rangefinder; turn the focusing ring until the split image becomes a sharp, clear, complete and undivided image

A split-image focussing screen is of no use when you're using autofocus. It can be very useful for manual focus, as aligning an object across the two halves can be much easier in determining whether your subject is in focus.

Hope this is clear. If not, let us know.

Cheers,

Marc.

[PacAce]

A split-screen focusing aid is that little circle in the middle of the focusing screen that looks like it's been cut into two equal parts with the cut usually running either diagonally at 45 degrees or horizontally. Each half of the circle is actually a small prism.

The way that it works is that when you point the circle over a subject that has vertical lines, when the subject is not in focus, the top half of the lines will not lineup with the bottom half. When you adjust the focusing ring so that the subject is in focus, the lines will all line up perfectly. The diagonal split has the advantage that you can also focus with it using horizontal lines.

The other common type of focusing screen is the micro-prism focusing screen. The same principle is applied here except that when the subject is out of focus, the image breaks down into lots of "speckles". When the subject is in focus, the speckles will not be evidient. Some people find this type of screen harder to use than the split-screen focusing screen.

[PacAce]

This is a quote from a website:

3mm diameter split-image spot, for precise pinpoint focusing on subjects with distinct contours, use the central split-image rangefinder; turn the focusing ring until the split image becomes a sharp, clear, complete and undivided image

A split-image focussing screen is of no use when you're using autofocus. It can be very useful for manual focus, as aligning an object across the two halves can be much easier in determining whether your subject is in focus.

Hope this is clear. If not, let us know.

Cheers,

Marc.
Although the range-finder camera does indeed have a split-screen type of focusing aid, it's not the same split-screen focusing screen that's used in SLR cameras.

[mdr]

Although the range-finder camera does indeed have a split-screen type of focusing aid, it's not the same split-screen focusing screen that's used in SLR cameras.
Think you're confusing terminology here. The split image on an SLR focus screen is called split-image rangefinder. The quote actually comes from the early 1980's manual of my FE, a manual SLR, so maybe it's old terminology.

[PacAce]

Think you're confusing terminology here. The split image on an SLR focus screen is called split-image rangefinder. The quote actually comes from the early 1980's manual of my FE, a manual SLR, so maybe it's old terminology.
OK, sorry. I thought you were talking about a range-finder camera which also focuses using a split image but works differently from that used in the SLR.

[Longwatcher]

The first thing I did when I got my 1DsMkII was to swap the standard EC-CIII laser focus screen for the EC-B split image screen. Works much better when I need to manually focus (as in I can do it now). My eye tends to adjust for bad focus (my eye will tend to put it in focus - even if it is out of focus), so I needed the split screen to make sure I am focusing correctly. So know I can use auto-focus or manual and get good results.

The reason I got the EC-B versus other splits is I was told the camera had less problem with it then other split focus screens (something to do with accurate exposure). I have not noticed any problems using it so far. But I use center weighted anyway as my default which the camera doesn't have problems with split image screens on anyway.

The split image circle is also what I am used to using from my old film camera days.

Just me and my experience,

[PhotosGuy]

Here's an example:

[schmoelzel]

Thanks for all the answers! Thank you photosguy for showing what this looks like in the actual viewfinder! (PERFECT)

[PhotosGuy]

That is a Nikon P screen. Your experience may differ! ;-) ;-)

[TomBrooklyn]

If I'm not mistaken, that screen also has a microprism "donut" around the 45 degree split part, like PacAce referred to.

[Quad]

Why? Just why?





Here I was exited and thought schmoelzel was back.

[Josh_30]

Wow, that brings back memories of my old AE-1 days. :D Still got it in the closet somewhere.

[Josh_30]

Just found this on google for those who wonder what this looks like. Split Screen Focusing (http://blog.epicedits.com/wp-content/uploads/manual-focus-indicator-1500.jpg)

[Jman13]

I have a Katz Eye (http://www.katzeyeoptics.com/) focusing screen for my 30D. Makes manual focus SO much easier (as the stock screen is essentially useless for manual focus.) Since I have a few manual focus only primes that I use, it was an essential piece of gear.