Zorki 1 - Transformation of an Ugly Duckling - Adjustment
Having reassembled most of the components, I proceeded with the necessary adjustments.
The Zorki 1 lacks a rear door, making the use of a shutter tester somewhat challenging, though not impossible. As I hadn't yet put the shell back on, accessing the shutter was relatively easy.
The adjustment procedure isn't well-detailed in Soviet manuals, which often suggest observing the movement of the shutter curtain with the naked eye.
For the initial setting, the tension of the opening shutter roller should be at 4-5 turns, while the closing shutter roller's tension should be adjusted to ensure similar transfer speeds for both shutter curtains. Leica manuals, however, describe a different procedure, recommending setting the closing shutter so that it just manages to close. Since the Zorki lacks any mechanism to control the speed of the closing shutter, the Leica manual's advice isn't directly applicable. I began by setting the tension of the opening curtain roller to 4 full turns and the closing shutter to 3 turns. From there, I fine-tuned the closing shutter in quarter-turn increments, aiming for consistent readings from the shutter tester. Two indicators are crucial: the first is the nominal tested shutter speed, and the second is the vertical travel speed of both curtains. If the curtains don't travel at comparable speeds, the exposure won't be consistent across the negative.
I opted to construct a unique support frame for my Zorki using... Lego, a delightful perk of having children. For testing, I utilized an affordable VFMOTO device from eBay, which includes a sensor, an LED light, and an Arduino controller. Positioning the sensor behind the camera and the light source in front, I switched the tester to vertical shutter mode, only to be met with no response. After some investigation, I realized the issue: the provided light source was insufficiently bright. Substituting it with an LED flashlight, I was able to obtain my initial measurements.
The initial tension of the opening shutter roller should be set between 4 to 5 turns. The closing shutter roller should be adjusted to ensure similar transfer speeds for both shutter curtains. Although Leica manuals describe a different procedure – specifically advising to set the closing shutter so that it barely closes – this advice is not applicable to the Zorki. Unlike the Leica, the Zorki lacks a mechanism to control the speed of the closing shutter. Initially, I set the tension of the opening curtain roller to 4 full turns and the closing shutter to 3 turns. Thereafter, I fine-tuned the closing shutter in quarter-turn increments, aiming for satisfactory readings from the shutter tester. Two indicators are key in this process: the first is the nominal tested shutter speed, and the second is the vertical travel speed of both curtains. If both curtains don't travel at similar speeds, the exposure will be uneven across the negative.
However, it's essential to note that there are inherent tolerances when measuring shutter speeds. Thus, obtaining measurements perfectly aligned with the predetermined shutter speed is not feasible.
In my observations, I found that there isn't a configuration where both shutter curtains achieve identical travel speeds. Depending on the selected times, each curtain displayed varying starting and ending speed measurements. I opted for a combination where these disparities were minimized.
This observation implies that technically, an evenly distributed exposure on both sides may never be fully achievable. However, in practice, these differences are either imperceptible or barely noticeable on film. This very challenge is likely why Leica continued to innovate their camera designs. Not long after the release of the Leica II model D, an enhanced model was introduced.
Trying to calibrate 1/60th speed
1/500th set
The above-described method provides a theoretical approach to properly setting tension. However, to ensure accuracy, it is advisable to conduct an additional check by placing a digital camera behind the Zorki shutter to determine if the exposure is evenly distributed across the entire frame. To perform this check, I placed my Zorki camera in a box and cut two holes – one in front of the Zorki and one on the opposite side – and positioned my DSLR behind it. I set my digital camera shutter to B mode and captured several test shots, checking Zorki’s shutter at different speeds. This process emulates the actual outcome of the shutter operation, enabling fine-tuning and the identification of the ideal setting.
Once the shutter is set up, it is time to reattach the shutter crate to the camera body and reattach the lens mount. Initially, paper shims were used between the lens mount and the camera body to ensure the correct flange focal distance. This should be exactly 28.8 mm with a tolerance of +-2 mm. However, since the original shims have deteriorated, I needed to create new ones.
To calculate the proper thickness of the new shims, I first placed the lens mount onto the camera without any shims and measured the distance between the flange and the focal plane. Then, I found a piece of cardboard that was thick enough to match the required size of the shims and used thin baking paper to add any missing fractions of a millimeter. Using the lens mount ring as a template, I cut the shims into the proper shape. In my case, I needed to prepare a set of four different shims for each of the mounting points where the lens mount is screwed onto the camera body.
After several attempts, I was finally able to achieve an exact distance of 28.80 mm across the entire frame. It is important to take measurements at different points, especially near the mounting screws, to ensure accuracy. Overall, the process took some time and effort to get the shims exactly right, but it was well worth it in the end.
Take-up spool
Removing the take-up spool when changing film can lead to some of your worst nightmares. While it might be tempting to adjust the friction between the spool and the spindle to the bare minimum, this can negatively affect the camera's functionality. The primary role of the take-up spool is to collect the exposed film. If the spool isn't securely fixed to the spindle, it might slip causing film to become lose. Without sufficient tension, the teeth meant to transport the film may not engage properly, leading to overlapping frames. I learned this the hard way, and it took me a while to reproduce the issue for further understanding.
Rangefinder calibration
Calibrating the rangefinder was one of the final steps in assembling the camera. Vertical alignment is adjusted by turning the left rangefinder window (when viewed from the front). It's labeled as number 9 in the picture below. First, you'll need to remove the ring cover. After that, you can achieve alignment by gently turning the assembly.
See Vishnevsky "Camera Repair"
Horizontal alignment can be adjusted by removing screw #13. By doing so, you'll gain access to another screw that's responsible for the alignment. Note that horizontal calibration can only be performed with the lens mounted. I recommend repeating the calibration process with various lenses to identify a setting that's compatible with all of them. There's a possibility that a camera calibrated with one lens might not achieve infinity focus with another. For instance, I use a set of four distinct lenses that work well for me: Industar 22, Industar 50, Jupiter 12, and Jupiter 8. However, different copies of lenses might yield varying results.
I calibrate the rangefinder both for infinity and for a distance of 1 meter. Finding the ideal combination for all lenses can be time-consuming, but the effort is worth it in the end.
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