Pentax K-3 Compatibility with S type Focus Screen

stevebrot · 07-10-2014, 02:19 PM

Originally posted by emalvick

I guess all the high praise for the screens are for unmarked ones?

It is hard to say. From what I can tell, it appears that very few K-3 owners have installed aftermarket screens. Either that or their participation on this forum is low.

Steve

Chris Mak · 07-10-2014, 03:16 PM

Originally posted by stevebrot

It is hard to say. From what I can tell, it appears that very few K-3 owners have installed aftermarket screens. Either that or their participation on this forum is low.

Steve

I received the S-type screen from focussingscreen.com, the version without the AF markings, and installed it.
Bottom line is: exposure is indeed a bit more consistent than with the screen with AF markings with my sigma 500/4.5 + 1.4tc, which is f6.3 wide open. The link a few posts back shows that at this aperture, the lines of the AF markings are very visible, and may very well influence exposure metering on the advanced K3, depending on the scene.
But when replacing the stock screen, you will get over- and under-exposure with different lenses, all behaving in their own way depending on chosen aperture in Av mode. My Zeiss ZK lenses are still all over the place, heavily under- or over exposing depending on aperture. But as long as this behavior is consistent, it's merely a matter of learning this behavior of your lenses and compensate for it. Granted: this takes some time.
I recently got a Sony A7r, and what a revelation this camera is with my Zeiss ZK lenses: just set the aperture with the aperture ring on the lens, put the camera in Av mode, and metering is always spot on, with the EVF compensating for the loss of light as you close the aperture. With the K3 I wouldn't see anything at f8, so I used Av mode with the aperture ring on the lens at the a(utomated) setting, and setting the aperture on the camera. The K3 then has to calculate the exposure at a chosen aperture, from the wide open light metering through the custom screen, and it just cannot do this right. With the stock screen, it was no problem.
Chris

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07-10-2014, 02:19 PM	#16
stevebrot Otis Memorial Pentaxian Join Date: Mar 2007 Location: Vancouver (USA) Photos: Gallery \| Albums Posts: 42,007 Original Poster	Originally posted by emalvick I guess all the high praise for the screens are for unmarked ones? It is hard to say. From what I can tell, it appears that very few K-3 owners have installed aftermarket screens. Either that or their participation on this forum is low. Steve

07-10-2014, 03:16 PM	#17
Chris Mak Pentaxian Join Date: Jan 2013 Photos: Albums Posts: 639	Originally posted by stevebrot It is hard to say. From what I can tell, it appears that very few K-3 owners have installed aftermarket screens. Either that or their participation on this forum is low. Steve I received the S-type screen from focussingscreen.com, the version without the AF markings, and installed it. Bottom line is: exposure is indeed a bit more consistent than with the screen with AF markings with my sigma 500/4.5 + 1.4tc, which is f6.3 wide open. The link a few posts back shows that at this aperture, the lines of the AF markings are very visible, and may very well influence exposure metering on the advanced K3, depending on the scene. But when replacing the stock screen, you will get over- and under-exposure with different lenses, all behaving in their own way depending on chosen aperture in Av mode. My Zeiss ZK lenses are still all over the place, heavily under- or over exposing depending on aperture. But as long as this behavior is consistent, it's merely a matter of learning this behavior of your lenses and compensate for it. Granted: this takes some time. I recently got a Sony A7r, and what a revelation this camera is with my Zeiss ZK lenses: just set the aperture with the aperture ring on the lens, put the camera in Av mode, and metering is always spot on, with the EVF compensating for the loss of light as you close the aperture. With the K3 I wouldn't see anything at f8, so I used Av mode with the aperture ring on the lens at the a(utomated) setting, and setting the aperture on the camera. The K3 then has to calculate the exposure at a chosen aperture, from the wide open light metering through the custom screen, and it just cannot do this right. With the stock screen, it was no problem. Chris