Katz eye, split prism focus screen

photo_mom said:

Lance B said:

An interesting side note. The central focus indicator is above the
split prism line rather than the split prism line going centrally
through the central focus indicator. Actually, the bottom of
central focus indicator sits almost directly on top the split prism
line.

Click to expand...

Hi Lance!

Glad you got yours! I love mine and can't imagine how I ever
managed to focus clearly without it. (An over-exaggeration, I'm
sure, but it is VERY nice, expecially with manual focus lenses).

Click to expand...

Hi Tracy,
I notice that I need to dial in -0.30EV now. How about you?

photo_mom said:

The focus indicator on mine does sit above the prism line and to
the right of center.

Click to expand...

My AF indicator is centred left to right, but not top to bottom if we assume that the split prism is exactly centred.

photo_mom said:

photo_mom said:

I could be wrong, but I would suggest that the split prism focusing
line would not be allowed to go through the centre of the focus
indicator as it may cause an upset of the AF in thew camera.
All I have to ascertain now is whether the focus indicator is
centrally located top to bottom in the middle of the screen or the
split prism is centrally located top to bottom in the middle of the
screen.

Click to expand...

Mine has 3rd's grid lines. From these it seems the prism is
exactly in the center of the screen both top to bottom and left to
right. Thanks Lance, now it seems that I've noticed that the focus
indicator is actually off-center. :-( LOL!

Click to expand...

I also have the 1/3rd grid lines, just like my Pentax LL60 focus screen that I bought to replace the original screen. I love the 1/3rd grid lines, so that is why I got it with the Katz Eye as well.

I haven't really checked to see if the split prism is in the exact middle, or the AF indicator of the camera, so I don't know which is correct.

photo_mom said:

--
Tracy
7:06 AM

Click to expand...

--
Lance B
Lady Astor: 'Winston, you're drunk'
Winston Churchill: 'And you madam, are ugly, but tomorrow I'll be sober'
Lady Astor: 'Winston, if you were my husband, I would poison your tea!'
Winston Churchill: 'Madam, if you were my wife, I'd drink it!'
GMT +10hours

Yes, but it is rather a feature than a defect.

This is the reason why there is both split prism and microprism. Split prism is quicker in good light but difficult to use in low light. Microprism is not so quick but more precise in all lighting conditions, and easy to use in low light conditions when you cannot use split prism.

To older Pentax bodies were made also focusing screens having only split screen or microprism.
--
Harri

http://www.kolumbus.fi/harri.raisanen/Gallery/default.htm

Lance B said:

Lance B said:

Lance B said:

line would not be allowed to go through the centre of the focus
indicator as it may cause an upset of the AF in thew camera.
All I have to ascertain now is whether the focus indicator is
centrally located top to bottom in the middle of the screen or the
split prism is centrally located top to bottom in the middle of the
screen.

Click to expand...

Click to expand...

Click to expand...

If we suppose the split prism is in the middle of the larger circle, thus it is not centered in the up/down direction. You can clearly see that the circle is not as far from bottom than from upper side of the viewfinder.

I suppose this has something to do with the lightmeasurement as you mentioned. Perhaps it lessens the effect of the split prism to the measurement.

--
Harri

http://www.kolumbus.fi/harri.raisanen/Gallery/default.htm

Harri R'is'nen said:

Lance B said:

Harri R'is'nen said:

Harri R'is'nen said:

line would not be allowed to go through the centre of the focus
indicator as it may cause an upset of the AF in thew camera.
All I have to ascertain now is whether the focus indicator is
centrally located top to bottom in the middle of the screen or the
split prism is centrally located top to bottom in the middle of the
screen.

Click to expand...

Click to expand...

Click to expand...

If we suppose the split prism is in the middle of the larger
circle, thus it is not centered in the up/down direction. You can
clearly see that the circle is not as far from bottom than from
upper side of the viewfinder.

Click to expand...

Yes, I actually think that the split prism circle is exactly centred, but the AF indicator is not.

Harri R'is'nen said:

I suppose this has something to do with the lightmeasurement as you
mentioned. Perhaps it lessens the effect of the split prism to the
measurement.

--
Harri

http://www.kolumbus.fi/harri.raisanen/Gallery/default.htm

Click to expand...

--
Lance B
Lady Astor: 'Winston, you're drunk'
Winston Churchill: 'And you madam, are ugly, but tomorrow I'll be sober'
Lady Astor: 'Winston, if you were my husband, I would poison your tea!'
Winston Churchill: 'Madam, if you were my wife, I'd drink it!'
GMT +10hours

Well.... I can only speak on about my *ist D body, but using original focusing screen the indicator is just between the brackets. And if you measure from detached screen, the bracket is just in the middle of the original focusing screen.

But if my measure is correct, split prism is not in the middle of the screen. The prism dividing line is just below the indicator and if you meassure it from detached screen itself, difference is sllightly less than 1mm. So split screen is 1mm below the centerline. Why, I do not know.
--
Harri

http://www.kolumbus.fi/harri.raisanen/Gallery/default.htm

I don't use any EV. The screen does cause shots to overexpose but I tend to underexpose everything so they cancel for the most part. Hope that makes sense. (I mostly use Tv mode and set the shutterspeed to faster than it should be. The aperture warning value blinks at me a lot.)

The biggest change I've had to accomodate with the screen is switching from spot to center-weighted metering. I've always used spot metering but it is adversely affected with the Katz Eye screen.

Lance B said:

Lance B said:

The focus indicator on mine does sit above the prism line and to
the right of center.

Click to expand...

My AF indicator is centred left to right, but not top to bottom if
we assume that the split prism is exactly centred.

Click to expand...

I came home from work today because a really big horse stepped on my foot last night. The refrigerator that they call an office where I work was just making it too miserable to sit with a throbbing foot. So I've got lots of time to play around with the camera this morning. ;-D

I just experimented with the focus indicator by focusing on a cross-hair. I tried to center the cross-hair in the middle of the 1/3 lines on the screen. The indicator is definitely to the right of what I can guesstimate as the center of the screen and above the prism line. Oh well, it hasn't caused a problem for me yet, but it's good to know about the offset.

--
Tracy
10:58 AM

http://cgi.ebay.de/PENTAX-Focusing-Screen-1-TOP-OV_W0QQitemZ7589878466QQcategoryZ4688QQrdZ1QQcmdZViewItem#ebayphotohosting

would this fit into the DS?

Hi stern,

No. That's an original Pentax screen. As they never made anyone with microprism collar for the *istD or DS it is another screen, suited for an unknown of their film SLR cameras.
The three screens Pentax makes for the digital SLR cameras are:
LF-60 (original)
LL-60 (engraved with one thirds rule lines, often spoken about here)
LI-60 (haircross scale type)

None of these has microprism or split view focusing aids. One could get tricked by the picture here as the new screens for the D and DS are delivered in small boxes looking exactly as the one in the auction.

regards,

Jonas

stern said:

http://cgi.ebay.de/PENTAX-Focusing-Screen-1-TOP-OV_W0QQitemZ7589878466QQcategoryZ4688QQrdZ1QQcmdZViewItem#ebayphotohosting

would this fit into the DS?

Click to expand...

Jonas B said:

Hi stern,
No. That's an original Pentax screen. As they never made anyone
with microprism collar for the *istD or DS it is another screen,
suited for an unknown of their film SLR cameras.
The three screens Pentax makes for the digital SLR cameras are:
LF-60 (original)
LL-60 (engraved with one thirds rule lines, often spoken about here)
LI-60 (haircross scale type)
None of these has microprism or split view focusing aids. One could
get tricked by the picture here as the new screens for the D and DS
are delivered in small boxes looking exactly as the one in the
auction.

Click to expand...

thx! i had the impression that something was fishy there...

Jonas B said:

regards,

Jonas

stern said:

http://cgi.ebay.de/PENTAX-Focusing-Screen-1-TOP-OV_W0QQitemZ7589878466QQcategoryZ4688QQrdZ1QQcmdZViewItem#ebayphotohosting

would this fit into the DS?

Click to expand...

Click to expand...