[PentaxPoke]

Pentax Poke: I saw your test for metering with the Katzeye, but was hoping to have a response from you on these words, taken directly from the Katzeye site:

"•Center Weighted Average (CWA) Metering Mode: Our testing showed CWA metering mode to be accurate for all AF lenses having a maximum aperture of f5.6 or larger (lower f number).
•Evaluative Metering Mode: Our testing showed evaluative metering mode to be accurate for all AF lenses having a maximum aperture of f5.6 or larger (lower f number).
•Spot Metering Mode: Our testing showed spot metering mode to be within factory tolerance for all AF lenses having a maximum aperture of f2.0 or larger (lower f number). Lenses having a maximum aperture smaller than f2.0 (lager f number) will show a significant shift toward increased exposure, with the shift increasing for lenses with smaller maximum apertures. Spot metering mode is NOT RECOMMENDED when using a split prism focusing screen with lenses slower than f2.0. However, if spot mode must be used, it is strongly advised to first take a test shot, check the histogram, and adjust exposure compensation as required."

I rely heavily upon spot metering.

Thanks for the kind words Ernest.
I agree with all of the bullet points above. I am just not seeing major problems with metering of any type. I just played around with it some more on my FA35, and all the metering modes work well. I don't do any "stop down" metering myself, but in the test steve just had me run, I am just not seeing huge problems with my screen. There is a small shift in the histogram from f/2 to f/16 with the stop down spot metering, but to me it is not a big deal in the tests I have done so far. If it were consistent I would just shift the EV. Maybe there really is a difference in metering between standard Katz and Optibrite Katz. I wish I could be more helpful in this regard. I don't know if my tests apply to lenses that you might be using.

Without question, this screen will be helpful to anyone with the type of lenses I have below. As you see, I do not have any pure manual lenses, so I can't comment on those. Steve may be the one to consult in that regard. I suspect though, that if your lenses are working with the split screen you mentioned, that they would work even better with the Katz.

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Last edited by PentaxPoke; 01-16-2009 at 12:15 AM.

[stevebrot]

Pentax Poke: I saw your test for metering with the Katzeye, but was hoping to have a response from you on these words, taken directly from the Katzeye site:

"•Center Weighted Average (CWA) Metering Mode: Our testing showed CWA metering mode to be accurate for all AF lenses having a maximum aperture of f5.6 or larger (lower f number).
•Evaluative Metering Mode: Our testing showed evaluative metering mode to be accurate for all AF lenses having a maximum aperture of f5.6 or larger (lower f number).
•Spot Metering Mode: Our testing showed spot metering mode to be within factory tolerance for all AF lenses having a maximum aperture of f2.0 or larger (lower f number). Lenses having a maximum aperture smaller than f2.0 (lager f number) will show a significant shift toward increased exposure, with the shift increasing for lenses with smaller maximum apertures. Spot metering mode is NOT RECOMMENDED when using a split prism focusing screen with lenses slower than f2.0. However, if spot mode must be used, it is strongly advised to first take a test shot, check the histogram, and adjust exposure compensation as required."

I rely heavily upon spot metering.

Ernest,
I posted about a month ago on this subject (only without the Optibright) and found that with A, FA, and DA lenses the behavior is as KatzEye states. Spot metering works with my A 50/1.7 and FA 35/2, but sucks on my DA 18-55/3.5-5.6. Ditto for my Tamron 70-150/3.5 and Tamron 28/2.5 using the PK/A mount.

You can see the source of the problem just looking in the viewfinder. The KatzEye "Plus" feature results in a brighter center section at smaller apertures. This does not cause too much of a problem with evaluative and center-weighted metering, but totally skews the spot metering.

Steve

[dazman]

Great review. Another item to put on my shopping list.

[PentaxPoke]

I just ran another test using my 18-250 to see if I could force that effect. I have to zoom the lens all the way out to 250 (so it is a f/6.3 minimum), and use spot metering to see it. I get perfect exposures for multi-segment and center weighted. Spot metering gives about a stop of overexposure. That extreme condition is the only place I have been able to produce that effect. Shifting the EV fixed it as Katz recommends.

[Jewelltrail]

Ernest,
I posted about a month ago on this subject (only without the Optibright) and found that with A, FA, and DA lenses the behavior is as KatzEye states. Spot metering works with my A 50/1.7 and FA 35/2, but sucks on my DA 18-55/3.5-5.6. Ditto for my Tamron 70-150/3.5 and Tamron 28/2.5 using the PK/A mount.

You can see the source of the problem just looking in the viewfinder. The KatzEye "Plus" feature results in a brighter center section at smaller apertures. This does not cause too much of a problem with evaluative and center-weighted metering, but totally skews the spot metering.

Steve

Steve--thanks. This is great to know. I guess it will be easier for me to finagle the Spot metering on smaller aperture lenses, than it will be for me to continue struggling with manual focus. It seems like everything in life is pretty much a tradeoff. With your post, as well as those of PentaxPoke and jbinpg kept in mind, I just ordered a Katzeye screen, with optibrite. Though I do not welcome any metering issues, I truly am very excited about nailing manual focus from here forward.

Thanks guys!

[Jewelltrail]

PentaxPoke
I just ran another test using my 18-250 to see if I could force that effect. I have to zoom the lens all the way out to 250 (so it is a f/6.3 minimum), and use spot metering to see it. I get perfect exposures for multi-segment and center weighted. Spot metering gives about a stop of overexposure. That extreme condition is the only place I have been able to produce that effect. Shifting the EV fixed it as Katz recommends.

This is very reassuring, indeed! Thanks again for all of the hardwork you have put into making the Pentax experience better for all of us!

[Jewelltrail]

BTW

There is currently a 10 percent discount off all orders at Katzeye!

[axl]

nice review, I only have one question: is spot metering possible with this screen? And how much did you pay for it,
PS: may I ask for link???

[ryan s]

It's too bad it comes with that huge circle on it :/

Hmmmmmmm...since the ist screens are darker than the stock KxD screens...I wonder if the KatzEye would provide more contrast as well. The ist screen I have is better than the one the camera came with...a good upgrade. Now if the ist one from KE would work like I think...

[Jewelltrail]

Axl:nice review, I only have one question: is spot metering possible with this screen? And how much did you pay for it,
PS: may I ask for link???

That is 3 questions:

He paid 105 for the screen plus 55 for the optibrite treatment, unless he has a special deal with Katzeye. There is currently a 10 percent discount--I just bought one an hour ago.

Axl, just read a few posts up, there is discussion here already on Spot metering.

Axl, Pentax Poke posted the link in his opening thread.

[Mechan1k]

I really need to put mine in my M42 "manual" K10D ... it's still sitting in it's packet.

I got the Opti-brite with Rulle of Thirds and 8X10 crops lines in it.
Now for some steady hand time ... I need to read those install instructions again.

[71Matador250]

Well, that finally pushes me over the edge, a fellow Oklahoman has vouched for the Katz eye screen! What will I tell the wife... ? Several months ago I communicated with Rachel Katz about the need for a 45 degree split screen with the microprism collar. I do wish they would make it available, it never hurts to think out of the frame. Shooting with the ME and Me Super, Super Program etc.. for so many years I really miss the split screen and collar on my K10D.
If you rely heavily on th spot metering, you should get a 1 degree spot meter. I use the zone system for b&w with my medium format gear and still carry both my Pentax Spot Meter and a light meter in my bag with the k10D. HDR Merge is great, but light meters can benefit all our images and still have a place in our bags. May be a bit old school, but ...Thanks PentaxPoke!

[sinus007]

What will I tell the wife... ? Several months ago I communicated with Rachel Katz

You already have half the answer: as soon as I get katz eye I'll stop talking with Rachel. The other half can be something about your failing vision: better spend $160 on katz eye than $300 on a pair of new glasses.

[kristoffon]

I guess you didn't read the text of my review then. Each of your 4 points and the brightness are addressed in the text, and demonstrate just the opposite.

Sure, reading a review clearly trumps any first-hand experience I had.

Oh, congrats on the viewfinder pictures, though. They're excellent.

The problem is that the apparent depth of field in the viewfinder with the stock screen is greater than the actual depth of field provided by the lens. At taking apertures wider than f/4, the stock screen may present an in-focus image, while the actual final image is clearly out of focus. This issue is present on all of my lenses faster than f/4.

I'm aware of that and I also have fast lenses. But unless your subject is dead center on the composition you'll have to move the camera to recompose and doing that you lose the focal precision the split screen gives you.

[PentaxPoke]

That is 3 questions:

He paid 105 for the screen plus 55 for the optibrite treatment, unless he has a special deal with Katzeye. There is currently a 10 percent discount--I just bought one an hour ago.

Axl, just read a few posts up, there is discussion here already on Spot metering.

Axl, Pentax Poke posted the link in his opening thread.

Thanks for the help Ernest. People might be surprised what they find if they would read a thread before posting.