Torque Tests for 15, 10, 6 MPH Wind Speeds

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?

15 thoughts on “Torque Tests for 15, 10, 6 MPH Wind Speeds

  1. I find it interesting that even the
    MeFoto Backpacker Air would
    theoretically work for the 16-55 (and
    smaller kit 18-55 lenses) even in
    15mph winds.

    1. Yeah, I was surprised how little tripod stiffness is actually necessary at these lower wind speeds. The wind pressure on the camera is surprisingly light. Note that this analysis doesn’t take into account any effect from the wind on the tripod itself. For most tripods I wouldn’t expect much torque, but on one like the MeFoto Air where the center column is permanently up, I expect the wind would push the tripod around no matter what camera was on it.

  2. Super interesting data! And super helpful in better understanding the impact of wind.

    I’d be interested to see data on a telephoto zoom (like the 55-200) that doesn’t have a
    tripod collar. It’s lighter than the 70–140, but it also is not as centrally balanced on the
    tripod… I wonder if it would require more or less stiffness.

    I’d also be curious to see how smaller lenses do at even higher windspeeds. Although
    that might have less practical implications. How many of us will be trying to setup a tripod
    at 20+ mph windspeeds?

    1. Hmm… not sure why the formatting is all wonky on my reply.

      Did want to add one other note. It would be interesting to test the stiffness/stability of tripods
      in a stream as well.

      1. Yep, I’m curious about that as well. I don’t have a particularly convenient way to test it though.

        1. Hrmmm… Kickstarter for David to build a stream simulator in his lab? 😛

          That’s helpful about the 120mm. I don’t have as easily accessibly immediate memory on the
          medium format equivalents as I do on MFT and APS-C variants compared to FF.

          1. I could use a backyard water feature :P. Don’t worry about the various multiplication factors between formats. The only thing that matters is focal length and pixel size. 5.3 micron for the medium format and 3.5 micron for the APSC in question.

    2. A smaller telephoto like the 55-200 should have a very similar wind profile to lenses such as the 120mm GF. You would then just have to account for the longer focal length and smaller pixels of the camera. So, multiply the stiffness needed by 2ish. Perhaps less since the lens has a smaller diameter.

  3. We are generally advised to switch off Image Stabilisation when using a tripod but I would be interested to
    see the relative impairment of having IS switched on or off in still conditions on, say, an averagely stiff
    tripod. Further it would be interesting to consider at what level of increasing wind speed it becomes
    beneficial to switch on IS.

    1. No problem. I need to organize the site a little bit better to make things easier to find. The blog format is not conducive to making past posts accessible via anything other than search engine.

  4. Perhaps you could quantify the aerodynamic contribution of the tripod by putting an inertial mass on the torque sensor and shielding it from the wind. Most of the measured torque will then come from the tripod itself.

    1. I’ve been thinking about how to do that. a large inertial mass could work, though I would worry about it starting to oscillate. Perhaps if it could also be fixed from above by some other assembly. Another much larger tripod maybe? wooden frame? Not that I really want to make a building project out of this.

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