From: J. Caldwell on
On Tue, 25 May 2010 14:56:43 +0100, Bruce <docnews2011(a)gmail.com> wrote:

>On Tue, 25 May 2010 13:48:53 +0100, "David J Taylor"
><david-taylor(a)blueyonder.co.uk.invalid> wrote:
>>
>>It seems to me that Nikon
>>and Canon want to make the best image quality and stabilisation system
>>available, by using in-lens IS. Of course, better quality will cost more,
>>but in the case of IS/VR lenses, not a lot more. And likely those newer
>>lenses will produce better images than the older ones....
>
>
>When IS lenses were first introduced, soon to be followed by VR, there
>was great scepticism, particularly among those who tested lenses, that
>they would be optically sound.
>
>The reasoning was that one of the most important factors in getting
>the best out of a lens design is that the optical centres of all the
>elements must coincide along the optical axis of the lens. This is a
>non-trivial issue because manual centering can be time consuming and
>therefore expensive.
>
>So the logic was that an optical anti-shake system (IS or VR) must
>result in inferior lens performance because it introduced a deliberate
>decentering of the optical axis.
>
>In practice, however, this was not seen to the case, and IS and VR
>lenses produce sensibly similar optical quality to their non-IS and
>non-VR predecessors.

Wrong. I suggest you start to examine any images taken with optical image
stabilization. Asymmetric CA is randomly imparted in many of the images
taken through such an optical system. In just the last year I pointed out 5
of the photographs posted to this very newsgroup where the asymmetric CA
was highly apparent even in the downsized images. To the great
embarrassment of that lens owner who was touting its superiority at the
time.

Take your blinders off.

From: John Navas on
On Tue, 25 May 2010 09:19:56 +0100, "David J Taylor"
<david-taylor(a)blueyonder.co.uk.invalid> wrote in
<htg17e$clu$1(a)news.eternal-september.org>:

>"John Navas" <jnspam1(a)navasgroup.com> wrote in message
>news:g3plv5hniphm3c8e9gor7ts05reavitr3f(a)4ax.com...
>[]
>> IS has to be cheap in a cheap lens.
>
>.. low-cost, and /still/ works better than in-body stabilisation.

Not necessarily.

>> The inescapable issue is cost. It's more cost effective to put IS in
>> the body than in all thee lenses for a given level of sophistication.
>
>Lower cost for lower performance, though. Your money, your choice.

Your assertion, your choice.

>On advantage of in-body (which can /also/ be applied when the lens has
>stabilisation) is the correction of body rotation about the axis of the
>lens.

Advantages of in-body stabilization include:
* Lower cost, especially with multiple lenses
* Serious processing power available
* Integration with shooting functions
* Image movement detection by image sensor
* No optical compromise
* No effect on Bokeh
* Simpler and more rugged lens design
* Stabilization of non-stabilized lenses
* Integration with dust removal system

--
Best regards,
John

"Assumption is the mother of all screw ups."
[Wethern´┐Żs Law of Suspended Judgement]
From: John Navas on
On Tue, 25 May 2010 09:22:54 +0100, "David J Taylor"
<david-taylor(a)blueyonder.co.uk.invalid> wrote in
<htg1cv$d6l$1(a)news.eternal-september.org>:

>"SMS" <scharf.steven(a)geemail.com> wrote in message
>news:4bfadf8d$0$1585$742ec2ed(a)news.sonic.net...
>[]
>> For people moving to a D-SLR from a P&S or ZLR, they are unlikely to
>> understand the advantages of in-lens VR/IS.
>
>They only need to look through the viewfinder with a long telephoto lens
>attached! Watch the image stabilise when the VR is enabled. Little
>understanding required - just a demonstration at the local shop.

His claim is absurd (what a shock), since so many compact digital
cameras have image stabilization.
--
Best regards,
John

Buying a dSLR doesn't make you a photographer,
it makes you a dSLR owner.
"The single most important component of a camera
is the twelve inches behind it." -Ansel Adams
From: John Navas on
On Tue, 25 May 2010 09:25:55 +0100, "David J Taylor"
<david-taylor(a)blueyonder.co.uk.invalid> wrote in
<htg1ik$dlj$1(a)news.eternal-september.org>:

>"Chris Malcolm" <cam(a)holyrood.ed.ac.uk> wrote in message
>news:860qn8FehdU1(a)mid.individual.net...
>[]
>> Don't forget that tecnology keeps improving. At any point in time what
>> you say is true. But is four year old in-lens IS better than today's
>> in-camera? I'll probably have a new camera in four years, which with
>> in-camera IS means the IS is upgraded. But I don't want to have to
>> renew all my lenses every four years.
>
>.. and if your new camera only has in-body IS you /still/ won't get the
>advantage of a stable image in the optical finder.

What real advantage is that? When IS is turned on for viewing, not only
do you get less feedback on how still you are holding the camera, but
also the IS is less effective when the image is captured. It's why
better cameras give you the option to turn off IS for viewing, which is
what I do.
--
Best regards,
John

Buying a dSLR doesn't make you a photographer,
it makes you a dSLR owner.
"The single most important component of a camera
is the twelve inches behind it." -Ansel Adams
From: John Navas on
On Tue, 25 May 2010 13:10:33 +0200, Alfred Molon
<alfred_molon(a)yahoo.com> wrote in
<MPG.2665ce947e742bf998c308(a)news.supernews.com>:

>In article <5kjkv51udne8hg9ggllarporrnnb6p2hm7(a)4ax.com>, Bruce says...
>> I wonder why Sony abandoned the in-camera anti-shake of the Alpha
>> system, instead using an in-lens anti-shake system for NEX?
>
>Obviously not enough space in that tiny body for an in-camera anti-shake
>system. Seems like Sony cut the corners too much here.

I agree. It's a great idea, but pushed just a bit too far.
--
Best regards,
John

Buying a dSLR doesn't make you a photographer,
it makes you a dSLR owner.
"The single most important component of a camera
is the twelve inches behind it." -Ansel Adams