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05-19-2011, 10:34 AM   #91
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how is this screen compared to this one for the K20D?
Focusing Screen

05-19-2011, 10:43 AM   #92
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QuoteOriginally posted by gybp Quote
how is this screen compared to this one for the K20D?
Focusing Screen
It has no markings or focusing aids (split prisms) of any kind. It is just a matte finish made up of fine micro-lenses.
05-19-2011, 10:45 AM   #93
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so why is it better for manual focusing?
05-19-2011, 11:06 AM   #94
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Because it's one of the rare screens able to accurately depict f/1.4 DoF, so the focus plane really leaps at you...
Other screens will only show DoF up to f/2 or even smaller, and so you don't really know where the focus plane is...

05-19-2011, 12:55 PM   #95
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and will the focusing screen that i posted help me focusing with my 50 1.2?? is really hard to do it with what comes with the k20d... why did they remove the focusing prism from modern cameras??
05-19-2011, 03:37 PM   #96
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QuoteOriginally posted by gybp Quote
and will the focusing screen that i posted help me focusing with my 50 1.2?? is really hard to do it with what comes with the k20d... why did they remove the focusing prism from modern cameras??
It's highly unlikely, most focus screens value brightness over DoF. The common theory is that split prisms disappeared because we live in AF-oriented times and the prisms can interfere with metering.
08-03-2011, 06:37 AM   #97
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I've been looking into this lately so I've been trying to find out the differences between the various Canon -S screens. Does this look about right?

ef-s - completely blank 1.6x crop factor screen for 40D etc

ee-s - completely blank 1.3x crop factor screen for 1D
ec-s - screen with oval and centre circle (for AF, not a split prism), 1.3x crop factor screen for 1D

eg-s - completely blank full frame screen for 5D

So obviously my next question is what are the dimensions of the ef-s screen, and can we use it in our Pentax cameras without cutting it down to size? (Or possibly with just a bit of filing?). I have tried lots of searching but the screen dimensions are quite elusive!
08-03-2011, 07:14 AM   #98
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The Ef-S focusing screen is for 1.6 crop and I believe it's slightly smaller than 1.5 crop. U should use the Ee-S and cut it to size like what dlacouture has done. I owned the Canon 40D and 5D before and I know how good this screen is. I have written to focusingscreen.com to ask whether they are interested to fabricate this screen for K5 and have not received any response so far. Maybe, we should approach them as a group to get their attention. Since I switched to K5, I am utterly loss without such a screen and I have tried various split focusing screens and none can match the Canon # S super precision matte focusing screen.


Last edited by Anthony Lee; 08-03-2011 at 07:46 PM.
08-03-2011, 08:06 AM   #99
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QuoteOriginally posted by thoughton Quote
I've been looking into this lately so I've been trying to find out the differences between the various Canon -S screens. Does this look about right?

ef-s - completely blank 1.6x crop factor screen for 40D etc

ee-s - completely blank 1.3x crop factor screen for 1D
ec-s - screen with oval and centre circle (for AF, not a split prism), 1.3x crop factor screen for 1D

eg-s - completely blank full frame screen for 5D

So obviously my next question is what are the dimensions of the ef-s screen, and can we use it in our Pentax cameras without cutting it down to size? (Or possibly with just a bit of filing?). I have tried lots of searching but the screen dimensions are quite elusive!
ee-s is also the screen for 5Dc (I have it!)

eg-s is the screen for 5DII
09-20-2011, 01:52 PM   #100
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Little update on this screen (I had to reinstall it since Pentax exchanged my K5 for a new one due to stains and a bad front wheel)...

Using a sigma 30/1.4, the perceived brightness at f/1.4 is 1/3Ev dimmer with the EE-S compared to the stock screen. Cross-correlated with the known stop-down behavior of the stock screen, one can conclude that with f/2-2.8 lenses, the viewfinder will be 1/2 to 2/3 Ev darker with the EE-S screen.

The EE-S screen has indeed a linear response to stop-down metering, with many lenses (tried with sigma 30/1.4, FA50/A.4 and Samyang 85/1.4), except for a slight 1/3Ev overexposure at f/1.4 (see below).

The DoF preview shows differences at the following apertures (stock screen values in parenthesis):
- Sigma 30/1.4 : f/1.7 (f/2.5)
- Pentax FA50/1.4 : f/1.8 (f/2.2)
- Samyang 85/1.4 : f/1.8 (f/2.2)

This means that this screen renders roughly a f/1.6 DoF, which is way better than the stock screen's best effort at f/2 ...
Which is also why f/1.4 is slightly overexposed when compared to the otherwise linear response of this screen : the camera does not see any difference between f/1.4 and f/1.6, thus metering 1/3Ev higher than necessary.

This is a truly exceptional behavior.

Aside note : my new K5 had a perfectly adjusted focus screen, whereas my previous one (bought one year ago) had 0.05mm excess shim (used a 0.40mm but needed a 0.35mm). Seems like quality controls improved quite a bit...
09-20-2011, 03:46 PM   #101
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Interesting findings, thx for the note.

On my front, I got the screen cut down and installed, but I need some serious shimming. Tried calling Pentax several times, but no luck getting through.
09-20-2011, 09:16 PM   #102
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K-5 S TYPE Focusing Screen (AF Frame)

Is this the same screen? It is at focusingscreen.com, an S type with af frame.
09-20-2011, 10:41 PM   #103
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QuoteOriginally posted by derekkite Quote
Is this the same screen? It is at focusingscreen.com, an S type with af frame.
OMG, I waited so long for them to respond to my request and ran out of patience, sold my K5 and now they have the # S super precision matte focusing screen in stock.

Yes, this is the Canon # S super precision matte screen.
09-20-2011, 11:43 PM   #104
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QuoteOriginally posted by jeffshaddix Quote
Interesting findings, thx for the note.

On my front, I got the screen cut down and installed, but I need some serious shimming. Tried calling Pentax several times, but no luck getting through.
In the end, I used thin stripes of scotch tape... You need 0.15mm less than what your stock screen uses, so if your stock screen was properly adjusted with a 0.40mm shim, then you need a 0.25mm shim for the EE-S...

Superpose several layers of Scotch tape until you reach the needed thickness (I needed 5 layers to reach 0.25mm, so that's 0.05mm by layer), then cut two thin stripes (say, 20mm x 1mm) and position them on the screen's ground side, right against the edge.

To continue with my ramblings, I found that the EE-S screen is really better in terms of exposure consistency between all my lenses. Saying that it overexposes by 2/3Ev with f/2-2.8 lenses when compared to the stock screen is in fact a good thing, as the stock screen was inducing a small underexposure with fast lenses (a FA50/1.4 will be underexposed when compared to a 18-55 @ 50mm).
09-21-2011, 07:05 AM   #105
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QuoteOriginally posted by Anthony Lee Quote
OMG, I waited so long for them to respond to my request and ran out of patience, sold my K5 and now they have the # S super precision matte focusing screen in stock.

Yes, this is the Canon # S super precision matte screen.
Thanks. It looks like it isn't clear of markings, but I would assume it brings the same focus benefits.
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