How about a free-moving focus point controlled by the shutterbutton?

On Tue, 23 Aug 2016 12:06:43 -0400, nospam wrote
in lid:

In article , Ken Hart
wrote:

What's the advantage to having lots of focusing points ?

I was going to say: "Well, /one/ of them must be right!".

Seriously, though, it means that focus can be tracked as the subject
moves across the frame etc. etc.

If you have a single focus point you can move that's an alternative
approach to selecting the focal point, but in a DSLR/phase-detect you
can't simply indicate the area on which to focus (like you can with
contrast detect focus and a touch-screen or selector) unless there
are actually focus sensors at the point where you want to measure.

In the old days, you simply moved the camera to focus, and then
re-composed to take.

In the old days, you turned a ring on the lens until the image looked
in focus.

fortunately, those days are *long* gone.

The rather new Lomography 85/2.2 has a knob on the side for focus
adjustments...
--
teleportation kills

On Tue, 23 Aug 2016 02:00:31 -0700 (PDT), Whisky-dave
wrote:

On Monday, 22 August 2016 21:54:33 UTC+1, Eric Stevens wrote:
On Mon, 22 Aug 2016 23:41:00 +1200, Me wrote:

On 22/08/2016 18:54, RichA wrote:
The shutter button could have a joystick function that would allow a precise focus point to be moved at will. When not in use, the shutter button would lock in place for normal use. If it was sensitive enough, it could move the frame width with little side to side movement of the button, thereby not compromising shutter button push ergonomics. It would help preserve composition because you wouldn't have to accommodate movement of the frame to secure a desired focus point.

What's wrong with the idea of using a 4-way selector button with your thumb?
I guess to answer that question myself, it's possible that your thumb
might be occupied using another button like AF-ON for continuous focus,
but OTOH unless you'd disabled focus on half press of the shutter
button, you could use your shutter finger to focus instead.

My Nikon D300 and now the D750 have that exact ability.
http://imaging.nikon.com/lineup/dslr/basics/16/02.htm shows how using
a camera with a limited number of focus points.
http://nikonrumors.com/wp-content/up...-AF-screen.jpg
shows the number of focus points available to a D750.

What's the advantage to having lots of focusing points ?

1) Dealing with complex subjects.

2) Being able to select a target focusing point which is not the
centre of the image.
--

Regards,

Eric Stevens

On Wed, 24 Aug 2016 01:53:51 -0700 (PDT), Whisky-dave
wrote:

On Tuesday, 23 August 2016 22:58:43 UTC+1, Eric Stevens wrote:
On Tue, 23 Aug 2016 02:00:31 -0700 (PDT), Whisky-dave
wrote:

On Monday, 22 August 2016 21:54:33 UTC+1, Eric Stevens wrote:
On Mon, 22 Aug 2016 23:41:00 +1200, Me wrote:

On 22/08/2016 18:54, RichA wrote:
The shutter button could have a joystick function that would allow a precise focus point to be moved at will. When not in use, the shutter button would lock in place for normal use. If it was sensitive enough, it could move the frame width with little side to side movement of the button, thereby not compromising shutter button push ergonomics. It would help preserve composition because you wouldn't have to accommodate movement of the frame to secure a desired focus point.

What's wrong with the idea of using a 4-way selector button with your thumb?
I guess to answer that question myself, it's possible that your thumb
might be occupied using another button like AF-ON for continuous focus,
but OTOH unless you'd disabled focus on half press of the shutter
button, you could use your shutter finger to focus instead.

My Nikon D300 and now the D750 have that exact ability.
http://imaging.nikon.com/lineup/dslr/basics/16/02.htm shows how using
a camera with a limited number of focus points.
http://nikonrumors.com/wp-content/up...-AF-screen.jpg
shows the number of focus points available to a D750.

What's the advantage to having lots of focusing points ?

1) Dealing with complex subjects.

What's a complex subject

All moving in different directions at different speeds
http://sportsscientists.com/wp-conte...gby-tackle.jpg

2) Being able to select a target focusing point which is not the
centre of the image.

http://tinyurl.com/grfxl2q

I've been able to do that since I discovered a focusing ring on my camera.

We are talking autofocus.
--

Regards,

Eric Stevens

On 8/23/2016 12:06 PM, nospam wrote:
In article , Ken Hart
wrote:

snip



In the old days, you turned a ring on the lens until the image looked in
focus.

fortunately, those days are *long* gone.


Fortunately, they are still here. Many of us who do macro work use MF.
There is a reason why lenses have focus rings and switches to change
from manual to auto focus.

--
PeterN

In article , PeterN
wrote:



In the old days, you turned a ring on the lens until the image looked in
focus.

fortunately, those days are *long* gone.


Fortunately, they are still here. Many of us who do macro work use MF.
There is a reason why lenses have focus rings and switches to change
from manual to auto focus.

completely missing the point.

On Wed, 24 Aug 2016 14:22:32 -0400, nospam
wrote:

In article , PeterN
wrote:



In the old days, you turned a ring on the lens until the image looked in
focus.

fortunately, those days are *long* gone.


Fortunately, they are still here. Many of us who do macro work use MF.
There is a reason why lenses have focus rings and switches to change
from manual to auto focus.

completely missing the point.

Somebody is.
--

Regards,

Eric Stevens

In article , Eric Stevens
wrote:


In the old days, you turned a ring on the lens until the image looked in
focus.

fortunately, those days are *long* gone.


Fortunately, they are still here. Many of us who do macro work use MF.
There is a reason why lenses have focus rings and switches to change
from manual to auto focus.

completely missing the point.

Somebody is.

and it's now two.

On Wed, 24 Aug 2016 05:38:34 -0700 (PDT), Whisky-dave
wrote:

On Wednesday, 24 August 2016 10:18:26 UTC+1, Eric Stevens wrote:
On Wed, 24 Aug 2016 01:53:51 -0700 (PDT), Whisky-dave
wrote:

On Tuesday, 23 August 2016 22:58:43 UTC+1, Eric Stevens wrote:
On Tue, 23 Aug 2016 02:00:31 -0700 (PDT), Whisky-dave
wrote:

On Monday, 22 August 2016 21:54:33 UTC+1, Eric Stevens wrote:
On Mon, 22 Aug 2016 23:41:00 +1200, Me wrote:

On 22/08/2016 18:54, RichA wrote:
The shutter button could have a joystick function that would allow a precise focus point to be moved at will. When not in use, the shutter button would lock in place for normal use. If it was sensitive enough, it could move the frame width with little side to side movement of the button, thereby not compromising shutter button push ergonomics. It would help preserve composition because you wouldn't have to accommodate movement of the frame to secure a desired focus point.

What's wrong with the idea of using a 4-way selector button with your thumb?
I guess to answer that question myself, it's possible that your thumb
might be occupied using another button like AF-ON for continuous focus,
but OTOH unless you'd disabled focus on half press of the shutter
button, you could use your shutter finger to focus instead.

My Nikon D300 and now the D750 have that exact ability.
http://imaging.nikon.com/lineup/dslr/basics/16/02.htm shows how using
a camera with a limited number of focus points.
http://nikonrumors.com/wp-content/up...-AF-screen.jpg
shows the number of focus points available to a D750.

What's the advantage to having lots of focusing points ?

1) Dealing with complex subjects.

What's a complex subject

All moving in different directions at different speeds
http://sportsscientists.com/wp-conte...gby-tackle.jpg

I'd find that a pretty easy subject.
Please explain why the focusing is so complex as you can only focus on ONE point even if you camera has millions of focus points.

If I was in a position to take that photograph I would not set the
camera to focus on just one point. I would probably start by using
continuous autofocus with a dynamic area of 21 focus points. I have no
experience with the D750 on this type of photography so I cant rule
out the possibility that I might end up using only 9 points.
Alternatively I could end up using all 51.




2) Being able to select a target focusing point which is not the
centre of the image.

http://tinyurl.com/grfxl2q

That's been achived before though I used to do it before camera had batteries.

I've been able to do that since I discovered a focusing ring on my camera.

We are talking autofocus.

the problem with autofocuing it it focusing on the point you want in focus isn't it.

The point on which you want to focus may not be at the centre of the
image. I expect you will say that you can (auto)focus first and then
lock it to enable you to recompose Unfortunately that is only of
limited help.

When you focus on a point at the centre of the image the camera sets
itself up to focus on all points in a plane. The nearest point in the
plane to the camera is the centre at a distance (say) 'd'. You then
swing the camera through an angle 'A' to enable you to recompose. The
object on which you previously focussed is no longer in the 'focussed'
plane but some distance behind or in front of it, depending on which
way you swung the camera. In other words, it is no longer in focus.
You don't have this problem if right from the very beginning you can
identify the object somewhere in the scene on which you want to focus
and don't have to later move the camera to recompose.

--

Regards,

Eric Stevens
--

Regards,

Eric Stevens

On Thu, 25 Aug 2016 02:00:56 -0700 (PDT), Whisky-dave
wrote:

On Wednesday, 24 August 2016 23:09:52 UTC+1, Eric Stevens wrote:
On Wed, 24 Aug 2016 05:38:34 -0700 (PDT), Whisky-dave
wrote:

On Wednesday, 24 August 2016 10:18:26 UTC+1, Eric Stevens wrote:
On Wed, 24 Aug 2016 01:53:51 -0700 (PDT), Whisky-dave
wrote:

On Tuesday, 23 August 2016 22:58:43 UTC+1, Eric Stevens wrote:
On Tue, 23 Aug 2016 02:00:31 -0700 (PDT), Whisky-dave
wrote:

On Monday, 22 August 2016 21:54:33 UTC+1, Eric Stevens wrote:
On Mon, 22 Aug 2016 23:41:00 +1200, Me wrote:

On 22/08/2016 18:54, RichA wrote:
The shutter button could have a joystick function that would allow a precise focus point to be moved at will. When not in use, the shutter button would lock in place for normal use. If it was sensitive enough, it could move the frame width with little side to side movement of the button, thereby not compromising shutter button push ergonomics. It would help preserve composition because you wouldn't have to accommodate movement of the frame to secure a desired focus point.

What's wrong with the idea of using a 4-way selector button with your thumb?
I guess to answer that question myself, it's possible that your thumb
might be occupied using another button like AF-ON for continuous focus,
but OTOH unless you'd disabled focus on half press of the shutter
button, you could use your shutter finger to focus instead.

My Nikon D300 and now the D750 have that exact ability.
http://imaging.nikon.com/lineup/dslr/basics/16/02.htm shows how using
a camera with a limited number of focus points.
http://nikonrumors.com/wp-content/up...-AF-screen.jpg
shows the number of focus points available to a D750.

What's the advantage to having lots of focusing points ?

1) Dealing with complex subjects.

What's a complex subject

All moving in different directions at different speeds
http://sportsscientists.com/wp-conte...gby-tackle.jpg

I'd find that a pretty easy subject.
Please explain why the focusing is so complex as you can only focus on ONE point even if you camera has millions of focus points.

If I was in a position to take that photograph I would not set the
camera to focus on just one point. I would probably start by using
continuous autofocus with a dynamic area of 21 focus points. I have no
experience with the D750 on this type of photography so I cant rule
out the possibility that I might end up using only 9 points.
Alternatively I could end up using all 51.

I donl;t know how to set the number of focus point or why I'd choose 1, 9, 51 or 1000,000.

Learn as you go. Or maybe not if you are not going anywhere.

2) Being able to select a target focusing point which is not the
centre of the image.

http://tinyurl.com/grfxl2q

That's been achived before though I used to do it before camera had batteries.

I've been able to do that since I discovered a focusing ring on my camera.

We are talking autofocus.

the problem with autofocuing it it focusing on the point you want in focus isn't it.

The point on which you want to focus may not be at the centre of the
image. I expect you will say that you can (auto)focus first and then
lock it to enable you to recompose Unfortunately that is only of
limited help.

There's not much in life that isnlt limited, but the skills are overcoming them.
We all know the problems with lenses only being able to focus on one point at a time.

In this case the skills are built into the camera. It is debatable
whether it easier to acquier the skills so as to apply them to a
simple camera or to acquier the necessary knowledge to have the camera
apply the skills on your own behalf. There are times when I think the
only advantage of having the camera apply the skills is that the
camera may be faster.


When you focus on a point at the centre of the image the camera sets
itself up to focus on all points in a plane. The nearest point in the
plane to the camera is the centre at a distance (say) 'd'. You then
swing the camera through an angle 'A' to enable you to recompose. The
object on which you previously focussed is no longer in the 'focussed'
plane but some distance behind or in front of it, depending on which
way you swung the camera. In other words, it is no longer in focus.
You don't have this problem if right from the very beginning you can
identify the object somewhere in the scene on which you want to focus
and don't have to later move the camera to recompose.
--

Regards,

Eric Stevens

On 8/24/2016 5:44 PM, nospam wrote:
In article , Eric Stevens
wrote:


In the old days, you turned a ring on the lens until the image looked in
focus.

fortunately, those days are *long* gone.


Fortunately, they are still here. Many of us who do macro work use MF.
There is a reason why lenses have focus rings and switches to change
from manual to auto focus.

completely missing the point.

Somebody is.

and it's now two.


Perhaps the person who claims to have made a point should restate it
clearly, so that the simpletons who missed it will understand.



--
PeterN