Photogtaphy Forums

Photography Forums > Camera Manufacturers > Nikon > Nikon Autofocus speed/accuracty dependent on body?

Reply
Thread Tools Display Modes

Nikon Autofocus speed/accuracty dependent on body?

 
 
Steven Green
Guest
Posts: n/a

 
      02-01-2009, 01:05 PM
I have the D40. Down the road I want an incarnation of the D700.
I keep taking pictures that are a little out of focus. Most of this is
my fault and I am trying to improve in this regard, but I was wondering
what the bodies role really is here. Will the D700 focus better than the
D40? (ignoring other autofocus options like the number of focus points
etc.

Additionally, will the same AF-S lens focus faster on the D700 than on
the D40?

Thanks,

Steven
 
Reply With Quote
 
 
 
 
frank
Guest
Posts: n/a

 
      02-01-2009, 05:57 PM
On Feb 1, 7:05*am, Steven Green <steven{dot}gree...@verizon.net>
wrote:
> I have the D40. Down the road I want an incarnation of the D700.
> I keep taking pictures that are a little out of focus. Most of this is
> my fault and I am trying to improve in this regard, but I was wondering
> what the bodies role really is here. Will the D700 focus better than the
> * D40? (ignoring other autofocus options like the number of focus points
> etc.
>
> Additionally, will the same AF-S lens focus faster on the D700 than on
> the D40?
>
> Thanks,
>
> Steven


Pictures of WHAT? Read the manual for where auto focus is a problem.

There are times when you have to use manual focus instead of auto
focus.

Remember, the camera is a tool. You need to use your brain to get it
to work properly.
 
Reply With Quote
 
 
 
 
SteveG
Guest
Posts: n/a

 
      02-01-2009, 07:56 PM
Steven Green wrote:
> I have the D40. Down the road I want an incarnation of the D700.
> I keep taking pictures that are a little out of focus. Most of this is
> my fault and I am trying to improve in this regard, but I was wondering
> what the bodies role really is here. Will the D700 focus better than the
> D40? (ignoring other autofocus options like the number of focus points
> etc.
>
> Additionally, will the same AF-S lens focus faster on the D700 than on
> the D40?
>
> Thanks,
>
> Steven


Judging by this and your other post about AF-S lenses you haven't taken
the time or trouble to learn anything about your D40 camera but expect
others to pass on this knowledge as a quick way of learning. This is a
poor substitute for doing your own research ... like reading the
flippin' manual :-)


Having said that, is the picture completely out of focus - as in not in
focus anywhere? In anything other than manual mode the D40 won't release
the shutter unless the camera thinks it has a good focus - not
necessarily where you were trying to focus, but somewhere in the frame.
The most common problem is when "nearest object" focusing is used and
you have an object to the side and closer to you than your main subject.
The camera focuses on the nearest object and your subject is out of
focus. You can force the camera to use the centre (or either of the
side) focus points ... it's in the manual :-)

As to AF speed: the electronics in the body sends signals to the lens
motor to adjust the focus until the AF sensor has an acceptable reading,
at which point it tells the motor to stop. Irrespective of whether the
D700 or D40 sends instructions to the lens faster the speed of autofocus
is determined by the lens drive and in the case of AF-S lenses that is
part of the lens not the body. Provided both bodies can send commands
quicker than the drive motor can carry them out then AF speed is limited
solely by the lens drive and would be the same for both bodies.

HTH :-)

--
Regards

Steve G
 
Reply With Quote
 
Paul Furman
Guest
Posts: n/a

 
      02-01-2009, 10:29 PM
Steven Green wrote:
> I have the D40. Down the road I want an incarnation of the D700.
> I keep taking pictures that are a little out of focus. Most of this is
> my fault and I am trying to improve in this regard, but I was wondering
> what the bodies role really is here. Will the D700 focus better than the
> D40? (ignoring other autofocus options like the number of focus points
> etc.
>
> Additionally, will the same AF-S lens focus faster on the D700 than on
> the D40?


For tracking a moving object, the fancier body will do better. Not much
difference for static scenes. Perhaps a small improvement in low light.

More likely your soft shots are the result of hand shake and too slow a
shutter speed. The D700 can help with that by having better high ISO
performance, you can crank up the ISO to regain the needed shutter
speed. At some point the noise will interfere with image detail more
than a little shake, and that point goes way up with the D700.

--
Paul Furman
www.edgehill.net
www.baynatives.com

all google groups messages filtered due to spam
 
Reply With Quote
 
N
Guest
Posts: n/a

 
      02-02-2009, 10:50 AM
"Steven Green" <steven{dot}(E-Mail Removed)> wrote in message
news:s6hhl.433$(E-Mail Removed)...
>I have the D40. Down the road I want an incarnation of the D700.
> I keep taking pictures that are a little out of focus. Most of this is my
> fault and I am trying to improve in this regard, but I was wondering what
> the bodies role really is here. Will the D700 focus better than the D40?
> (ignoring other autofocus options like the number of focus points etc.
>
> Additionally, will the same AF-S lens focus faster on the D700 than on the
> D40?
>
> Thanks,
>
> Steven



What result do you get when the camera is on a tripod?

 
Reply With Quote
 
Jeremy Nixon
Guest
Posts: n/a

 
      02-02-2009, 05:35 PM
Steven Green <steven{dot}(E-Mail Removed)> wrote:

> I have the D40. Down the road I want an incarnation of the D700.
> I keep taking pictures that are a little out of focus. Most of this is
> my fault and I am trying to improve in this regard, but I was wondering
> what the bodies role really is here. Will the D700 focus better than the
> D40? (ignoring other autofocus options like the number of focus points
> etc.
>
> Additionally, will the same AF-S lens focus faster on the D700 than on
> the D40?


The higher-end bodies have better autofocus systems -- but assuming you're
on a static (non-moving) subject and can place the AF point on it, the
difference won't be anything significant for you at this point. In other
words, buying a D700 will not fix your focusing problem.

It just takes some practice to learn to use it. Since it's digital, there
is no reason you can't just sit on your sofa watching TV, focusing on
random things in the living room, taking the shot, and zooming in on the
camera's display to see how close you got it. Then just delete the picture
and do it again.

Also, as a more concrete suggestion, make sure the autofocus system is set
to "S" rather than "C" mode -- in "S" mode the camera will focus and then
stop when it achieves focus. In "C" mode it will keep on focusing all the
time. Then, ensure that the camera is set to "focus priority" (it will be
in the menus somewhere), the mode that will make the camera wait until it
has focus before actually taking the shot. I've seen people have problems
with these things on unexpected settings.

--
Jeremy Nixon | address in header is valid
(formerly (E-Mail Removed))
 
Reply With Quote
 
Steven Green
Guest
Posts: n/a

 
      02-02-2009, 10:38 PM
>
> Also, as a more concrete suggestion, make sure the autofocus system is set
> to "S" rather than "C" mode -- in "S" mode the camera will focus and then
> stop when it achieves focus. In "C" mode it will keep on focusing all the
> time. Then, ensure that the camera is set to "focus priority" (it will be
> in the menus somewhere), the mode that will make the camera wait until it
> has focus before actually taking the shot. I've seen people have problems
> with these things on unexpected settings.
>

Actually, I have not played with this setting as yet. I assume it is
still in "A" mode since I have not changed it.

I am actually taking pictures of birds on my feeder (well squirrels have
discovered it so this has not worked the past couple of days). I have
been focusing on the feeder, but may try mode "C" and focus on the birds
instead.

Here is where much of my focusing problems seem to lie, I know it is
less than ideal but I am still trying to do all I can to make less than
blurry pictures. So lets see if we can count all the ways I am messing
up my focus.

I am using a tripod and the 70-300 VR zoom, VR off. I am setting iso to
200 and taking pictures in indirect light at around f8-11 in the early
afternoon when the birds come. Now here is where it starts getting ugly.
It is winter here and the 70-300 is not particularly long for cardinals
and smaller birds so I need to be relatively close to them. The feeders
are setup on the porch, close to a window. If the window is open and the
birds see/hear me they scatter. Additionally, I don't want to let all
the heat out so I have the window closed and take the picture through
the window at the moment. I am still trying to see how good of pictures
I can take through the window, but my next attempts are likely to be
outside.

I have ordered the remote, but have not gotten it yet. My next attempts
will be setting up the tripod outside pointed at the feeder and use the
remote to snap the picture with me indoors and the camera outside. I am
curious to see if the clicking of the camera causes them to scatter too.
If so, the remote was less than $20 so I am not out much. If anyone has
any recommendations with regard to putting the camera outside in the
cold (bringing it down to temp for condensation reasons etc.) I would
love to hear it.

As a side note, I considered doing shots with the mirror locked up as an
additional step in getting the focus right, but the D40 does not support
shooting with the mirror locked up as near as I can tell, only sensor
cleaning.
 
Reply With Quote
 
Paul Furman
Guest
Posts: n/a

 
      02-02-2009, 11:12 PM
Steven Green wrote:
>>
>> Also, as a more concrete suggestion, make sure the autofocus system is
>> set
>> to "S" rather than "C" mode -- in "S" mode the camera will focus and then
>> stop when it achieves focus. In "C" mode it will keep on focusing all
>> the
>> time. Then, ensure that the camera is set to "focus priority" (it
>> will be
>> in the menus somewhere), the mode that will make the camera wait until it
>> has focus before actually taking the shot. I've seen people have
>> problems
>> with these things on unexpected settings.
>>

> Actually, I have not played with this setting as yet. I assume it is
> still in "A" mode since I have not changed it.
>
> I am actually taking pictures of birds on my feeder (well squirrels have
> discovered it so this has not worked the past couple of days). I have
> been focusing on the feeder, but may try mode "C" and focus on the birds
> instead.
>
> Here is where much of my focusing problems seem to lie, I know it is
> less than ideal but I am still trying to do all I can to make less than
> blurry pictures. So lets see if we can count all the ways I am messing
> up my focus.
>
> I am using a tripod and the 70-300 VR zoom, VR off. I am setting iso to
> 200 and taking pictures in indirect light at around f8-11 in the early
> afternoon when the birds come. Now here is where it starts getting ugly.
> It is winter here and the 70-300 is not particularly long for cardinals
> and smaller birds so I need to be relatively close to them. The feeders
> are setup on the porch, close to a window. If the window is open and the
> birds see/hear me they scatter. Additionally, I don't want to let all
> the heat out so I have the window closed and take the picture through
> the window at the moment. I am still trying to see how good of pictures
> I can take through the window, but my next attempts are likely to be
> outside.
>
> I have ordered the remote, but have not gotten it yet. My next attempts
> will be setting up the tripod outside pointed at the feeder and use the
> remote to snap the picture with me indoors and the camera outside. I am
> curious to see if the clicking of the camera causes them to scatter too.
> If so, the remote was less than $20 so I am not out much. If anyone has
> any recommendations with regard to putting the camera outside in the
> cold (bringing it down to temp for condensation reasons etc.) I would
> love to hear it.
>
> As a side note, I considered doing shots with the mirror locked up as an
> additional step in getting the focus right, but the D40 does not support
> shooting with the mirror locked up as near as I can tell, only sensor
> cleaning.


Try opening the window & use the timer for a remote release... just the
empty bird feeder for a test. That's your benchmark for sharpness.
Bracket different apertures & see if they vary.

--
Paul Furman
www.edgehill.net
www.baynatives.com

all google groups messages filtered due to spam
 
Reply With Quote
 
Steven Green
Guest
Posts: n/a

 
      02-02-2009, 11:13 PM
>
> Judging by this and your other post about AF-S lenses you haven't taken
> the time or trouble to learn anything about your D40 camera but expect
> others to pass on this knowledge as a quick way of learning. This is a
> poor substitute for doing your own research ... like reading the
> flippin' manual :-)
>

Yes, I admit that on some of these issues I was still researching when I
made these posts. For the tele-converter issue from another thread I had
searched but for the wrong things. Had I looked for tele-converter
reviews I would have found what I was looking for right away, but that
search had not occurred to me.

As for the histogram post I had read the manual for this, but it was not
very enlightening and the books I have that include the histogram to go
very deep into them. I have learned more from that thread than either
the books or manual offered.

For this one, I thought I already knew the answer and was just
confirming my suspicions.

Then there was my ulterior motive. I usually read a bunch of RSS feeds,
my email and this group. Nothing of interest was happening in any of
them and I got bored, so I posted the current questions I was digging
into to this group ... it is much more interesting now
 
Reply With Quote
 
Jeremy Nixon
Guest
Posts: n/a

 
      02-03-2009, 12:03 AM
Steven Green <steven{dot}(E-Mail Removed)> wrote:

> Actually, I have not played with this setting as yet. I assume it is
> still in "A" mode since I have not changed it.


Okay, this got me thinking. The focus-mode options are S, C, and M,
for single, continuous, and manual. I don't have a D40 specifically,
so I went and looked at the pictures of it on Nikon's site and it
doesn't have a dedicated control for this, though -- and, as it turns
out, from looking at the manual, there *is* an A setting on the D40.

(The A/M selection on the lens is a different thing from what I'm
talking about.)

The D40's A setting is a bit troubling, too, since it actually chooses
between "single" and "continuous" depending on what it thinks is best
for the current situation. And this is the default setting. Also by
default, the camera uses closest-subject autofocus, whereby the camera
chooses one of the several focus points. So as a result it's hard to
even determine what the camera is going to be doing in your situation.

I think this might be a factor here. The camera may be focusing on
something other than what you intend, if there is something in the
frame that is closer (part of the bird feeder, for example). And it
may be switching to "continuous" focus mode on its own, too.

So, here's what I'd like you try. First, switch the camera to the
"AF-S" mode. This is on page 23 of the manual (at least in the online
PDF version). In this mode, the camera focuses when you half-press
the shutter button, and then once it achieves focus, it stops.

On the next page of the manual is "AF-Area Mode". Switch this to
"Single area" mode. In this mode you select the focus point using
the directional selector on the back of the camera; the selected
one will be highlighted in the viewfinder. Just leave it on the
center point and don't move it. If you move it by accident, you'll
notice the wrong focus point lighting up when you try to focus,
in which case you can just move it back to the center.

Now, when you go to take a shot, place the center focus point on
the point where you want the focus, and half-press the shutter
button. The camera will focus. When it stops, you can take the
shot. Try this and see if it now focuses where you want.

The default settings are not really ideal for things like birds
with a long telephoto lens, where focus really is critical. It's
more of a "snapshot mode" where you just want the camera to get
focus and don't really care about being absolutely precise about
what you're focusing on, but with a 300mm lens and birds, that's
probably just not good enough.

> Additionally, I don't want to let all the heat out so I have the
> window closed and take the picture through the window at the moment.
> I am still trying to see how good of pictures I can take through the
> window, but my next attempts are likely to be outside.


Shooting through the window will definitely make a difference, but is
not the source of the problem you're having with focus. Think of that
as the next step.

> If anyone has any recommendations with regard to putting the camera
> outside in the cold (bringing it down to temp for condensation reasons
> etc.) I would love to hear it.


The camera can handle the cold just fine; it is the changes in temperature
that cause the problem. Just putting the camera outside and leaving it
there won't be a problem; you may get condensation when you bring it
back inside.

> As a side note, I considered doing shots with the mirror locked up as an
> additional step in getting the focus right, but the D40 does not support
> shooting with the mirror locked up as near as I can tell, only sensor
> cleaning.


This won't help anyhow.

--
Jeremy Nixon | address in header is valid
(formerly (E-Mail Removed))
 
Reply With Quote
 
 
 
Reply

Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are On
Pingbacks are On
Refbacks are Off


Similar Threads
Thread Thread Starter Forum Replies Last Post
Nikon autofocus lenses Nikon User Nikon 17 10-17-2005 03:28 AM
Polarizer on Nikon Autofocus Lens Mike - EMAIL IGNORED Nikon 4 10-10-2005 10:29 AM
Nikon zoom lens won't do macro autofocus Guv Nikon 0 08-04-2003 04:51 PM