D770 focus observations

Started Sep 2, 2000 | Discussions thread
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Lin Evans
Lin Evans Forum Pro • Posts: 16,987
Re: D770 focus observations

Bryan Biggers wrote:

My .02 monitary units on this...

First, the focus is very very critical. It is very hard to judge proper
focus in the viewfinder at all. Just one or two servo "clicks" from
proper focus can wreck a shot at F2.0

I have been doing this and having better results with manual focus. This
is a little different than the techniques that I have seen recommended.
Try it and see if it works for you.

1) Set out some nice discrete object for the camera to focus on. Set the
camera to F2.0 to minimise depth of field.
2) Set AF mode, let the camera fous. Take a picute, call this "A"
3) Now adjust the diopter correction, with your eyes relaxed or focused
how you would normaly look through the viewfinder. Adjust so that the
object looks sharpest in the viewfinder. Forget the black lines in the
viewfinder, depending on your eyes they might be slightly out of focus.
4) Switch to manual, but don't change the focus. Take a picture, call
this "B"
5) manual focus Take a picture, call this "C".
6) Now move the focus by say two "clicks" in any direction and take a
picture , call this "D"

Now what I see is... assuming that "A" is in good focus, "B" looks just
like it, proving that just switching to MF is not a bad thing and does
not mess up the focus. It is not some kind of problem where all manual
shots are off or anything. What "C" looks like depends on how good you
are at reproducing the focus that you saw at first when you set the
diopter adjustment. Unfortunately, the focus on the screen is not very
sensitive to small motions of the focus ring. Look at your "D" shot, out
of focus isn't it? Only two clicks of the ring did that, and it was
probably a barely visible difference on the screen.

Bryan

Assuming there's nothing mechanically or electrically wrong with the focus assembly, here's the adjustment procedure which Mike Chaney (QimagePro author) discovered over a year ago when we were having fits with the D700's. I put out a query on the Sony Cyber Shot forum in case someone had saved it, and was fortunate enough to get two responses. One the original link, and one from Rob Cotton who copied it. Use at your own risk -

Lin

Lin, is this the posting you were looking for?

Rob Cotton

-- hide signature --

Original Message --------
Subject: [D700] Manual focus: at home surgery!
Date: Sun, 11 Jul 1999 17:06:55 -0400 (EDT)
From: Michael Chaney
Reply-To: D700@onelist.com
To: d700@onelist.com

From: Michael Chaney

I'll put the disclaimer at the top just to make sure. I'M NOT
SUGGESTING THAT
ANYONE ELSE DO THIS! I did it just out of curiosity.

Well, it's taken me 5 hours but I have successfully adjusted the
viewfinder
focus so that it agrees with the lens!!! At home!!! with a
screwdriver!!!

Ok, before anyone gets too excited, let me say that this may only work
if you
don't have any broken parts in the camera. There have been reports of
parts
replaced, but somehow I wonder if the adjustment that I did today is all
the
Sony "guys" do? Before anyone else contemplates voiding their warranty
like I
just did, I'd like to hear from Richard Auger to get his thoughts on
what I
just did.

Here's what I did.

(1) Removed 8 screws and popped the top rear cover off (the one with the
top
LCD). The eight screws are located as follows:

  • Pop the flash up. Two screws are in the front part of the flash bay.

  • 1 screw in the front of the camera under the little green eye.

  • 1 screw between the AF/MF switch and the control wheel.

  • 2 screws above the viewfinder in the back.

  • 1 screw on the top between the spinner wheel and the strap.

  • 1 screw inside the battery compartment (take the battery out to see

it).

(2) Gently pop the top cover off. When it pops off, you'll see:

(3) The identified screw is labeled "viewfinder focus adjustment screw"
because it is attached directly to a lens that moves up/down. How do I
know?
Because I peeled the mirror off and looked in there! You can see the
mirror on the top with the yellowish glue around it. Loosen the focus
adjustment screw and move up/down until focus agrees with the lens.
This took
considerable setting/resetting to get it right but after a few hours
of
playing with it, focus is now dead-on. Most of the time here was taking
comparison pics. Also, it took extra time because you have to readjust
the
diopter each time. It's like adjusting two screws on an old
carburetor... it
takes time and patience. I found it easiest to just pop the cover back
on and
take pics without putting any screws back in until I was done.

(4) Reverse order to reassemble.

Notes:

  • My camera was pretty far off before and I'm intimately familiar with

the
diopter which had no effect whatsoever.

  • The camera was consistent before this operation, always needing a

little
turn clockwise on the focus ring to get perfect focus.

  • Moving the "viewfinder focus adjustment screw" too far one way would

cause
you to have to correct focus one way, too far the other way... the
opposite.
Getting it in just the right position produced correct focus. This was
repeatable and predictable so I know that this "adjustment" screw can
be
used to make this adjustment. Whether this is what it was meant
for... I
don't know... Richard???

  • Unless you have contrasty subjects, the viewfinder is still not really

sufficient as an SLR focus mechanism. Although my viewfinder now
matches my
LCD and lens, I think I still prefer to manually focus using the LCD
when
lighting permits. I can get good pics in focus now throught the
viewfinder,
but it takes longer (and more hunting) than using the LCD. Of course,
the LCD
is useless outside.

Funny notes:

  • You can unplug both of the ribbon cables and set aside the top cover,

but I
don't suggest doing so. I got my top LCD to do some pretty weird dances
by
not plugging them back in just right.

  • The camera still works with the top cover removed and the ribbon

cables
disconnected!

The above is my experience... YMMV.

Mike

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