Heres a weird one..

[barrington]

A few days ago I took my Yashica Mat 124G out for a few days shooting in the wilds of North Yorks.It seems to have an odd fault that I cant figure out.Its hard to explain but..here goes..

I cant focus on infinity.Well,yes I can but not where infinity should be.If I focus on something in the distance,the scale on the focussing knob is telling me its only about 40'-50' away.If I focus past this to where infinity should be the image once again goes out of focus.According to the viewfinder,the image is sharp yet,as far as I know,to get infinity,the front standard has to be fully retracted.I cant work out why this should be the case.I know for a fact the camera has not taken any knocks and hasnt been mistreated so I have ruled out the mirror being out of alignment.The focusing is completely smooth and the standard is square to the body so it aint that either.The only way to find out is to develop a film and I will do so tomorrow.I have been scratching my head about this for the last week so,if anyone else has any ideas,please let me know.Maybe its a design fault.The last results I had were perfect but they were pictures taken at close quarters and not at any distance worth talking about.If anyone can shed some light on this then please post here.I'm getting bald patches from pulling my hair out and I'm too young to go bald!

Barrington

[barrington]

Ps..

A knowledgeable friend has suggested someone has-in the past-removed the mirror and has put too many or to few shims under the mirror.Could this be the cause?

Barrington

[doubs43]

The first thing I'd do is place a piece of groundglass at the film plane and with the shutter open at maximum aperture, focus at infinity as seen on the glass through a 6X~10X loupe. Then I'd check to see that my focusing screen was also at infinity. If both are correct and the focus knob is still off, I'd next try the step below.

While I'm not at all familiar with the 124G, is it possible to remove the focusing knob, set visual focus on the screen to infinity and put the knob back on at the infinity mark? If it's a multi-tooth mesh-type affair, then I'd think it possible. If it only goes on in one set position, the gears behind it may be set incorrectly.

Walker

[bobm]

I don't have the 124G but I do have a 635 with which the mirror IIRC slides into a carrier and is secured by a clip arrangement - I don't recall seeing any obvious adjustment screws or shims in that area.

At least nothing fell out when I removed the mirror.....

[barrington]

Problem solved! I sat and thought about it for a bit.I figured that if the focus was falling short then the mirror must be too close to the screen.Solution? I placed a shim of about 0.75mm under each of the 3 clips and..perfect focussing now! I guess I will never know why it went in the first place but..who cares? It's back to normal and I can get back to shooting with it.Tomorrow possibly!