Re: katz eye focusing screen and slow apertures

[Jan van Wijk]

Hello Roman,

On Fri, 06 Jun 2008 10:09:01 +0300, Roman Melihhov wrote:

Note:
I have only been using for for about two weeks :-)

>How catz eye focusing screen works with apertures slower than 4 - 5.6? 

Fairly well, but be aware that there are a few variations:

 - regular ones
 - OptiBright enhanced ones
 - split-prism PLUS ones

The one I have has an PLUS enhanced split-prism and it also has 
the microprism ring (but no line markings at all to keep it clean :-)

You'll have to read up on their website about the exact differences.

What I understood is that the PLUS treatment is for the split-prism
only, and helps to make that usable with small appertures.

I just did some tests, and allthough you need quite careful
positioning of the eye, it still works at F/16 (with a 200mm lens)

The microprisms still work sort-of, but I find them MUCH less
usable than the split-prism. So when any straight lines are in
the image I tend to use that :-)


> From my earlier experience with non-pentax bodies and AF-screen with 
>microprisms it's not so good on apertures 5.6 and slower. In fact - it 
>may be useless or disturbing and given that some good DA series lenses I 
>own are f/4.0 or f4.0-6.3, I'd rather hear your practical opinion before 
>I decide to change my installed K20D AF-screen for katz eye.

I have the DA* lenses mounted most of the time, so that will be F/4 or better,
but just tested with an old FA 28-200mm Pentax, which is F/5.6 at the long end.

That also works just fine, even when forced down to F/16 with the DOF preview.

I agree with Bill Rob that in ANY case it is an improvement 
over the standard screen.


I used it last week with the A* 200mm macro and combined 
with the superb manual focussing with that lens, the split-prism 
is an absolute joy to use ...


Note:
I hardly ever use spot-metering, which is the one area a split-prism
may bite you by influencing the metering system ...


Regards, JvW

--
Jan van Wijk;   http://www.dfsee.com/gallery



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Re: katz eye focusing screen and slow apertures

[Beaker]

On Jun 6, 2008, at 11:03 AM, William Robb wrote:

>
> - Original Message -
> From: "Roman Melihhov"
> Subject: katz eye focusing screen and slow apertures
>
>
>> How catz eye focusing screen works with apertures slower than 4 -  
>> 5.6?
>> From my earlier experience with non-pentax bodies and AF-screen with
>> microprisms it's not so good on apertures 5.6 and slower. In fact  
>> - it
>> may be useless or disturbing and given that some good DA series  
>> lenses I
>> own are f/4.0 or f4.0-6.3, I'd rather hear your practical opinion  
>> before
>> I decide to change my installed K20D AF-screen for katz eye.
>>
>
> I just tried the A400/5.6.
> The microprism is fine, the split image is fine, but make sure your  
> eye is well centered on the
> viewfinder or else there is blackout on the split image.
> With the A400/5.6 and the 1.4X converter mounted, the microprism is  
> fine, the split image is
> suffering partial blackout, but is still usable.
> With the A400/5.6 and the 2x converter, the microprism is fine, the  
> split image is suffering
> partial blackout, but is still usable.
>
> In all cases, it is easier to focus the K20 with the Katz Eye than  
> the K10 with the stock
> screen, though not by a huge margin. As I mentioned the other day,  
> the K20 AF seems to be more
> accurate than what I can acheive with manual focus, which I expect  
> says more about my eyesight
> than anything elses.
> I did get the optibrite treatment for the Katz Eye.
> Were I only using AF lenses, I wouldn't bother with a replacement  
> screen, but I use a mix of
> manual focus and auto focu lenses, and i think I will find the Katz  
> Eye helps my manual
> focusing, especially with the longer focal lengths such as the 400  
> and 600mm.
>
> William Robb
>
>


Is anyone using a Katz Eye screen on a K1000? Will it help make up  
for the dimmer pentamirror?

cheers
Mike

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Re: katz eye focusing screen and slow apertures

[William Robb]

- Original Message - 
From: "Roman Melihhov"
Subject: katz eye focusing screen and slow apertures


> How catz eye focusing screen works with apertures slower than 4 - 5.6?
> From my earlier experience with non-pentax bodies and AF-screen with
> microprisms it's not so good on apertures 5.6 and slower. In fact - it
> may be useless or disturbing and given that some good DA series lenses I
> own are f/4.0 or f4.0-6.3, I'd rather hear your practical opinion before
> I decide to change my installed K20D AF-screen for katz eye.
>

I just tried the A400/5.6.
The microprism is fine, the split image is fine, but make sure your eye is well 
centered on the 
viewfinder or else there is blackout on the split image.
With the A400/5.6 and the 1.4X converter mounted, the microprism is fine, the 
split image is 
suffering partial blackout, but is still usable.
With the A400/5.6 and the 2x converter, the microprism is fine, the split image 
is suffering 
partial blackout, but is still usable.

In all cases, it is easier to focus the K20 with the Katz Eye than the K10 with 
the stock 
screen, though not by a huge margin. As I mentioned the other day, the K20 AF 
seems to be more 
accurate than what I can acheive with manual focus, which I expect says more 
about my eyesight 
than anything elses.
I did get the optibrite treatment for the Katz Eye.
Were I only using AF lenses, I wouldn't bother with a replacement screen, but I 
use a mix of 
manual focus and auto focu lenses, and i think I will find the Katz Eye helps 
my manual 
focusing, especially with the longer focal lengths such as the 400 and 600mm.

William Robb 


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Re: katz eye focusing screen and slow apertures

[Andreas Pfotenhauer]

Hi Roman,

haven't bought one yet (still not 100% convinced if i need it) but from 
what owners tell the KatzEye is usable up to aperture 11 or even more, 
especially with the "OptiBrite" treatment. Maybe some katzeye owners 
here on the list can confirm tah ..
> How catz eye focusing screen works with apertures slower than 4 - 5.6? 
>  From my earlier experience with non-pentax bodies and AF-screen with 
> microprisms it's not so good on apertures 5.6 and slower. In fact - it 
> may be useless or disturbing and given that some good DA series lenses I 
> own are f/4.0 or f4.0-6.3, I'd rather hear your practical opinion before 
> I decide to change my installed K20D AF-screen for katz eye.
>
> Thank you in advance,
>
> Roman.
>
>
>   


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katz eye focusing screen and slow apertures

[Roman Melihhov]

How catz eye focusing screen works with apertures slower than 4 - 5.6? 
 From my earlier experience with non-pentax bodies and AF-screen with 
microprisms it's not so good on apertures 5.6 and slower. In fact - it 
may be useless or disturbing and given that some good DA series lenses I 
own are f/4.0 or f4.0-6.3, I'd rather hear your practical opinion before 
I decide to change my installed K20D AF-screen for katz eye.

Thank you in advance,

Roman.


-- 
K20D, DA10-17mm, DA16-45mm, FA50mm_f1.4, DA50-200mm, Dörr DStudio 
strobes roman.blakout.net 

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