I am floored!!! I actually do have backfocus!!! (Large test pic)

[snriley]

http://forums.dpreview.com/forums/read.asp?forum=1034&message=8385749

What about this???

...not to mention camera reviewers.

AX

 

[msport]

I thought we were discussing the test results for your camera. So far we are seeing a nonparallel target (nonperpendicular to the axis) and a subject to camera distance right at the minimum focussing distance of the lens. Some great suggestions have been offered to you.

AX

 

[snriley]

Then what about taking macro pics?

I am not always going to be 8 feet away from my subjects.

Not trying to be rude, I appreciate the help, but I am frustrated.

See this:



Look at the last black line of text, right above the blue line, I focused on the word "baby's". You will see it is softer than the words that curve to either side - those words are more focused!

-Steve

What is that supposed to mean???

Sorry, but I do not understand your question. I think I've said
what I said

So, what? sensor has some size, and it is positioned not exaxtly
where you see the mark in viewfinder.

Testing should be done at approx. 8 feet from the target, and
something contrasty (black cross on white paper) should be mounted
to the ruler, so that focusing plane would be perpendicular to the
lens axis. Lens zoomed to 50mm, good light 1/60 @ 5.6 for 200 ISO
--
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[Iliah Borg]

Then what about taking macro pics?

depends greatly on focusing technique, understanding of DOF for macro, stable support, smooth release, ...

I am not always going to be 8 feet away from my subjects.

that is how the tests are done.

Not trying to be rude, I appreciate the help, but I am frustrated.

You should not be no rude , nor frustrated. SLR cameras are not that easy, if you want to put them through paces.

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[GagBagger]

Well, I guess what comes around goes around. When I got home I
tested my D70 using http://www.photo.net/learn/focustest/ and it
turns out that I have backfocus!!!

That's not backfocus at all, but WELL within tolerance. Did you push the shutter release more than once, or just one time? Did you test wide open or at a reduced aperture?

My 10D had SEVERE backfocus issues. It would be focused on the 3-4 range while my D100 was spot-on.

What you're experiencing is normal. You'd likely see that VERY subtle deviance in a D1x or D2H as well.

My advice? Relax. You're golden.

Brendan
--
Things that make you go, hmmmm...

 

[Iliah Borg]

focusing aid is white cardboad with contrasty black cross. should be sufficiently large.

--
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[msport]

This is a nice setup for focus testing. Thanks!

AX

 

[Iliah Borg]

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[fuigo]

If you manually focus it, why would it still backfocus???

fuigo
--
web: http://homepage.mac.com/fuigo

 

[Team Critter]

Only 1 person on this forum reported that it was checked out fine...and now Nikon has decided to recheck it to ensure they were correct. We are still waiting on the results.

Gizmo

Here's an example showing the camera aimed at a subject that is
parallel. And with a ruler in the scene to act as the reference
and not ALSO as the subject. Apparently that matters per some.



AX

 

[umc76]

Very good question.

If you manually focus it, why would it still backfocus???

fuigo
--
web: http://homepage.mac.com/fuigo

--
My Nikon D70 Photos:
http://www.pbase.com/umc/newshots

 

[msport]

for the lens was used, so foreground cannot have focus, but background can. In an earlier post he mentioned that the camera to subject distance was increased slowly until the AF could lock. Even if you MF, the optics in the lens cannot break the laws of Physics.

AX

 

[Robert Jenson]

If you take a picture of any cylinder shaped object; I used a 3 liter pepsi bottle, the center is always soft and focus gets sharp nearer the lateral edges. This is another practical test of backfocus.

I am not always going to be 8 feet away from my subjects.

Not trying to be rude, I appreciate the help, but I am frustrated.

See this:



Look at the last black line of text, right above the blue line, I
focused on the word "baby's". You will see it is softer than the
words that curve to either side - those words are more focused!

-Steve

What is that supposed to mean???

Sorry, but I do not understand your question. I think I've said
what I said

So, what? sensor has some size, and it is positioned not exaxtly
where you see the mark in viewfinder.

Testing should be done at approx. 8 feet from the target, and
something contrasty (black cross on white paper) should be mounted
to the ruler, so that focusing plane would be perpendicular to the
lens axis. Lens zoomed to 50mm, good light 1/60 @ 5.6 for 200 ISO
--
no text

 

[msport]

AF results on an angled subject, the distances vary as seen by the AF sensor. Since there is curvature. Center is closest, near center on either side is further away, yet all are seen by the same distance sensor which has a width and height.

AX

 

[David SL]

Well, I guess what comes around goes around. When I got home I
tested my D70 using http://www.photo.net/learn/focustest/ and it
turns out that I have backfocus!!!

That's not backfocus at all, but WELL within tolerance. Did you
push the shutter release more than once, or just one time? Did you
test wide open or at a reduced aperture?

My 10D had SEVERE backfocus issues. It would be focused on the 3-4
range while my D100 was spot-on.

What you're experiencing is normal. You'd likely see that VERY
subtle deviance in a D1x or D2H as well.

My advice? Relax. You're golden.

Brendan
--
Things that make you go, hmmmm...

--

 

[demyers]

In a few simple tests shooting at curved food jar labels, I also see what appears to be backfocus (kit lens at 70mm, object about 20mm farther than closest focus distance, tripod, timer). But I get identical results with manual focus.

Now, maybe that's because I wear glasses and I don't have the diopter adjusted correctly.

But isn't also possible that there's nothing wrong with the D70 autofocus system, but that the position of the CCD is slightly out of spec?

If you manually focus it, why would it still backfocus???

 

[Iliah Borg]

In a few simple tests shooting at curved food jar labels, I also
see what appears to be backfocus (kit lens at 70mm, object about
20mm farther than closest focus distance, tripod, timer). But I
get identical results with manual focus.

How exactly do you focus manually - by the focus confirmation light, or by max. sharpness in the viewfinder?

But isn't also possible that there's nothing wrong with the D70
autofocus system, but that the position of the CCD is slightly out
of spec?

if true manual focus, not by green light, but by max. sharpness in viewfinder, fails - camera needs alignment, most probably it is the mirror. But that is very doubtful. Any AF system has it's limitations, and it is important to know how to use it.

--
no text

 

[fuigo]

So the person was actually focusing too close???

fuigo

for the lens was used, so foreground cannot have focus, but
background can. In an earlier post he mentioned that the camera
to subject distance was increased slowly until the AF could lock.
Even if you MF, the optics in the lens cannot break the laws of
Physics.

AX

--
web: http://homepage.mac.com/fuigo

 

[ScubaGuyJohn]

See my real world backfocus test at my site...

I was one of those who have been laughing and joking about the so
called backfocus issues.

Well, I guess what comes around goes around. When I got home I
tested my D70 using http://www.photo.net/learn/focustest/ and it
turns out that I have backfocus!!!

Here is my test:



I don't know what to do - I bought my camera from B&H back in the
middle/end of March - so it has been more than two weeks. And they
don't have any anyways. What should I do???

Help,
Steve

P.S. Sorry to those that I ever doubted, really sorry...

--
ScubaGuyJohn

'Too many pictures, not enough time'

http://www.pbase.com/scubaguyjohn/new_d70

 

[demyers]

I was focusing by viewfinder sharpness.

I just repeated the manual focus test and got excellent center sharpness. The green light was not on where I saw the sharpest focus.

In a few simple tests shooting at curved food jar labels, I also
see what appears to be backfocus (kit lens at 70mm, object about
20mm farther than closest focus distance, tripod, timer). But I
get identical results with manual focus.

How exactly do you focus manually - by the focus confirmation
light, or by max. sharpness in the viewfinder?

But isn't also possible that there's nothing wrong with the D70
autofocus system, but that the position of the CCD is slightly out
of spec?

if true manual focus, not by green light, but by max. sharpness in
viewfinder, fails - camera needs alignment, most probably it is the
mirror. But that is very doubtful. Any AF system has it's
limitations, and it is important to know how to use it.

--
no text