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05-19-2014, 08:07 PM   #676
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The moment we start to compare a lens to another we introduce another variable.

How much light what you call a "slow lens" lets in at f4 might not be the same amount of light, (again what you identify as a "faster lens") lets in at f4. There are transmission values inherit in lens designs that will stuff this up for us. It should be pretty close, but introducing another variable won't help us get to the bottom of if the etchings on your screen effect the exposure.

What is important for me tho, is that what ever lens I seem to put on the front of my camera now, my light meter is seemingly much much more accurate in calculating the required shutter speed, accros all apertures. This is a gigantic improvement from how my K10 previously metered non-cpu lenses. And for that. This focus screen is suburb. "shrugs"

I'm not sure if we can design anything further that will be of use with my camera and screen, that will help you further work out it the etchings are causing the issue.

05-19-2014, 08:14 PM   #677
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QuoteOriginally posted by tromboads Quote
You all see the madness in this right?
No...We just have a disconnect. Carefully consider my instructions above. I am asking you to evaluate the metering with two lenses wide open. Despite transmission differences, the measured EV(100) for the subject should be close to the same. Use an evenly-lit, uncomplicated subject to remove the metering pattern and field of view from the equation.

It may be hard to believe, but I do fault isolation as part of my work.



It would be nice if you could humor a couple of people on the other side of the world so that we can provide a more complete picture to the manufacturer when we send our items back and so that we can also provide a clear indication to future users on this site whether there is any risk associated with purchase of the Type-S screen. To tell you the truth, I was sorely disappointed since much of my work is done with slower lenses or legacy glass in stop-down mode. I also just purchased a very nice Sigma 17-70/2.8-4 and its metering is skewed at the f/4 end. Not happy...


Steve

Last edited by stevebrot; 05-19-2014 at 08:19 PM.
05-19-2014, 08:31 PM   #678
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Tromboads - hear what you are saying and agree about the variables. However, MY issue is the LACK of consistency in the light metering. Again it appears slower lenses (f3.5?) combined with this screen causes the light meter to suggest exposures 1.5 stop or so too low..

Considering I have a number of slower lenses (15ltd, 21ltd, 18-135, 55-300, 300) which all appear to be affected, the screen is not a slam dunk for me.
05-19-2014, 09:14 PM   #679
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Right. Dug out my industar 50mm And yes, it seems you are all on to something.

Index of /media/ees/test 3


Industar f3.5 = s1/30
Super Tak f1.4 = s1/90

So counting from the Super Tak

f1.4 1/90
f2 1/45
f2.8 1/20
f4 1/10

Lets say f3.5 should have been 1/15 to match the Super Tak. It seems the industar underexposed by near enough a single stop. Having said that, if i set exposure Comp to +1 i get a linear response out to f22 with exposures accurate

Bizarre. Using my Super tak f1.4 and stopping it down, everything working fine in a linear fashion, but the industar, well there is the error you are looking for. So it must simply be due to the physical size of the glass front, or entry before the aperture of the slower lens?? Again that sounds like it shouldn't make sense.

Are you guys getting consistent meeter readings in M as well as AV?


Last edited by tromboads; 05-19-2014 at 09:47 PM.
06-05-2014, 05:44 PM - 1 Like   #680
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QuoteOriginally posted by tromboads Quote
Are you guys getting consistent meeter readings in M as well as AV?
M mode metering is matching the other modes. Generally OK with faster lenses and often severely underexposed with others. I took the combo on a one day photo safari a few weeks ago and probably half of my shots were underexposed despite shooting with relatively fast glass most of the day.

After several attempts, I was able to contact focusingscreens.com by e-mail. Their response was that it is my responsibility to determine the appropriateness of a screen for a particular camera and that they only accept returns of unopened items within the first 7 days after receipt.

In other words, even though it is described as being made for the K-3, if it does not work with that camera, it is my fault for being dumb enough to give them my money. Great product, lousy post-sale customer service.

The stock screen is back in my K-3 and I am pondering the $100 hole in my wallet along with the white elephant screen on the table. One bright spot is that the camera metering is 100% spot on most the time again.


Steve

Last edited by stevebrot; 06-05-2014 at 05:50 PM.
06-05-2014, 05:47 PM   #681
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Does the ee-s screen for the K-5 series fits the K-3?
06-05-2014, 07:28 PM - 1 Like   #682
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QuoteOriginally posted by stevebrot Quote
M mode metering is matching the other modes. Generally OK with faster lenses and often severely underexposed with others. I took the combo on a one day photo safari a few weeks ago and probably half of my shots were underexposed despite shooting with relatively fast glass most of the day.

After several attempts, I was able to contact focusingscreens.com by e-mail. Their response was that it is my responsibility to determine the appropriateness of a screen for a particular camera and that they only accept returns of unopened items within the first 7 days after receipt.

In other words, even though it is described as being made for the K-3, if it does not work with that camera, it is my fault for being dumb enough to give them my money. Great product, lousy post-sale customer service.

The stock screen is back in my K-3 and I am pondering the $100 hole in my wallet along with the white elephant screen on the table. One bright spot is that the camera metering is 100% spot on most the time again.


Steve
While I agree that customer service is not their strong suit, I don't blame them a bit for not accepting returns on such a delicate item. I also agree that it is the buyer's responsibility to determine the suitability of the screen to a given camera pre-purchase.

I honestly don't see what the big issue is, though I don't have any markings on my screen. My s-screen absolutely allows better metering than the Katz-eye I had before. Metering is going to vary a bit anyway and it's usually down to the lens being used. Just try a Zeiss ZK lens on any modern Pentax camera. This is yet another reason why the photographic gods blessed us with the RAW format.

The better metering has always been just icing on the the cake that is the better manual focusing ability of the s-screen anyway. Kinda blows my mind that you'd prefer to give that up to get the more predictable (for you) metering of the stock screen. That's certainly your choice to make, but this forum is chock-a-block with folks who feel quite differently. I have one in both my current bodies and will continue to use them for the foreseeable future. They just plain make manual focusing much more precise, something at which the stock screen is woefully inadequate.

---------- Post added 06-05-14 at 09:29 PM ----------

QuoteOriginally posted by carrrlangas Quote
Does the ee-s screen for the K-5 series fits the K-3?
Yes, the K-5 and K-3 are inter-changeable, screen wise.
06-05-2014, 08:41 PM   #683
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QuoteOriginally posted by DogLover Quote
I also agree that it is the buyer's responsibility to determine the suitability of the screen to a given camera pre-purchase.
I bought the screen indicated for the camera on which it was installed and the meter ceased to work properly. What more could I have done, pre-purchase, to avoid this problem?

As for why this is a serious issue, perhaps you would like to go out for a day with your camera randomly applying -2 stops exposure compensation with all lens series (DA, FA, A, etc.). That is what essentially is happening. If I wanted to manually meter each frame with a hand-held meter and/or chimp each and every shot and redo, yes, I guess this is a great frame and a wonderful thing. That is not my perspective and it is my expectation that if there are probable metering issues with a particular camera, it is the vendor's responsibility to indicate such in the item description. At least that is what Katz Eye has done on their Web site.

I suspect you might feel differently if your screen (w/o the bright lines) were behaving the same. Since that is not the case, perhaps you would be interested in purchasing my screen from me. It is in excellent condition and very lightly used. I will give you the very special price of $55 USD including shipping. That is half what it would cost to order from Taiwan.


Steve

06-05-2014, 08:57 PM   #684
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QuoteOriginally posted by stevebrot Quote
I bought the screen indicated for the camera on which it was installed and the meter ceased to work properly. What more could I have done, pre-purchase, to avoid this problem?

As for why this is a serious issue, perhaps you would like to go out for a day with your camera randomly applying -2 stops exposure compensation with all lens series (DA, FA, A, etc.). That is what essentially is happening. If I wanted to manually meter each frame with a hand-held meter and/or chimp each and every shot and redo, yes, I guess this is a great frame and a wonderful thing. That is not my perspective and it is my expectation that if there are probable metering issues with a particular camera, it is the vendor's responsibility to indicate such in the item description. At least that is what Katz Eye has done on their Web site.

I suspect you might feel differently if your screen (w/o the bright lines) were behaving the same. Since that is not the case, perhaps you would be interested in purchasing my screen from me. It is in excellent condition and very lightly used. I will give you the very special price of $55 USD including shipping. That is half what it would cost to order from Taiwan.


Steve
Why on earth would I want to buy your screen? I already have two.

That makes me remember, though, that the one in my K-5IIs has the grid lines (rectangles in each corner) and I haven't ever noticed an issue with that one, either.
06-05-2014, 09:02 PM   #685
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QuoteOriginally posted by DogLover Quote
Why on earth would I want to buy your screen? I already have two.
So that you could prove that it is not an issue, of course and comment from actual experience. Or you could simply swap the AF frame line version onto your K-3 and share in my joy. I am sure you will enjoy it as much as I have. It should be an absolute pleasure to use with your DA 15/4 Limited.


Steve
06-05-2014, 09:03 PM   #686
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I am equally frustrated with the metering inconsistencies. I have been playing around with several manual focus lenses, and the screen makes it much more viable to use them. However, I have enough slow good AF lenses (15, 21, 300) which are clearly affected by this.

I have seen variances between lenses before, and it is of course to be expected. However the variance I have seen here is beyond what you can just ignore, and defintely require exposure compensation with (in my case) slower lenses, unless you are willing to loose shadow detail. A 1-2 stop exposure error is not a small error...

I exchanged PMs with another PF member that have the plain screen, He appears to have the opposite problem with fast lenses over exposing. In short these exposure issues do not seem to be isolated one person, nor to just the etched screens.

Right now I am considering moving the screen from my k-3 (my primary camera) to my k-5 and sell the extra k-5 screen I bought. I am defintely not going to put this screen in both my cameras.

---------- Post added 06-05-14 at 09:28 PM ----------

QuoteOriginally posted by DogLover Quote
That makes me remember, though, that the one in my K-5IIs has the grid lines (rectangles in each corner) and I haven't ever noticed an issue with that one, either.
I noticed you have mostly fast glass. Why not try and see if you experience the same difference as Steve and I when you use one of your slower lenses (100-300 or your 15) ? Simple put the 15 on and see suggested exposure in AV mode using regular compared to live view. I get 1.5 stop difference. Since you have both screen types maybe check if you get different results.
06-05-2014, 09:31 PM - 1 Like   #687
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QuoteOriginally posted by HenrikDK Quote
I exchanged PMs with another PF member that have the plain screen, He appears to have the opposite problem with fast lenses over exposing. In short these exposure issues do not seem to be isolated one person, nor to just the etched screens.
I would actually be much more skeptical of that than I am of the underexposure you guys are getting.

---------- Post added 06-05-14 at 11:38 PM ----------

QuoteOriginally posted by HenrikDK Quote
---------- Post added 06-05-14 at 09:28 PM ----------[/COLOR]

I noticed you have mostly fast glass. Why not try and see if you experience the same difference as Steve and I when you use one of your slower lenses (100-300 or your 15) ? Simple put the 15 on and see suggested exposure in AV mode using regular compared to live view. I get 1.5 stop difference. Since you have both screen types maybe check if you get different results.
Ok, I'll see if I can do that sometime in the next couple of days.
06-05-2014, 09:39 PM   #688
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QuoteOriginally posted by DogLover Quote
I would actually be much more skeptical of that than I am of the underexposure you guys are getting.
I agree - sounded weird. Maybe he will post here. Is it possible the screen could be inverted and cause an issue?
06-05-2014, 09:39 PM   #689
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QuoteOriginally posted by DogLover Quote
Ok, I'll see if I can do that sometime in the next couple of days.
Cool


Steve

---------- Post added 06-05-14 at 09:40 PM ----------

I have started a new thread regarding this issue in the K-3 section of the forums:

https://www.pentaxforums.com/forums/172-pentax-k-3/265003-pentax-k-3-compatib...us-screen.html


Steve
06-06-2014, 06:15 PM   #690
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just to add more to this ongoing metering sager, well a video might be most useful to explain...


Did we previously know about back light, / stray light through the eye piece effecting the metering? Or did we file that under only older cameras were affected by this?
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