Mirror Lockup Necessary on Tripod?

Bob Salomon wrote:
In article ,
Stacey wrote:

Bob Salomon wrote:

I have regularly hand held the 6006 and
6008 at 1/15th and have prints up to 30x40" at this speed.

But how many "good" ones would you get in a row? Hand holding always comes
down to "rolling the dice", sometimes it's the only way to get the shot but
it's always risky.

No problem handholding the 6008 while doing auto bracketing at 1/15 to
1/30.

Sure. It is no real problem to enlarge _any_ neg to 30x40". The question
is how sharp it will be. Are you sure that you could see the difference
between a Apo-Rodagon (old) and a Apo-Rodagon-N (latest version) with
this 1/15s-handhold negs?

Martin (SL66, MLU, 12kg Linhof tripod for anything slower than 1/250s...)

In article ,
Bob Salomon wrote:

No problem handholding the 6008 while doing auto bracketing at 1/15 to
1/30.

You must trip the shutter between heart beats.

Seriously, I do digitial video and have some pretty steady young men who
shoot for me as well. When handholding the camera w/o a steady, and as
still as we can, using a long lens we can see camera movement, and under
the best circumstances the subtle bounce is from the photographers
_heartbeat_. Hard to get around that, but then we are all thin or
muscular. Dunno how a proserously built person would do.

Mxsmanic wrote:

Mirror movement is most critical when the shutter speed is comparable to
the duration of the movement. That is, if it takes 1/15 of a second for
the mirror to move, a shutter speed of 1/15 of a second is particularly
likely to show the blurring effects of mirror movement. Shorter
exposures are so short that the mirror can't move very far and the
blurring is minimal; longer exposures are so long that the brief period
during which the mirror moves the camera doesn't have much effect on the
total exposure. A speed of 1/15 second on many cameras is one of the
most vulnerable, but it varies from one camera to another.

If anything, the frequency and amplitude of the vibrations caused when the
mirror hits the solid camera frame are what matter. Not (just) the mirror
bounce. These vibrations depend on how the camera is put together, on the
ratio of moving to inert masses, and how the camera's inert mass is
distributed.
It is correct that vibrations will have most effect at certain
shutterspeeds.

[...]
I've heard some say that even a tripod doesn't help!

A tripod does not help with mirror movement; you need to lock the mirror
up before making the exposure. A tripod only minimizes external sources
of camera motion, such as your trembling hands.

A tripod can indeed worsen the effect of the vibrations caused by the
mirror. The vibrations originating inside the camera are transfered to the
tripod, which, when all moving parts are fastened tightly, will resonate.

However, this resonation can be avoided, and a significant amount of
dampening added, by leaving a little bit of play in the tripod head's
fastenings, not tigthening them as fast as possible. Allowing the tripod
head to move (and it will move only very, very little) will effectively
absorb vibrations caused by the camera itself.

Q.G. de Bakker wrote:



However, this resonation can be avoided, and a significant amount of
dampening added, by leaving a little bit of play in the tripod head's
fastenings, not tigthening them as fast as possible. Allowing the tripod
head to move (and it will move only very, very little) will effectively
absorb vibrations caused by the camera itself.

Wouldn't the cork used on some tripod mount plates help in this regard? I've
seen "upgraded" plates that are all metal, might be a bad idea to do this?

--

Stacey

Stacey wrote:

Wouldn't the cork used on some tripod mount plates help in this regard?
I've
seen "upgraded" plates that are all metal, might be a bad idea to do this?

Perhaps a bit, yes. The camera is secured to the head by a very solid metal
screw though.
The cork is meant to provide friction, stopping the camera from sliding on
the head, rotating around the screw with which it is fastened to the tripod
head.
When the camera starts vibrating (due to mirror slap), the screw will act as
a pivoting point. A flexible material, like cork, pressing against the
camera will help dampen these vibrations.

In article , "Q.G. de
Bakker" wrote:

Stacey wrote:

Wouldn't the cork used on some tripod mount plates help in this regard?
I've
seen "upgraded" plates that are all metal, might be a bad idea to do this?

Perhaps a bit, yes. The camera is secured to the head by a very solid metal
screw though.
The cork is meant to provide friction, stopping the camera from sliding on
the head, rotating around the screw with which it is fastened to the tripod
head.
When the camera starts vibrating (due to mirror slap), the screw will act as
a pivoting point. A flexible material, like cork, pressing against the
camera will help dampen these vibrations.

This thread has been an interesting example of impressionistic keyboard
engineering carried way, way too far.