Image Stabilisation - why?

On 7 Jan 2007 06:47:29 -0800, "Bill Hilton"
wrote:

David Dyer-Bennet wrote:

Too bad no camera I've owned in 38 years of semi-serious photography
(i.e. I'm not counting my Pixie 127 or even my mother's old Bolsey 35, I
don't start the clock until I got my first SLR) has had MLU.

Do you have a dSLR? Even the cheapest entry level Canon digital Rebel
has MLU

No it does't. Mirror *lock up* means just that - the mirror
is locked in the up position until the lock is released.
Most modern cameras allow a delay to be inderted between
lifting the mirror and opening the shutter which sometimes
can be used as a substitute for MLU, but it isn't the same
thing.


--
John Bean

David Dyer-Bennet wrote:
dwight wrote:

I have cameras and lenses without IS, cameras and lenses with it. As a
rank amateur, I wish that EVERY piece of equipment had IS. And the
first time I experienced it, it was a marvel to me.

Doesn't the Canon IS (and Nikon VR) system put additional air-glass
interfaces in the light path? So it probably has some impact on how
prone a lens is to flare, and all those other issues. I've seen people
recommending the Nikon 80-200 f/2.8 in preference to the newer (forget
the *exact* focal lengths) VR equivalent for that reason (for
applications where the VR wasn't a big win, at least).

Image stabilization is another tool in your camera bag, one which
helps you get more out of less. Why would you NOT want it?


Because it has costs -- money, battery life, possibly lens lifespan?,
possibly some image-quality issues. If it were completely *free*, then
it's a no-brainer.

(Note that the sensor-shifting based IS used by some other companies
avoids the extra air-glass interface problems.)

1) it is not clear that one needs to add glass to a lens, or just
use one of the lens groups already there.

2) when a lens contains 8-15 lenses already, big deal if one more
is added, especially if it's part of a new design.

3) in-camera sensor moving IS cannot cope with the large range of
lenses you can put on a DSLR. They will have decreasing effectiveness
as the focal length increases.

I have had SLR cameras for about 40 years, starting with manual,
and started with IS lenses soon after they came out (mid 1990s).
I have IS lenses ranging from 28mm to 500 mm (f/4 L IS). When
I got a 28-135 IS just before a trip to Ireland, and wondered
if it was worth paying extra for IS. I was shooting Velvia
(ISO 50) hand held at 1/8 second in dimly lit churches and they came
out very sharp. There are so many conditions where IS enables
you to get a sharp image that you would normally not be able
to get. My first trip to Alaska was without IS, and I lost
a spectacular photo of a mother eagle feeding its chick in a nest.
I got images, but none real sharp--I was on a boat.
So many conditions where IS helps, e.g. moving platforms like
cars, boats, airplanes, horseback, as well as quick grab shots
when you don't have time to set up a tripod.

IS really shines when you do telephoto work. Super telephotos
on a tripod following action: the micro vibrations can ruin
the sharpness in an image unless at very fast shutter speeds.
IS enable sharp images in so many situations in my experience.
With wildlife action, you only get one chance to get the peak action
and without IS your probability of a great image is diminished
in many situations.

I won't buy another lens unless it is IS or is a specialty lens not
available in IS.

Roger
Photos at: http://www.clarkvision.com

"John Bean" wrote:
"Bill Hilton" wrote:

David Dyer-Bennet wrote:

Too bad no camera I've owned in 38 years of semi-serious photography
(i.e. I'm not counting my Pixie 127 or even my mother's old Bolsey 35, I
don't start the clock until I got my first SLR) has had MLU.

Do you have a dSLR? Even the cheapest entry level Canon digital Rebel
has MLU

No it does't.

Interesting. You're right. The 300D seems to be missing mirror lockup. (Or
at least hides it so well I'd have to RTFM.)

Mirror *lock up* means just that - the mirror
is locked in the up position until the lock is released.
Most modern cameras allow a delay to be inderted between
lifting the mirror and opening the shutter which sometimes
can be used as a substitute for MLU, but it isn't the same
thing.

Dunno about "most" but the 5D gives you both mirror lockup (press shutter
release and mirror goes up and stays there; press again and shutter fires
and mirror drops (not much use unless you have a remote release of some
sort, thoughg)) and delayed release (press release, mirror goes up, camera
beeps for 2 seconds, shutter fires).

The funny thing is, I find the "two-phase MLU" (enabled from a menu) on the
5D _worlds_ easier to use than the MLU levers on any of the film SLRs I've
owned (500C, OM-1n, Mamiya 645Pro), yet the lack of a dedicated MLU control
is an incredibly common complaint (and the complainers are incredibly
vociferous) about the 5D. IMHO, they're trying to shoot themselves in the
foot.

David J. Littleboy
Tokyo, Japan

Bill Hilton

Even the cheapest entry level Canon digital Rebel
has MLU

John Bean wrote:

No it does't.

Yes it does. You set it with CF-7 ... I just got thru using it last
week.

Mirror *lock up* means just that - the mirror
is locked in the up position until the lock is released.

This is how it worked with the older mechanical cameras, like my
original Minolta SRT-102 ... with the electronic cameras it works
differently. The 'lock' is released electronically after each shot
instead of manually. (Actually some of the electronic cameras will
keep the mirror locked up during a bracketing sequence too).

Most modern cameras allow a delay to be inderted between
lifting the mirror and opening the shutter which sometimes
can be used as a substitute for MLU, but it isn't the same
thing.

With the Rebel you can set MLU, press the shutter once and the mirror
locks up, then wait before pressing the shutter a 2nd time, which fires
the shot and releases the mirror. You don't have to use the shutter
delay (which is only 2 sec with this model, so not practical).

This is the same function as the older mechanical cameras, the only
difference being that the mirror releases when you press the shutter a
2nd time and the camera manuals also call it "mirror lockup", so why
this meaningless quibble about the definition? The only difference is
that with the mechanical cameras you had to release the mirror by hand
when done. Big deal.

Bill

"Roger N. Clark (change username to rnclark)" wrote:

3) in-camera sensor moving IS cannot cope with the large range of
lenses you can put on a DSLR.

When you attach an older lens (which does not communicate focal length
info) on the Pentax K10D, the camera's IS asks you to select a number
between 8 and 800mm. I imagine this helps the IS adapt to suit.

I've verified that setting the IS to 500 was a tremendous advantage with my
500mm mirror lens... a hand-held shot while the viewfinder image wobbled
all over the place still came out sharp.

--
Anti-Spam address: my last name at his dot com
Charles Gillen -- Reston, Virginia, USA

On 7 Jan 2007 07:34:28 -0800, "Bill Hilton"
wrote:


Bill Hilton

Even the cheapest entry level Canon digital Rebel
has MLU

John Bean wrote:

No it does't.

Yes it does. You set it with CF-7 ... I just got thru using it last
week.

Mirror *lock up* means just that - the mirror
is locked in the up position until the lock is released.

This is how it worked with the older mechanical cameras, like my
original Minolta SRT-102 ... with the electronic cameras it works
differently. The 'lock' is released electronically after each shot
instead of manually. (Actually some of the electronic cameras will
keep the mirror locked up during a bracketing sequence too).

Then it's not a lock. Think about a situation when you have
a lens that would foul the mirror - you use MLU and an
external viewfinder to make the pictures. You may never want
or need MLU, but that's one situation where delayed shutter
release is not a substitute for MLU.


This is the same function as the older mechanical cameras, the only
difference being that the mirror releases when you press the shutter a
2nd time and the camera manuals also call it "mirror lockup", so why
this meaningless quibble about the definition? The only difference is
that with the mechanical cameras you had to release the mirror by hand
when done. Big deal.

Yes, it can be a big deal when the mirror and lens try to
occupy the same space at the same time. Not all manuals call
it "mirror lockup" either - my Olympus E-1 refers to it as
"anti-shock" to indicate it's primary use.

--
John Bean

Bill Hilton wrote:
With the Rebel you can set MLU, press the shutter once and the mirror
locks up, then wait before pressing the shutter a 2nd time, which fires
the shot and releases the mirror. You don't have to use the shutter
delay (which is only 2 sec with this model, so not practical).


Why is it not practical? My camera has a .4s delay (in addition to
MLU), and it is very practical indeed for lots of situations (more than
the MLU in some). Eg using a beanbag and an exposure of a few seconds
with a 90mm lens; using the shutter release button twice with MLU
negates the purpose.Or resting the camera against some makeshift
support (a pillar in a church). And so on.

I think the point is that there is more to this than using very long
lenses on tripods (which is probably what you mean).

This is the same function as the older mechanical cameras, the only
difference being that the mirror releases when you press the shutter a
2nd time and the camera manuals also call it "mirror lockup", so why
this meaningless quibble about the definition? The only difference is
that with the mechanical cameras you had to release the mirror by hand
when done. Big deal.


It's not meaningless, there are lenses that protrude into the mirror
box and therefore cannot be used unless you can really lock the mirror
up between mounting and unmounting the lens.

John Bean wrote:

Yes, it can be a big deal when the mirror and lens try to
occupy the same space at the same time. Not all manuals call
it "mirror lockup" either - my Olympus E-1 refers to it as
"anti-shock" to indicate it's primary use.


Indeed, on my D200 this function is called "M-Up", which I suppose is
shorthand for mirror up. There is a "mirror lock-up", which is a true
lock-up accessed through the menu and intended for cleaning the sensor
(so can't be used for taking photos).

In article , John Bean
wrote:

On 7 Jan 2007 06:47:29 -0800, "Bill Hilton"
wrote:

David Dyer-Bennet wrote:

Too bad no camera I've owned in 38 years of semi-serious photography
(i.e. I'm not counting my Pixie 127 or even my mother's old Bolsey 35, I
don't start the clock until I got my first SLR) has had MLU.

Do you have a dSLR? Even the cheapest entry level Canon digital Rebel
has MLU

No it does't. Mirror *lock up* means just that - the mirror
is locked in the up position until the lock is released.
Most modern cameras allow a delay to be inderted between
lifting the mirror and opening the shutter which sometimes
can be used as a substitute for MLU, but it isn't the same
thing.

YES, it does. In mirror lockup mode, my Canon 400D (as well as the
formaer 350D) raises the mirror with one shutter release (button,
timer, or cable) and it STAYS that way until I release the shutter a
second time. I believe that that fits the definition of Mirror Lockup,
don't you?

Don't speak with authority of that which you do not know.

--
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

acl wrote:

Bill Hilton wrote:

This is the same function as the older mechanical cameras, the only
difference being that the mirror releases when you press the shutter a
2nd time and the camera manuals also call it "mirror lockup", so why
this meaningless quibble about the definition? The only difference is
that with the mechanical cameras you had to release the mirror by hand
when done. Big deal.

It's not meaningless, there are lenses that protrude into the mirror
box and therefore cannot be used unless you can really lock the mirror
up between mounting and unmounting the lens.

How is this practical? You couldn't focus or even compose
an image accurately. I never needed it in 40+ years
of photography, not even on a telescope, where I would
open the shutter and open the back of the film camera
and focus using a Foucault test in the film plane.
Then put the film in. You can't do that on a digital
camera, so I see no point in having that function
anymore. I don't need a buggy whip for my car either,
and my car need not be backwards compatible with
buggy whips.

(If permanent MLU it were needed, it would be a simple
firmware upgrade.)

Roger