Locked Mirror?
- Thread starter melvin
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The conventional use is to eliminate the strong vibrations caused by the mirror movement milliseconds before the shutter opens.
On some Canon DSLRs, a secondary use may be to prevent the mirrors from falling out ...
This is to prevent any movement when we trip the shutter, else the mirror slap may cause some movement for the more flimsy tripod setups. Normally used in conjunction with either a timed release or a remote release.
minimize movement of the camera to improve sharpness due to decreasing factors such as handshake
in a perfect photographer's world, everything would be done with this
however, it is not practical, since the lockup is minimum 2 seconds for most brands, and needs a tripod, very ley chey.
the mirror lockup is usually done prior to a long exposure (anything more than a second, i suppose, or where you can no longer handhold it).
It's actually more useful for intermediate exposure times (i.e. anything that cannot be hand-held to about second or so). For very short exposures, vibrations are not an issue. For very long exposure (seconds), the vibrations will decay so quickly (tens, maybe hundreds of milliseconds) that the time during which the camera shakes is a negligible fraction of the total exposure time.
Normally used in a high magnification setup like macro or super teles where the slightest vibration will cause a longer pronounced oscillation of the entire setup. Otherwise not of much use.
hi melvin, look at this link http://photo.net/learn/nature/mlu
from the graph you should see when mirror flip up, it introduce high vibration to camera itself that if your shutter is slow, that may degrade your picture sharpness..
from the graph you should see when mirror flip up, it introduce high vibration to camera itself that if your shutter is slow, that may degrade your picture sharpness..
I did once on a telescope setup which I didn't balance properly. Even with MUp, the vibration from the shutter actually shook the setup as well.. ;p
Mirror lockup is most useful on a tripod when your exposure time is between roughly 1/20s and 1-2 seconds (any longer and it is less useful) and when you are doing macro or have a long telephoto.
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