D70 focusing issues

Hi all,

I have been using - or rather experimenting with - D70 for a month now and conversion from manual focus cameras seems more challenge than I expected.... wonder something how AF on D70 (and F/N80 I guess) works... I am having trouble occasionaly geting right (auto)focus, especially with wideagle end of 18-70 lens.. for example two or three people walking away from me seem to be to small for AF sensor to lock on them, ok, it should have been "swallowed" by depth of field.. AF locks on something, camera beeps, but the pics @ wideangle are just not sharp enough.. at least not enoguh what I'd expect from lens carrying "Nikon" and "ED" marks.

Also, when the subject is rather flat, I put AF sensor right on the edge of the subject (as I did with split-prism on MF cameras), how can I be sure that it will lock on subject, not background???

Another issue that gives me a headache are portraits... too many not-sharp-enough pics of people close-ups taken at or near 70mm end.. very inconsistent results.. AF-S all the time, focus locks (beep) but pics turn out bit blurry.. shutter speed is ok. On the contrary, I have tested AF-C on some cars moving towards me and it was pin-sharp, even with what is though to be slow focusing lens (80-200/2.8 non-AFS). And when I tested 18-70DX on non-live subject (car details for example) it focused OK, but for some reason would not focus on people's eyes... on some photos it appears to be infamous backfocus problem, while other are just not enough sharp.. the same happens when on mid-zoom or wideangle I (auto)focus on person that is close (50cm-1m) in foreground, nothing is in focus, neither the person, nor the background...

Your views and comments greately appreciated,

Regards,

Pozdrav,

Salinger Igor, Beograd, Srbija i Crna Gora

The AF on SLR cameras including the D70 senses contrast underneath the AF sensor. In other words it does not measure distance to your subject directly with lasers or otherwise. It tries to make a contrasty part of the subject appear the sharpest when focusing.

What that means is that you have to place something contrasty underneath your AF sensor for the camera to focus reliably. For portraits for example you should focus on an eye of your subject as it is much darker than the subject's skin, hence contrast is easily detected.

Also, whenever possible try to use the central AF sensor in the viefinder as it is the one crosshatched, as opposed to linear as the side sensors. It will be much more reliable in low light.

For starters you should also practice with non-moving objects with your camera set to single-servo focusing mode (AF-S) with predictive AF disabled (no plus signs representing AF points on your top LCD).

Regards,
przemek

salinger said:

Hi all,

I have been using - or rather experimenting with - D70 for a month
now and conversion from manual focus cameras seems more challenge
than I expected.... wonder something how AF on D70 (and F/N80 I
guess) works... I am having trouble occasionaly geting right
(auto)focus, especially with wideagle end of 18-70 lens.. for
example two or three people walking away from me seem to be to
small for AF sensor to lock on them, ok, it should have been
"swallowed" by depth of field.. AF locks on something, camera
beeps, but the pics @ wideangle are just not sharp enough.. at
least not enoguh what I'd expect from lens carrying "Nikon" and
"ED" marks.

Also, when the subject is rather flat, I put AF sensor right on the
edge of the subject (as I did with split-prism on MF cameras), how
can I be sure that it will lock on subject, not background???

Another issue that gives me a headache are portraits... too many
not-sharp-enough pics of people close-ups taken at or near 70mm
end.. very inconsistent results.. AF-S all the time, focus locks
(beep) but pics turn out bit blurry.. shutter speed is ok. On the
contrary, I have tested AF-C on some cars moving towards me and it
was pin-sharp, even with what is though to be slow focusing lens
(80-200/2.8 non-AFS). And when I tested 18-70DX on non-live subject
(car details for example) it focused OK, but for some reason would
not focus on people's eyes... on some photos it appears to be
infamous backfocus problem, while other are just not enough sharp..
the same happens when on mid-zoom or wideangle I (auto)focus on
person that is close (50cm-1m) in foreground, nothing is in focus,
neither the person, nor the background...

Your views and comments greately appreciated,

Regards,

Pozdrav,

Salinger Igor, Beograd, Srbija i Crna Gora

Click to expand...

Here is a site with good info on back-focusing and a printable chart to use to check your system:

http://md.co.za/d70/chart.html

D70's these days are past the back-focus problem of early days but checking it for yourself can be good for the peace of mind.

As you said, make sure you're on AF-S but also make sure you're not on dynamic-area mode. Make sure the focus-lock is locked onto the center AF sensor unless you have a reason to be doing otherwise. As already mentioned, the center AF zone is a cross-hair, while the surrounding zones are single vertical or horizontal lines. The AF is looking for contrasting edges and tries to make the contrast between neighboring pixels of those edges the highest it can, therefore the sharpest. So find edges to focus on, as opposed to expanses of skin or sky.

When you use the focus/recompose technique, be aware that you can move the camera position and/or angle enough when recomposing that your focus requirement will not be the same after the movement. This will depend on your DOF.

Since it's a new camera, expect to have to remaster some stuff you haven't thought about for a while, like hand-hold technique, DOF behavior, etc. Also, be aware that any DSLR image needs some sharpening at some stage. This is because of the A-A filter. It can be done in-camera or, most would say more effectively, at later stages in post-processing. Sharpening is a very complex subject in its own right and you should read up on it.

Hi.. thanks for the imputs.

sorry if I am expecting too much, but does everything said mean that in 21st century I am stuck with camera that focuses good just on static subjects at central focus point?!? So how about focus tracking, dynamic AF etc.. is all that just markething? Or is much in the lens itself, as I tried AF-C with cars moving towards and even at close distance hit rate was pretty high with (non AF-S) 80-200..

Yes, I like to compose photos with of-centre subjects in focus and as you nicely noticed recompose techniques might well need focus adjustment due to different angle or even distance if it is critical (ie portrait close-up)... and that is where I have hoped that camera with 5 AF sensors is better that one with one. Unfortunately D70 viewfinder is pretty small and dim (at least compared to manual focus Canons I got used to) that I can't focus manualy with precision..

I did check backfocus using chart you mention.. at full aperture it is barely noticeable (about 2mm to back) but with smaller aperture (higher F number.. 8, 11...) the focus moves further back.. and only on 18-70 DX lens, other I have tested appear to be within 2 mm + - tolerance..)

Regards,

Pozdrav,

Salinger Igor, Beograd, Srbija i Crna Gora

reck said:

Here is a site with good info on back-focusing and a printable
chart to use to check your system:

http://md.co.za/d70/chart.html

D70's these days are past the back-focus problem of early days but
checking it for yourself can be good for the peace of mind.

As you said, make sure you're on AF-S but also make sure you're not
on dynamic-area mode. Make sure the focus-lock is locked onto the
center AF sensor unless you have a reason to be doing otherwise. As
already mentioned, the center AF zone is a cross-hair, while the
surrounding zones are single vertical or horizontal lines. The AF
is looking for contrasting edges and tries to make the contrast
between neighboring pixels of those edges the highest it can,
therefore the sharpest. So find edges to focus on, as opposed to
expanses of skin or sky.

When you use the focus/recompose technique, be aware that you can
move the camera position and/or angle enough when recomposing that
your focus requirement will not be the same after the movement.
This will depend on your DOF.

Since it's a new camera, expect to have to remaster some stuff you
haven't thought about for a while, like hand-hold technique, DOF
behavior, etc. Also, be aware that any DSLR image needs some
sharpening at some stage. This is because of the A-A filter. It can
be done in-camera or, most would say more effectively, at later
stages in post-processing. Sharpening is a very complex subject in
its own right and you should read up on it.

Click to expand...

I have the same thing you describe with my kitlens.

It has even been to Nikon repair for backfocus..but the problem is still there. And it is only with portraits. Very frustrating.

Some time ago I came across an article that explains why wide angle lenses havew difficulties with AF. (forgot the link..)

salinger said:

sorry if I am expecting too much, but does everything said mean
that in 21st century I am stuck with camera that focuses good just
on static subjects at central focus point?!? So how about focus
tracking, dynamic AF etc.. is all that just markething? Or is much
in the lens itself, as I tried AF-C with cars moving towards and
even at close distance hit rate was pretty high with (non AF-S)
80-200..

Yes, I like to compose photos with of-centre subjects in focus and
as you nicely noticed recompose techniques might well need focus
adjustment due to different angle or even distance if it is
critical (ie portrait close-up)... and that is where I have hoped
that camera with 5 AF sensors is better that one with one.
Unfortunately D70 viewfinder is pretty small and dim (at least
compared to manual focus Canons I got used to) that I can't focus
manualy with precision..

I did check backfocus using chart you mention.. at full aperture it
is barely noticeable (about 2mm to back) but with smaller aperture
(higher F number.. 8, 11...) the focus moves further back.. and
only on 18-70 DX lens, other I have tested appear to be within 2 mm
+ - tolerance..)

Regards,

Pozdrav,

Salinger Igor, Beograd, Srbija i Crna Gora

reck said:

Here is a site with good info on back-focusing and a printable
chart to use to check your system:

http://md.co.za/d70/chart.html

D70's these days are past the back-focus problem of early days but
checking it for yourself can be good for the peace of mind.

As you said, make sure you're on AF-S but also make sure you're not
on dynamic-area mode. Make sure the focus-lock is locked onto the
center AF sensor unless you have a reason to be doing otherwise. As
already mentioned, the center AF zone is a cross-hair, while the
surrounding zones are single vertical or horizontal lines. The AF
is looking for contrasting edges and tries to make the contrast
between neighboring pixels of those edges the highest it can,
therefore the sharpest. So find edges to focus on, as opposed to
expanses of skin or sky.

When you use the focus/recompose technique, be aware that you can
move the camera position and/or angle enough when recomposing that
your focus requirement will not be the same after the movement.
This will depend on your DOF.

Since it's a new camera, expect to have to remaster some stuff you
haven't thought about for a while, like hand-hold technique, DOF
behavior, etc. Also, be aware that any DSLR image needs some
sharpening at some stage. This is because of the A-A filter. It can
be done in-camera or, most would say more effectively, at later
stages in post-processing. Sharpening is a very complex subject in
its own right and you should read up on it.

Click to expand...

--

Click to expand...

--
gallery's @ http://www.illdesign.nl

salinger said:

Hi.. thanks for the imputs.

sorry if I am expecting too much, but does everything said mean
that in 21st century I am stuck with camera that focuses good just
on static subjects at central focus point?!? So how about focus
tracking, dynamic AF etc.. is all that just markething? Or is much
in the lens itself, as I tried AF-C with cars moving towards and
even at close distance hit rate was pretty high with (non AF-S)
80-200..

Click to expand...

No, these parametes we gave you are just there for you to reliably test the accuracy of your autofocus. You know that if you want to be sure that you focus well, you should focus on static objects - use a tripod too idally. The other "21st century" modes work just fine, but don't complain about AF "problems" in various situations if you haven't figured out the most basic focusing operation.

Przemek

salinger said:

Hi.. thanks for the imputs.

sorry if I am expecting too much, but does everything said mean
that in 21st century I am stuck with camera that focuses good just
on static subjects at central focus point?!? So how about focus
tracking, dynamic AF etc.. is all that just markething? Or is much
in the lens itself, as I tried AF-C with cars moving towards and
even at close distance hit rate was pretty high with (non AF-S)
80-200..

Yes, I like to compose photos with of-centre subjects in focus and
as you nicely noticed recompose techniques might well need focus
adjustment due to different angle or even distance if it is
critical (ie portrait close-up)... and that is where I have hoped
that camera with 5 AF sensors is better that one with one.
Unfortunately D70 viewfinder is pretty small and dim (at least
compared to manual focus Canons I got used to) that I can't focus
manualy with precision..

I did check backfocus using chart you mention.. at full aperture it
is barely noticeable (about 2mm to back) but with smaller aperture
(higher F number.. 8, 11...) the focus moves further back.. and
only on 18-70 DX lens, other I have tested appear to be within 2 mm
+ - tolerance..)

Click to expand...

Based on your results I conclude that you DO HAVE back focus, that simple.

The notion that back focus on D70 has been fixed does NOT match my experience I purchased 2 new D70 latest serial numbers a few weeks ago, both had back focus, I exchanged the first one and when the second one also had back focus I decided to adjust it myslef using instructions I found on the net, it took me 10 minutes.

http://www.leongoodman.com/d70focus.html

The d70 test chart is great but it has to be used carefully.

Use it outdoors in shade ONLY!!!!!!!!!!!!!!!!!

Indoors under artifical lights no matter how bright or flash it does NOT work properly, it iwll give you misleading results.

Use a tripod and align the chart carefully outdoors ONLY in shade.

With a lens wide open the depth of field should be centred on the focus line, a slight front focus with 2.8 or faster lenses is Ok but the DOF must cover the focus line.

As you close the lens down the focus line should be in focus and the DOF extends backwards further and further as you close the lens down, using a f2.8 lens at f8 the DOF should be 1/3 forward of the focus line and 2/3 back of the focus line, at f2.8 it shoudl IDEALLY be centred on the focus line, some lenses will have the DOF at f2.8 centered forward of the focus line but the focus line must be within the DOF.

Test at more than one aperture, NOT just fully open, test from wide open to f8 at least in 1/3 stop increments.

Any lens that suddenly at a particular aperture does not follow the trend of the DOF progresiivley moving back whilst still having the focus line in focus is a suspect, run to have it exchanged.

Salinger said:

Regards,

Pozdrav,

Salinger Igor, Beograd, Srbija i Crna Gora

reck said:

Here is a site with good info on back-focusing and a printable
chart to use to check your system:

http://md.co.za/d70/chart.html

D70's these days are past the back-focus problem of early days but
checking it for yourself can be good for the peace of mind.

As you said, make sure you're on AF-S but also make sure you're not
on dynamic-area mode. Make sure the focus-lock is locked onto the
center AF sensor unless you have a reason to be doing otherwise. As
already mentioned, the center AF zone is a cross-hair, while the
surrounding zones are single vertical or horizontal lines. The AF
is looking for contrasting edges and tries to make the contrast
between neighboring pixels of those edges the highest it can,
therefore the sharpest. So find edges to focus on, as opposed to
expanses of skin or sky.

When you use the focus/recompose technique, be aware that you can
move the camera position and/or angle enough when recomposing that
your focus requirement will not be the same after the movement.
This will depend on your DOF.

Since it's a new camera, expect to have to remaster some stuff you
haven't thought about for a while, like hand-hold technique, DOF
behavior, etc. Also, be aware that any DSLR image needs some
sharpening at some stage. This is because of the A-A filter. It can
be done in-camera or, most would say more effectively, at later
stages in post-processing. Sharpening is a very complex subject in
its own right and you should read up on it.

Click to expand...

--

Click to expand...

I talked to a photographer that had focus problems and he had the dynamic focus turned on. Look at the CCD in the top of the camera and you will see the picture of the viewfinder with the center focus zone marked. Only one should be there and if it has a plus sign in it, you are in dynamic focus. Item #3 in the menu should be "single area"

The problem had been bugging him for many months and that fixed it. I wrote that procedure for fixing the backfocus and have followed through with many who did not need to adjust the focus, only changed their focus habits. Also review the steps for "Focus and re-compose" A nervous finger will mess you up.

--
TANSTAAFL - There aint no such thing as a free lunch.
If it sounds too good to be true it just might be so.

D70, kit lens, Nikon 50mm f1.8, Nikon 28-200G, 12-24 Sigma, SB800, Bogen 3001,3030, Epson P2000
http://www.pbase.com/photoleon
http://www.leongoodman.com

Leon, all,

thanks for the replies.

So about dynamic focus feature.. is it that useles or even faulty... camera manual says that is is for erraticaly moving subjects... any use of it in real world? So I guess one is supposed to stick ti single area AF-S for still and AF-C for moving subjects?

And re fixing backfocus as you describe on the website, if I understood right after the fixture, not all focus points are of use? Is that right?

BTW, I talked to Nikon authorised service here and they say that they are aware of backfocus problem and that is "in the software", not hardware? Any comments?

Regards,

Pozdrav,

Salinger Igor, Beograd, Srbija i Crna Gora

PhotoLeon1935 said:

I talked to a photographer that had focus problems and he had the
dynamic focus turned on. Look at the CCD in the top of the camera
and you will see the picture of the viewfinder with the center
focus zone marked. Only one should be there and if it has a plus
sign in it, you are in dynamic focus. Item #3 in the menu should be
"single area"

The problem had been bugging him for many months and that fixed it.
I wrote that procedure for fixing the backfocus and have followed
through with many who did not need to adjust the focus, only
changed their focus habits. Also review the steps for "Focus and
re-compose" A nervous finger will mess you up.

--
TANSTAAFL - There aint no such thing as a free lunch.
If it sounds too good to be true it just might be so.
D70, kit lens, Nikon 50mm f1.8, Nikon 28-200G, 12-24 Sigma, SB800,
Bogen 3001,3030, Epson P2000
http://www.pbase.com/photoleon
http://www.leongoodman.com

Click to expand...

Yes, Single area, AF-S and no Dynamic focus for still subjects is a safe place to be.

If Nikon has made any comment about the causes of backfocus, I would be surprised. It is a BIG, BIG Secret! The one thing that doesn't make sense is that different lenses behave differently. That should not be. If the solution is software then it might be related to critical timing with the lenses that have internal motors that move very rapidly. If the timing is such that a lens can over-shoot the focus point, then that could be so. You would think that software/firmware upgrades would have been made to fix all the D70s.

If anyone from another country could confirm what you have heard, I would certainly like to know. I made the only obvious adjustment and it worked for me. Does anyone else have some input on this?

salinger said:

thanks for the replies.

So about dynamic focus feature.. is it that useles or even
faulty... camera manual says that is is for erraticaly moving
subjects... any use of it in real world? So I guess one is supposed
to stick ti single area AF-S for still and AF-C for moving subjects?

And re fixing backfocus as you describe on the website, if I
understood right after the fixture, not all focus points are of
use? Is that right?

BTW, I talked to Nikon authorised service here and they say that
they are aware of backfocus problem and that is "in the software",
not hardware? Any comments?

Regards,

Pozdrav,

Salinger Igor, Beograd, Srbija i Crna Gora

PhotoLeon1935 said:

I talked to a photographer that had focus problems and he had the
dynamic focus turned on. Look at the CCD in the top of the camera
and you will see the picture of the viewfinder with the center
focus zone marked. Only one should be there and if it has a plus
sign in it, you are in dynamic focus. Item #3 in the menu should be
"single area"

The problem had been bugging him for many months and that fixed it.
I wrote that procedure for fixing the backfocus and have followed
through with many who did not need to adjust the focus, only
changed their focus habits. Also review the steps for "Focus and
re-compose" A nervous finger will mess you up.

--
TANSTAAFL - There aint no such thing as a free lunch.
If it sounds too good to be true it just might be so.
D70, kit lens, Nikon 50mm f1.8, Nikon 28-200G, 12-24 Sigma, SB800,
Bogen 3001,3030, Epson P2000
http://www.pbase.com/photoleon
http://www.leongoodman.com

Click to expand...

--

Click to expand...

--
TANSTAAFL - There aint no such thing as a free lunch.
If it sounds too good to be true it just might be so.

D70, kit lens, Nikon 50mm f1.8, Nikon 28-200G, 12-24 Sigma, SB800, Bogen 3001,3030, Epson P2000
http://www.pbase.com/photoleon
http://www.leongoodman.com

salinger said:

I did check backfocus using chart you mention.. at full aperture it
is barely noticeable (about 2mm to back) but with smaller aperture
(higher F number.. 8, 11...) the focus moves further back.. and
only on 18-70 DX lens, other I have tested appear to be within 2 mm
+ - tolerance..)

Click to expand...

I saw this behavior with my early-production D70. If I hadn't seen it myself in careful testing, I wouldn't have believed it. You would just assume that stopping down to f8 or so would cause depth of field to erase the visibility of any minor focus discrepancy, but the focus would just keep shifting farther and farther back the more you stopped down! This occured with a half dozen different Nikon lenses I used with this body, both primes and zooms.

Mine went back to Nikon for calibration, and it tested fine upon return. This was last April/May. Over the last few weeks, though, I've been seeing OOF (always tending toward backfocus) images appearing more frequently again, and am going to run some careful tests again this week, as my warranty is about to expire. I can't imagine why the problem would reappear at this point, and I'm hoping it proves not to be there when I test, because if it is present again it does not bode well for the future sans warranty...

Will report back when I've done the tests.

Spike

I adjusted my D70 backfocus using these instructions.

http://www.leongoodman.com/d70focus.html

Then I wondered what happens when the mirror slapping against that eccentirc screw wears the plastic and alters the adjustment?

Have a look at the diagrams on that web page.

I hope that isn't what you are experiencing.

spiked said:

salinger said:

I did check backfocus using chart you mention.. at full aperture it
is barely noticeable (about 2mm to back) but with smaller aperture
(higher F number.. 8, 11...) the focus moves further back.. and
only on 18-70 DX lens, other I have tested appear to be within 2 mm
+ - tolerance..)

Click to expand...

I saw this behavior with my early-production D70. If I hadn't seen
it myself in careful testing, I wouldn't have believed it. You
would just assume that stopping down to f8 or so would cause depth
of field to erase the visibility of any minor focus discrepancy,
but the focus would just keep shifting farther and farther back the
more you stopped down! This occured with a half dozen different
Nikon lenses I used with this body, both primes and zooms.

Mine went back to Nikon for calibration, and it tested fine upon
return. This was last April/May. Over the last few weeks, though,
I've been seeing OOF (always tending toward backfocus) images
appearing more frequently again, and am going to run some careful
tests again this week, as my warranty is about to expire. I can't
imagine why the problem would reappear at this point, and I'm
hoping it proves not to be there when I test, because if it is
present again it does not bode well for the future sans warranty...

Will report back when I've done the tests.

Spike

Click to expand...

Wally OZ said:

I adjusted my D70 backfocus using these instructions.

http://www.leongoodman.com/d70focus.html

Then I wondered what happens when the mirror slapping against that
eccentirc screw wears the plastic and alters the adjustment?

Have a look at the diagrams on that web page.

I hope that isn't what you are experiencing.

Click to expand...

Personally I think you'd have to be crazy to fiddle with your camera a la those instructions. This definitely is NOT how Nikon calibrates the autofocus at their service center, as it gives you a camera where only the middle (horizontal) row of AF sensors are the only ones that work correctly - the ones above and below don't work after this tweak.

Quote from Leon's webpage: "Turning the stoppers will not only change the distances, but it will also tilt the image, so, aligning the distances for the central (and also left and right) focus point can misalign distances for the upper and the lower focus points. This will limit your abilities to use mostly P, A, S and M modes and choose the central, left or right focus points."

When you sell your camera someday, will you mention to the buyer that it's been whacked out like this when you do?

And if any of your scraping around in the mirror boxis at all visible, you run the real risk of voiding your warranty.

So those contemplating this hack should seriously consider the implications. If my focus testing reveals any consistent back focus has creeped back in over the last year, I will send it to Melville and get it done right.

Spike

P.S. My camera has had fairly light use ( 5k pics in the last year). A lot of other heavy users should be seeing more wear to the 'stoppers' than me if that's an issue, and I haven't heard of it being so. Besides, judging from the schematic of the mirror/AF system, any wear to the stop would result in front-focus using Len's theories, not back focus.

I see your point.

I waited 3 months for my Pentax *istD to go all the way back to Pentax Japan to repair a focusing issue, when it came back it wouldn't focus on any lens, so I did a swap for some Nikon lenses with the importer.

In the meantime while waiting, I purchased a new D70, 3 weeks and 6000 pics later it was stolen, I purchased a second new D70, it had back focus [this is in January 2005] so I took it back and exchanged it, the new exchange D70 had backfocus also so I adjusted it myself, took me 10 minutes, no scratches or any other damage, all the sensors work despite the article you quote.

I am not a teenager, I have extensive experience in designing, building and repairing computerised electronic equipment far more complex than my D70, I have worked on projects with Japanese companies much bigger than Nikon in the past, I am not exactly lacking in qualifications.

Having read a recent D70 repair horror story on this forum involving Maxwell [the Australian Nikon importer/distributor] I am so glad I did NOT send it in for repair with them.

I should mention that Maxwell took 2.5 YEARS!!!! to fix my Nikon FE shutter, yes I still have it, it has not been used since, by the time I got it back I was using 2 well worn Olympus OM cameras purchased aftre the FE went in for repairs.

I have also read similar bad repair stories from USA Nikon service centres involving backfocus repairs, is Melville that good?.

I have no intention of selling my D70, I still have all my cameras except the Pentax *istD, I am not into selling my junk on ebay.

So what is the way Nikon officially fix the backfocus problem which according to some posters on this forum is no longer a problem yest still is, my 2 D70's very recent serial numbers, NOT old stock.

This is MY D70 I will do whatever I choose to do with it, if I break it I will not cheat and lie, I will just buy another one, I couldn't go through the saga with Maxwell again, life is too short.

I have taken 3800 shots with my D70 since January, I purchased it to take pics, not to admire it or worry about upseting Nikon or its lame distributor Maxwell.

I appreciate the lecture but....

spiked said:

Wally OZ said:

I adjusted my D70 backfocus using these instructions.

http://www.leongoodman.com/d70focus.html

Then I wondered what happens when the mirror slapping against that
eccentirc screw wears the plastic and alters the adjustment?

Have a look at the diagrams on that web page.

I hope that isn't what you are experiencing.

Click to expand...

Personally I think you'd have to be crazy to fiddle with your
camera a la those instructions. This definitely is NOT how Nikon
calibrates the autofocus at their service center, as it gives you a
camera where only the middle (horizontal) row of AF sensors are the
only ones that work correctly - the ones above and below don't work
after this tweak.

Quote from Leon's webpage: "Turning the stoppers will not only
change the distances, but it will also tilt the image, so, aligning
the distances for the central (and also left and right) focus point
can misalign distances for the upper and the lower focus points.
This will limit your abilities to use mostly P, A, S and M modes
and choose the central, left or right focus points."

When you sell your camera someday, will you mention to the buyer
that it's been whacked out like this when you do?

And if any of your scraping around in the mirror boxis at all
visible, you run the real risk of voiding your warranty.

So those contemplating this hack should seriously consider the
implications. If my focus testing reveals any consistent back focus
has creeped back in over the last year, I will send it to Melville
and get it done right.

Spike

P.S. My camera has had fairly light use ( 5k pics in the last
year). A lot of other heavy users should be seeing more wear to the
'stoppers' than me if that's an issue, and I haven't heard of it
being so. Besides, judging from the schematic of the mirror/AF
system, any wear to the stop would result in front-focus using
Len's theories, not back focus.

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