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 _____________________________
