[WMBP]

I've decided to buy a new focusing screen for at least one camera. I'll probably buy for my *ist DS first and if I'm pleased with the results, I'll get something for the K10D, too.

Anyway, the question is: Katz Eye or Pentax? I gather that the Katz Eye screen is like the nice focusing screens I had in my old cameras, where the image out of focus seems to be separated from itself in the middle, and as you focus, the separated parts come together. Am I right about that? I can't tell if the Pentax replacement screens do that, or do they simply provide different marks on the screen?

Will

[David]

Hi Will, I have had the Katz Eye Pro with Rule of Thirds and 8x10 crop markings for three weeks now and I am very happy. No change to focussing and works with all my zoom and fixed focal length lens, 1.7 through to 5.6 manual and autofocus.

Thought about a chinese version but decided to pay for quality and went with Katz.

Take Care

David

[Matt Miller]

As far as I know, Pentax doesn't offer a split prism focusing screen like what you are describing. Katz Eye does, and it is wonderful.

[WMBP]

Hi Will, I have had the Katz Eye Pro with Rule of Thirds and 8x10 crop markings for three weeks now and I am very happy. No change to focusing and works with all my zoom and fixed focal length lens, 1.7 through to 5.6 manual and autofocus.

David,

Just to clarify: What do you mean by "no change to focusing"? I want a change to focusing, that is, I expect that the Katz Eye will allow me to focus manually more quickly and more accurately.

Thanks,

Will

[WMBP]

As far as I know, Pentax doesn't offer a split prism focusing screen like what you are describing. Katz Eye does, and it is wonderful.

Thanks, Matt.

So I'm wondering, what is the point of the Pentax products? Is it simply that they have orientation marks on them?

I also wonder, why doesn't Pentax use a split prism focusing screen in its dslrs? There must be a reason, but I can't imagine what it would be.

Will

[Lowell Goudge]

Will

to answer your questions, I looked into the Katz eye, and have decided to hold off on it for the K10D, although I am interested in getting split image focusing.

The reason I held off is because of some things I read on the Katz eye site about metering inaccuracies with certain lenses (specifically the ones with higher minimum apatures)

with respect to the "no impact on focusing" comment made by others, I believe this is with respect to autofocus, Clearly there is a big impact on manual focus, because that is why you want a split image.

[WMBP]

to answer your questions, I looked into the Katz eye, and have decided to hold off on it for the K10D, although I am interested in getting split image focusing.

The reason I held off is because of some things I read on the Katz eye site about metering inaccuracies with certain lenses (specifically the ones with higher minimum apatures)

Thanks, Lowell. I've heard some of these reports, too, and they have concerned me a bit. That's part of the reason I have been thinking of putting a Katz Eye on my *ist DS first, to see if I like it. I gather that you can keep your original screen and put it back if you have trouble with the Katz Eye (although you'd be out the cost of the Katz Eye).

with respect to the "no impact on focusing" comment made by others, I believe this is with respect to autofocus, Clearly there is a big impact on manual focus, because that is why you want a split image.

Oh, I see. But if the Katz Eye does reduce the amount of light coming into the camera, why would that not affect the camera's ability to auto-focus in low light?

Will

[Lowell Goudge]

Will

WIth respect to the second question and impact on focusing.

it does not reduce the amount of light coming into the camera, as the screen is obviously above the mirror, but I think I know the real point. If the AF sensor is taking light off the focusing screen for the evaluation of contrast, and it goes black, as split images do on slow lenses or in low light, it might render the AF non functional. This could b recovered of course, by switching away from the central (and theoretically best and most important) AF sensor. Something for someone else to answer.

As I said, I am still sitting on the fence.

[Matt Miller]

I have noticed no change in autofocus with the katz eye in my K10D. I have, however, noticed some meter funkiness. The k10D doesn't have the best metering system to begin with, and I think the katz eye throws it off a little now and then. Not much, but a little. We're shooting digital though, so it's easy to check the histogram, adjust, and continue. I pretty much know now how to set my EV adjustment with what lens in what light before I shoot.

I love the katz eye. Manual focusing, for me, is much more accurate than auto focusing. More fun too.

[afs760bf]

[QUOTE=Lowell Goudge;153364]Will

If the AF sensor is taking light off the focusing screen for the evaluation of contrast, and it goes black, as split images do on slow lenses or in low light, it might render the AF non functional.


The usual reason for half of the focusing circle going black is that, on longer focal-length lenses, the eye must be looking straight through the focusing circle to see both sides equally. Otherwise, one semi-circle wll appear to black out. Readjusting the position of your eye in relation to the circle will bring both halves back to "light," so to speak.

I have the Katz Eye. I have used it with a Vivitar Series 1, 100-500mm lens. At 500mm, f8 is the maximum aperture. The screen works great. I have the split-ring and the 8X10 markings. It has not adversely affected the auto-focus of any of my other lenses. The only thing I don't like about the Katz Eye is the black circle line around the whole focus area. There's no reason for it to be there. I emailed Katz Eye about it and they agreed that it was probably not the best design, but they had purchased all the stock with it on there, so it will stay there until the current supply of stock is exhausted. After you get used to it, though, it's fine.



Taken at 500mm (750mm equivalent), hand-held, full frame, with K10D and using Katz Eye

[andrei46]

The reason I held off is because of some things I read on the Katz eye site about metering inaccuracies with certain lenses (specifically the ones with higher minimum apatures)

with respect to the "no impact on focusing" comment made by others, I believe this is with respect to autofocus, Clearly there is a big impact on manual focus, because that is why you want a split image.

Hi Will! Hi Lowell Goudge!
I have the same doubt as you; I sugest you to read in Fernando E. Aznar ::· c r o q u i · d e · l u z ·:: - Manual Focus Ain't So Easy, por Jay Turberville
Regards!

[davef]

Hi Will. I have the Katz Eye in my K10. I haven't had any problems with autofocus. Manual focus is a joy to use again -- I regularly end up switching my F300 to manual focus when the light is marginal and it starts to hunt. Metering, including spot metering, works fine except for lenses slower than f2.8. For those lenses, the other 2 metering modes work fine.

I looked into the Chinese screens as well and decided to pay the premium fot the Katz after I read all of the "shim and trim" stories. I suspect whether or ot it works for you will depand on your lens choices and your metering choices.
Dave

[kenyee]

AFAIK, the metering issue is because of the split focus area....it shows up to the metering system as a large black spot, so you'll get overexposure...

[David]

Hi Will, I meant no adverse affect on focussing. The split image focussing is fast (remember the old film cameras before high aperture zoom lens became the vogue) for both manual and auto. The view finder is bright and I cannot detect any difference in autofocussing or metering with the new Katz Eye screen. However, I use manual focus and manual metering in the majority of my shots with fast lenses, ie 1.7 to 2.8.

I would never go back to the original K10D screen.

David

[WMBP]

Andrei: Thanks for that link. Very interesting reading.

David: I understand now, no bad effect on focusing.

Thanks to everybody else who has responded, especially those of you who have the Katz Eye on your K10Ds. My original idea was to buy the Katz Eye for the *ist DS first and test it out. But I'm thinking now about taking a deep breath and buying the screen for the K10D instead. I can remove it and revert to the original screen if I don't like it, right?

Will