Pentax K10D focus screen


johnb

Link Posted 10/09/2007 - 19:51
help, how do I remove the focus screen from my K10d to clean it? Pentax UK does not answer my E-mails. Thanks John

Mannesty

Link Posted 10/09/2007 - 22:27
1: Are you sure you need to remove it?
2: Are you really sure you need to remove it?
3: If you are absolutely certain that you need to remove it . . .
4: DON'T touch it as its easily damaged.
5: Have a pair of surgical tweazers at the ready (to avoid you touching it) . . .
6: Remove the lens and fit rear lens cap . . .
7: Usinger finger nail or suitably blunt instrument pull the tab at the front edge of the focussing screens mount towards the front of the camera.
8: Did I mention "DON'T TOUCH IT".
9: The focussing screen holder will drop down enabling the cleaning of the inside surface with a blower. The focussing screen itself is loose inside its holder so beware of it falling out. If it does . . . . "DON'T . . . "you've got the message.
10: Ensure that the screen is sitting squarely in its holder before returning the holder to its original position.

Easy really, as long as you DON'T TOUCH IT.
Peter E Smith

My flickr Photostream

golfdiesel

Link Posted 11/09/2007 - 05:13
years ago I removed the focussing screen from a SLR to clean it. It only made it worse and after "cleaning" it seemed to attracht a lot more dust.

If there is a spec of dust on it, just leave it there.
Camera:K20D|Ist*DS|Spotmatic II|MZ-10
Pentax Lenses: DA16-45|DA50-200|50A 1.7
Tamron Lenses: 28-200
Takumar Lenses: SMC 55 1.8
Sigma Lenses: EX DG 50-500 'Bigma'|EX 50mm Macro
Flashes: Metz 58 AF-1|Samsung SEF-36PZF|Pentax AF-220T

johnriley

Link Posted 11/09/2007 - 07:58
As it has no effect on the image, cleaning a focusing screen is best avoided.

The screens are very soft and fragile and can be easily damaged.
Best regards, John

golfdiesel

Link Posted 11/09/2007 - 09:00
I had another bad experience with removing a focussing screen, I removed one to clean it (it was a split/microprism screen) and I put it in upsidedown... This caused all of my pictures to be out of focus...

It was this old beast, my first SLR... I still have it but it doesn't work anymore...



Camera:K20D|Ist*DS|Spotmatic II|MZ-10
Pentax Lenses: DA16-45|DA50-200|50A 1.7
Tamron Lenses: 28-200
Takumar Lenses: SMC 55 1.8
Sigma Lenses: EX DG 50-500 'Bigma'|EX 50mm Macro
Flashes: Metz 58 AF-1|Samsung SEF-36PZF|Pentax AF-220T

Clarky

Link Posted 11/09/2007 - 09:01
Well said Mannesty i love it
Sitting at work laughing my head off like an idiot
Camera:|K-7|
Pentax Lenses:|DA12-24/f4 ED AL|DA35Ltd Macro|FA31Ltd|FA77Ltd|FA50/1.4|F70-210|FA20-35 f4/AL|A*200/f4 Macro ED|A50/1.7|A50 Macro f2.8|1.7xAF adapter|
Voigtlander|125/f2.5SL Macro APO Lanthar|
Sigma Lenses:|EX DG 100-300 f4|2X & 1.4X TC|
Flashes:|AF540FGZx2|RingFlash AF160FC|

johnb

Link Posted 11/09/2007 - 09:56
Thanks for the advice.

Regards John

Smeggypants

Link Posted 27/06/2010 - 19:13
Just searching the forum for info on cleaning behind focus screens. I've been getting a build up of dust and small hair like crap behind my K20D focus screen. I've tried to ignore it until now as it doesn't affect the image but now there's a hair like creature sitting right in the centre and is affecting the AF ( as well as being highly annoying ). I think I'm gonna have to bite the bullet and clean it.

I do have a question if any pentax design engineers are reading ( as if ) .... Why not design the camera so the area behind the focus screen is sealed? Unless I'm missing something that would actually make some sense.
[i]Bodies: 1x K-5IIs, 2x K-5, Sony TX-5, Nokia 808
Lenses: Pentax DA 10-17mm ED(IF) Fish Eye, Pentax DA 14mm f/2.8, Sigma 17-70mm f/2.8, Pentax-A 28mm f/2.8, Sigma 30mm F1.4 EX DC, Pentax-A 50mm f/1.2, Pentax-A 50mm f/1.4, Pentax-FA 50mm f/1.4, Pentax-A 50mm f/1.7, Pentax DA* 50-135mm f/2.8, Sigma 135-400mm APO DG, and more ..
Flash: AF-540FGZ, Vivitar 283

Anvh

Link Posted 27/06/2010 - 21:13
Smeggypants wrote:
JI've tried to ignore it until now as it doesn't affect the image but now there's a hair like creature sitting right in the centre and is affecting the AF ( as well as being highly annoying ).

An hair on the focusing screen will never be able to affected auto focus, by the simple fact that the AF doesn't look through it.

The AF is placed on the underside of the camera and use a special smaller mirror fitted behind the large mirror.

Here is a drawing,
4 is the focus screen
7 the AF sensor



What a dirty focus screen can have an effect on is the exposure metering, that sensor does look through it and i'ts #1 in the drawing.
Stefan


K10D, K5
DA* 16-50, DA* 50-135, D-FA 100 Macro, DA 40 Ltd, DA 18-55
AF-540FGZ
Last Edited by Anvh on 27/06/2010 - 21:14

Smeggypants

Link Posted 27/06/2010 - 22:01
hmmm? interesting. Thanks for the diagram maybe there's some crap over the AF unit at the bottom then. Coincidentally the AF ( on all lenses started randomly not working well when the crap on the focus screen appeared. Coincidence I guess.

Focus screen looks like a farmyard anyway, so I think I'm going to give it a clean anyway. Does someone make a small vaccuum cleaner?
[i]Bodies: 1x K-5IIs, 2x K-5, Sony TX-5, Nokia 808
Lenses: Pentax DA 10-17mm ED(IF) Fish Eye, Pentax DA 14mm f/2.8, Sigma 17-70mm f/2.8, Pentax-A 28mm f/2.8, Sigma 30mm F1.4 EX DC, Pentax-A 50mm f/1.2, Pentax-A 50mm f/1.4, Pentax-FA 50mm f/1.4, Pentax-A 50mm f/1.7, Pentax DA* 50-135mm f/2.8, Sigma 135-400mm APO DG, and more ..
Flash: AF-540FGZ, Vivitar 283

Oggy

Link Posted 28/06/2010 - 00:07
Mannesty wrote:
1: Are you sure you need to remove it?
2: Are you really sure you need to remove it?
3: If you are absolutely certain that you need to remove it . . .
4: DON'T touch it as its easily damaged.
5: Have a pair of surgical tweazers at the ready (to avoid you touching it) . . .
6: Remove the lens and fit rear lens cap . . .
7: Usinger finger nail or suitably blunt instrument pull the tab at the front edge of the focussing screens mount towards the front of the camera.
8: Did I mention "DON'T TOUCH IT".
9: The focussing screen holder will drop down enabling the cleaning of the inside surface with a blower. The focussing screen itself is loose inside its holder so beware of it falling out. If it does . . . . "DON'T . . . "you've got the message.
10: Ensure that the screen is sitting squarely in its holder before returning the holder to its original position.

Easy really, as long as you DON'T TOUCH IT.

I think Peter is on the right lines with this post, but I am not sure he has emphasised enough - DON'T TOUCH IT.

Smeggypants

Link Posted 28/06/2010 - 01:10
Heard loud and clear
[i]Bodies: 1x K-5IIs, 2x K-5, Sony TX-5, Nokia 808
Lenses: Pentax DA 10-17mm ED(IF) Fish Eye, Pentax DA 14mm f/2.8, Sigma 17-70mm f/2.8, Pentax-A 28mm f/2.8, Sigma 30mm F1.4 EX DC, Pentax-A 50mm f/1.2, Pentax-A 50mm f/1.4, Pentax-FA 50mm f/1.4, Pentax-A 50mm f/1.7, Pentax DA* 50-135mm f/2.8, Sigma 135-400mm APO DG, and more ..
Flash: AF-540FGZ, Vivitar 283

Anvh

Link Posted 28/06/2010 - 12:16
Smeggypants wrote:
hmmm? interesting. Thanks for the diagram maybe there's some crap over the AF unit at the bottom then. Coincidentally the AF ( on all lenses started randomly not working well when the crap on the focus screen appeared. Coincidence I guess.

Focus screen looks like a farmyard anyway, so I think I'm going to give it a clean anyway. Does someone make a small vaccuum cleaner?

Yes that could be the problem, or the smaller mirror is dirty but that's so hard to clean.

Some do make a vacuum cleaner, I believe it works with special compressed air and I don't know how great the suction is.
Stefan


K10D, K5
DA* 16-50, DA* 50-135, D-FA 100 Macro, DA 40 Ltd, DA 18-55
AF-540FGZ

doingthebobs

Link Posted 28/06/2010 - 21:56
Cleaned mine the other day. Just whipped it out and dusted it down with a jet of air from the blower. Wished I had done it ages ago instead of trying to ignore all the bits that were there.

Getting it out is quite straightforward but you will need some tweazers, I have a sprung pair that grip when released.

There is a video here link shows you how to change the screen.
Bob
Last Edited by doingthebobs on 28/06/2010 - 21:57

George Lazarette

Link Posted 03/02/2011 - 20:47
OP,

Judging by your user-name and picture, you're presumably the captain of the Sloop John B, the one who wasn't around when the crew had the famous fight off Nassau Town, and felt so broke up that they just wanted to go home?

Hope your focussing screen is still usable.

Cheers

G
Keywords: Charming, polite, and generally agreeable.
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