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10-05-2011, 03:58 AM   #1
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What are the advantages and dis-advantages of using a Focusing Screen?

I am planning to buy one of these and change the original focusing screen on my K-X because basing from what I've read and know, which is somewhat limited this things should improve the quality of pictures taken by correctly/accurately focusing something especially when using manual lenses...

Correct me if I'm wrong or have the wrong notion on what the focusing screen really is for. All i wanted is a correctly focused eyes (not the nose) for portrait and all other things.

Thanks in advance

10-05-2011, 04:02 AM   #2
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I use split image finders in 2 of my bodies specifically for MF and find them quite good, but not perfect, and not always as demanding (or accurate) as the camera's own focus indicator. It is just easier, in many instances to get close focus.

For getting the eyes perfect, sometimes increasing DOF is thebest, because the eyes are quite small relitive to , for example, the nose
10-05-2011, 05:14 AM   #3
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Focus Screens

I use a Katzeye focus screen in my *ist DL2 and in my K-7. I enjoy using manual focus lenses and this aid definitely assists my old eyes. However, these focus screens are expensive and may not be for everyone, particularly if you have young eyes. As Lowell says, the green focus indicator may be enough to get you where you need to be. There may also be less expensive alternatives out there.

Unfortunately I needed something else and I am happy with the Katzeye. That said, you should check your actual focus point using a tool like the LensAlign or a sheet of newsprint because you can still get front or back focus, even with a focus aid like the Katzeye. Every camera and lens is just a little bit different and to get the most out of your camera/lens combo you really should check.
10-05-2011, 06:17 AM   #4
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I don't bother personally - after-market focus screens foul up the spot metering which I use 75% of the time with my work. I use the stock screens on my K7 and K10 with no magnifying eyepiece and I can focus quite well even with a 50mm f/1.2 lens at f/1.2 without the extra paraphernalia in my viewfinder, though bear in mind my eyesight is considered to be extremely good.

10-05-2011, 06:50 AM   #5
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I have split-screens in both of my DSLRs & wouldn't be without 'em... But I shoot with MF lenses probably 75% of the time.
10-05-2011, 07:30 AM   #6
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I was used to such screens on my 135/FF film cameras. I bought a katzeye-type clone for my K20D soon after buying the camera. I find it helpful but not sufficient for manual focusing since it requires a well-lit contrasty subject field, preferably with a line in it. With my delaminating eyeballs, I depend on a combination of the split-screen, the Focus Confirmation (FC) light, and Catch-In-Focus (CIF), in ascending order. So, the screen get me into the neighborhood of focus; FC narrows it down; and CIF locks it in. The screen alone doesn't help much if the subject field is dim or bland.
10-05-2011, 07:57 AM   #7
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I used manual focus lenses about 75% of the time and I originally purchased a Katzeye for my K10 because that was what I was used to for years with film cameras. It works great, and I love it, I just have to be careful of metering issues in certain situations, it is definitely very handy, while a little pricey. I didn't buy a new screen when I got the K20 but I soon found that I could focus easily enough using the a combination of the green focus confirmation and catch in focus. Since the green light reports in focus over a small depth of distance I had to test each lens, focusing on newsprint, lens align, etc. to see where in the focus range they were catching the focus. Once I knew that it became very easy to get focused shots without the use of the Katzeye. All that being said, if the subject has something in line with the split screen I can get focus a little quicker with the Katzeye than without.
10-05-2011, 09:19 AM   #8
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I'm afraid I have to be a bit of a wet blanket here. From what I hear about the various focusing screens, you'll be very lucky if you find it works correctly at first attempt; mostly, for really accurate focusing, you'll need to re-shim. You can but a set of shims cheaply enough, but fitting the correct one will be a laborious trial-and-error affair. Also, the split-image focusing aid in most of the screens, whilst it's useful, do note that you have to line up the images very carefully for best focus. Microprism areas are, in my view, totally useless. I suspect the best/fastest focusing is achieved without the focusing aids, but I have my doubts that the replacement screens are that much better than the standard fit (even when correctly shimmed). I may be wrong, of course.

As for the camera's focus indication, I find that it's only accurate for a handful of lenses (most of my '50s, actually). It's absolutely dire for my 28s and 135s - but that may be just me (or my camera).

10-05-2011, 09:41 AM   #9
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I find that a Katzeye screen works very well on my K10D. However, I (along with many others by what I can tell) have found that manual focusing with my K-7 is off. As m42man mentioned, the focus screen in my K-7 is incorrectly shimmed/calibrated. I am about to order a set of shims for the camera, but I have been putting it off for a bit because of the trouble I will have to go through to get it right. This is apparently a common problem with K-7 cameras which is masked by the fact that most people just use the auto-focus. Just to clarify, the focusing is not any more off with the Katzeye screen than it is with the orginal screen. Replacing your focusing screen doesn't alter whether it is calibrated correctly or not (because it is the surface of the screen against the shim that the image is focused on). It's just that manually focusing wide aperture lenses reveals even small calibration issues, and that's usually what people who replace the focus screen are doing.
10-05-2011, 01:40 PM   #10
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I got a Katzeye for my *ist DS when I started using a lot of manual focus lenses. I figured the price was justified because the lenses were so much cheaper than AF versions. I noticed that I had less eyestrain than when using the stock screen.

I kept the stock screen with the K-7. With a lot more practice at focusing, the eyestrain isn't that bad, and the stock screen is OK.

I recently tested seven MF 28mm lenses for sharpness on the K-7. Before I downloaded all the images to the computer and compared 100% crops, I ranked the lenses on how easy they were to focus properly. I repeat the tests three times and select the best-focused results for comparison, so I also knew which lenses I could focus well. My conclusion: Sharper, faster lenses are way easier to manually focus. Not too surprising, but sometimes I don't think wide-open sharpness is important for the image. It does contribute to focus accuracy though.
10-05-2011, 08:04 PM   #11
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Thanks a lot for all of your replies/post...

Basing from what I've read here, it seems that there isn't much difference/advantage with the original screen. I wouldn't bother then to purchase one... next stop flash Hope you'll still support me with your opinions with the flash as i was trying to complete my kit...
10-05-2011, 08:27 PM   #12
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I use the Katz Eye screen on my K10D and would not be without it for my manual focus glass. That is particularly true for my faster lenses such the Jupiter-9 85/2, the Pentax-FA 77/1.8 Limited and any of my fast 50s. Focus confirm is not up to the task (poor precision and not knowing just what feature has been chosen as being in focus) and the stock focus screen has an exaggerated DOF.


Steve
10-06-2011, 07:27 AM   #13
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QuoteOriginally posted by stevebrot Quote
I use the Katz Eye screen on my K10D and would not be without it for my manual focus glass. That is particularly true for my faster lenses such the Jupiter-9 85/2, the Pentax-FA 77/1.8 Limited and any of my fast 50s. Focus confirm is not up to the task (poor precision and not knowing just what feature has been chosen as being in focus) and the stock focus screen has an exaggerated DOF.
Steve
I agree with Steve here. Just because I have been putting off recalibrating the focus screen on my K-7 doesn't mean I don't think a Katzeye screen is worth it on the camera. If I no longer had my K10D with the Katzeye screen, then I would have already taken care of the K-7 issue. I've just been using my K10D a lot still (since I have several MF lenses).
10-06-2011, 07:44 AM   #14
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QuoteOriginally posted by m42man Quote
From what I hear about the various focusing screens, you'll be very lucky if you find it works correctly at first attempt; mostly, for really accurate focusing, you'll need to re-shim. You can but a set of shims cheaply enough, but fitting the correct one will be a laborious trial-and-error affair.
QuoteOriginally posted by CFWhitman Quote
Just to clarify, the focusing is not any more off with the Katzeye screen than it is with the orginal screen. Replacing your focusing screen doesn't alter whether it is calibrated correctly or not (because it is the surface of the screen against the shim that the image is focused on). It's just that manually focusing wide aperture lenses reveals even small calibration issues, and that's usually what people who replace the focus screen are doing.
You guys are spot-on. The bad news is calibrating a screen is a pain in the butt. The good news is once you're done shimming it up for accurate focus, it's done & you won't ever need to do it again.

For others, a split-image screen isn't necessary or desirable. For me, they're indispensable. Depends on what your shooting style is, I guess.

If anyone's reluctant to fork over the big bucks for the KatzEye, the cheap Chinese ones on eBay work nearly as well.

Cheers,
Bobbo :-)
10-06-2011, 07:54 AM   #15
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I didn't have to calibrate my K-x when I put in the KatzEye screen. The little prism in it is extremely helpful for making sure I am in focus with my manual focus lenses, or even to make sure the autofocus got the right thing in focus.
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