Sharpness Loss from not Using a Cable Release

Conventional wisdom has long been to use a cable release when shooting off of a tripod to eliminate any movement of the camera caused from physically pressing the shutter.  I agree with this wisdom, but needed to put it to a quantitative test.

For this test, I placed the Fuji GFX and 120mm GF lens on a couple different tripods.  The first was a very stable RRS TVC-33 and BH-55 ballhead.  This is the standard for what people generally consider to be a very high quality tripod setup.  The second was a Feisol CT-3342 Tournament and Sirui FD-01 pan-tilt head.  While no slouch, this setup is notably weaker than the RRS one.  I am not listing exact stiffness here because the connection between the RRS L-bracket and the camera appeared to be a significant, and unknown contributor to the stiffness of the system as a whole, and the point I am presently trying to make isn’t exactly dependent on overall tripod stiffness.

Previously, I measured the amount of torque placed on the camera when I was pressing the shutter button.  I observed large enough torques to indicate that only the very stiffest tripods ( much more so than the RRS-TVC33 ) could hold the camera steady enough for razor sharp pics when pressing the shutter manually.  Those torques occurred on a fairly slow time scale though, and so it was an open question as to what shutter speeds would be most detrimentally affected.

Here, I use MTFmapper to measure the sharpness of images in cycles/pixel (higher values = sharpe  images) for a range of shutter speeds.  At each shutter speed I take 3 images and report the average MTF observed from the set.  As always with camera shake, there is variance between the shake observed in each image so the data is somewhat noisy.  Below is the plotted loss in sharpness observed when not using a cable release for the two tripods referenced above as well as a control tripod.

The results largely speak for themselves.  At faster shutter speeds around 1/60s and above, we observe virtually no loss in sharpness from pressing the shutter button by hand.  Slower than 1/60s, and we begin to see a steady decrease in the average sharpness of the images that doesn’t appear to stop even at the slowest exposure time tested of 2 seconds.  The stiffer TVC-33 did a better job at holding the camera steady by approximately 2 stops, but there will still plenty of soft images.  The relatively small and lightweight Peak Design Travel tripod had no trouble holding the camera steady while a cable release was used to trigger the shutter.  Use a cable release.

If a cable release is not available, using the camera’s built in 2 second timer can also work.  The plot below shows the same data as above except that RRS data was removed and replaced by another series taken with the Feisol and a 2 second timer.

 

When the 2 second timer is used, I observed no loss in sharpness.  This is of course dependent on the damping of the tripod being sufficient to steady the camera in under 2 seconds.  Cameras also typically have a 10 second timer, but this isn’t practical for real world shooting.  For analysis on exact damping times, stay tuned.

Note that the loss in sharpness observed in these plots is not huge.  Above 0.30 cycles/pixel, the images are stunningly tack sharp in a way that only the very best lenses can achieve.  At 0.25 and above, the images still look pretty sharp to the eye, though in a head to head comparison it is clear some fine detail is being blurred.  On its own though, you would still label this image as sharp.  0.20 is still pretty good and probably usable.  0.15 shows some noticeable blurring when viewed at 100%, but could still be used for smaller prints.  See the previous post for some examples.  So we aren’t talking about massive losses in sharpness here.  But if you are spending the big bucks on the best glass, get a $5 cable release too.

Takeaways:

  • Use a cable release or 2 second timer at mid to slow shutter speeds.

 

*Edit*

I have received some flak for using MTF 50 for this analysis vs. MTF 20.  Here is the data set for hand pressing the shutter with the CT3342 tripod using both MTF 50 and MTF 20:

The results are essentially the same, but as expected, MTF20 occurs at higher spatial frequencies.  MTF20 is a much noisier measurement as the MTF is not particularly well behaved in general for looking at the loss of sharpness due to image shake.  For example, here is a particularly poorly behaved MTF curve for an edge showing significant image shake:

A properly behaved edge showing only a little bit of image shake is as such:

 

10 thoughts on “Sharpness Loss from not Using a Cable Release

    1. 🙂 Yes, but sadly not anytime soon. I was using a pre-production version here and will be waiting for a production version for a full review.

      1. FYI, given the extent of your
        involvement with Peak Design, you
        might consider adding a disclosure
        about it on your site somewhere.
        You’re off to a good start with this
        site and it would be a shame for your
        reputation to be compromised by the
        perception that your testing and
        commentary is biased as a result of
        the consulting work you have done /
        are doing for them.

        1. Thanks, yes, I will do that when I review the PD tripod. There will be a big fat disclaimer in there explaining my involvement with them. In this post, I just used a PD tripod since it was the closest one at hand. I would have gotten the same result with literally any other tripod. I chose to use the PD because it is relatively weak compared to the others in this test, and to make the point that technique matters more than the tripod in these circumstances.

          1. IMO, this disclosure needs to be made
            separately from the PD tripod review,
            as the issue isn’t just the potential
            of you being biased in its favor, but
            also you being biased against its
            competition, whether it’s directly or
            indirectly, because one never knows
            what the future has in store for you
            or PD…

            In a past life, I was the editor of a
            high-end audio magazine and avoiding
            the appearance of bias, either pro or
            con, was always a bit of a tight-rope
            walk. But it was also an important
            one, with potentially dire
            consequences if I ever got it wrong…

          2. Thanks, that is a fair point which I hadn’t considered. I could have unconscious bias against other products. I will think about how to add a disclaimer to the site. I certainly hope that the reviews themselves and unbiased nature of the testing itself will alleviate any concerns, but its still good to be upfront.

  1. Any update on when we might see Peak Design scores? Given then sheer obnoxiousness of the marketing for that tripod, I’m curious how it actually performs.

      1. Aww, I thought they were promised in September or October of this year, at first.

        Either way, I do agree that the “PDTT” makes a fine example of how beneficial a cable release can be,
        …since it’s a pretty dang wobbly tripod overall and I wouldn’t EVER use it WITHOUT a cable release or 2-
        sec timer and E-shutter.

        1. Given that I saw a significant loss in sharpness even when using a RRS TVC-33, I would always use a cable release or 2 sec timer, no matter the tripod. But yes, especially with lighter travel tripods such as the PDTT.

Leave a Reply to Sean Cancel reply

Your email address will not be published. Required fields are marked *