Author Topic: Inifinity focus is not happening...help!  (Read 365 times)

astrobeck

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Inifinity focus is not happening...help!
« on: March 09, 2024, 06:21:04 PM »
Hey all!
I've been going though my herd of cameras and testing them all so I can give some away at a local swap we are having and discovered one of my Sears (Ricoh) KS Super won't go to infinity focus.
I've tried several lenses and it is the same story, none will go to infinity focus.

I've got a roll of test film in the camera right now to test it and see if it does focus at infinity, regardless of what I see in the viewfinder, but even this seems like an exercise in truly wasting film...
any ideas of other things to test.
I really like this camera...

Thanks

Bryan

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Re: Inifinity focus is not happening...help!
« Reply #1 on: March 09, 2024, 08:19:39 PM »
The mirror may not be seating into position properly.  That would throw off the focus in the viewfinder.

Francois

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Re: Inifinity focus is not happening...help!
« Reply #2 on: March 10, 2024, 01:22:37 PM »
It's either that or there are missing shims under the groundglass.
I know some medium format cameras tend to do that.

But if putting the lens on the infinity mark doesn't allow the camera to reach infinity, then there is an issue with the lens being either too close or too far from the film.

The only way to know for sure is to reverse collimate the lens and camera...
Francois

Film is the vinyl record of photography.

Pete_R

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Re: Inifinity focus is not happening...help!
« Reply #3 on: March 10, 2024, 02:46:16 PM »
But if putting the lens on the infinity mark doesn't allow the camera to reach infinity, then there is an issue with the lens being either too close or too far from the film.

If the lens really doesn't reach infinity, as opposed to going beyond infinity, and it's really happening at the film plane (doubtful) then the lens would be too far away form the film. But it's very unlikely that's the case unless someone has added too many shims under the lens mount ring. It's more likely this is just happening in the viewfinder which suggests the mirror is too low or the focus screen is too high. Unlikely the screen has moved (if it's a removeable screen it's more likely to have dropped lower, not gone higher) so that leaves the mirror. Most likely the mirror stop has lost it's cover, if it has one, or, if it's sprung, the spring has come off.
"I've been loading films into spirals for so many years I can almost do it with my eyes shut."

astrobeck

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Re: Inifinity focus is not happening...help!
« Reply #4 on: March 11, 2024, 04:39:24 AM »
Aha!
After comparing a similar Ricoh I have to the Sears body, I see that there is a tiny square little bumper pad missing on the underside of the mirror that will not go to inifinity focus.
Pete, that is just the problem.  A missing bumper.
The next question is, is there any substitute for that pad material that I can use to replace it?
Is it unique to each camera?
Will a couple layers of electrical tape cut into tabs work?

I'm very determined to make this camera work.

Thanks!
« Last Edit: March 11, 2024, 04:45:16 AM by astrobeck »

Pete_R

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Re: Inifinity focus is not happening...help!
« Reply #5 on: March 11, 2024, 10:20:27 AM »
Aha!
After comparing a similar Ricoh I have to the Sears body, I see that there is a tiny square little bumper pad missing on the underside of the mirror that will not go to inifinity focus.
Pete, that is just the problem.  A missing bumper.
The next question is, is there any substitute for that pad material that I can use to replace it?
Is it unique to each camera?
Will a couple layers of electrical tape cut into tabs work?

I'm very determined to make this camera work.

Thanks!

The main thing is the thickness needs to be correct to get the mirror at the correct height. Maybe you can measure the thickness of the one on the other camera then find something of the same thickness. I guess it should be rubber or something similar. Might be a bit if trial and error too as there is usually an internal adjuster so the two cameras may not be set exactly the same.
"I've been loading films into spirals for so many years I can almost do it with my eyes shut."

astrobeck

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Re: Inifinity focus is not happening...help!
« Reply #6 on: March 11, 2024, 07:48:46 PM »
T H A N K   Y O U!

I dinked all morning with the "I can't go to infinity" camera and I think I have it remedied, for now at least.
I used three thicknesses ( because four was too many and two was not many enough) of electrical tape stuck one on top of the other, then cut a tiny, about a 1/8th inch little square out of those stacked layers to fit in the spot where the original pad fell off.
And Viola!  It goes to infinity focus again and I have measured distances with a yard stick and so far, so good.
The proof of the pudding will be this upcoming weekend on a short jaunt down to White Sands to see it all the distances actually correlate to the film plane as seen in the viewfinder.

So, thanks again to everyone that offered help and especially Bryan and Pete R, who nailed it right away and solved my particular case.
I owe you all a beer, or tacos...or mac and cheese...
« Last Edit: March 11, 2024, 08:03:25 PM by astrobeck »

Francois

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Re: Inifinity focus is not happening...help!
« Reply #7 on: March 11, 2024, 08:11:11 PM »
I would definitely take the Mac & Cheese 😁
Francois

Film is the vinyl record of photography.

astrobeck

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Re: Inifinity focus is not happening...help!
« Reply #8 on: March 15, 2024, 07:09:10 AM »
it works!
a quick test on a local sign I find uber silly...

thanks again all!!!!