Mirror slap?

Zen Diver wrote in
:

You still need the mirror lock-up to clean the sensor

That can be dangerous, as some cameras cancel mirror-lockup after a number
of seconds.

--


John P Sheehy

In article , Neil
Harrington writes

With modern SLRs I don't think mirror slap is a factor to be concerned about
at any shutter speed.

Get real - if anything, mirror slap is a lot worse on modern AF cameras
with their double mirror arrangements than it ever was with a
conventional MF film camera.

I moved from Olympus OM to Canon 5D about 18 months ago and initially
thought that the extra mass of the 5D and Canon glass over the light OM
bodies and lenses would reduce the effect of mirror slap. In fact, it
is worse - a lot worse.

Astro photos I took with an OM-4Ti (which had a double mirror to enable
spot metering) were impossible to reproduce on the 5D even after locking
the mirror up because even the shutter slap on the Canon is worse than
the mirror slap on an OM, despite the Canon being more than double the
mass.
--
Kennedy
Yes, Socrates himself is particularly missed;
A lovely little thinker, but a bugger when he's ****ed.
Python Philosophers (replace 'nospam' with 'kennedym' when replying)

On Apr 1, 10:08 pm, M-M wrote:
In article ,
Bob Williams wrote:

When mounted on a telescope for astro photography, Mirror Slap will wipe
you out.

Absolutely true. But the shutter delay of .4 sec on the Nikon seems to
work well.

--
m-m

My recollection from literature about vibration reduction is that
about 1/15 sec tends to generate the most vibration and blur. For
astro photgraphy local ground level winds also have an effect.

Astrophotography is more and more being done through compositing
multiple images taken more or less like those from a video camera.
Some companies are selling the equivalent of a video camera lens that
mounts directly to the scope, and requires an attached computer to set
the scope focus, etc.

But for moon shots and star trails, traditional style (including
digital) cameras work just fine. Do watch for noise increases with
longer exposures as electronic noise will increase as the sensor warms
up from continuous use. Subtracting a black frame may make a
diffference by elimating the "hot" pixels..

Joe

On Apr 1, 6:11 pm, Kennedy McEwen wrote:
In article , Neil
Harrington writes

With modern SLRs I don't think mirror slap is a factor to be concerned about
at any shutter speed.

Get real - if anything, mirror slap is a lot worse on modern AF cameras
with their double mirror arrangements than it ever was with a
conventional MF film camera.

I moved from Olympus OM to Canon 5D about 18 months ago and initially
thought that the extra mass of the 5D and Canon glass over the light OM
bodies and lenses would reduce the effect of mirror slap. In fact, it
is worse - a lot worse.

Astro photos I took with an OM-4Ti (which had a double mirror to enable
spot metering) were impossible to reproduce on the 5D even after locking
the mirror up because even the shutter slap on the Canon is worse than
the mirror slap on an OM, despite the Canon being more than double the
mass.
--

My experience with the OM cameras was they always seemed to have very
little vibration. Perhaps it was they way the balanced the system -
who knows? But I once did a test between my OM2s and my fathers Pentax
Spotmatic F, by balancing a nickel on it's end at the end of a
telephoto lens and then releasing the shutter with an extension. With
the Pentax, the nickel fell of, but not so with the OM2s. We were all
pretty impressed! But for the little bit of astrophotography I did
with my later OM4, I used the self timer which locked up the mirror at
the start of the timer, then ran the shutter after the countdown.
Seemed to work well. However, I had a bugger of a time trying to focus
the damn system!

My experience is that mirror slap is more of a factor for shutter
speeds of 1/15 down to 1" or so. Longer than that, the movement takes
place over a very small percentage of the actual exposure. Then with
shutter speeds of 1/30 or faster, the shutter isn't open long enough
to be affected by the mirror slap.

Karl Winkler
http://www.karlwinkler.com

On Apr 2, 12:52 pm, M-M wrote:
In article .com,
"Karl Winkler" wrote:

My experience is that mirror slap is more of a factor for shutter
speeds of 1/15 down to 1" or so. Longer than that, the movement takes
place over a very small percentage of the actual exposure. Then with
shutter speeds of 1/30 or faster, the shutter isn't open long enough
to be affected by the mirror slap.

sigh
When you're shooting through a telescope at 150X a microscopic movement
is magnified the same amount. You cannot make any rules about shutter
speed without considering this.

No argument. I was referring to using the camera with a normal type of
lens. All bets are off when using the camera with a telescope. But I
don't think it's only that the vibration is magnified 150x so much as
that it is such a large system that the vibration hangs around a lot
longer. Severe vibration that only lasts for 1/100th the length of the
exposure would hardly be noticed.

-Karl

"Bob Williams" wrote in message
...


Neil Harrington wrote:
"William4" wrote in message
...

Assuming film - dig slrs are the same in this respect (but query relates
to dslr);

When does mirror slap, or whatever it is called today, show itself.
Faster or slower shutter speeds or does it really 'all depend',
I.a. is it a pretty quick event that I might see at very high speeds and
has little impact (relatively) at low speeds,
or a slow one that might be a problem with longer exposures.


With modern SLRs I don't think mirror slap is a factor to be concerned
about
at any shutter speed.

Neil


Au Contraire!
When mounted on a telescope for astro photography, Mirror Slap will wipe
you out.
Bob Williams

That may be true for the 0.0018% of SLR owners who use their cameras for
astrophotography. The OP's post does not suggest he does that.

Neil

"Kennedy McEwen" wrote in message
...
In article , Neil Harrington
writes

With modern SLRs I don't think mirror slap is a factor to be concerned
about
at any shutter speed.

Get real - if anything, mirror slap is a lot worse on modern AF cameras
with their double mirror arrangements than it ever was with a conventional
MF film camera.

I haven't used MF in decades, and never in an SLR so I can't comment on
that. Mirror slap doesn't cause any problems for me in digital and hasn't
caused me problems in 35mm either, at any shutter speed. All modern cameras
I've used have had well-damped mirrors. Some SLRs that I owned 30+ years ago
did have visible mirror bounce on the return, but that of course would not
affect the exposure anyway.



I moved from Olympus OM to Canon 5D about 18 months ago and initially
thought that the extra mass of the 5D and Canon glass over the light OM
bodies and lenses would reduce the effect of mirror slap. In fact, it is
worse - a lot worse.

Astro photos I took with an OM-4Ti (which had a double mirror to enable
spot metering) were impossible to reproduce on the 5D even after locking
the mirror up because even the shutter slap on the Canon is worse than the
mirror slap on an OM, despite the Canon being more than double the mass.

Obviously then it isn't a mirror slap problem in that case, and mirror slap
is the subject under discussion.

Your post plus that of the other poster who mentioned astrophotography also
makes me wonder if this isn't a problem peculiar to that kind of
photography. When you have the camera mounted on a high-magnification system
like a telescope, the camera itself not being solidly mounted as it would be
on a tripod, but rather at one end of a larger system perhaps prone to
vibration, you may have a situation far more likely to cause that kind of
problem.

Neil

Neil Harrington wrote:
"Kennedy McEwen" wrote in message


Get real - if anything, mirror slap is a lot worse on modern AF cameras
with their double mirror arrangements than it ever was with a conventional
MF film camera.

I haven't used MF in decades, and never in an SLR so I can't comment on
that. Mirror slap doesn't cause any problems for me in digital and hasn't
caused me problems in 35mm either, at any shutter speed. All modern cameras
I've used have had well-damped mirrors. Some SLRs that I owned 30+ years ago
did have visible mirror bounce on the return, but that of course would not
affect the exposure anyway.

With lighter weight mirrors and better dampening around for a while now,
I've yet to see any documented proof of mirror slap being a problem for
those other than astrophysicists' use.

--
John McWilliams

All good stuff (as usual).

I'll go with 1/15 & longer could be an issue - just after a guide/thoughts
really.

Yes, tripod stability is probably the main problem. Not much into astro,
but my last lunar eclipse photos were rather soft - I put that down to the
lens but they were still good (for me), just a shame not very sharp (but it
is a long way away!)

[D80 no lockup? how do these folk on the web get away with cleaning their
filters every 5 minutes (so it seems)]

In article , John
McWilliams wrote:

Neil Harrington wrote:
"Kennedy McEwen" wrote in message


Get real - if anything, mirror slap is a lot worse on modern AF cameras
with their double mirror arrangements than it ever was with a conventional
MF film camera.

I haven't used MF in decades, and never in an SLR so I can't comment on
that. Mirror slap doesn't cause any problems for me in digital and hasn't
caused me problems in 35mm either, at any shutter speed. All modern cameras
I've used have had well-damped mirrors. Some SLRs that I owned 30+ years
ago
did have visible mirror bounce on the return, but that of course would not
affect the exposure anyway.

With lighter weight mirrors and better dampening around for a while now,
I've yet to see any documented proof of mirror slap being a problem for
those other than astrophysicists' use.

Sounds to me as if you have't bothered to look, and/or haven't bothered
to try it, or just don't want to believe it. As I noted in another
post, I just had it seriously affect some photos just the other night
using a 500mm lens - enough to see the difference on the camera
display, let alone at full resolution.

It DOES makes a difference. Whether YOU believe it or not.

--
You need only reflect that one of the best ways to get yourself a
reputation as a dangerous citizen these days is to go about repeating
the very phrases which our founding fathers used in the struggle for
independence.
-- Charles A. Beard