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  • Ed Dozier

Should you Turn IBIS Off When Using a Tripod?

I have read on several occasions that you should always turn off IBIS (in-body image stabilization) when you use a tripod. I’m such a terminal skeptic that I decided to try it for myself.

 

For my tests, I decided to pick on my Nikon Z9 and the 24-120 f/4 S Nikkor lens at 120mm and f/4. This lens doesn’t have any internal vibration reduction, and instead it entirely relies on the camera IBIS system.

 

I used a wired remote release and my heaviest tripod and on top of a concrete/porcelain tile floor indoors, so that any other kind of vibrations should be minimal. I got about 3 meters from my target, which is the edge of a tiny razor blade.

 

I picked a fairly slow (1/30 second) shutter speed, which should in theory readily show image motion (if there is any).

 

The Nikon Z9 (and Z8) have pure electronic shutters, plus they focus at the shooting aperture (through f/5.6). This means that these tests won’t be affected at all by ‘shutter-shock’ or moving aperture blades.

 

I used my MTFMapper program to evaluate the image resolution, which is much, much more sensitive than the naked eye in seeing any sharpness loss from vibrations.

 

I should mention that the orientation of the edge being evaluated will change the measured resolution. Every combination of sagittal and meridional direction will give a different result, which is big reason why it’s impossible to give a single-number answer to overall lens resolution.

 

I re-focused the lens (AF-S mode) using pinpoint focus mode in between each shot. This means that there should be a small variation in resolution between each test shot, due to the focus distance natural variation.

 

The target (edge) was far enough away that I did my measurements on just a 226-pixel portion of the razor blade. The whole point in this setup was to give the IBIS system the maximum chance to mess up the sharpness.



Extreme crop of frame showing the target selection (in cyan)




The whole frame




Spreadsheet of resolution results

 

 

Taking 20 shots with and then without camera IBIS active, I plotted the resolution results and got the average and standard deviation of the MTF50 resolution, in lp/mm units.

 

The average resolution using IBIS was 95.5 lp/mm. With IBIS turned off, the average was 94.1 lp/mm. The data spread (standard deviation) for active IBIS was 1.82 versus 2.55 without IBIS.

 

In other words, there’s hardly any difference when using IBIS or not, when mounted on the tripod. If anything, there is a slight improvement using IBIS. This is the exact opposite of what I’ve been reading on the internet.

 

It’s possible, of course, that the effect of using IBIS might be highly dependent upon which camera model you use. I only know that my Nikon Z9 and Z8 cameras use the exact same IBIS system.

 

Since it’s a pain to mess with switching IBIS on/off in different situations, I’m glad to know that you needn’t bother with turning IBIS off when mounting these cameras to a tripod.

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