[Lowell Goudge]

All the time I have been sitting on the fence (figuratively) regarding getting a split image screen

I am interested because I have 8 MF lenses ranging from 24mm to 400mm and because I use spot metering heavily, yet see anecdotal reports of messed up metering, specifically spot metering when a split image screen is installed.

I already own a K10D, which has very specific metering flaws for manual appature lenses, and therefore I am really interested on exactly what the impacts of these different screens actually is, under somewhat controlled conditions.

I would be willing to help out with the analysis part, but need people who have each version of focusing screen and a K10D to do some tests.

The tests are simple. Under uniform lighting conditions (clear sky is the best) set the K10D to the following:
- manual mode
- contrast neutral
- the image tone to normal
- ISO setting to one ISO value (i.e. not auto) that gives exposures within the working range of the camera (i.e. wide open apature is less than 1/3000 shutter and completely stopped down is higher than the minimum shutter speed
- Green button function to set shutter speed based upon apature

Take a set of photos of a uniform surface (concrete wall , paved path etc) using spot metering, and green button to set exposure.

Do this test with both K mount lenses and lenses with “A” and the split image screen you have, in ½ stop increments and advise on the grey scale value for each apature.

[Zewrak]

All the time I have been sitting on the fence (figuratively) regarding getting a split image screen

I am interested because I have 8 MF lenses ranging from 24mm to 400mm and because I use spot metering heavily, yet see anecdotal reports of messed up metering, specifically spot metering when a split image screen is installed.

I already own a K10D, which has very specific metering flaws for manual appature lenses, and therefore I am really interested on exactly what the impacts of these different screens actually is, under somewhat controlled conditions.

I would be willing to help out with the analysis part, but need people who have each version of focusing screen and a K10D to do some tests.

The tests are simple. Under uniform lighting conditions (clear sky is the best) set the K10D to the following:
- manual mode
- contrast neutral
- the image tone to normal
- ISO setting to one ISO value (i.e. not auto) that gives exposures within the working range of the camera (i.e. wide open apature is less than 1/3000 shutter and completely stopped down is higher than the minimum shutter speed
- Green button function to set shutter speed based upon apature

Take a set of photos of a uniform surface (concrete wall , paved path etc) using spot metering, and green button to set exposure.

Do this test with both K mount lenses and lenses with “A” and the split image screen you have, in ½ stop increments and advise on the grey scale value for each apature.

Spot metering wont work properly, simple as that. You will not be able to trust it. No matter what screen you put in.

[Lowell Goudge]

Spot metering wont work properly, simple as that. You will not be able to trust it. No matter what screen you put in.

That is not the question. On the K10D, the metering with Manual apature lenses does not work properly but it does behave in a very systematic manner.

It also changes behavior (actually meters correctly/properly for manual apature lenses) if you install an *istD screen, because of the transmission properties and differences between screens. But with the *istD screen, due to the software correction in the K10D for the "correct" screen, the K10D meters with a consistent but different error for each different maximum apature.

What I would like to know, without spending money first, is how the metering behaves with the split image. the fundamental issue is, is it consistent? I appreciate it may not be accurate, but at least is it consistent? How does it not "work properly"

All I ask is someone be precise with these statements.

[Zewrak]

That is not the question. On the K10D, the metering with Manual apature lenses does not work properly but it does behave in a very systematic manner.

It also changes behavior (actually meters correctly/properly for manual apature lenses) if you install an *istD screen, because of the transmission properties and differences between screens. But with the *istD screen, due to the software correction in the K10D for the "correct" screen, the K10D meters with a consistent but different error for each different maximum apature.

What I would like to know, without spending money first, is how the metering behaves with the split image. the fundamental issue is, is it consistent? I appreciate it may not be accurate, but at least is it consistent? How does it not "work properly"

All I ask is someone be precise with these statements.

When you use a splitscreen the centre of the screen is always darker then the rest. I guess that any smaller aperture then 2.0 will shoot the metering way off. Give me a few minutes and ill try.

[stevebrot]

That is not the question. On the K10D, the metering with Manual apature lenses does not work properly but it does behave in a very systematic manner.

It also changes behavior (actually meters correctly/properly for manual apature lenses) if you install an *istD screen, because of the transmission properties and differences between screens. But with the *istD screen, due to the software correction in the K10D for the "correct" screen, the K10D meters with a consistent but different error for each different maximum apature.

What I would like to know, without spending money first, is how the metering behaves with the split image. the fundamental issue is, is it consistent? I appreciate it may not be accurate, but at least is it consistent? How does it not "work properly"

All I ask is someone be precise with these statements.

I have not used the screen, but from other comments my understanding is that spot metering is inconsistent with some lens. As for KatzEye, here is the comment from their site regarding screens for the K10D:

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.

[Lowell Goudge]

I have not used the screen, but from other comments my understanding is that spot metering is inconsistent with some lens. As for KatzEye, here is the comment from their site regarding screens for the K10D:

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 hear you but please note the following with respect to the K10D and metering, as measured by me, using the method I suggested, and Manual Apature (i.e. K mount) Lenses, or with lenses taken out of A mode.

Starting at F1.4 the camera will under expose by 1 to 1.5 stops, shifting to over exposure by 1 to 1.5 stops at F5.6 to 2 stops over exposed by F8-16 and a slight reversion back to over exposing by 1.5 stops by F22 - F32.

It may be that the metering is in reality no worse than the present metering not because of the split image but simply because there is a problem with the K10D screen at present (which appears to have been compensated for in software).

I actually posted in the forums previously a curve of how the K10D performed with it's origonal screen, vs the K10D with *istD screen, vs the *istD with its origonal screen.

[Zewrak]

I skipped 1.8 because 2.0 and 1.8 is identical and works fine.

All pictures are taken with ISO 100 in Raw. Manual mode and green button between every picture.

Test
2.0 : 1/250
2.8 : 1/90
4.0: 1/15
5.6: 1/6
8.0: 1/4
11: 1/4
16: 1/4

Test wall 2:
2.0 : 1/125
2.8 : 1/45
4.0: 1/8
5,6: 0,3"
8.0: 0,5"
11: 0,5"
16: 0,5"

Included some pictures to show what happens. 2.8 and 11.0 seem to be most correctly exposed.

Attached Images

   

[Lowell Goudge]

I skipped 1.8 because 2.0 and 1.8 is identical and works fine.

All pictures are taken with ISO 100 in Raw. Manual mode and green button between every picture.

Test
2.0 : 1/250
2.8 : 1/90
4.0: 1/15
5.6: 1/6
8.0: 1/4
11: 1/4
16: 1/4

Test wall 2:
2.0 : 1/125
2.8 : 1/45
4.0: 1/8
5,6: 0,3"
8.0: 0,5"
11: 0,5"
16: 0,5"

Included some pictures to show what happens. 2.8 and 11.0 seem to be most correctly exposed.

I have copied your table and shown in grey scale and stops rhoughly where the split image oputs you.


Question is, is this consistent?

2.0 : 1/250 GS=65 (-1.2 stop)
2.8 : 1/90 GS=93 (-.5)
4.0: 1/15 GS=168 (+1.5)
5.6: 1/6 GS=193 (+2)
8.0: 1/4 GS=163 (+1.5)
11: 1/4 GS=113 (+0)
16: 1/4 GS = 62 (-1.3)

[qksilver]

is that with a Chinese screen or a katz eye?

[WerTicus]

id start with the 20$ Chinese one and if its not good enough then get the expensive ones... im of the opinion the 20$ one is good.

[ll_coffee_lP]

Chinese screen here from Ebay seller "Shoot-ing". $30. Works great. No complaints whatsoever.

I was interested in trying a split screen and didn't want to pay $200+. I love my new screen and won't bother getting the more expensive one, as the one I have works as it's supposed to.

c[_]