SE5400: no accurate focus in Vuescan

  • Thread starter Thread starter Markus Malmqvist
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Markus Malmqvist

Hi,

I have tried Vuescan, my main problem was focus accuracy. It seems that the
program skips a fine tuning phase when focusing. Is there a cure for this?

--markus
 
Markus Malmqvist said:
Hi,

I have tried Vuescan, my main problem was focus accuracy. It seems that the
program skips a fine tuning phase when focusing. Is there a cure for this?

--markus
Click to expand...

What scanner are you using?
 
John said:
What scanner are you using?
Click to expand...

Apparently, he's using a Minolta Dimage Scan Elite 5400 (hence 'SE5400').

Markus, did you try dragging the focus point to a different location on
the image (it's an 'x' with a blinking circle around it)?
What you can also do is set 'autofocus' in the Input tab to Manual.
Then, select Scanner > Focus and check out the numerical focus
indication after the scanner has refocused. Repeat this for different
locations of the focus point. If the readouts are very different, there
may be a lack of contrasty areas in the image. In that case you could
try to enter values between -1 and +1 manually and try to find the
optimal focus setting by trial-and-error scanning of a very small area
near the center of the image.
 
Wilfred said:
Markus, did you try dragging the focus point to a different location on
the image (it's an 'x' with a blinking circle around it)?
What you can also do is set 'autofocus' in the Input tab to Manual. Then,
select Scanner > Focus and check out the numerical focus indication after
the scanner has refocused. Repeat this for different locations of the
focus point. If the readouts are very different, there may be a lack of
contrasty areas in the image. In that case you could try to enter values
between -1 and +1 manually and try to find the optimal focus setting by
trial-and-error scanning of a very small area near the center of the
image.
Click to expand...

Maybe so. But since the Minolta Software uses fine tuning, and provides
sufficient focus with 99% certainty (failing only if the center of the image
is too dark), I would not like to do that exercise.

--markus
 
Markus said:
Maybe so. But since the Minolta Software uses fine tuning, and provides
sufficient focus with 99% certainty (failing only if the center of the image
is too dark), I would not like to do that exercise.
Click to expand...

What you report here is strange. In my experience, autofocusing with
VueScan is at least as accurate as autofocusing with the Minolta
software. The fact that focusing with the Minolta software takes more
time does not mean it includes fine-tuning.
 
....
What you report here is strange. In my experience, autofocusing with
VueScan is at least as accurate as autofocusing with the Minolta software.
The fact that focusing with the Minolta software takes more time does not
mean it includes fine-tuning.
Click to expand...

Perhaps it has something to do with the fact that I was not able to keep the
film completely flat. Even mounted glassless slide usually has some blurred
edges after scanning. Vuescan for some reason seemed to make the edges sharp
instead.

With Minolta SW the focusing has two phases. You can clearly see how the
film holder moves sideways quickly in the first phase. In the second phase
movement speed is much lower. The only rational explanation I can find is
that the second phase fine tunes the focus found in first phase. Vuescan
only does the fast moving phase.

--markus
 
Markus said:
...



Perhaps it has something to do with the fact that I was not able to keep the
film completely flat. Even mounted glassless slide usually has some blurred
edges after scanning. Vuescan for some reason seemed to make the edges sharp
instead.

With Minolta SW the focusing has two phases. You can clearly see how the
film holder moves sideways quickly in the first phase. In the second phase
movement speed is much lower. The only rational explanation I can find is
that the second phase fine tunes the focus found in first phase. Vuescan
only does the fast moving phase.
Click to expand...

That's not what Ed Hamrick says:
http://tinyurl.com/67482
 
message SNIP
With Minolta SW the focusing has two phases. You can clearly see how
the film holder moves sideways quickly in the first phase. In the
second phase movement speed is much lower. The only rational
explanation I can find is that the second phase fine tunes the focus
found in first phase. Vuescan only does the fast moving phase.
Click to expand...

No, VueScan first goes through the entire range (you can see that when
you watch the manual focus knob), and then homes in on the best range.
The first phase is very fast, maybe you blinked with your eyes? ;-)
In my experience VueScan's focus is better on average than with the
Minolta SW, and it can be tuned better when set to manual.

Bart
 
.....
No, VueScan first goes through the entire range (you can see that when you
watch the manual focus knob), and then homes in on the best range. The
first phase is very fast, maybe you blinked with your eyes? ;-)
Click to expand...

:-) OK, anyway the higher speed actually made it to feel less reliable then
Minolta focus. Why does Vuescan need manual offsetting with focus and
Minolta not?
In my experience VueScan's focus is better on average than with the
Minolta SW, and it can be tuned better when set to manual.
Click to expand...

Maybe I need to try that again, but for me Vuescan never even made grain
visible in the central part of the photo, while Minolta SW never fails to do
that.

--markus
 
message SNIP
Why does Vuescan need manual offsetting with focus and Minolta not?
Click to expand...

Both allow manual focus, but it is optional. Standard setting is
autofocus.
Maybe I need to try that again, but for me Vuescan never even made
grain visible in the central part of the photo, while Minolta SW
never fails to do that.
Click to expand...

Just make sure that you position the focus marker, in VueScan's
Preview pane, where you want to focus on. It is also possible that the
film curl made the focal plane move during the scan as the film heated
up. You can check the tendency for that by setting the focusing method
to manual and by checking the focus value when you invoke a refocus
several times.

Bart
 
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