In the previous post, I detailed the methodology for testing how much torque wind places on different camera and lens combinations. I used a leaf blower mounted on a tripod and an anemometer to measure the exact wind speed being delivered. That post only contained data for a 20 MPH wind speed. Here, I repeat that methodology for three lower wind speeds. While 20 MPH are not uncommon, especially in such photogenic places like Iceland and Patagonia, lower wind speeds are much more common.
First, here is the measured torque and calculated amount of tripod stiffness necessary to obtain sharp images for each camera and lens combination at 15 MPH wind speed:
This data is consistent with our previous set. The amount of torque is in each case less, and thus is the amount of tripod stiffness necessary. Again though, we see that holding the telephoto lenses stable can only be done with the largest, stiffest tripods available. For the smaller normal focal length lenses though, small lightweight tripods should be sufficient.
Here is the data for 10 MPH:
Again, the torques are lower as expected. The amount of stiffness required for the telephotos is approaching a more reasonable range.
And the data for 6 MPH wind:
The air pressure at 6 MPH is incredibly light. Only for the 400mm lens on the X-H1 do we need a particularly stiff tripod. Note that 0.1 N*cm is the smallest amount of torque that the torque meter can measure. It hardly matters at that level though. Basically any tripod will provide the necessary amount of stiffness.
Here is the required tripod yaw stiffness assembled for each wind speed:
The results are intuitive. The more wind speed and the larger, longer focal length lens used, the more tripod stiffness is necessary. The weight and sensor format of the camera are not particularly relevant. A stiffer tripod allows the shooter more flexibility in shooting longer focal lengths in windier conditions.
There isn’t a lot of fanfare around this post in particular, but it is going to be central towards forming this site’s recommendation for how much tripod stability you need based on your equipment. As we have shown here, this approximation will lack subtlety and precision but will be critical to the site’s message and usefulness. Most users aren’t carrying around an anemometer to measure wind speed, or know the moment of inertia for their camera. We thus want to form a general guide people can start from when selecting a tripod and have them end up with reasonable results.
Moving forward, we need to test the actual loss in measured sharpness while taking long exposures on some specific tripods with the wind speeds measured above. Also, wind is far from the only force acting upon the camera. We need to measure the effects from shutter shock, handling the camera controls, my dog’s tail hitting the tripod leg, or whatever.
Taking the question list from before and adding to it:
How much torque will we see from lesser wind speeds, such as 15mph? 10 mph? 5 mph?
- How much loss of sharpness do we actually see from wind on tripods of differing stiffness?
- 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 torque with camera placement on the tripod?