[martin42mm]

What I have done in the past for shim adjustment is if you are lucky and your shim is too thin I just keep gluing lens paper to the shim using crazy glue and weight it down until it hardens, cut out the shim check if its thick enough and repeat until you reach the correct thickness.

I also in the past for shims used an acid bath to cut very thin stock of brass or copper used in shimming material. coat what you don't want cut out with wax and drop in your acid bath

Old-ish post i know, but still relevant. So please if you can avoid using super-glue/crazy glue anywhere near plastic, especially focus screens-it is lethal to plastic, and can outgas for some time even after it has hardened.

[UncleVanya]

Old-ish post i know, but still relevant. So please if you can avoid using super-glue/crazy glue anywhere near plastic, especially focus screens-it is lethal to plastic, and can outgas for some time even after it has hardened.

I would suggest Titebond Wood Glue - Type III I think is the one that is moisture resistant.

[sprint113]

One thing I experimented with recently is plastic shim stock. I took the original shim, used packaging tape to affix it to the plastic shim stock, and cut along the edges with an xacto knife to get a replica. Very tedious, especially with the thicker material and the edges have lots of burrs. I might try and see if my friend's cricut machine can cut the shim stock with enough precision to get cleaner results. The shims provided by focusing-screen was good enough for now, but eventually I'll see if I can get greater accuracy with these shims I made.


In other news, uscamera is no longer able to order repair parts from Pentax (only Precision camera can order parts) so they're not able to order the OEM shim set anymore.

[AgentL]

Are folks still ordering and using screens from FocusingScreen on their K-1's? I could be tempted, very easily indeed, since I use manual lenses a lot.

[Casion]

At issue is precision.* The focus confirm feature has a focus sensitivity (ability to detect an OOF condition) of f/2.8 with the center AF point. This is acceptable for general shooting with f/2.8 and slower lenses, but does not offer acceptable precision for fine focus or at apertures wider than f/2.8. The better split image focus aides offer a focus sensitivity of f1.2 or better. The Canon S screens mentioned above provide focus sensitivity of f/1.8 but at the price of significant dimming at f/2.8 and narrower (affects metering).


Steve

* Precision is the ability to attain accurate focus over multiple attempts. Even a well-calibrated (accurate) system is fairly useless if precision is poor.

Focus confirmation accuracy has nothing to do with the point being only F2.8. The only reason the focus confirmation is inaccurate is Pentax' incompetence. Even Nikon D300 confirms focus better.

[martin42mm]

Focus confirmation accuracy has nothing to do with the point being only F2.8. The only reason the focus confirmation is inaccurate is Pentax' incompetence. Even Nikon D300 confirms AF better.

Just use those two God-given miracles called eyes-far better than AF any day of the week. Hence the need for decent focus screens. I hate AF with a vengence, and this subject causes more arguments and complaints than any other subject where modern cameras are concerned. Probably the worst addition to the world of photography ever.

[Casion]

Just use those two God-given miracles called eyes-far better than AF any day of the week. Hence the need for decent focus screens. I hate AF with a vengence, and this subject causes more arguments and complaints than any other subject where modern cameras are concerned. Probably the worst addition to the world of photography ever.

You'll struggle trying to use more than one God-given miracle at a time, plus it won't even let me focus on the moon because of blooming.

[UncleVanya]

Just use those two God-given miracles called eyes-far better than AF any day of the week. Hence the need for decent focus screens. I hate AF with a vengence, and this subject causes more arguments and complaints than any other subject where modern cameras are concerned. Probably the worst addition to the world of photography ever.

As I age I find autofocus much easier to love.

[martin42mm]

As I age I find autofocus much easier to love.

Now that I can agree with, but while I can still use BOTH my peepers ( I know, someone had to take the choice of two as literaly using both at once!), it remains my favourite method of focusing,although with a point-and-shoot camera, and for some sport work where objects are moving fast, AF does have its uses. However I have always found that when actually composing a shot where speed is not the prime criterium, the ability for me to decide exactly what I want in focus, and therefore the depth of field afforded by whatever aperture I am using, AF just gets in the way, no matter how many AF points have been selected. Hence the need for focus sceens that match the accuracy of those previously avaialble in manual- focus cameras. When composing with AF, and then using stop-down to give an accurate depth of field, the two fight againist each other. Therefore AF stays off 99.9% of the time in my cameras.

But that's just me-however this thread is about focus screens, not the trials and tribulations of AF.

[Casion]

Are there any options other than Canon 1D screens and FocusingScreen.com?

[Casion]

Okay, I got and 1Dx focusing screen and it was reasonably easy to install. There is 0,5mm metal shim from factory in K-1 which is too thick (front focus), I replaced it with 3 layers of 0.1mm thick adhesive. The manufacturer is Bresson.com.cn . Funny thing is that the split image circle is slightly off-centre and looks funny unless I disable overlay. But K-1 does not store overlay settings in U1-U5, so that's a bit inconvenient.

[martin42mm]

Okay, I got and 1Dx focusing screen and it was reasonably easy to install. There is 0,5mm metal shim from factory in K-1 which is too thick (front focus), I replaced it with 3 layers of 0.1mm thick adhesive. The manufacturer is Bresson.com.cn . Funny thing is that the split image circle is slightly off-centre and looks funny unless I disable overlay. But K-1 does not store overlay settings in U1-U5, so that's a bit inconvenient.

Back in my Spotmatic etc. film days, I never really got on with split-image screens, which only really work effectively with some focal length lenses anyway. My preferred choice has always been a plain ground-glass screen, or when available, one with a microprism centre-spot. These seems to work far better with my eyes than a split-image..To me a screen is not only for critical focus, but also composition, and the split-image seems a distraction. I fitted a very good cut-down Canon plain screen to my K-S1, but the supplied screen in my KP seems absolutely fine.

[Casion]

Also, funniest thing I found out is that the split screen blacks out at F5.6 only if you do not place your eye against the center of the viewfinder! So you can actually use it quite fine at F5.6 if you are not in a hurry.

[Casion]

How does vignetting in viewfinder depend on the focusing screen used? I'm almost sure I now get noticeably more vignetting in viewfinder now.

[martin42mm]

How does vignetting in viewfinder depend on the focusing screen used? I'm almost sure I now get noticeably more vignetting in viewfinder now.

Many early screens had microprism rings to counteract the fall-off at the edges, but most modern screens don't bother-all DSLRs I've seen have plain ground-glass/matte finish overlaid with some focus aids. Personally I prefer a plain screen, and some are definitely better than others. I much prefer that to any so-called focus aid. And the fall-off is not reflected in the final image, so if it is there, I ignore it. Let's face , if you've used a Zenit with a plain screen you can deal with any edge fall-off!