[MrThallid]

I am a PROUD owner of a K-x and tout it to all of my friends and co-workers. I have recently acquired an "A" 50mm 1.7 and an "A" 400mm 5.6, both manual focus. when I spoke ot my dad about my troubles with manual focus, he explained that "back in the day", the focusing screen would have 2 half images and you knew you were in focus when the images lined up.

Do replacement focus screens (katzeye or other) do the same thing today with digital?


I thank you for the education I am about to receive!

[jellyfish26]

Here is a review on the focusing screens
https://www.pentaxforums.com/forums/pentax-dslr-discussion/46978-my-k20d-katz...-pictures.html

[RioRico]

My old eyeballs are delaminating. I have a katzeye-clone screen on my K20D, but find that subjects need to be contrasty and well-lit for it to be useful. So with my (mostly) manual lenses, I depend a great deal on Catch-In-Focus (CIF). I need merely frame the image, hold the shutter down, and twist the focus ring. When focus is achieved, the shutter snaps automagically. This even works well with moving subjects on the street, like grab-shots of passersby. With a fairly wide lens I hardly even need to raise the camera to my eyes. Just aim and twist and shoot. Almost as good as AF, eh?

Yes, a split-image screen can be useful, but not so much with dimmer light and bland subjects. It's great when your subject has sharp features, so you can tell when the split halves align. Some of my manual lenses don't support CIF so I *do* carefully watch those split images. But I keep watch for the green focus-confirmation light too. With either CIF or the split-screen, plus the confirmation light, I find manual focusing to be easy and straightforward. Very few of my MF shots are out-of-focus. Unless I'm sloppy, of course..

[Just1MoreDave]

I got the KatzEye split-prism focus screen about a year after getting my first DSLR. You have some more choices on the market today. Although the KatzEye seems quite costly for a bit of plastic, look at it in terms of lens prices. It's less than the difference between an A50/1.7 and an F50/1.7.

I found that the split-prism screen made a big difference in eyestrain when using manual focus. It is extremely precise, better than phase AF and equal to CD-AF and live view. It works in challenging conditions, like with a 16mm fisheye, where details in the viewfinder are very small, or very low light.

It doesn't affect AF. You can still use Catch-in-Focus or the green hexagon if you want. On my camera, I had no affect on multi-segment or center-weighted metering. Spot metering can be affected with some lenses, so I never used spot metering.

The prism is in the center, so it's really great at focusing in the center. Off-center, you have the same choices as the regular screen - focus/recompose or try to see focus on the matte field. (With manual-focus lenses, only the center AF point is active, so the center-only behavior is similar.)

Half of the prism can black out under certain conditions, and this is really annoying. The KatzEye is better than cheap versions here. The blackout happens with slower lenses or accessories like teleconverters that reduce light. I don't have a problem with it until f16 but others report issues at f5.6. (K-mount lenses focus wide open so the relevant number is the lens's maximum aperture. You can still shoot at f11 or whatever.) You can ofen shift your eye position slightly to see both prisms again.

I didn't get a KatzEye for my K-7 and I can still focus OK without it. I think some of that is practice and experience. It's more work. I miss the precision sometimes.

[Marc Sabatella]

In an ideal world, there would be a split prism you could switch on or off. Most of the time, I find split prism viewfinders incredibly distracting and annoying. But they do come in handy at times.