[fanofcc]

I have Super Takumar 50 f1.4; Vivitar 200 f3.5, so big aperture is f/1.4 and a have only M42 lens.
My eyes are very bad with serious myopia.
Could you give me some advise that what focus screen i should buy, EE-S or Ec-A?

[Soap]

After shooting with the camera for a couple weeks I came to the conclusion I was backfocusing just slightly. I removed the reddish colored shim, added just one of the clear shims and I had a slight front focus. Added the second clear shim and it's bang on to my eye and the sensor. I'm able to get good focus, even at f1.7 now.

So if you seem to be missing with your new EE-S screen don't be afraid to experiment with the shims. I've gotten to the point not I can switch them in about 2 minutes.

Now, to get some of the dust of the screen...which honestly doesn't bother me too much at all.

How about a youtube example video

[Transit]

Hi Folks,
Is there a poor mans shim alternative, post it note strips or something ?
I've got quite noticable back focus. Teach me to cut down my own screen
Pete

[baro-nite]

Is there a poor mans shim alternative, post it note strips or something ?

Yes, you can use Post-it strips as shims; that's what I did when I first discovered that my stock focusing screen was misaligned. Theoretically they could be more likely to expand/contract in changing humidity, but I found them to work well for the relatively short time I used them (before upgrading to the S-type screen).

[dlacouture]

You can also use scotch tape... Each layer is approx. 0.05mm thick, so it's quite easy to build up to the desired thickness...

[Transit]

Excellent ! thanks to you both

[Musto Pentaxian]

You can also use scotch tape... Each layer is approx. 0.05mm thick, so it's quite easy to build up to the desired thickness...

I agree, the supplied shims didn't quite hit the sweet spot for me on my K5, either a touch of back focus or a touch of front focus.
I used some red litho tape over the top of one of the thin supplied shims and it was perfect to my eye.

It really is worth the effort to calibrate, If you can trust the screen then it makes manual focussing and quick shift adjustments so much more precise.

I have a split screen in my Kr, but this screen is a whole level better, the depth of field simulation is just exquisite...

Cheers

Chris

[KHatfull]

Just today I received my "focus adjustment washers" from Pentax parts (Wildernest Logistics).

I got the full A-I set, 0.10-0.50 in 0.05 increments. Nice, metal, just like the original. I figured since I was paying the shipping I might as well get the full set given they're only $1.50 each. The whole set including UPS shipping was just a tad over $20.

Hopefully tonight I can measure what I'm currently using (two of the clear ones provided by focusingscreen.com, nice to have a caliper ) and move up a little to fix my slight backfocus.

Just for posterity here are the part numbers...

M22 - 00A Focus adjusting washer a (0.1) 1 77240-M22-00A 4D4
M22 - 00B Focus adjusting washer b (0.15) 1 77240-M22-00B
M22 - 00C Focus adjusting washer c (0.2) 1 77240-M22-00C
M22 - 00D Focus adjusting washer d (0.2.5) 1 77240-M22-00D
M22 - 00E Focus adjusting washer e (0.3) 1 77240-M22-00E
M22 - 00F Focus adjusting washer f (0.3.5) 1 77240-M22-00F
M22 - 00G Focus adjusting washer g (0.4) 1 77240-M22-00G
M22 - 00H Focus adjusting washer h (0.45) 1 77240-M22-00H
M22 - 00I Focus adjusting washer i (0.5) 1 77240-M22-00I

...the contact info for the gal at Wildernest who handles Pentax parts...

Lynn Badillo
National Parts Administrator
Wildernest Logistics Solutions, Inc.
PENTAX Division
3500 N. Windsor Dr. Suite-400
Aurora, CO 80011
Ph. (720)988-2653
Fax (303)799-9213
E-Mail: lynn.badillo@wildernestlogistics.com

...and the K-5 parts diagram she sent me as well.

K-5PartsDiagram.pdf

Enjoy.

[KHatfull]

Just today I received my "focus adjustment washers" from Pentax parts (Wildernest Logistics).

...and I just spent 90 minutes dialing the K-5 in.

I'm curious if anyone else has experienced this: testing against a "target" seemed to give me a different result then shooting at actual subjects. I have a borrowed LensAlign (yes apisto, back to you very soon! ) and I had it on the table and I'd test against it when I would adjust shims. Then I'd go around the house and shoot a little and seem to not be as close as when I was shooting the LensAlign.

So I dispensed (figuratively!) with the LensAlign and adjusted the shims to what I experienced shooting 20 or so pics around the house after each adjustment. I ended up removing shim thickness and getting to the Pentax 0.25 shim (which is actually 0.24, they all were short on my decent caliper). I had originally tried both the 0.10 and 0.20 shims together which gave me about 0.28 total. That produced a slight but noticeable front focus. Then I went to the 0.25 (0.24) and it seems to be really, really good now. I think even < 0.05 can make a real and noticeable difference.

I find now that I'm hitting acceptable focus on 80% of shots, given enough contrast. And this is walking around the house here at midnight...it's not very bright around here at the moment.

Maybe your eyes do something different with the black and white very high contrast of the LensAlign as opposed to a real subject. I don't know. But had I not worked from "experience" I might still be mucking with it. I was questioning my decision to go with all A lenses...Man I look at the below pics and, wow...the lenses and camera are simply stellar.

Here are a couple of shots with the A50/1.7 at 1.7 just pointing and shooting. First is without flash, the second with the 540FGZ ceiling bounced. I think it's as good as I'm going to get and I'm anxious to try outside in good light to see what I get.

Please chime in with comments.

[dlacouture]

Just today I received my "focus adjustment washers" from Pentax parts (Wildernest Logistics).

I got the full A-I set, 0.10-0.50 in 0.05 increments. Nice, metal, just like the original. I figured since I was paying the shipping I might as well get the full set given they're only $1.50 each. The whole set including UPS shipping was just a tad over $20.

I'm so jealous!
Here in Europe, we are facing a 5€ price apiece!

And that's once you can get your hands on them, as:
- Pentax France does not deal directly with customers (and they are not even aware of what shims are!)
- P2MS (the company doing Pentax' service) does not deal directly with customers, and ask you to go through your local vendor...
- local vendors don't understand what you are talking about, and do their best to tell you that no such thing exists... And those that take the trouble to understand what you want only charge you ludicrous amounts...

I'd gladly pay someone 30$ to send me a whole set of shims...

Anyway, as someone suggested in this thread, I had a little talk with Deki (from FocusingScreen), and seeing how much Pentaxians I've sent him in the past 2 years with this thread (and all those I've started on the others forums), he kindly offered me a 50% rebate on a S-type screen!!!

Yeeeehaaaa!

[vonBaloney]

...and I just spent 90 minutes dialing the K-5 in.

I'm curious if anyone else has experienced this: testing against a "target" seemed to give me a different result then shooting at actual subjects. I have a borrowed LensAlign (yes apisto, back to you very soon! ) and I had it on the table and I'd test against it when I would adjust shims. Then I'd go around the house and shoot a little and seem to not be as close as when I was shooting the LensAlign.

So I dispensed (figuratively!) with the LensAlign and adjusted the shims to what I experienced shooting 20 or so pics around the house after each adjustment. I ended up removing shim thickness and getting to the Pentax 0.25 shim (which is actually 0.24, they all were short on my decent caliper). I had originally tried both the 0.10 and 0.20 shims together which gave me about 0.28 total. That produced a slight but noticeable front focus. Then I went to the 0.25 (0.24) and it seems to be really, really good now. I think even < 0.05 can make a real and noticeable difference.

I find now that I'm hitting acceptable focus on 80% of shots, given enough contrast. And this is walking around the house here at midnight...it's not very bright around here at the moment.

Maybe your eyes do something different with the black and white very high contrast of the LensAlign as opposed to a real subject. I don't know. But had I not worked from "experience" I might still be mucking with it. I was questioning my decision to go with all A lenses...Man I look at the below pics and, wow...the lenses and camera are simply stellar.

Here are a couple of shots with the A50/1.7 at 1.7 just pointing and shooting. First is without flash, the second with the 540FGZ ceiling bounced. I think it's as good as I'm going to get and I'm anxious to try outside in good light to see what I get.

Please chime in with comments.

Doing too much adjustment and my eyes would zone out after a while and I couldn't trust them. You have to set the diopter on the eyepiece to where you want it and make sure it stays there through the process. Also need to use a fast lens so the DoF is very thin. The resulting look of the image vs the viewfinder is never quite the same anyway (even if the focus is spot-on) so rather than just focus and shoot and then check the result, it can help to lock it on a tripod and then take the same shot twice: one focused via live view (which is always exact off the sensor) and the other focused through the viewfinder ("scramble" the focus between shots so you have to re-focus from scratch). Then compare those two shots and adjust/repeat until you can't tell the difference between them. If you are getting differences between the tests and real-life shooting, in my experience it is because it is still off and maybe you just need a break or maybe certain kinds of lighting affect your focus (does tungsten cause humans to miss focus as well as AF systems?). I experienced the same thing, but then went back to the tests with fresh eyes later and could see that they were off. Once you get it spot-on for real, it just *works* all the time and you can focus with confidence. But I did find that shooting too many test charts all at once did make it so after a while I couldn't tell what I was focused on.

And the camera will probably go out of adjustment again at some point. Mine did suddenly one day for no apparent reason -- manual focus was suddenly off, AF was also suddenly off and needed adjustment -- it was just like the sensor moved suddenly. And then a few hours later that same day my on-board flash failed -- don't know if it was related or not. It seemed like it had been dropped or something but it hadn't. It actually seemed to happen just between shots while I was holding it. Eventually sent it in to get the flash repaired and had them calibrate the AF again and then when I got it back and re-did the shims for the custom screen (I put the stock screen back in for repair) I ended up using different ones than before. So it really was like the sensor just changed position forward or back slightly...

[KHatfull]

Doing too much adjustment and my eyes would zone out after a while and I couldn't trust them. You have to set the diopter on the eyepiece to where you want it and make sure it stays there through the process.

Yep, that was the very first thing I did long ago.

Also need to use a fast lens so the DoF is very thin.

Yep, 50/1.7 wide open.

The resulting look of the image vs the viewfinder is never quite the same anyway (even if the focus is spot-on) so rather than just focus and shoot and then check the result, it can help to lock it on a tripod and then take the same shot twice: one focused via live view (which is always exact off the sensor) and the other focused through the viewfinder ("scramble" the focus between shots so you have to re-focus from scratch). Then compare those two shots and adjust/repeat until you can't tell the difference between them. If you are getting differences between the tests and real-life shooting, in my experience it is because it is still off and maybe you just need a break or maybe certain kinds of lighting affect your focus (does tungsten cause humans to miss focus as well as AF systems?). I experienced the same thing, but then went back to the tests with fresh eyes later and could see that they were off. Once you get it spot-on for real, it just *works* all the time and you can focus with confidence. But I did find that shooting too many test charts all at once did make it so after a while I couldn't tell what I was focused on.

I think we came to the same conclusion two different ways. When I made an adjustment I took 20-25 shots just around the house, refocusing in between, coming from near and far focus both. When 80% of the shots indicate back focus that tells me I still have an issue. So I shimmed in 0.05 increments. When the acceptably in focus rate got to 80% I was at the 0.25 (0.24) Pentax shim.

We'll see how it does in real world for a couple days, then I'll likely throw it back on the tripod and check again against a target.

One thing I wondered...back on the film days did the factory spend a lot more time calibrating the focus screen than in the digital age? Seems like almost everyone now who wants to seriously use MF has issues with the screen.

[vonBaloney]

One thing I wondered...back on the film days did the factory spend a lot more time calibrating the focus screen than in the digital age? Seems like almost everyone now who wants to seriously use MF has issues with the screen.

No, just by the time you got the film back you had forgotten what you focused on and anything you missed was chalked up to "user error"...

[drougge]

And the camera will probably go out of adjustment again at some point. Mine did suddenly one day for no apparent reason -- manual focus was suddenly off, AF was also suddenly off and needed adjustment -- it was just like the sensor moved suddenly. And then a few hours later that same day my on-board flash failed -- don't know if it was related or not. It seemed like it had been dropped or something but it hadn't. It actually seemed to happen just between shots while I was holding it. Eventually sent it in to get the flash repaired and had them calibrate the AF again and then when I got it back and re-did the shims for the custom screen (I put the stock screen back in for repair) I ended up using different ones than before. So it really was like the sensor just changed position forward or back slightly...

More likely the mirror moved. (The top is probably well fixed, but the bottom moves by design, so might well decide to have a different rest position.)

[vonBaloney]

More likely the mirror moved. (The top is probably well fixed, but the bottom moves by design, so might well decide to have a different rest position.)

Could be, but if the mirror rest position moved, wouldn't that also change the angle of the mirror slightly and make the view all wonky? It was strange anyway, and then the flash failed the same day. Can't figure out what happened there...