Valletta skyline at night, Malta – 30sec exposure… on a very wobbly, broken tripod!

In a recent blog post I talked about using “mirror lockup”.  I thought I’d take a few moments to explain a little more about mirror lockup, why and when I would use it.

The problem

When on tripod there is always a risk that pressing the shutter release will cause a slight but perceptible jolting of the camera.  This is why photographers use remote triggers or cable-releases, to prevent that from happening. Additionally if your tripod is not absolutely rock solid, even the effect of the mirror flipping-up introduce a slight vibration.

So what can you do on those occasions when you don’t you don’t have a cable release or remote trigger for your camera?  And how can you prevent the vibration introduced by the mirror flipping up?

The Solution

The solution to both is “mirror lockup”.

Let’s look firstly at the scenario where you have a remote trigger but you are concerned about vibration caused by the mirror flipping up.  Enable mirror lock-up. This is usually done within your cameras menu system.  For more recent Canon cameras you will find it on the first of the camera menu screens (see the image below) for other cameras you may need to check your manual or search through the menus.

mirror lockup

When enabled the first time you press the shutter release on your remote control the mirror will flip up.  Wait a few seconds then press the shutter release again and the image will be created.

But what if you don’t have a cable release or remote trigger? If this is the case you need to enable self-timer.  Most cameras will give you two versions of self timer.  10secs is the standard but your camera should also offer you a 2sec timer.  This latter option is designed to work with mirror lock up.  Press the shutter release on the camera.  The mirror will flip up.  The after two seconds the image will be created.  The two second pause ensures any vibration from the mirror flipping up has died down and that there is time for you to get your hands away from the camera so that you aren’t going to nudge the tripod.

It is worth noting that on some cameras if you enable mirror lockup, and then select self-timer a timer duration of 2secs may be automatically selected.  I once had once camera where enabling mirror lockup was the only way to get a 2sec self-timer.

Things to think about

If you need to start your exposure at a precise time (eg as a train passes a certain point) it is very tricky to work using the 2sec self-timer, and the only sensible approach is to use a remote trigger, press the shutter release once and wait for the precise moment you need to take the image and then press the shutter release on the remote trigger a second time.

Using mirror lockup as described above I have successfully taken sharp long exposure images on some very wobbly tripods.  This is worth knowing if you are travelling abroad and need to keep the weight of your camera gear down to an absolute minimum.  There is no substitute for a good solid tripod if you have access to one, but mirror lockup is a useful tool when one is not available.

The image I started this blog post with is just one such occasion.  I was travelling with a light-weight travel tripod and the tripod head of broke while I was on the trip.  While I was still able to attach the camera to the tripod it was far from stable.  Mirror lockup enabled me to get a sharp image event with a 30sec exposure.