Mirror and Shutter-Induced Shock

High resolution DSLRs, and even mirrorless cameras like Sony's original Alpha 7R, have the potential for image shake from the vibrations induced by the mirror and/or shutter mechanism. We undertook a massive study to see how much such mirror and shutter shake affects image quality at a variety of shutter speeds across a number of cameras: the Canon 5DS R, Nikon D810, Nikon D750, and Sony a7R. We also took a look at the impact of optical image stabilization (IS) in lenses. Finally, Canon offers a number of drive options for helping control vibrations: mirror-up pre-delays, or 'silent shooting' mode which dampens the mirror mechanism for quieter, more vibration-free shooting - all at the cost of speed. Live View offers an electronic first curtain that completely eliminates all potential sources of shake.

Canon has done an impressive job at minimizing the impact of the mirror and shutter actuation on image sharpness... sharpness cost is limited to affecting a relatively narrow range of shutter speeds.

The take-home? Canon has done an impressive job at minimizing the impact of the mirror and shutter actuation on image sharpness, both by redesigning the mirror mechanism, and by offering silent shooting and mirror-up pre-delay modes. Furthermore, Canon's IS system on lenses helps reduce the impact of vibrations, not exacerbate it as Nikon's VR systems do. That said, due to the mirrored DSLR design and the lack of an electronic first curtain in viewfinder shooting, the 5DS/R cameras cannot always achieve the entirely vibration-free images Sony's comparable camera, the a7R II, can provide. Some sharpness cost still remains in typical shooting at longer focal lengths, but the good news is that it's limited to affecting a relatively narrow range of shutter speeds, and Canon provides workarounds that mitigate the sharpness cost significantly.

In-Depth

Have a look at our comprehensive study below. The 1st, 2nd, 3rd, 4th, and 5th drop-downs control camera, lens, drive mode, image stabilization, and shutter speed, respectively. The drive modes include exposure delay, mirror up pre-delay, silent shooting, and electronic first curtain modes offered by the various cameras. Switching the 'camera', 'lens', 'drive', or 'image stabilization' drop-downs for the first crop at upper-left changes that parameter for all crops, but changing them in any other crop only changes the parameter for that crop. This makes it easy to change all crops to a certain mode (by changing the desired mode in the upper left crop only), or change only a specific crop's mode by changing the mode in any crop but the upper left crop. 

Note that all in-line hyperlinks (in bluein the following text change the state of the widget above, so please refer back to it upon clicking any link.

At a high level, we see that in its default 'Single' drive mode paired with a 70-200 F2.8L IS II lens at longer focal lengths (200mm), mirror and shutter actuations can impact image sharpness at longer focal lengths at shutter speeds of 1/125s and slower. Turning IS on helps, but even then if you're hoping to get the sharpest hand-held images at longer focal lengths, you'll have to steer clear of shutter speeds 1/80s and slower at longer focal lengths. Notably, we consistently see the worst results around 1/60 - 1/50s, where the 5DS/R in default modes perform worse than the Nikon D810. Image sharpness recovers at slower shutter speeds, where the vibration from the mirror and shutter become an increasingly smaller portion of the longer exposure. Of course, your mileage will vary based on focal length, with shorter focal lengths yielding far fewer issues. 

Live View Yields the Sharpest Photos

Switching to Live View removes the mirror slap from the equation, and uses an electronic first curtain by default to eliminate any potential shutter shock. It's your best bet for the sharpest photos on Canon DSLRs, which is why many landscape photographers tend to use it. Comparing the most problematic shutter speeds (1/80 - 1/30s) vs the sharpest results you can get in Live View, you can get an idea of the sharpness cost to shooting in typical Single drive mode during viewfinder shooting. The differences are more dramatic if you don't have IS, as expected given the beneficial impact of IS.

For most other types of photography, though, shooting a DSLR in Live View isn't practical: you lose all AF benefits of dedicated phase-detection systems. Hence, the performance of the camera during viewfinder shooting is of utmost importance. So what can you do to maximize sharpness during viewfinder shooting?

Silent Shooting Benefits

Thankfully, Silent Shooting largely mitigates the issue, particularly when combined with IS. While technically there's still a little bit of softening compared to the tack sharp Live View results when using Silent Shooting with IS at shutter speeds between 1/40 - 1/80s, it's minimal and won't be noticed in most real-world shooting. Turning IS off yields slightly worse results but, again, it's not too bad.

vs. Nikon D810

Although at its problematic shutter speeds the 5DS/R in Single drive can fall behind the Nikon D810 in its 'S' drive mode (as long as VR is off on the Nikon), Silent Shooting reverses things, allowing the 5DS R to catch up to the D810, and even slightly* surpass it with IS on, particularly at slower shutter speeds (~1/30s) where the D810 tends to suffer. Turning VR on doesn't help the D810; in fact, it makes matters worse, particularly at higher shutter speeds, where parasitic interactions between Nikon's VR system and the mirror/shutter actuation downright ruin image quality.

What about Mirror-Up Pre-Delays?

Canon includes a number of mirror-up pre-delay options that build a short delay in between the mirror and shutter actuation. In these modes, you push the shutter button to actuate the mirror, and then the camera waits for the pre-defined delay time before firing the mechanical shutter. Delay times of 1/8, 1/4, 1/2, 1, and 2 seconds are available. Combining these pre-delays with silent shutter reduces vibrations further. We investigated if these pre-delay modes in Single drive mode actually help, and to what degree.

Looking at the most problematic shutter speeds with IS off, Single drive fares the worst, 1/8s fares better, 1/4s fares even better, with 1/2s and 2s delays showing similar performance to 1/4s pre-delay. Comparing all pre-delay modes, as well as the Silent Shooting mode, to our Live View 'reference point' (bottom right), it's apparent that most of the mirror vibrations are dampened by 1/4s, with any residual sharpness cost coming from the mechanical shutter itself. In other words, most of the more dramatic image softening we've been seeing comes from 'mirror shock', not 'shutter shock'. And while the shutter itself does cause some image softening (the left column results isolate the effects of the shutter, as a 2s delay is long enough to remove mirror vibrations), shutter shock itself, like mirror shock, is mitigated by Canon's IS system. 

Handheld Results

OVF 1 2 3 4 5 6 7 8 9 10
Live View 1 2 3 4 5 6 7 8 9 10

To verify that our tripod-based tests correlate with real-world hand-held results, we shot a variety of shutter speeds hand-held, and correlated the results back to our tripod-based results. On the whole, the story was exactly the same, with 1/60s being the most problematic in typical hand-held shooting. Above, we show 10 sequential shots taken handheld with IS on at 200mm using the 70-200 F2.8L IS II (top row), and compare them to 10 shots taken handheld in Live View (bottom row). As should be clearly evident, mirror and shutter-induced shock can cause image softening and a double-image that would not result if the mirror and shutter actuations were removed from the equation (as they are in Live View). 


* We say that the 5DS R only slightly surpasses the D810 in Silent Shooting mode because in our test, two things are hurting the D810 somewhat unfairly: (1) default ACR conversion adds more contrast to the Canon compared to the Nikon, and (2) the D810 wasn't re-focused after the addition of the Vari-ND filter used to achieve slower shutter speeds (below 1/125s). Hence, D810 shots below 1/125 are ever-so-slightly sub-optimally focused. You can see all this here: note how even in electronic shutter modes, the D810 look softer at 1/100s and below compared to itself at 1/160 and above (the ND filter was used for 1/125 and slower). This compounded with the lower contrast makes the D810 look slightly worse than it is in relation to the Canon even when there is no image-degrading vibration, so we're trying not to over-interpret the data when we say 'slightly surpasses'.