[renix]

Hi to all,
recently I placed on my K3 an "Bresson" dual 45° split image focusing screen bought on ebay. Pressing green button to read correct exposure seems works fine, with M mode, from 1,2 to 2,8 on my manual lenses but in I use from 4 to 11 the images are really too too overexposed.
And then I placed again factory K3 screen and, whit the same test, it's all ok!
Is there a problem of my focusing screen or it's normal with any focusing screens? I'm thinking about to buy and Canon ee-s focusing screen but if the problem would then be the same I don't buy it.
Could anyone tell me his really experience and suggestions?

[DanGleabols]

I'm not an expert, so I'm sure somebody more knowledgable will pop along soon. However, I believe DSLRs meter the exposure after the focus screen and split screen focus screens always effect metering. I think some metering modes are effected more (spot metering, I think) more than others. The ee-s screen aren't as renowned for effecting the metering, or at least if they do it's in a more consistent manner.

[david94903]

Years ago I put a Katzeye focusing screen with OptiBrite in my K20D and never noticed any metering issues. Your issues could be related to your metering mode. Katzeye's website recommends not using the spot metering mode on lenses slower than 2.0 for the K10D, and they suggested this may be true for the K20D too. With my K20D I typically used the spot metering mode and never noticed any metering issues in any of my lenses, so maybe the K20D doesn't have the same issue. However, this issue may be true for the K3. Try it with different metering modes and see if that affects your results.

[renix]

Years ago I put a Katzeye focusing screen with OptiBrite in my K20D and never noticed any metering issues. Your issues could be related to your metering mode. Katzeye's website recommends not using the spot metering mode on lenses slower than 2.0 for the K10D, and they suggested this may be true for the K20D too. With my K20D I typically used the spot metering mode and never noticed any metering issues in any of my lenses, so maybe the K20D doesn't have the same issue. However, this issue may be true for the K3. Try it with different metering modes and see if that affects your results.

Thanks friend... from 1,2 to 2,8 it's ok metering!!! But from 4 to 11(or 22) increase underexposing... very quickly and with all my lenses. I tried with spot and center weight metering modes with same results

[felixkh]

The EE-S screen from focusing screen.com is a wonderful screen. I have used it on my K7 and then K5. Sold it away with the K5 and am now thinking of getting it again for the K3. Another former who installed it has no issues with metering on the K3.

Those eBay ones do cause a lot of other issues too.

[tim60]

I just looked at the focusingscreen site for k3 and did not see any screen called EE-S. Which one do you mean?


When you use that screen does the image show sharp really effectively for focusing, like old film screens did. I find the stock screens in k100DS and K3 both seem a bit like trying to focus on a window glass.

[renix]

The EE-S screen from focusing screen.com is a wonderful screen. I have used it on my K7 and then K5. Sold it away with the K5 and am now thinking of getting it again for the K3. Another former who installed it has no issues with metering on the K3.

Those eBay ones do cause a lot of other issues too.

Can you grant me that from f/4 and up there aren't metering problems? I'll use it few on fast aperture

[savoche]

Can you grant me that from f/4 and up there aren't metering problems? I'll use it few on fast aperture

I know several of us do have problems with occasional underexposure with slower lenses when using the EE-S screen with etched markings - and on the K-5. Unlike the original screens with black painted markings, the ones from focusingscreen.com have etched guidelines that are brighter than the ground glass in certain situations.

I don't know, but I would guess a screen without such guidelines would measure correctly.

Haven't tried the EE-S on the K-3 as I find the bigger and brighter viewfinder quite good for manual focusing already.

[felixkh]

I just looked at the focusingscreen site for k3 and did not see any screen called EE-S. Which one do you mean?


When you use that screen does the image show sharp really effectively for focusing, like old film screens did. I find the stock screens in k100DS and K3 both seem a bit like trying to focus on a window glass.

Here is the link to the EE-S screen called the S type.
Focusing Screen

There re other variants too
Focusing Screen

Focusing Screen

Focusing Screen

---------- Post added 12-30-2014 at 08:19 PM ----------

Can you grant me that from f/4 and up there aren't metering problems? I'll use it few on fast aperture

I have used it on F4 to F8 and there were no issues. go to

Focusing Screen

and read up as they have examples to show too.

I use the one without any grid lines. Just a plain seen. You can really see the difference when focusing.

[renix]

Here is the link to the EE-S screen called the S type.
Focusing Screen

There re other variants too
Focusing Screen

Focusing Screen

Focusing Screen

---------- Post added 12-30-2014 at 08:19 PM ----------



I have used it on F4 to F8 and there were no issues. go to

Focusing Screen

and read up as they have examples to show too.

I use the one without any grid lines. Just a plain seen. You can really see the difference when focusing.

Ok I've seen S type focus screen... Is there really really big differencies with k3 kit focusing screen? In "screen comparision" I can see how use S type... but is there possibility to magnify scene on VF during focusing? or isn't necessary?

[maxfield_photo]

Most split prism screens cause metering issues particularly with slower glass, and in center weighted or spot metering modes. This is from the Katzeye website: metering - KatzEye Optics

With the K3's sophisticated matrix mode, that is probably your best option. If you need to do spot metering for zone system exposures, it's probably best to get an external meter anyway. I use a Katzeye screen with Optibrite, but I use a Sekonic 758 to judge exposure, so i can't really comment on metering errors.

[lm4187]

Is there a problem of my focusing screen or it's normal with any focusing screens?

From what I've read, that is normal behavior for split image screens. Non split image screens (EE-S) shouldn't show the problem.

The light is metered after the focusing screen and the split prism deflects (?) some of this light, leading to overexposure.

Check out: https://www.pentaxforums.com/forums/6-pentax-dslr-discussion/52091-optical-pa...ure-meter.html for more detailed information on the exposure metering system.

Cheers,
Lou

[savoche]

From about this post in the EE-S thread you'll find some info about issues with underexposure as well as some comparisons with the K-3 standard screen.

The image in the VF can't be magnified - not without attaching something like the O-ME53.

[bobpur]

Different types of screens disperse the light in different ways and since the sensor is after the screen it can be affected, my K10 was useless with fast
takumars until I replaced the screen but then it changed the exposure for " A " lenses.
Found that the best is the original screen for most manual lenses except wide ones, in that case the focus confirm or CIF does it.

[tim60]

Here is the link to the EE-S screen called the S type.
Focusing Screen

.

Thanks. I saw S type in their page and was confused because everyone here calls it EE-S. My training makes me think that represents a different thing! NTD2500/2600 seems like a sensible price.


I get the impression that focusingscreen is someone's 'second job', probably done in evenings and weekends at the house. I bought one of their screens a few years back and got emails sent at odd out of hours times. Seems to be how a lot of businesses in Taiwan get going.