Bessa Rangefinder Calibration

12 CommentsFriday • August 1, 2008 • by Arran

No matter what rangefinder you use, theres a good chance that you’ll need to have the rangefinder calibrated one time or another. This is no big deal if you’re aware that the problem can happen (often as a result of bumping or dropping the camera)
Some cameras will need adjustment more than others, and the Voigtlander Bessa range seem to be more prone to rangefinder misalignment than others (this can be said for the Epson RD aswell, which is basically a digital Bessa).
Alot of older cameras have a pretty simple adjustment process, and theres quite alot of info on the net documenting the process. However the Bessa range are still pretty new, and at first it seems as though the whole adjustment process is a guarded secret. Naturaly, many Bessa owners werent too keen on paying a full service fee for a 5 minute RF alignment, so they begun to search for ways to do it themselves.

Theres alot of info floating around the internet on this subject, but i noticed they either didint come with pictures, or the descriptions were missing simple steps. I’ve tried to bring all of the relevant info together in one place and write some instructions based off my own personal experience. This process was completed on a Bessa R3, however i’m told most of the Bessa range is very similar.
*Disclaimer. It’s recommended you ignore these instructions and get your Bessa calibrated by a registered Voigtlander technician if :

• You dont have experience pulling apart and fixing cameras,
• You’re not confident with small tools,
• You’re clumsy,
• You dont take responsibility for your own actions and will want to blame your broken camera on me!

1. First of all, to calibrate the rangefinder you wont necessarily need to take the entire top plate off. It is possible to remove part of the hot shoe that will give you access to the adjustment screws. This can be a tricky process particularly if you dont want to scratch the black pain on your hot shoe. You’ll need a small flat head screwdriver or a toothpick to wedge and pop/lift up the cover plate illustrated in the photo below.

When you lift the edge up enough, the cover will pop up and you can slide it out in the direction of the arrow above. It’s important to have patience with this step, as it’s really easy to get frustrated and be a little too forceful. You dont want to break or scratch anything.
2. When you get the cover off, you’ll see the bracket held on with 4 screws shows in the image below

Taking these screws off should be pretty simple, they werent on too tight with my camera. You’ll need a size #00 phillips head screwdriver for this.
3. Now that you have the bracket off you’ll be able to access the adjustment screws. I could only get a photo of one, but i’ve show where the others are using blue circles. The screws are numbered from 1 to 3 for reference purposes.

You’ll need a long flat head screwdriver to adjust these screws. Also, you may need to remove any “loctite” or similar residue around the screws that prevent you from turning them.
The adjustment process
Below is a description of what each screw does. Quite often you’ll only need to adjust one of these so dont freak out.

Screw 1: Rangefinder patch focus adjustment
Screw 2: Horizontal (left/right) adjustment for Infinity focus
Screw 3: Vertical (up/down) adjustment
*There is a 4th screw also, but to access it you need to remove the entire top plate. It calibrates the base length but you’ll probably need to adjust it. (pray you dont)

Now we can start calibration. Once your camera is adjusted at infinity focus, everything should be fine for close focus aswell, but check just incase. My camera needed horizontal adjustment, yours might need vertical (or both). Find a place to set your camera up on a tripod where you have clear vision to something you can focus on for infinity (make sure its atleast 5 blocks away, its better to be safe than sorry). Adjusting horizontal alignment wont affect vertical alignment, so dont worry.

RF Patch Focus: If you’re rangefinder patch isnt sharp than you’ll need to calibrate it also. Doing this first will make the other steps easier. Also, i’ve heard that adjusting this screw can sometimes move the horizontal alignment aswell, keep that in mind. Turn screw#1 to calibrate this. You may also want to do this with the Vertical alignment leaving the infinity and close focus adjustments to last. It’s not absolutely necessary though.
Horizontal: Set lens focus to infinity (use a lens you know is accurate), and then point the rf patch at an object in the distance. Adjust screw #2 which will move the patch left to right and stop when its properly aligned. Be very delicate and precise as its quite sensitive.
Vertical: With the lens still focused at infinity, adjust screw#3 which moves the patch up and down. It’s a larger screw and isnt as deep as the others so it might be easier to get to. Once again be very precise.
Close Focus: I’ve never done this adjustment before, so cant speak from experience. Every time i’ve adjusted at infinity the close focus has been fine. To calibrate close focus you’ll need to remove the top plate and access another screw which isnt covered in this guide. However i’ve been told that very small adjustments can be made using screw#1. You should be adjusting your lens at 1m for close focus calibration.

After you’ve adjusted all the screws for calibration you can put something on them like “loctite” that will help prevent misalignment in the future. To reassemble everything you just reverse the disassembly process.
Have fun

Posted in: Camera, Tech/Repairs, Voigtländer

Tagged with: alignment, bessa, calibration, rangefinder