Yashica TLR focus - too far?

[zesbaugh]

Just got a 635 off ebay for dirt cheap (no 35 kit, only wanted for 6*6 ability). Ugly, ugly, ugly - but shutter, ap, and timer are all in working order.

One issue - focus at infinity is well "past" infinity.
Close up focus is as it should be (can focus at any distance actually) but will go past infinity focus when knob is only halfway there. Then everything out of focus after that point. It's as if there's too much throw in focus, but everything is nice and tight...
Can't quite figure out how this is possible, if close focus was off I could wrap my head around it, but close focus is fine - matches with distance scale on knob up to about 6 feet.
Don't have film in yet to test if viewing and taking lenses badly out of whack - they appear to be on the same plane though...

Any ideas?

[Ektagraphic]

With my Rollei, infinity is past infinity.....What you could do is place a ground glass over the film plane, set shutter to bulb, look through ground glass then once that is in focus look though the viewfinder to see if that is in focus. If they are both in focus, you are all set.....

[Ian Grant]

Test it with film, it's most likely fine. The viewing lens is not identical to the taking lens so don't read to much into it without using it.

I use both a Yashicamat & a Rollei and in practice there's no problems, remember that the viewing lens is a different aperture to the taking lens

Ian

[Rick A]

Since you dont have any film in yet, open the back up and place a piece of waxed paper on the film plane and check the focus against the knob and the viewfinder. This will verify if all is well.

Rick

[Ektagraphic]

I Never thought of wax paper as ground glass!

[Anscojohn]

I Never thought of wax paper as ground glass!

*****
Yup. Just don't use ground glass for wrappin' your samwitches!!

[kevs]

Zesbaugh, your viewing screen could be out of alignment; the lenses won't be out of alignment with each other - unless they've been seriously tampered with - because both are fixed on the front panel, which unscrews as a single piece. The lenses are identical f3.5 Yashikor (at least on mine, some 635s have Yashinon). The 635 focuses to about three and a half feet, or one metre, so you're losing quite a lot of close-focusing ability if yours only focuses to six feet. Do the ground-glass check (I use opaque plastic stretched over the film plane) to confirm the problem, then you can have it corrected, or do it yourself if you're brave.

My 124 G had a similar problem when I bought it.

[zesbaugh]

Thanks for the focus testing idea, will give the GG/wax paper method a try tonight.

Think maybe I didn't make myself clear about the focus issue though. I can focus down to 1M no problem, and anything in between to infinity.

The issue is that the focus knob only needs to travel about 1/3 of its range to hit focus at infinity. Distance scale on knob shows as 3M (just a guess - didn't make note) so although inf. focus is attained the knob still has 2/3 of its range left. If you turn knob past 3M mark everything is thrown out of focus. Distance scale on knob is accurate to about 2 meters (roughly 6 feet) - hence my confusion, math doesn't add up for me. The way I see it if 3M marker on knob actually focuses at infinity then 1M shouldn't actually focus on 1M, but something further out...

[zesbaugh]

[QUOTE=kevs;965529]Zesbaugh, your viewing screen could be out of alignment...QUOTE]

This is an interesting idea, from design of camera I don't see much room to adjust it though. Unless GG and screen are reversed, you may have hit it!

Should the GG be on top or the screen???

[Ian Grant]

[quote=zesbaugh;965543]

Zesbaugh, your viewing screen could be out of alignment...QUOTE]

This is an interesting idea, from design of camera I don't see much room to adjust it though. Unless GG and screen are reversed, you may have hit it!

Should the GG be on top or the screen???

Sometimes screens are shimmed, some one takes them off to clean and looses the shims.

Ian