Voigtlander Bessa RF 6x9

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PFMcFarland
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Re: Voigtlander Bessa RF 6x9

Post by PFMcFarland »

A reversed element would give you center sharp, with the focus falling off towards the edges, especially at wide open aperture. And it usually involves flipping the middle element on a triplet, or the second element (could be a cemented doublet) on a four element lens.

If it's too difficult to make a mark on the front element side and lens barrel, I just note what letter or symbol on the name plate of these older front focusing lenses winds up at Top Dead Center (TDC) when it separates from the barrel. Usually it's not necessary to do the same with the rear element, just insure it doesn't get flipped.

For checking focus, I use a piece of clear plastic from something like a CD case, cut to fit the frame space over the inside rails (usually, there will be two sets of rails, the inner ones are for holding the film at the focus plane, and the outer two are for keeping the film in register). I put some frosted tape on the side that will face the lens. This acts as a ground glass surface, and gives you something to focus on. Mount the camera on a tripod, and open the lens at maximum aperture on T or locked on B. Look at something high contrast, like a wooden fence line or trees at least 30 meters (100 feet) away (a bit farther doesn't hurt, it's not a hard number), and start turning the front element until it is in focus. As Julio has suggested, whomever did the cleaning of the shutter may have not checked the focus after putting the lens back together, so you may have to try different landings until you hit on the right one. Then put the focus ring back on at the Infinity mark, and clamp it down with the set screws, trying not to move the front element from it's Infinity focus position which you have just determined. Then check the near focus to make sure it is good. If not, then refocus the Infinity setting until you get a decent close image (that's physics for you). Maybe choose a target that is farther away for the Infinity setting. You'll get there eventually.

Then of course you need to see if the Infinity setting agrees with the rangefinder, and also the close focus setting. It can be a long, drawn out affair, or you might hit it right on the first try, Alex.

PF


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alexvaras
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Re: Voigtlander Bessa RF 6x9

Post by alexvaras »

I agree with the way if doing it yes, the bad thing is in this camera the front lens has no screws to keep it in position, just the thread till this end. This is a camera that all the lenses move when focusing, not only the first one as Ikonta o Perkeo II.
Today I hope I have more time and I will go to the rear lens, which one I found pretty loose, but the front element was really tight to unscrew.
Yes, I do two pics when I take out a lens, the starting position and the loose position, I use numbers and letter on the front and marks on the metal in the rear one.
Another bad thing in my case is the winter, when I get home is dark already, no way to focus the fence :) but I will use the way the film with marks and the digital camera as first approach.
Thank you for the tips!! :)


alexvaras
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Re: Voigtlander Bessa RF 6x9

Post by alexvaras »

I looked carefully to the front and read lens threads and there is only one way to put the lens.

So I looked closer and I realized Im new to this camera and probably idiot, the camera wasn't fully open, I had a big clack :) and checking with the digital camera and the film test at the open back, it seems fine the infinity setting.
Tomorrow is a shoot day test :)


scott
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Re: Voigtlander Bessa RF 6x9

Post by scott »

A superlative infinity object for setting focus is the moon on a clear night...


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PFMcFarland
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Re: Voigtlander Bessa RF 6x9

Post by PFMcFarland »

That loose rear element could be your culprit.

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alexvaras
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Re: Voigtlander Bessa RF 6x9

Post by alexvaras »

I would love that Scott, but I have to wait till February or March.
Last December, we had 6 hours of sun (official announcement) in the whole month.

I have two cameras at school waiting for the sun as PF signature:)


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Re: Voigtlander Bessa RF 6x9

Post by PFMcFarland »

As luck would have it, there is a full moon on the night of Jan 31st.

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alexvaras
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Re: Voigtlander Bessa RF 6x9

Post by alexvaras »

Well another roll.

Setting on the three first pictures was f8.

This one is infinity setting, out of focus (or without the definition that it should)
000080850001.jpg
This other was 3 metres focus, same thing, focus object : the rope
000080850004.jpg
Here at 7 meters focus everything seems to be in place, focus object: the fence.
000080850007.jpg
And here (forgive me Lisa) all good at 2 meters focus.
000080850008.jpg
Another issue is those white band along the up and down borders, they were not before in the last roll.
Everything was shot in 5 minutes and the last one 10 min later, I followed as PF says, just don't wing all the film, open and then position the new frame to expose. The camera had the case put, so light leaks from back are not probable, could be light leaking when the roll is exposed and rolled when I delivered to the lab?

So I continue with focusing problems, but I guess I'm nearer than before (could be a solution take out the shutter to quit or put spacers?)
And light leaks, just checked the bellows and they are fine, if any they are super super small.

Ideas welcome :)


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Re: Voigtlander Bessa RF 6x9

Post by Julio1fer »

Well, it is converging! Much better! The 7-meter shot seems quite right to me. I think that your focus is right enough now.

I have got similar light leaks from not-enough-tight rolling of the film into the take-up spool. If the leaks increase as you go from the first frame to the last, that is a probable cause. You could also have a leak on the back of the camera, in that case the leaks would be irregular depending on the time between shots.

Was that roll really tight when you opened the camera?

I am not familiar with the Bessa, but usually there is a spring or device in the take-up spool, that presses against the paper to make sure the take-up roll is tight. The spring might need a little bending to to a better job.


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PFMcFarland
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Re: Voigtlander Bessa RF 6x9

Post by PFMcFarland »

Loose rolls are the bane of all 120 users. Like Julio says, check the tension spring to see if it is against the film roll. Don't know what to say about the focus, except to keep working at it. It will be a fine camera, Alex, once you get that sorted out.

PF


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