VueScan evaluation...

[Bart van der Wolf]

SNIP

The only unknown is the preview exposure. Am I correct in assuming
that the preview scan was done with Analog Gain (AG) at 0?

Yes, whatever the initialization (on start-up) determined as average
non-clipping exposure of the unobstructed light source.

In other words, in the above example, a multiplier of ~30 (i.e. +5 EV)
is applied to AG of 0 to get the correct exposure for the actual scan.
That sounds about right, since I'm using a dark Kodachrome as my test
slide.

Apparently it is quite dark.

It's also one (rare ;-)) plus point on VueScan's side of the ledger
because NikonScan *artificially* limits AG boost to 4 EV. However, the
lack of individual channel AG control in VueScan is a big minus. :-(

I would also prefer individual channel exposure options, but the hardcoded
defaults are not too far off.

Bart

 

[Don]

SNIP

Apparently it is quite dark.

As far as Nikon LS-30 is concerned *all* Kodakchromes are dark!

How does that proverb go: To a man with a hammer everything looks like
a nail. ;o)

Seriously though, it's not really dark. When projected it looks just
fine.

I would also prefer individual channel exposure options, but the hardcoded
defaults are not too far off.

On principle, I intensely dislike "bossy" software which thinks it
knows what I want. I always consider that a very, very bad sign.

The same way of "thinking" told us we will never need more than 640KB
of RAM, or need to address more than 64KB at a time, etc...

Anyway, thanks very much for all the answers, Bart!

Don.

 

[Bart van der Wolf]

SNIP

Seriously though, it's not really dark. When projected it looks
just fine.

Hard to judge for me so I'll have to take your word on that, but don't
underestimate the human eye's capability to adjust to luminance differences
withing an area of as little as 1 degree field of view.

SNIP

On principle, I intensely dislike "bossy" software which thinks it
knows what I want. I always consider that a very, very bad sign.

I am (also) a bit of a control freak ;-) but the defaults could have been
chosen worse, and Ed Hamrick is usually open for suggestions that improve
VueScan's commercial potential. If however an improvement for a few means a
disadvantage for most, he will understandably not give in, although he has
been known to (reluctantly) add an "Advanced" option or two if persuaded of
the merits (future addition of a Curves control is such an example).

Bart

 

[Don]

I am (also) a bit of a control freak ;-)

I am a control freak, a lot! And proud of it!
(Although, I never impose my way on others.)

But control is not what this is about...

but the defaults could have been
chosen worse, and Ed Hamrick is usually open for suggestions that improve
VueScan's commercial potential. If however an improvement for a few means a
disadvantage for most, he will understandably not give in, although he has
been known to (reluctantly) add an "Advanced" option or two if persuaded of
the merits (future addition of a Curves control is such an example).

In this case it's not a question of control but of *choice*.

How can choice disadvantage anyone?

In general, when any software is written with such a condescending
attitude - as far as I'm concerned - it starts on a wrong foot, I get
very suspicious and I start to closely scrutinize other programming
decisions.

Don.

 

[Ed Hamrick]

In general, when any software is written with such a condescending
attitude - as far as I'm concerned - it starts on a wrong foot, I get
very suspicious and I start to closely scrutinize other programming
decisions.

Jeez, relax. You might consider the possibility that VueScan
doesn't have separate controls for analog gain because doing so
would mess up color correction. The built-in ICC calibration
depends on a fixed ratio of analog gain between the red, green
and blue colors, and I didn't have the time to add custom tags
to the raw scan files to contain the analog gain settings used
when creating the raw scan files.

Since there's little practical gain from varying analog gain
between colors (compared with varying the overall analog gain),
I haven't prioritized this very high. In addition, very, very
few people have ever asked for this, and nobody has ever given
a convincing technical argument for why this would make a
visible improvement in the final image quality.

Nobody writes software with "attitude" or is "condescending". Most
software decisions (at least the ones I make) are purely for technical,
pragmatic or practical reasons. I also have to make certain decisions
because there are only 24 hours in a day.

I've always let customers drive the evolution of VueScan - they
use it more than I do, and know a lot more about photography.

Regards,
Ed Hamrick

 

[Don]

Jeez, relax.

Erm... I am relaxed!? ;o)

You might consider the possibility that VueScan
doesn't have separate controls for analog gain because doing so
would mess up color correction.

That's not only self-evident but my point exactly! I, for one, want
the *option* to "mess up" automatic color correction when in my
estimation it's inadequate. (I'm sure you don't mean to imply above
that VueScan is always right and infallible?) And I want to do that at
the earliest possible scanning stage - not after the fact. I can (and
do) do post-processing in PS.

VueScan's goal is clearly to do color correction as unattended as
possible. To give the user more "control" (to use a loaded term) by
the means of individual AG adjustment, of course, complicates this
design decision and opens up a can of worms programmatically.
Flexibility, in general, is always more difficult to program. That's a
given and I didn't think stating the obvious was necessary.

Nobody writes software with "attitude" or is "condescending". Most
software decisions (at least the ones I make) are purely for technical,
pragmatic or practical reasons. I also have to make certain decisions
because there are only 24 hours in a day.

I did *not* write the relevant paragraph specifically with VueScan in
mind. I even went as far as including "In general" and "any software"
in order to avoid it being misconstrued.

I've always let customers drive the evolution of VueScan - they
use it more than I do, and know a lot more about photography.

So far, two devoted VueScan customers who responded to my questions
both expressed a wish for individual AG control.

However, in the free marketplace it's entirely your prerogative to do
whatever you want, just as it's a customer's prerogative to make any
purchasing decision they want. In both instances the key word, again,
is: choice.

Don.