Mirror lock up

Messages
2,669
Name
Dominic
Edit My Images
Yes
#1
I was just wondering how many of you use this feature.
I understand it's used mainly or exclusively for long exposure/slow shutter speeds, but how necessary is it?
If you have a good steady tripod, remote shutter release, will the mirror moving out of the way really create enough vibration to have an effect?
I could be wrong, but when in live view the mirror is up (obviously), but does it come back down and up again when you take the shot?
 
Messages
3,334
Name
Gary
Edit My Images
No
#2
I was just wondering how many of you use this feature.
I understand it's used mainly or exclusively for long exposure/slow shutter speeds, but how necessary is it?
If you have a good steady tripod, remote shutter release, will the mirror moving out of the way really create enough vibration to have an effect?
I could be wrong, but when in live view the mirror is up (obviously), but does it come back down and up again when you take the shot?
When you go into live view the mirror flips up and the shutter opens so that light falls on the sensor, which is what you see on the back of the camera.

When you press the shutter button to take the image the shutter closes, the sensor resets and then the shutter reopens for the designated length of time.
 
Messages
1,356
Name
Chris
Edit My Images
Yes
#3
I was just wondering how many of you use this feature.
I understand it's used mainly or exclusively for long exposure/slow shutter speeds, but how necessary is it?
If you have a good steady tripod, remote shutter release, will the mirror moving out of the way really create enough vibration to have an effect?
I could be wrong, but when in live view the mirror is up (obviously), but does it come back down and up again when you take the shot?
It was decades ago in my film SLR days when I got a contract to photograph some high murals in a dim church. With a long lens on a tripod, careful manual focus, and remote shutter release to avoid button press camuera shake, it took me a while to discover why my long exposure shots weren't sharp. Mirror vibration. My next extremely annoying discovery was that my camera didn't have mirror lock-up! Instead it had reassuring words from the manfacturer that due to some kind of special technology it didn't need mirror lock. A few experiments proved to me that that definitely wasn't true. I immediately added mirror lock up (or absence of a flapping mirror) to be on the list of essential features I would never in future buy a camera without.

Years later, having got away from the flapping mirror camera shake problem, I discovered something very like mirror vibration, except smaller in its blurring effect, and happening at a higher range of shutter speeds. That turned out to be camera vibration caused by the retraction of the shutter curtain. Avoiding that in my next camera upgrade got added to my list of essential features.

Once I'd got away from both those problems I discovered that my 500mm lens was both sharper than I'd thought it was, and with good support capable of really sharp images of stationary things at much slower shutter speeds that I'd thought possible.
 
Messages
4,493
Name
Dave
Edit My Images
Yes
#4
I was just wondering how many of you use this feature.
I understand it's used mainly or exclusively for long exposure/slow shutter speeds, but how necessary is it?
If you have a good steady tripod, remote shutter release, will the mirror moving out of the way really create enough vibration to have an effect?
I could be wrong, but when in live view the mirror is up (obviously), but does it come back down and up again when you take the shot?
There's bound to be a small range of shutter speeds where it makes a difference to avoid mirror slap, shutter movement and pressing the release button, but by just a few seconds of long exposure I doubt it makes a difference at all if the tripod is any good

I've seen people shoot 30secs plus with mirror up and remote releases to avoid camera shake, who then let their camera strap flap about in the wind which must be more of an issue as it adds vibration throughout the full shutter open period

One thing that made me think it was a waste of time, most of the time, was when I was shooting one evening on a pedestrian bridge at around 30 secs - my problem was that I could feel that the bridge bounced a wee bit as people walked by and they kept appearing just after I'd set the exposure going , which was frustrating me. Eventually I had a few periods where I got my shot and no-one came onto the bridge. Back at the mac and viewed at 100% I couldn't tell which images were supposedly blurred by the people walking by and which weren't, they were all the same as far as I could tell. So yes, I think its an overplayed issue

Dave
 
Messages
717
Name
Phil
Edit My Images
No
#5
There's bound to be a small range of shutter speeds where it makes a difference to avoid mirror slap
There is, as exposure times increase the evidence of mirror slap diminishes to the point it becomes invisible and other factors as you mention start to have a greater impact, of course the damping on the mirror systems are improving all the time too.

When working with film and using a Hasselblad body on the rear of a Sinar for macro photography under tungsten light (This was in the old days) then MLU was needed as was near optical bench stability for everything.

MLU is largely a thing of the past when using Live View is so much more convenient, particularly on Canon.
 
Messages
1,971
Edit My Images
Yes
#6
I understand it's used mainly or exclusively for long exposure/slow shutter speeds, but how necessary is it?
The opposite. With long exposures, the duration of the vibration from the mirror is a minute portion of the exposure. With shorter exposures, the vibration from the mirror moving can last for longer than the exposure. For landscapes, it is totally pointless - the landscape itself will move more (clouds, leaves in the wind, birds, etc). For critical studio work it is an advantage but live view will work better.
 
Messages
249
Name
David
Edit My Images
No
#7
Thanks for reminding me about mirror lock up - only time I ever use it is for fireworks pics - perfectly timed reminder :)

And I found last year that it did make a difference
 
Last edited:
Messages
22,771
Name
Richard
Edit My Images
No
#8
Mirror-slap and shutter-shock are very real problems, particularly on a tripod when you're not holding the camera - hands are very effective at damping this kind of vibration.

With DSLRs, mirror-slap is usually most prominent around 1/8-1/15sec. The effects are reduced at faster speeds, and at longer speeds the camera has time to settle for most of the exposure time, but different models vary. It's easy enough to do some simple tests to compare.

Shutter-shock really only applies to some older mirrorless cameras with poorly damped shutters that first have to close and then reopen again for the exposure. Some of the earlier Sony A7-series cameras were particularly poor, Olympus too as I recall. This form of vibration tends to be more high-frequency, affecting shutter speeds around 1/100sec. The only cure is to bolt a heavy weight directly underneath the camera, like 1kg of lead. That works :D (google)*

Using live-view can be a fix for mirror-slap but only with those cameras (eg most Canons) with an electronic first curtain feature, so mirror lock-up isn't necessary.

*Edit: link to one of many reports of shutter-shock issues with the Sony A7R
https://www.sonyalpharumors.com/the-shutter-vibration-issue-explained-by-joseph-holmes/

*Edit 2: this Tony Northrup review just out on the Nikon Z6 shows clear evidence of shutter-shock when the mechanical first-curtain is used, compared with switching to electronic first-curtain. It's illustrated right near the start
View: https://www.youtube.com/watch?v=pAnxOEnIduo
 
Last edited:
Messages
22,771
Name
Richard
Edit My Images
No
#10
If id planned to use 1kg of sand would it work as well as the lead ? ;)
Possibly not. The weight really needs to be solidly attached to the base of the camera - zero movement, no rubber pads or joints - so the vibration goes directly into it.

The only really practical and total solution to shutter-shock is electronic first curtain so there's no vibration to start with. Alternatively, hand-holding with image-stabilisation can actually be more effective than a tripod in some situations.
 
Messages
1,214
Name
Peter
Edit My Images
Yes
#11
I can’t see that he mentions using EFCS. He talks about electronic shutter which is different.
The Sony A7iii (I believe) has EFCS set by default. On the Nikon you have to enable it.
The tests I have seen indicate it is better for everyday use than mechanical, up to 1/2000, when the camera switches to mechanical.
Plenty of chat about this in the DPR Nikon Z section,
 
Messages
1,356
Name
Chris
Edit My Images
Yes
#12
Mirror-slap and shutter-shock are very real problems, particularly on a tripod when you're not holding the camera - hands are very effective at damping this kind of vibration.

With DSLRs, mirror-slap is usually most prominent around 1/8-1/15sec. The effects are reduced at faster speeds, and at longer speeds the camera has time to settle for most of the exposure time, but different models vary. It's easy enough to do some simple tests to compare.

Shutter-shock really only applies to some older mirrorless cameras with poorly damped shutters that first have to close and then reopen again for the exposure. Some of the earlier Sony A7-series cameras were particularly poor, Olympus too as I recall. This form of vibration tends to be more high-frequency, affecting shutter speeds around 1/100sec. The only cure is to bolt a heavy weight directly underneath the camera, like 1kg of lead. That works :D (google)*
Maybe sometimes it works. When I discovered I was suffering from shutter shock (with a 500mm lens on a Sony A550) at shutter speeds under around 1/250th sec I tried tightly securing the camera to a handy horizontal scaffolding pole. That didn't work. So I then added another strong elastic strap securing the lens to the pole as well as the camera body. Made not the slightest improvement.
 
Top