[alex.r]

It does seem to get very complex indeed, I've been following most of these threads as well. I already received my focusing screen for my ist DL. However it is, according to jinfinance where I bought it (link is here), the same one used for K100/200, whereas the ist DS seems to be the same focusing screen as the K10/20. I find this rather weird, as I was under the assumption that the DS and the DL are very similar in most aspects.
However I did not get any shims supplied, just the focusing screen. Does this mean I won't be needing shims, you think? I haven't found a place that will do the installation for me yet – I don't have a very steady hand (I know, and I have one of the latest Pentax dSLR's that doesn't have SR...) and am a bit afraid to do it myself. I really don't want to scratch or damage anything in there.

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Last edited by alex.r; 03-27-2009 at 01:57 PM. Reason: typo + added link

[deejjjaaaa]

However I did not get any shims supplied, just the focusing screen. Does this mean I won't be needing shims, you think? I haven't found a place that will do the installation for me yet

if shim will be necessary you can make it yourself... it might be that you just did not notice it ? I read a lot of stories when people were installing focusing screens w/ protecting film still attached to the surface ...

[milesy]

this might sound like a really dumb question, but is it obvious to tell when there is a protective film on the screen, as i didnt remove any so took it back from the camer and havent been able to peel anything off easily

[fwcetus]

It does seem to get very complex indeed, I've been following most of these threads as well. I already received my focusing screen for my ist DL. However it is, according to jinfinance where I bought it (link is here), the same one used for K100/200, whereas the ist DS seems to be the same focusing screen as the K10/20. I find this rather weird, as I was under the assumption that the DS and the DL are very similar in most aspects.

I am not surprised that the DS and DL are different, since the DS uses a pentaprism, while the DL uses a pentamirror. (The point is not that there is a fundamental difference in focus screens between pentaprism and pentamirror systems, but simply that the DS and DL have different finder constructions, not surprisingly making for different screen mountings.)

I do know that the Katz-Eye screen for my DS (pentaprism) fits just as well in my K20D (pentaprism) (and, in fact, Rachel Katz at Katz-Eye confirmed that by email).

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Last edited by fwcetus; 03-28-2009 at 06:01 AM.

[alex.r]

I do know that the Katz-Eye screen for my DS (pentaprism) fits just as well in my K20D (pentaprism) (and, in fact, Rachel Katz at Katz-Eye confirmed that by email).

That is one of the reasons (besides the higher price) why I didn't order at Katz Eye. I emailed Rachel Katz to ask her which of the screens they have is compatible with the DL2 that I have, because none were clearly described as such. She told me she wasn't a hundred percent sure about it.

Anyhow, I'll let you know how things turn out once I find someone who will place it for me

[RawheaD]

Whether or not you need a shim depends entirely on calibration, so yes, in fact, you may very well need a shim on your K20D.

Or, to be more precise, you may need a different shim than the one that is pre-installed for you at the Pentax factory.

Case in point; my K20D had a front focus issue with the manual focus. It had a 0.15mm shim preinstalled, and it HAD to be replaced (thanks to KatzEye) with a Pentax genuine 0.30mm shim in order for the FF to be fixed.

It has nothing to do with the screen, because the focus plane is the bottom side of the screen (i.e., the side that is facing the mirror). Unless we're talking about really *really* shoddily made screens, that side is going to be nice and flat and (important point-->) flush against the housing for the focusing screen.

Thus if there is a front/back focus issue, it is almost 100% a problem with where that housing is. In order to compensate for minor fluctuations in manufacture, Pentax themselves deal with FF/BF issues of the focusing screen using different thickness shims.

The problem arises because with the factory screen, which, according to something I read somewhere, the DoF of the image you see on the factory screen is something equivalent to an image generated by an F4.0 lens, it is virtually impossible to visually recognize a 2~3mm even 10mm front focus problem (when shooting with a 50mm f1.4 lens from, say 30 cm away).

Which means that, so far as factory screens are concerned, Pentax can be lax about the calibration, and it wouldn't make any difference to the user (who, even if crazy enough to use manual focus fast prime lenses, would more likely than not just rely on AF confirmation light).


Unless, of course, you get one of these screens.


So that's the reason why I would recommend KatsEye above other cheaper options, despite their higher costs; not so much the quality, which might not be that important for some people, but because they *will* take care of any FF/BF issue your camera has. After all, a $30 focusing screen is nice and cheap, but if you have a severe FF issue that you can't fix on your own (and there's a good chance Pentax can't do it for you either), you've wasted 100% of those $30. At least with a KatzEye, you spend $150-$200 and you are guaranteed that screen will do what it's supposed to do.

[ytterbium]

Where can you get those shims, quick e-bay search returned nothing.

[fwcetus]

Whether or not you need a shim depends entirely on calibration, so yes, in fact, you may very well need a shim on your K20D. Or, to be more precise, you may need a different shim than the one that is pre-installed for you at the Pentax factory.

[snipped excellent explanation]

So that's the reason why I would recommend KatsEye above other cheaper options, despite their higher costs; not so much the quality, which might not be that important for some people, but because they *will* take care of any FF/BF issue your camera has. After all, a $30 focusing screen is nice and cheap, but if you have a severe FF issue that you can't fix on your own (and there's a good chance Pentax can't do it for you either), you've wasted 100% of those $30. At least with a KatzEye, you spend $150-$200 and you are guaranteed that screen will do what it's supposed to do.

I am trying to make sure I unnderstand everything in that last paragraph.

1. When you say "because they *will* take care of any FF/BF issue", is the "they" referring to Katz-Eye the ~company~, or to Katz-Eye ~screens~?

2. When you say "you spend $150-$200", are you referring to the typical price of a Katz-Eye screen (exact price dependent on options), or are you referring to an additional fee to have Katz-Eye work on your Pentax body to get its focus "up to snuff"?

Thanks.

[RawheaD]

I am trying to make sure I unnderstand everything in that last paragraph.

1. When you say "because they *will* take care of any FF/BF issue", is the "they" referring to Katz-Eye the ~company~, or to Katz-Eye ~screens~?

2. When you say "you spend $150-$200", are you referring to the typical price of a Katz-Eye screen (exact price dependent on options), or are you referring to an additional fee to have Katz-Eye work on your Pentax body to get its focus "up to snuff"?

Thanks.

Sorry for the late response.

(1) I'm talking about the company. You see, and I'll tell you I learned this the hard way––KatzEye people are pros when it comes to focusing screens (duh). You'd expect the same with Pentax or any other camera maker, but that's just not the case. Because they don't care about manual focus (especially when they aren't making them themselves any more), they either can't, or won't, necessarily rectify your BF/FF problem. That's what happened with me; I sent my K20D to Colorado with VERY detailed information regarding my front focus issue, verly clearly stating how it's not a problem with the AF but with the MF (and hence the location of the screen). 2 weeks later, the camera came back without ANYTHING done about the FF problem.

KatzEye on the other hand has the know-how to test for, spot, and recrtify these problems. The HAVE TO, because that's their lifeline. They make products that, unlike the stock screen, let's you focus down to the last fraction of a millimeter. That product becomes useless if the camera has a FF/BF issue that is of an order of magnitude larger than that; they need to be able to fix that.

(2) KatzEye screens are around $100. You can get OptiBright which is another $55 or so, so the screen is going to be 100-150USD. Their calibration & installation service is $45 on top of that, hence my number 150-200USD.

[Jewelltrail]

ytterbium
Where can you get those shims, quick e-bay search returned nothing

Pentax sells the shims--some focus screen vendors selll them too. Many people at the forum say the shims are easily reproduced.

[fwcetus]

Sorry for the late response.

No problem - thank you for replying.

KatzEye on the other hand has the know-how to test for, spot, and recrtify these problems. The HAVE TO, because that's their lifeline. They make products that, unlike the stock screen, let's you focus down to the last fraction of a millimeter. That product becomes useless if the camera has a FF/BF issue that is of an order of magnitude larger than that; they need to be able to fix that.

That's useful to know, just in case...

Thanks.

[ytterbium]

Pentax sells the shims--some focus screen vendors selll them too. Many people at the forum say the shims are easily reproduced.

Any link with worldwide shipping would be appreciated.

[Jewelltrail]

ytterbium: Any link with worldwide shipping would be appreciated.

A quick Google got me this:


Pentax Online Store - Customer Care

Call the 1-800 # and ask questions. This is not a parts link, but I'm sure someone there can hook you up.