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Mirror Lock and shoot

Hi Guys,

Using the Mirror Lock option in Camera controls disables the 'Shoot' function?

I would like to press 'shoot' to ' lock the mirror' then press 'shoot' again to take the image to make full use of a mirror lock setup. Am I doing something wrong?

I'm using a Canon 100D



Actually this is the current behaviour, let me explain how the Mirror Lockup feature is intended to be used.

When the Mirror Lockup setting is enabled on a camera, then the camera needs two trigger activations to take a photo; the first trigger will raise the mirror, then the second trigger will activate the shutter (and put the mirror down again). Right now the Smart Shooter UI does not have the ability to allow this two step triggering, so when the app detects the camera is in Mirror Lockup mode, it will disable the 'Shoot' button.

So to use Mirror Lockup, its a requirement that you trigger the cameras manually with some external trigger.

The reason Smart Shooter has the ability to enable/disable Mirror Lockup, is that its a useful feature for multi-camera control. Using Mirror Lockup reduces camera shake, so its desirable to use to use it during capture, but its also very useful to be able to enable/disable it quickly across many cameras, without having to individually operate and change each camera. Thats why we included it in Smart Shooter.

I opened a feature request for this.

Let me know if its important for you!



Hi Francis,

This would be very useful as this would perhaps allow me to trigger my cameras without the need for a separate triggering system. The caveat being the degree/accuracy of sync when using USB and across that many cameras.

Do you have any experience with triggering multiple Cameras via USB and the degree of synchronicity?

The remote system we are running is very accurate, stable and reliable, but its a lot of cables and the ability to trigger the cameras and the PC at the same time could be advantageous.

Thanks for the reply.

Andy M

Triggering over the USB connection has very poor accuracy.

The delay between each camera is around 150ms, so its not really feasible for multi-camera triggering.

The fundamental problem is that USB communication is not a broadcast. Instead the 'trigger' command has to be sent individually in sequence to each camera, and the overhead of USB communication handshake introduces this long delay.

That's a shame and it does mean my request to trigger the camera with mirror lock would be redundant for my needs. It might still be useful for a single camera setup where timing is less important.

I also made a request for separate delays per camera .. you can scratch that off as well.

Thanks for the feedback!

I'm suprised, because it is something which works in DSLR remote pro...

Hi Frederic,

Which bit were you referring to?

Being able to trigger multiple cameras from software, or triggering a camera with Mirror lock up mode?

Hello Francis... I was refering to being able to triggering a camera with Mirror lock up mode...

Ah OK I see.

The tricky thing about mirror lock up mode (MUP), is that I was not able to get the current mirror state from the camera.

To trigger the camera in MUP mode, the software has to send two separate commands to the camera; the first lifts the mirror, the second triggers the shutter. So because Smart Shooter cannot get the current state of the mirror, it makes it difficult to know which command to send! What if the user already manually pressed the button on the camera to lift the mirror, how does the software know this, to then be able to trigger it correctly?

So to avoid such complications, Smart Shooter simply disables the 'Shoot' button when it detects MUP mode is enabled.

This was the case for the Canon 100D, which is the camera I added MUP support for.

For Nikon cameras, actually this may be possible. What cameras are you using?


I shoot a D810 in studio - table top product (single camera).  Camera shake is an issue, even more so when I'm shooting macro, which is most of the time.  I would think that the camera's button is nothing more than a contact closure that camera software interprets and then either triggers the camera normally or in MUP, triggers the mirror first and then the shutter second.

Disabling during MUP is not desirable for those in my situation.  So, would it be possible to add a feature that would allow MUP users to send multiple trip signals to the camera and allow your software to ignore the mirror state?  The photographer would have to be smart enough to keep track of his own mirror state to know when, or not, mirror is up vs. tripping the shutter.

That would be fine for me . . . or something like that.


The Canon 5Dr s is capable of doing a timed release for Mirror up mode. It would be nice if you could implement this in a single trigger release.

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