Re: LX focussing problem - update (long)
From: Alistair Lax [EMAIL PROTECTED] Date: 2006/04/16 Sun PM 03:44:01 GMT To: PDML pentax-discuss@pdml.net Subject: LX focussing problem - update (long) A couple of months ago I mentioned my LX focus problem, where the top and bottom of the screen were out of focus in opposite directions. It proved surprisingly difficult to deal with, although the cause and solution turned out to be simple in concept and may be of interest. Snip That's a keeper, Alistair, thanks. Rather scary about the quality of service, though. Who did it? mike - Email sent from www.ntlworld.com Virus-checked using McAfee(R) Software Visit www.ntlworld.com/security for more information
Re: LX focussing problem - update (long)
Alistair Lax wrote: A couple of months ago I mentioned my LX focus problem, where the top and bottom of the screen were out of focus in opposite directions. It proved surprisingly difficult to deal with, although the cause and solution turned out to be simple in concept and may be of interest. (snippage of long but excellent post) You're a very brave man, Alistair! But I'm very glad for you that you managed to fix the LX. ERNR
Re: LX focussing problem - update (long)
Hi Alistair, I didn't snip your post, as many subscribers only seem to read the PDML through my quotes On 16/4/06, Alistair Lax, discombobulated, unleashed: A couple of months ago I mentioned my LX focus problem, where the top and bottom of the screen were out of focus in opposite directions. It proved surprisingly difficult to deal with, although the cause and solution turned out to be simple in concept and may be of interest. I took it for a service and was told it was an unusual problem - an ominous start, as the service didn't sort it. I took it back, and it turned out that the repair technician had trouble seeing the focus on the screen and relied on the split image. He then adjusted the angle of the screen holder and there was a small improvement. However the screen holder was left dramatically tilted upwards, which didn't seem right. As suggested by several of you, the most likely option was that the mirror was misaligned. I noticed it appeared to sit higher than the mirror on my other LX, and the adjustment lever was also higher. I realised that an incorrectly aligned mirror would also explain why I sometimes cut off the top of pictures - perhaps not just my incompetence! So, having scanned the internet and PDML archives for information ... I printed out a target of concentric rectangles and made a ground glass screen consisting of perspex (plexiglass) that sat on the outer film rails with magic tape strips facing forwards, ie approximately in the film plane. As predicted, an image that was perfectly centred in the viewfinder sat too low in the film gate. Adjusting the mirror position is a nightmare, as the mirror stop is spring loaded and its resting position is held by a lever that has a pivot and locking screw. Over a couple of hours the mirror position varied wildly in either direction, but my technique improved and eventually I got it adjusted spot-on without either dropping the screwdriver on the shutter curtain or irreversibly damaging the screwheads. In comparison, the screen adjustment was simple as it can be done incrementally. A slight complication is that one of the four screws is about halfway down one side - the others are in the corners. This is fine if you want to move it without changing the angle, but requires some calculation if it needs to be tilted. However within a short time it was level, in focus right across its plane and the infinity focus was set. I took some photos of an angled target (as described in http://www.photo.net/learn/focustest/) and will use that to fine tune the adjustment. Relief! Further relief when I checked my other LX and found its mirror angle was perfect - I had had that one serviced at the same time. I'm sure the focus problem originated from bad service work before I had the camera. The repair guy pointed out that both cameras were missing seals and that the mirror buffers were non-standard. It's a pity he didn't think to check the mirror adjustment. Now back to actually using them! thanks to all for your helpful suggestions Alistair Well done mate, what a lot of hard work, but it paid off. You can wipe that smug grin off yer face too ;-) Cheers, Cotty ___/\__ || (O) | People, Places, Pastiche ||=|http://www.cottysnaps.com _
Re: LX focussing
There are rubber bumpers on the mirror supports that are collapsing. It's a relative of the sticky mirror syndrome. They and probably all the other rubber parts, including seals, need to be replaced. Alistair Lax wrote: I'm delurking for a while, partly to ask the brother- and sister-hood for their expert advice. I've had an LX for almost 2 years. It doesn't have a sticky mirror, but it now appears to have a focussing problem. It has the standard SC-21 screen. When the split screen is in focus, neither the top nor bottom of the screen is focussed. The top focuses closer and the bottom of the screen farther away. The focus suggested by the split screen appears to be correct and the full frame is sharp on film, but I'm losing confidence in the camera's ability to focus correctly. It has probably had this problem all along, and I've only noticed it recently, having just picked up a M50mm/f1.4. A possibly related problem is that very occasionally the split screen focuses too close - the opposite of a sticky mirror problem - this problem can be sorted by moving the mirror up and down a couple of times. It clearly shouldn't do this - my second LX acquired last month doesn't have this problem. It looks like a mirror misalignment to me, as the screen appears to be properly in place, but I'd be grateful to hear any suggestions. thanks Alistair -- When you're worried or in doubt, Run in circles, (scream and shout).
Re: LX focussing
From: Alistair Lax [EMAIL PROTECTED] Date: 2006/01/25 Wed AM 07:48:53 GMT To: PDML pentax-discuss@pdml.net Subject: LX focussing I'm delurking for a while, partly to ask the brother- and sister-hood for their expert advice. I've had an LX for almost 2 years. It doesn't have a sticky mirror, but it now appears to have a focussing problem. It has the standard SC-21 screen. When the split screen is in focus, neither the top nor bottom of the screen is focussed. The top focuses closer and the bottom of the screen farther away. The focus suggested by the split screen appears to be correct and the full frame is sharp on film, but I'm losing confidence in the camera's ability to focus correctly. It has probably had this problem all along, and I've only noticed it recently, having just picked up a M50mm/f1.4. A possibly related problem is that very occasionally the split screen focuses too close - the opposite of a sticky mirror problem - this problem can be sorted by moving the mirror up and down a couple of times. It clearly shouldn't do this - my second LX acquired last month doesn't have this problem. It looks like a mirror misalignment to me, as the screen appears to be properly in place, but I'd be grateful to hear any suggestions. Almost certainly misalignment, possibly a problem with the bumper that the mirror rests on. Should be a simple and (comparatively) inexpensive fix. Where did you get your second from? m - Email sent from www.ntlworld.com Virus-checked using McAfee(R) Software Visit www.ntlworld.com/security for more information
Re: LX focussing
Thanks Mike. Second one was bought on Ebay - luckily the guy I bought it from lives on my route home, so I was able to check it over before bidding. There had been a glut of LX sales, so I got it for a reasonable price. Alistair Almost certainly misalignment, possibly a problem with the bumper that the mirror rests on. Should be a simple and (comparatively) inexpensive fix. Where did you get your second from?
Re: LX focussing
- Original Message - From: Alistair Lax Subject: LX focussing I'm delurking for a while, partly to ask the brother- and sister-hood for their expert advice. I've had an LX for almost 2 years. It doesn't have a sticky mirror, but it now appears to have a focussing problem. It has the standard SC-21 screen. When the split screen is in focus, neither the top nor bottom of the screen is focussed. The top focuses closer and the bottom of the screen farther away. The focus suggested by the split screen appears to be correct and the full frame is sharp on film, but I'm losing confidence in the camera's ability to focus correctly. It has probably had this problem all along, and I've only noticed it recently, having just picked up a M50mm/f1.4. A possibly related problem is that very occasionally the split screen focuses too close - the opposite of a sticky mirror problem - this problem can be sorted by moving the mirror up and down a couple of times. The bumper that the miror rests on is misaligned, and possibly in need of a replacement rubber pad. William Robb
RE: LX Focussing probem
Hi Peter, - put the camera onto a tripot. - glue a transparent tape ( TESA ) over the shutter window or remove the screen and put it with as much care as possible to the film plane ( with the correct side ). - turn the lens to infinity. - set the camera to B, release and let the shutter stay open. If the picture on this screen is OK, then the mirror is misaligned. Before buying, ask at Pentax about the costs. Maybe the momentary owner is not willing to reduce the price accordingly. regards Bernd - This message is from the Pentax-Discuss Mail List. To unsubscribe, go to http://www.pdml.net and follow the directions. Don't forget to visit the Pentax Users' Gallery at http://pug.komkon.org .
Re: RE: LX Focussing probem
Hi, Here is my take on the LX problem: 1. It cannot be the lens because the peoplem occurs with various lenses. 2. It may be that the screen does not sit properly. Take it out, inspect it for damage, check the screen bed for dirt or other obstacles, then put the screen back in. 3. The rubber rest(s) underneath the mirror are not properly aligned or are beginning to desintegrate (is there only one rest or two? I forget). Lock the mirror up, inspect them. Apply slight pressure. How do they react? If they are beginning to get sticky, sticky mirror is around the corner. If they are not sticky, then they are not properly aligned. Bernd's procedure for testing the mirror alignment is a very good one, but one minor adjustment needs to be made --- do not set the lens to infinity (infinity is not always exactly there where it is marked). Instead, focus very well on a close object, then check if the image on the film plane is sharp. - put the camera onto a tripod. - glue a transparent tape ( TESA ) over the shutter window - turn the lens to infinity. - set the camera to B, release and let the shutter stay open. If the picture on this screen is OK, then the mirror is misaligned. Cheers, Boz - This message is from the Pentax-Discuss Mail List. To unsubscribe, go to http://www.pdml.net and follow the directions. Don't forget to visit the Pentax Users' Gallery at http://pug.komkon.org .
Re: LX Focussing probem
At the risk of sounding simplistic could it be the prism and the diopter settings? Sign up for SBC Yahoo! Dial - First Month Free http://sbc.yahoo.com - This message is from the Pentax-Discuss Mail List. To unsubscribe, go to http://www.pdml.net and follow the directions. Don't forget to visit the Pentax Users' Gallery at http://pug.komkon.org .
Re: LX Focussing probem
At the risk of sounding simplistic could it be the prism and the diopter settings? Are the labels for the LED's at the right side of the finder clear, or are they out of focus, too? Fred - This message is from the Pentax-Discuss Mail List. To unsubscribe, go to http://www.pdml.net and follow the directions. Don't forget to visit the Pentax Users' Gallery at http://pug.komkon.org .
Re: LX Focussing probem
When I had a split image screen on my LX, *every* single lens that i have showed (ever so slightly) different inf. focusing (some were focusing beyond inf. mark, some before). After i put the frid screen, all my worries disappeared :) However if the focusing is bad to the point that you can actually see it being out of focus on the matte field, that's probably a different story. I don't think you can insert the screen wrong way up in there (it has an assymetric tab), can be a number of things, like mirror alignment. I'd check with KEH automated estimate service how much that would cost. Mishka From: Peter Smekal Subject: LX Focussing probem Date: Tue, 02 Jul 2002 05:37:04 -0700 My son is considering to buy an LX. He has even found one and has the chance to try it for a couple of days. Cosmetically it is really minty and there is no sticky mirror AFAICS. There is one problem though: when focussing to (infinite) the image in the viewfinder is not really sharp, neither on the matte screen, the microprism nor in the split image. I don't think it depends on the lense. We have tried with different lenses. We exposed one role of film today and I don't think it shows on the images. But it still is anoying. What could the problem be? Is it a common LX problem? Is it difficult or expensivee to fix? Could it depend on the way the screen is inserted? Thanks for any advice or help. Peter Sign up for SBC Yahoo! Dial - First Month Free http://sbc.yahoo.com - This message is from the Pentax-Discuss Mail List. To unsubscribe, go to http://www.pdml.net and follow the directions. Don't forget to visit the Pentax Users' Gallery at http://pug.komkon.org .
Re: LX Focussing probem
Thanks for the answer Mishka! A different screen be a solution of course. It's mostly split image that shows straight line being non-alligned But also on the matte screen we can see the lack of sharpness. (Let's say you focus on some letters on a wall some hundred meters away.) I checked the screen, It seems to sit alright. Probably it's the mirror alignment, although the mirror does not seem to stick. Peter Peter Smekal Uppsala, Sweden [EMAIL PROTECTED] - This message is from the Pentax-Discuss Mail List. To unsubscribe, go to http://www.pdml.net and follow the directions. Don't forget to visit the Pentax Users' Gallery at http://pug.komkon.org .
Re: LX Focussing probem
So, please have a check on the alignment of the lens elements. It could be one reason for out of focus images at infinity. Could be of course, but we have the same problem with different lenses. Peter Peter Smekal Uppsala, Sweden [EMAIL PROTECTED] - This message is from the Pentax-Discuss Mail List. To unsubscribe, go to http://www.pdml.net and follow the directions. Don't forget to visit the Pentax Users' Gallery at http://pug.komkon.org .
Re: LX Focussing probem
At the risk of sounding simplistic could it be the prism and the diopter settings? It helps a little to change the diopter settings, but spit image line still do not align. Thanks Peter Peter Smekal Uppsala, Sweden [EMAIL PROTECTED] - This message is from the Pentax-Discuss Mail List. To unsubscribe, go to http://www.pdml.net and follow the directions. Don't forget to visit the Pentax Users' Gallery at http://pug.komkon.org .
Re: LX Focussing probem
At the risk of sounding simplistic could it be the prism and the diopter settings? Are the labels for the LED's at the right side of the finder clear, or are they out of focus, too? Fred Hi Fred, No. LED's are clear! Peter Peter Smekal Uppsala, Sweden [EMAIL PROTECTED] - This message is from the Pentax-Discuss Mail List. To unsubscribe, go to http://www.pdml.net and follow the directions. Don't forget to visit the Pentax Users' Gallery at http://pug.komkon.org .
Re: LX Focussing probem
Danke Heiko! Your explanations seem plausible! Even if these things are difficult to see. Peter Hi Heiko, on 02 Jul 02 you wrote: Don't ask me for a source, Now you can ask;-) Here it is: http://members.ozemail.com.au/~distudio/lxproblems.html --Start ... Side Effects A small rest can be seen screwed to, and protruding from the wall of the LX mirror box when the mirror is locked up. The surface of this rest is covered with a pad of elastic material and generally if the shutter is sticky this pad will also show signs of deterioration and have become slightly compressed causing focus inaccuracies. When the mirror rest becomes compressed the mirror is effectively supported at a lower position which alters the plane of focus at the finder screen relative to the film plane. The effect can be seen when photographs captured at wide apertures show a plane of focus in front of the subject which was selected as the plane of focus through the finder or if infinity focus cannot be obtained through the finder. ... End And further down: --Start ... Excerpts from correspondence with other LX users ... Thought you might like to know of another variant.. I have had what I call type1 - the mirror doesn't move from rest immediately, accompanied by lack of infinity focus. Fixed very cheaply, locally. ... End So it seems to be a side effect or variant of the sticky mirror problem. Regards, Heiko - This message is from the Pentax-Discuss Mail List. To unsubscribe, go to http://www.pdml.net and follow the directions. Don't forget to visit the Pentax Users' Gallery at http://pug.komkon.org . Peter Smekal Uppsala, Sweden [EMAIL PROTECTED] - This message is from the Pentax-Discuss Mail List. To unsubscribe, go to http://www.pdml.net and follow the directions. Don't forget to visit the Pentax Users' Gallery at http://pug.komkon.org .
Re: LX Focussing probem
Hi Antti-Pekka, Easy to fix? Is it a job for Pentax, or could you do it yourself? Who is Mr Murphy? Did that apply also to new LX's? Peter This problem is related with the sticky mirror problem. The rubber mirror rest bumpers have too much wear or they are mis-aligned, making the mirror rest in the wrong position. Easy to fix, but I recommend a complete CLA while the LX is in the service. The CLA will take care of the possibly lurking sticky mirror problem as well (according the Mr Murphy, the LX will start showing the sticky mirror problem a month after the purchase). Antti-Pekka Peter Smekal Uppsala, Sweden [EMAIL PROTECTED] - This message is from the Pentax-Discuss Mail List. To unsubscribe, go to http://www.pdml.net and follow the directions. Don't forget to visit the Pentax Users' Gallery at http://pug.komkon.org .
Re: LX Focussing probem
My guesses: 0. The finder's diopter adjustment is set to something weird. 1. The mirror can be out of alignment. This can be related to the well-known sticky mirror bug. 2. The lens mount can be out of alignment. I don't think an LX should have such problems, but I've seen several (much cheaper) cameras with it. 3. The screen may be out of it's place. Try to remove and re-insert it properly. Gabor 0. Checked. Is ok. 3. 2. Hopefully not, sounds like something expensive to fix. 1. Seems plausible. Others had the same idea. Thanks Gabor Peter Peter Smekal Uppsala, Sweden [EMAIL PROTECTED] - This message is from the Pentax-Discuss Mail List. To unsubscribe, go to http://www.pdml.net and follow the directions. Don't forget to visit the Pentax Users' Gallery at http://pug.komkon.org .
Re: LX Focussing probem
Peter Smekal wrote: Who is Mr Murphy? Did that apply also to new LX's? Mr. Murphy of Murphy's Law fame: If something can go wrong, it will. The root of countless corollaries, such as: The likelihood of bread falling jelly-side down is directly proportional to the cost of the carpet. My own favorite: Murphy was an optimist. Cheers, Stephen _ Programmer who creates truth table writes Boole sheet - This message is from the Pentax-Discuss Mail List. To unsubscribe, go to http://www.pdml.net and follow the directions. Don't forget to visit the Pentax Users' Gallery at http://pug.komkon.org .
Re: LX Focussing probem
At the risk of sounding simplistic could it be the prism and the diopter settings? Are the labels for the LED's at the right side of the finder clear, or are they out of focus, too? Fred Hi Fred, No. LED's are clear! Then it's most likely due to mirror alignment, which is likely due to incipient sticky mirror syndrome. Therefore, a CLA is due in the near future, since all of your critical focusing is going to be off a bit until then (unless you were to compensate by just the right amount in the he right direction), resulting in blurry photos whenever the DOF is shallow. Fred - This message is from the Pentax-Discuss Mail List. To unsubscribe, go to http://www.pdml.net and follow the directions. Don't forget to visit the Pentax Users' Gallery at http://pug.komkon.org .
Re: LX Focussing probem
1. Prism setting(s) have no effect on either film focus or focus screen focus. 2. Diopter setting have no effect on either film focus or focus screen focus. 3. Improper focus screen latching will have no effect on film focus, but will affect focus screen focus. 4. Poorly positioned mirror (the usual problem) will have no effect on film focus, but will affect focus screen focus. 5. Poorly positioned lens mount will effect both film focus and focus screen focus, but they will track together. 6. Poorly aligned lens may effect both film focus and focus screen focus but they will track together. 7. Poorly aligned back plane has no effect as it is the reference and therefore always correct (unless warped or otherwise damaged). Regards, Bob... From: MPozzi [EMAIL PROTECTED] At the risk of sounding simplistic could it be the prism and the diopter settings? Sign up for SBC Yahoo! Dial - First Month Free http://sbc.yahoo.com - This message is from the Pentax-Discuss Mail List. To unsubscribe, go to http://www.pdml.net and follow the directions. Don't forget to visit the Pentax Users' Gallery at http://pug.komkon.org .
Re: LX Focussing probem
4. Poorly positioned mirror (the usual problem) will have no effect on film focus, but will affect focus screen focus. Actually, Bob, mirror misalignment ~will~ affect film focus, albeit indirectly. (However, directly or indirectly, the effect is going to be that the image cast onto the film will not be sharp.) Since the user will be focusing the lens so as to make the focus screen image as sharp as possible, if the mirror is out of alignment, he/she will always be setting the lens so as to cause the image landing on the film plane to be out of focus. (A pentaprism SLR always makes the assumption that the mirror focus is aligned with the film plane focus - if they don't match, then out-of-focus images will be captured at the film plane.) Therefore, a poorly positioned mirror ~will~ have an effect on film focus. Fred - This message is from the Pentax-Discuss Mail List. To unsubscribe, go to http://www.pdml.net and follow the directions. Don't forget to visit the Pentax Users' Gallery at http://pug.komkon.org .
Re: LX Focussing probem
I presumed this fact to be intuitively obvious to the most casual observer. Nevertheless, if the scale on the lens is correct, misalignment of the mirror will not affect film focus using the scale and a tape measurement. Regards, Bob... From: Fred [EMAIL PROTECTED] 4. Poorly positioned mirror (the usual problem) will have no effect on film focus, but will affect focus screen focus. Actually, Bob, mirror misalignment ~will~ affect film focus, albeit indirectly. (However, directly or indirectly, the effect is going to be that the image cast onto the film will not be sharp.) Since the user will be focusing the lens so as to make the focus screen image as sharp as possible, if the mirror is out of alignment, he/she will always be setting the lens so as to cause the image landing on the film plane to be out of focus. (A pentaprism SLR always makes the assumption that the mirror focus is aligned with the film plane focus - if they don't match, then out-of-focus images will be captured at the film plane.) Therefore, a poorly positioned mirror ~will~ have an effect on film focus. - This message is from the Pentax-Discuss Mail List. To unsubscribe, go to http://www.pdml.net and follow the directions. Don't forget to visit the Pentax Users' Gallery at http://pug.komkon.org .
