在今年的五月我们收到了Alfonso的邮件，在按照之前的文章《voigtlander Bessa RF 黄斑不准维修，黄斑校准》调整维修Bessa rf的时候遇到了问题
This is a hard repair documented by Alfonso, a photography enthusiast from Barcelona, Spain, including the repair process and email communication with me.
Finally, Alfonso perfectly repaired the focus failure of the Voigtländer Bessar RF and took perfect photos, Here we explain the problem and log all the messages exchanged, so that friends who encounter the same problem can find some reference information. The English version is also kept here for reference.
Comparison of photos before and after repairs.
The sample after BESSA RF repair, you can see the focus on infinity, the distance is clear
100% screenshot of the previous image, you can see the sharpness is good
This picture is a photo before maintenance. It can be seen that the distant scene is not clear, and there is also a little optical axis that is not correct.
In May of this year, we received an email from Alfonso, who encountered a problem while repairing the Bessa RF according to theinformation from a previous article in this web.
我正在尝试调整 voigtlander Bessa RF 的测距仪，我发现了你的有趣文章。 我已经检查了当顶部焦点顶部轮子处于无限远和 1 米时相机对焦是否正确。 我可以在无限远时调整测距仪，但是当我尝试在 1 米处对焦时，它就失焦了。 如果我在 1 米处调整，则无限远失焦。 你能告诉我调整无限和1米的最佳程序吗？ 您显示有两个螺钉可以水平调整测距仪（一个是箭头 2，另一个是左箭头）。 左箭头上的螺丝是什么用途？ 您还说，在螺钉 2 的顶部，您可以垂直调整镜子。 最后一次调整的效果是什么？
I am trying to adjust the rangefinder of a Vöigtlander Bessa RF and I have found your interesting article. I have checked that the camera focus correctly when the top focus top wheel is at infinite and at 1 meter. I am able to adjust the rangefinder when it is at infinite but when I try to focus at 1 meter it is out of focus. If I adjust at 1 meter then the infinite is out of focus. Can you tell me the best procedure to have both infinite and 1 meter adjusted? You shows there are two screws to adjust horizontally the rangefinder (one is arrow 2 and the other is on the left arrow). Which is the purpose the screw on the left arrow? You also say that on top of screw 2 you can adjust the mirror vertically. Which is the effect of this last adjustment?
2. 每次调整都要从黄斑窗观察。 你需要注意固定相机以及调焦位置。
4、无限远位置调整完成后，即可安装。 最后，使深无限位置与聚焦无限一致，即拉到最近的位置时候 景深指示也是最近的。
位置1是调整上下黄斑，位置2是调整左右黄斑。 同样，在左箭头处也有一个类似的螺钉。 2上面有一个螺丝可以调节反光板的垂直角度。
- Move the focus wheel at the infinite position and look a faraway object. Adjust the rangefinder image to be accurate up, down, left and right
- Each adjustment should be observed from the rangefinder window. You need to pay attention to fix the rangefinder as well as focus position.
- Don’t let the focus gear fall off (otherwise you will have to start again)
- After the infinity position adjustment is completed, you can mount everything again.
- To check if the rangefinder is accurate, you can open the back cover, set the focus to infinity and place a frosted glass (or translucent plastic film) where the photographic film should be and observe if the projected image is in focus using a magnifying glass.
Position 1 is to adjust the upper and lower rangefinder image, and position 2 is to adjust the left and right. Similarly, there is a similar screw at the left arrow. There is a screw above 2 to adjust the vertical angle of the reflector.
COMMENT FROM ALFONSO AFTER FINISIHING THE REPAIR
I found it easier to adjust the movable mirror (which I marked with the number 3 in red) than the fixed mirror which you marked with number 2.
At least in my case, in order to move number 2 I had to loosen the screw that I have marked with a blue arrow.I had to tighten it again when I finish and, in doing so, I moved the mirror a little bit and misaligned it again.
Adjusting with the screew marked with 3 (red) this did not happen.
Perhaps the mirror 2 allows an initial larger adjustment and the 3 is used to make a finer one.
Problem: (At this point, the eccentric wheel for focusing should have been misaligned, which would require an overall adjustment)
When I move the focusing wheel from infinity to about 20 feet, the rangefinder does not move because the lever arm does not move.
I found the problem but I do not know the solution. Maybe you can help me.
I have seen that the my camera, when I move the focusing wheel from infinite to around 20 feet, the rangefinder mirror do not rotate because the lever arm does not move.
I have seen that the eccentric shaft that makes the lever move has a flat area just between infinity and 20 feet or so.
I then tried to change the position of the eccentric axis so that when I focused to infinity, the lever would be right at the point where the flat area of the eccentric axis ends. In this case when I moved the focus wheel from infinity I saw that the rangefinder was moving but….when I turned to minimum focus I reached a point where the lever arm didn’t move again either!
I have seen that in that case, the lever arm loses contact with the eccentric axis. Is this something that has happened to you? Is it very complicated to adjust infinity with the end of the flat area of the eccentric axis to make sure that when focusing close, the lever still has contact with the axis?
As with my first encounters, this is the most tedious work and testing waiting for you to do.
I will try my best to explain the structure of this position. When you understand the structure of this part, you can continue to test to find the correct position.
- External: This is the last step of installation
1.Fix the focus wheel: This screw can be removed with a tic-tac-toe wrench and can be fixed at any position
2. Focusing limit mechanism: This position is very important. If it is not fixed correctly, the screw will be disengaged after the closest focusing distance, and then everything will start from scratch. Observe that there are five screw holes below. These five holes can be selected according to the needs, and the limit mechanism can be tightened.
B.Focusing structure: In the following image you can see the problem you encountered occurs here. If you turn the focusing wheel too far to the closest distance, the optical mechanism and the rangefinder, mechanism is disengaged from the rangefinder mechanism..
3. Focusing wheel: The transmission gear responsible for focusing is also responsible for the linkage of the rangefinder mechanism, mainly the position of this thing, which I will discuss in detail later.
4. Transmission gear to the optical mechanism: no need to deal with
5. Rangefinder linkage lever: When it is close to 3, the focus should be close to the infinity position, and when he is far away from 3, the lens is in the closes possible focus. (You can observe carefully and try to find the pattern)
6, If this mechanism is visible as in the picture, the focusing wheel has rotated too far and the lens displacement mechanism is disengaged from the focusing wheel. You can engage it again but all calibration should start again!
This image shows the mechanism when the focusing gear 3 is removed. The lever arm (5) should be at this position near infinity (but not exactly). The focusing lens engaging mechanism (showed in 6) should be all contracted like the picture below.
Now I will talk about the 3 focusing wheel structure.
F refers to a position close to infinity, and 5 should be close to this position.
C refers to the position of the most recent focus. At this time, 5 is close to this position, which needs to be found by testing.
Next, I will talk about the complete testing process, which is just a general idea, and the specific details need to be discovered when you test.
1. Rotate the focus wheel 3 and set the position of 6 to the innermost, infinity position.
2. Open the B door of the lens shutter, and use translucent glass to observe whether the infinity position is correct and whether the image is clearly visible. If it is visible, this position is the infinity position. If not, move 6 small steps outward to find a clear position at infinity. then mark
3. At this time, 3 should give the F position to 5, which is the nearest position. fixed.
4. Calibration The rangefinder left and right, up and down looking and object far away (infinite) and using the screws 1 and 2
5. Install, fix 1, then rotate to close to the closest focusing distance, taking care that 6, do not fall off. Then fix 2 in place.
1-5 need to be repeated many times for the real test to be accurate
I have tried to do as you instructed without success.
But I think I have found the reason.
Please watch the attached picture and you can see the lever arm touching the center prism (I put a piece of paper and I am stretching it until it can be easily removed). If you look at where the lever arm is off-centre when it no longer touches the glass, you’ll see that it’s too far from the F point you showed in the detailed manual.
I think the mirror needs to be displaced to give the lever arm more room to move, what do you think? If so, do you know which screw moves the center glass?
I also saw that the eccentric allows some light to pass through (see attached photo). I don’t know if this is normal (it can’t be adjusted, I’m afraid).
I’ve also attached a photo of the full mechanism, if you see any difference from yours (at first I suspected the lever arm was deformed, but I don’t think so since I’ve seen this problem with the central glass position and the interference with the lever arm
Thanks again. I think I’m close to solving this problem.
Hi. I haven’t contacted you until now because I’ve been busy trying to adjust the camera.
I finally found the problem! The central prism was displaced and was contacting the lever arm. It was just a matter of pushing the prism to the right position with a screwdriver and I was able to calibrate the rangefinder.
I have done some tests but I still haven’t got correct results.
I have tested indoors at f4 and I can see that the focus is not good at all.
Maybe it needs a little more adjustment. I have made a setup with a digital camera and a 400 mm lens (270 full frame on an APS-C) focusing to infinity. The focus didn’t look bad but I think there is room for improvement.
I have also supplemented the pressure plate with foam to ensure that there is enough pressure on the negative and that it is as flat as possible.
I have a question to ask you, on your Voigtlander Bessa RF cameras, are you able to focus correctly at f3.5 – f4, or at those apertures, is the depth of field so narrow that any rangefinder/focal plane error makes the picture out of focus? Your cameras are enough well calibrated to shoot at f3.5?
Great to hear your new progress.
Regarding the deformation of the middle lens, I don’t think it is deformed. I should have encountered this problem. In fact, it is just adjusting the screws to calibrate the viewfinder and the position of the split image screen. Those screws are not very easy to adjust.
The gear piece is not deformed, in fact, this is what I said needs to be adjusted,
Rotate the gear when the gear reaches the infinity position, whether the corresponding transmission to the split image screen is also coincident with the infinity focus (you need to see with your eyes, you can use a tripod to fix it), do this first, and then check whether the split image screen is facing upwards. If the downward direction does not coincide, adjust the screw again, because after the position of the gear finds the correct position, there is no need to adjust it again, just fix it.
I think you are almost done successfully.
Regarding the Bressa RF and bressa II cameras when the distance is too close to the maximum aperture, I have a hard time getting a clear picture but I think your problem is caused by the fact that the focusing mechanism is not fully adjusted in place, and at present your camera can basically meet the requirements of normal shooting.
PS: Occasionally, uncompressed film can also cause blurry shots, I’ve encountered that twice.
The attachment a photos taken probably at the maximum possible aperture because it was taken in the evening（bessa rf helomar) showas that a picture can be taken with no blur.
It took me a few months to calibrate the Vöigtlander camera.
I wanted to finish the calibration quickly before going on vacation last July, but due to the rush, I made some mistakes. First, I took a building 100 feet away as a reference (close to infinity but not enought, I think), so the infinity reference for the rangefinder calibration was not completely correct.
On the other hand, to project the image, I used a translucent sheet of paper, but I don’t think It was perfectly flat. Another mistake.
I tried it again after the summer holidays and I created a system like the one shown here to ensure focus and not just my eyes.
I glued the translucent paper to a flat transparent glass to ensure it is completely flat.
Lastly, a final adjustments were made after shooting a last test roll. The results are incredible.
I now have another camera for my collection and am excited about the opportunities this camera opens up for landscape and portrait photography.
Thank you very much!
The whole maintenance process is long, but the result is very pleasing. In fact, during the process, because the adjustment process cannot be directly seen, the suggestions on the poison mirror are not very precise, and even some are general, so only I can constantly mark the process pictures finely, so that the communication can be clearer.
I am very grateful to Alfonso for his support and trust. He seriously repaired the BESSA RF camera and helped me to complete the writing, proofreading, and English translation of this article. I hope Alfonso can take more photos that he like.