We have been focusing on the forces that wind pressure places on the camera, but wind is far from the only external force that acts on a camera. In this post we are going to look at the amount of torque placed on the camera from handling the controls and pressing the shutter button. We want to know how long it will take to damp out the vibrations from touching the camera and know what kind of tripod stiffness we need to obtain sharp images if not using a cable release.
For this set of tests, I mounted the test camera onto the torque meter and recorded 20 second of torque data while taking images without a cable release. I also recorded the torque involve for changing a variety of settings and generally handling the camera. Unfortunately, the torque meter only measure one axis, so we only have data for the yaw torque applied to the tripod. The yaw stiffness is generally weakest on tripods, so this approach is at least somewhat reasonable. I also measured the yaw torque with the camera mounted in landscape orientation with a telephoto lens with lens foot. This should at least tell us if we are getting drastically different amounts of torque in the pitch direction under normal usage.
Before diving into the data below, please take these results with a grain of salt. Most of the tests on this site are precise and should be repeatable by a third party. This one, not so much. Everyone’s hands are a little different, and will handle the camera differently. I tried to handle the camera and press the shutter button as gently as possible, but certainly there are people out there with more precise control. From this data, I just want to extract a reasonable estimate of how much torque is placed onto the system in normal usage. As we will see in posts later on regarding damping, the exact amount of torque is going to be less important than pulling a consistent number out that we can apply across all tripods for comparison purposes.
Here is the torque observed over four exposures using the GFX 50S and 45mm GF lens:
Its a mess. But we see that while taking the exposures, I am putting an average of about 15 N*cm of yaw torque on the camera. Because my hand is on the camera, and hands are fantastic dampers, we don’t see the same kind of high speed oscillation observed with the wind. This has interesting implications for what kinds of mid-range shutter speeds can be used in each situation, but we won’t get into that now. I also tested things with the 120mm GF lens attached, but the results were pretty much the same in terms of torque.
Here is the torque for GFX 50S and 250mm GF. This is of course a little bit different as the camera is mounted away from the center of rotation:
It is much more obvious and consistent when my hand is placed on the camera. Surprisingly, the magnitude of the torque is roughly the same. As advertised, here is the torque with the same lens but the camera rotated into portrait orientation to simulate pitch torque:
Again, similar, but actually a little bit less torque. Close enough though that we really don’t have to worry about the pitch torque being dramatically different than yaw.
Now, instead of having the hand on the camera to take exposures, Here I just manipulate the settings on the lens and camera as I would during normal shooting. I am changing the shutter speed, aperture, ISO, focus point, menu buttons, etc:
The peak torque is much higher. The average torque is roughly the same. Some settings on the camera required much more force to change than others.
I took data in the style of the graphs above for a number of camera and lens combinations. I am going to spare us both and not post any more of the torque graphs. There really isn’t anything to be gained. You are just going to have to trust me that they are all mostly the same. Instead, I recorded the average peak torque from each graph in the tables below:
So for each camera and lens combo, I have taken three sets of torque measurements, each of which consisted of roughly four exposures. I took the rough average max torque in each set. Those are then recorded, and themselves averaged. We aren’t looking for absolute precision here, just to test consistency. And reasonably consistency was in fact observed.
The last column “Necessary Stiffness” shows the amount of yaw stiffness a tripod would have to have in order to hold the camera and lens pixel-level still while my hand was taking the picture. These are pretty large numbers, and you may question these results based on past experience of obtaining sharp images on weaker tripods. Given the slow nature of the torque, the camera is also moving about somewhat slowly. Thus only shutter speeds in a certain range would show loss of image sharpness. This likely would be in the 1/15 – 2 sec range, but I don’t know for certain, and would depend on focal length. Additional testing needed.
Here are the results from observing the torque while adjusting the camera settings:
Again, these are the result of 20 second trials where I took the rough maximum from each. We observe significantly more torque, but we are still easily within the same order of magnitude. We also see more variance here. This is reasonable. While testing it was obvious that the controls on the smaller X-H1 camera were lighter and moved easier. This resulted in smaller torques being exerted.
I didn’t calculate a stiffness column here because we generally don’t care about keeping the camera still while adjusting the settings. We just want the vibrations from doing so to settle in a reasonable amount of time. The situation is the same for pressing the shutter button when using the camera’s built in timer. In this case though we want to make sure that any vibrations from hitting the shutter will die out within the 2 second timer that is most commonly used.
We will be using this data as a basis for actually calculating these damping times in a future post. We also want to take a look at the necessary stiffness of tripod for it to be used without a cable release or timer. Just use a cable release though.
Taking the question list from before and adding to it:
- How much torque will we see from lesser wind speeds, such as 15mph 10mph, 5mph?
- How much loss of sharpness do we actually see from wind on tripods of differing stiffness?
- At what shutter speeds do we see a loss in sharpness from hand pressing the shutter button?
How much torque is placed on the system from pressing the shutter button?
- How much damping is necessary for that vibration to damp out in a reasonable time?
- Can we minimize wind torque with camera placement on the tripod?