[Jonas B]

Jonas, did you cover the viewfinder (with an eye for instance) when testing your lenses? Just guessing, but sun at the grey card, camera at the grey card, sun at the viewfinder…. On the other hand, your obviously not alone.

I sure did, yes.

[Jonas B]

Another DS success story (pretty good f2.8 and on (slight glitch at f4, but not really significant. Wide open and f16 seems to fit the general pattern of Pentax cameras...)
Thanks, wasn't sure you tried "the trick" Any side effects to report?

I wasn't sure either. Side effects... maybe a notch darker viewfinder and at the same time one notch easier to focus manually. I can't confirm that 100% though - it may be just a psychological side effect. To the soup a KPS viewfinder magnifier should be added.

I also tried with a "Virtual Village" split image screen at the same time. It gave another pattern in return but I think it should be left aside for this discussion.

[Jonas B]

I'll do the same later today and post here on my results. The only semi-controlled tests I did were with an f/4 lens that did in fact increase exposure moderately on the K10 beyond f/8 but not noticeably on the DS.

At the f/22 end of the range (not that I'd ever use it) the K10 needed -1 exposure compensation. Since some (normally calm) members can get heated about this issue, I suspect that not all cameras/focus screens behave identically. I'll try to repeat your test with a similar lens that you used.

I'm looking forward to see your results Sean. I hope you have a chance to do the test in daylight (thinking of the color blind DS light meter).

Heated? People get upset for all sorts of things. One cannot stay away from certain topics all the time.

[Jonas B]

Another DS success story (pretty good f2.8 and on (slight glitch at f4, but not really significant. Wide open and f16 seems to fit the general pattern of Pentax cameras...)
Thanks, wasn't sure you tried "the trick" Any side effects to report?

Now I have a side effect to report Jeff: After having taking mostly causual leisure picture just for fun for a while I wanted to try some different ideas the other day. Puzzling result: the focus was not where expected. The AF worked fine (when it decided to lock on what I thought was important. That center spot is really big!) but manually focusing did not. I have now checked and I get back focusing with the K10D and the DS (LL-60) screen.

So, I am back to the original K10D screen: it is brighter and manual focusing is harder. Pretty much everything in the viewfinder look sharp. The DS screen is way better for manual focusing, on a DS. Pentax needs to do what Canon do: a viewfinder screen for manual focusing!

[Artymous]

With the 135mm f/3.5 M, I get almost *Spot* on exposures on the *ist Ds

If using it on the K10D, however, I'm always at least one stop over-exposed, sometimes two stops.. so for the one shoot I had the 135mm on the K10D, I started just putting the shutter-speed up two stops (If it exposed at 350, say, I'd jump it to 500), and that seemed to do the trick.

[jeffkrol]

Now I have a side effect to report Jeff: After having taking mostly causual leisure picture just for fun for a while I wanted to try some different ideas the other day. Puzzling result: the focus was not where expected. The AF worked fine (when it decided to lock on what I thought was important. That center spot is really big!) but manually focusing did not. I have now checked and I get back focusing with the K10D and the DS (LL-60) screen.

So, I am back to the original K10D screen: it is brighter and manual focusing is harder. Pretty much everything in the viewfinder look sharp. The DS screen is way better for manual focusing, on a DS. Pentax needs to do what Canon do: a viewfinder screen for manual focusing!

Thanks.. Try flipping the screen.....
Anyways another thread has been started w/ "glowing results" ... Maybe they haven't tried MF yet.......
https://www.pentaxforums.com/forums/pentax-dslr-discussion/6724-k10d-ll-60-fo...-m-lenses.html

[Jonas B]

Thanks.. Try flipping the screen.....
Anyways another thread has been started w/ "glowing results" ... Maybe they haven't tried MF yet.......
https://www.pentaxforums.com/forums/pentax-dslr-discussion/6724-k10d-ll-60-fo...-m-lenses.html

I didn't see that thread. And they didn't see this one I guess.

I don't believe in flipping the screen. The error isn't that big and I guess flipping the screen will be a pain just to see that the situation is the same but opposite. Ahem.

But the original screen is bad for manual focusing. I'l have to look further into this some day.

regards,

[ben-pentax]

Now I have a side effect to report Jeff: After having taking mostly causual leisure picture just for fun for a while I wanted to try some different ideas the other day. Puzzling result: the focus was not where expected. The AF worked fine (when it decided to lock on what I thought was important. That center spot is really big!) but manually focusing did not. I have now checked and I get back focusing with the K10D and the DS (LL-60) screen.

So, I am back to the original K10D screen: it is brighter and manual focusing is harder. Pretty much everything in the viewfinder look sharp. The DS screen is way better for manual focusing, on a DS. Pentax needs to do what Canon do: a viewfinder screen for manual focusing!

Jonas - after reading this I tested my K10D with the DS screen for manual focus accuracy. As far as I could see - everything is just fine. Edited my original post with this findings also.

Ben

[Jonas B]

Jonas - after reading this I tested my K10D with the DS screen for manual focus accuracy. As far as I could see - everything is just fine. Edited my original post with this findings also.

Ben

That's interesting. Are we experiencing sample differences maybe?

Here is what I did: At first I noticed some back focusing when I had the camera on a tripod doing some experiments involving short distances and a small main subject. The subject obviously never was focusd. I had to use AF, or deliberatley set the focus point a few centimeters in front of the subject.

So, I took a ruler, evenly lit from the side and angled upward about 30 degrees. At 40cm distance I had a whopping 4cm of back focusing. I focused very carefully, using a 2.5x magnifier and evaluated the pictures on the LCD screen at 20x enlargement. Then I switched to the original K10D viewfinder screen. The matte is somewhat different (allowing more light which is good for AF system but harder to focus manually) but there was no problem using the magnifier. Now the backfocus was down to around 1mm (Lol, let's say there was no back- or front focusing any longer).

Hmm... Well, I have another DS LL-60 screen and also an old split image screen with microprism collar. I'll check them as well and see what differences there may be. Maybe I can modify one of the LL-60 screens if necessary until focus is spot on.

Thank you for posting - it makes it wortwhile to do some further tries! Maybe you can elaborate a little? How did you do your test?

[ben-pentax]

That's interesting. Are we experiencing sample differences maybe?

...

Thank you for posting - it makes it wortwhile to do some further tries! Maybe you can elaborate a little? How did you do your test?

Tripod, 45 degrees, focusing chart. Used the 50 mm lens, the 50mm with the 2X TC and an old AF (but of course used it manually this time) Sigma 28-200 at several focal lengths.

Then shot some objects around the house with the 50 mm. See here https://www.pentaxforums.com/gallery/index.php?n=2082 - hand held, focus on the plastic ring.

One other thing - the manual focusing totally agrees with the auto focus (the green sign and the red light show when I think it's in focus)

[Jonas B]

Tripod, 45 degrees, focusing chart. Used the ....show when I think it's in focus)

That's a good read. I'll try my two LL-60 screens again and see what happens. A "focus shift" may depend on very minor misaligned screen in the screenholder. I'll check for that as well and get back here later with the result.

thanks again (encouraging as it is),

[Jonas B]

Ha! Preliminary tests show that my brand new LL-60 screen works fine with the K10D. I now have a back focus (MF) of about 2mm (being a bit too exact but that's my estimation) at 500mm distance. I see this as no problem and I'm grateful that ben-pentax posted about his working DS screen and K10D combo. (The AF confirmation lamp, green, is all over the place. It believes things are sharp when they are close to sharp, sharp and for some time when they are fading out of focus again. The center sensor is just too big.

I couldn't see any hints about the screen having been misaligned. I don't think you really can mount the screen wrongly, at least not without really forcing the holder while closing it.

So, everything is fine again, and the old K and M lenses are if not perfect so at least ok to use again with manual metering.

I still wish there was a counterpart to the Canon Ee-S screen available. I improved the situation somewhat though; while I were at it I also moved my KPS 1.35x viewfinder magnifier from the DS to the K10D.

So be it,

(Jeff, you read this as well I guess?)

[jeffkrol]

Ha! Preliminary tests show that my brand new LL-60 screen works fine with the K10D. I now have a back focus (MF) of about 2mm (being a bit too exact but that's my estimation) at 500mm distance. I see this as no problem and I'm grateful that ben-pentax posted about his working DS screen and K10D combo. (The AF confirmation lamp, green, is all over the place. It believes things are sharp when they are close to sharp, sharp and for some time when they are fading out of focus again. The center sensor is just too big.

I couldn't see any hints about the screen having been misaligned. I don't think you really can mount the screen wrongly, at least not without really forcing the holder while closing it.

So, everything is fine again, and the old K and M lenses are if not perfect so at least ok to use again with manual metering.

I still wish there was a counterpart to the Canon Ee-S screen available. I improved the situation somewhat though; while I were at it I also moved my KPS 1.35x viewfinder magnifier from the DS to the K10D.

So be it,

(Jeff, you read this as well I guess?)

Yes, but I'm a bit confused. You had one screen w/ severe BF (which screen?) and you then replaced it w a LL-60 and it worked (2mm diff).
So the bad one was an alignment error or upside down? or a bad screen?

[Jonas B]

Yes, but I'm a bit confused. You had one screen w/ severe BF (which screen?) and you then replaced it w a LL-60 and it worked (2mm diff).
So the bad one was an alignment error or upside down? or a bad screen?

I don't understand it either. The K10D with my old LL-60 backfocused considerably. I didn't note until the other day as described above. After reading ben-pentax's posts I switched to the brand new LL-60 screen I had at home. The back focus is now down to approx 2mm when taking a picture with the sensor plane 500mm away from the target.

I don't think the first LL-60 was misaligned. It surely wasn't upside down. I don't know how I could miss this when installing it. I don't know how it could have changed during the 10 days of use. So, I'm sorry, but I have no answers to this.

User error (and signicantly enough I can't figure out what that would be)? Probably. Right now I am not interested in experimenting and switching screens repeatedly. Some other day when I'm insanely bored perhaps.

regards,

[KennJ]

I may be mistaken but I thought I saw some screens for the K10D on B&H's site in the same place as the LL-60's.
In fact they are here Focusing Screens - Camera Accessories
Kenn