[Spodeworld]

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Hi.

I think I need a new focus screen for my D20D.

I could buy the replacement Pentax model. Alternatively, I could get something like the following:
Focusing Screen

or, one like this
Diagonal Split Image Focus Screen 4 Pentax k10D k20D DS | eBay

Here's a more extensive list from focusingcreen.com: K20D focus screens. There are a whole bunch there, the FSB looks adequate, but I did hear someone say that the K3, which is much more expensive, is quite good.


Does anyone have a recommendations? With grid...without? (Katz eye is too expensive.)

I will be using it primarily with manual lenses. But, I'd like to know if the split screen ones interfere with auto focusing.

Thanks.

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Last edited by Spodeworld; 08-20-2011 at 06:43 AM.

[Ole]

Split screen does not interfere with auto focus. It may interfere with spot metering, because the center spot can go dark with small aperture lenses.

If you mainly use manual focus lenses a split screen is the preferable option. I have installed a split screen from KatzEye on my *istD for use with Takumar lenses. It works well.

[Spodeworld]

How much of a problem does it present for spot metering? Is it something you are rarely likely to encounter?

Split screen does not interfere with auto focus. It may interfere with spot metering, because the center spot can go dark with small aperture lenses.

If you mainly use manual focus lenses a split screen is the preferable option. I have installed a split screen from KatzEye on my *istD for use with Takumar lenses. It works well.

[stevewig]

I have the focusingscreen.com k3 screen on my K10d and recommend it highly. However, I have the the KatzEye (with optibrite) on my K20d and I recommend it even more.

Basically you get what you pay for - the more the better.

Previously I used the cheap $20 Chinese screen which is quite recommended in various discussions on this forum. It works but I didn't like it due to early "blackout" (above F5.6) and its more pronounced negative effect upon metering.

[excanonfd]

How much of a problem does it present for spot metering? Is it something you are rarely likely to encounter?

A split prism focus screen effectively renders spot metering useless. If spot metering is something you use routinely, a split prism screen is not recommended. Alternatively, you can use LL-60 focus screen from istD DSLR camera for manual focusing because this screen has characteristics similar to the classic ground glass focus screens. I found the LL-60 useful up to about f8.0 and it does not interfere with the spot meter. Unfortunately, LL-60 is no longer available from Pentax North America. You can try to obtain one used in the Marketplace, I bought mine new from Japan by making a request to "tom1803" a forum member in Japan, the cost is on par with split prism screens from focusingscreens.com.

Hope this helps,

[Spodeworld]

What are the practical differences between the pentax supplied k20d focus screen and the ll 60? Are there any compromises using the ll 60 in the k20d? Also, are they the same size?

[excanonfd]

Would it help if I mention that I shoot with K20D?

[Spodeworld]

Yes. But it sounds like there are advantages to using the ll60. Just wondering what they are.

I'm seeing a lot of talk about using the ll60 over 80 for the d20k. Do you lose anything by not using the 80? If not i'll probably look for the 60.

[excanonfd]

I apologize for the late reply...

I guess if you have not shot with any manual focus SLR camera, you probably do not understand what I mean when I say LL-60 has similar characteristics as the old ground glass focus screen. When you look in your viewfinder, the image that you see is basically the image that's been projected on to the focus screen. But unlike a projector, the light also has to pass through the focus screen to the AF sensor and the light meter. Therein lies the problem, you are trying to manually focus a legacy lens on a focus screen that's optimized for the AF sensor. It doesn't mean the LF-80 cannot be used for manual focus, it's just very difficult and too much of a 'hit or miss' for my comfort. An older manual focus, 35mm SLR has a focus screen that was designed for manually focusing the lens by sight and to further aid the process, most SLR focus screens has a split prism surrounded by a band of micro prism in the centre of the focus screen. Even though istDS camera is an AF digital camera, it's focusing screen has similar characteristics as those focus screens found in the old MF SLR.

Just for curiosity sake, I held up both LL-60 and the LF-80 against my desk lamp held about 30cm from my eyes. Through the LF-80 I can see a distinct outline of the CF light bulb, but through the LL-60 the shape of the CF light bulb is more diffused, an amorphous bright blob. The LF-80 passes more light through the screen to the AF sensor but the LL-60 blocks more light allowing for better manual focus. As I've said before, the advantage of LL-60 over LF-80 is that you can manually focus better, doesn't affect the meters because there is no split prism to confuse the AF sensor, there might be a discrepancy in metering with LL-60 vs LF-80 but by how much, I do not know.

Hope this helps,

[Spodeworld]

Thanks...I went ahead and ordered the LL-60. Just wondering though, if it passes less light, does it make focus more difficult for AF lenses. esp in low light situations?

[excanonfd]

Thanks...I went ahead and ordered the LL-60. Just wondering though, if it passes less light, does it make focus more difficult for AF lenses. esp in low light situations?

I don't know, but that's a possibility. You are getting the LL-60 for better manual focus, there may be a trade-off of diminished AF. Myself, I only shoot with MF lenses except for the Sigma 10-20/4-5.6 ultra wide AF lens, that's something you would have to ascertain for yourself.

Thanks,

[rockmaster1964]

The focus screen does not affect auto focus. It does affect metering.

[Spodeworld]

Shows how little I know. I would have thought something with a name like focus screen might have an impact on Autofocus.