LS2000, NikonScan, exposure again

[stuart]

in a previous thread I had asked a few questions concerning
exposure when scanning negatives. I was advised to try
scanning "raw", i.e. turn off the autoexposure and adjust
the exposure using the analog gain.

Well, I've tried it and I must be missing something, because
I can't get it to work.

I disabled autoexposure in three places in Preferences, exited
NikonScan and then turned off the scanner. After some minutes
I turned the scanner back on, entered NikonScan fed my strip
of 4 negatives into the scanner and after the thumbnails had
been scanned I chose the one I wanted to scan and pressed
Preview. The picture came up (a bit too light) and the histogram
showed the intensities off to the right of the graph. I adjusted
the analog gain to -0.4 and pressed the redraw button and
immediately got a darker preview and a better positioned
histogram (according to the help this is merely simulated).
I pressed Preview and the picture and histogram looked good.
But when I pressed scan I got the original light picture. I've
tried adjusting Analog Gain between 0 and -2.0 but it seems
to have no effect on the *scan* although the preview shows
these changes.

OK, so then I pressed Autoexpose and got a histogram filling
the full scale. Adjusting Analog Gain and pressing redraw
showed changes in the preview and the histogram as before,
pressing Preview also showed the changes and when I press
Scan I got a picture reflecting the changes to Analog Gain.

So at the moment I seem to have a system in which Analog Gain
is only working *after* I've used Autoexposure!

I'd rather not use Autoexposure, because I have the feeling
that the colour balance is being fiddled about with here.

Has anyone else experienced this? Is the some magic way to
turn on the analog gain?

stuart

 

[Don]

I disabled autoexposure in three places in Preferences, exited
NikonScan and then turned off the scanner. After some minutes
I turned the scanner back on, entered NikonScan fed my strip
of 4 negatives into the scanner and after the thumbnails had
been scanned I chose the one I wanted to scan and pressed
Preview. The picture came up (a bit too light) and the histogram
showed the intensities off to the right of the graph. I adjusted
the analog gain to -0.4 and pressed the redraw button and
immediately got a darker preview and a better positioned
histogram (according to the help this is merely simulated).
I pressed Preview and the picture and histogram looked good.
But when I pressed scan I got the original light picture. I've
tried adjusting Analog Gain between 0 and -2.0 but it seems
to have no effect on the *scan* although the preview shows
these changes.

That is indeed very odd. I can't think of anything offhand other than
re-installing (which seems a bit over the top) but maybe someone else
can jump in...?

OK, so then I pressed Autoexpose and got a histogram filling
the full scale.

That's the reason why I don't "trust" AutoExposure. It doesn't just
adjust the exposure but seems to fiddle with the contrast and who
knows what else...

Has anyone else experienced this? Is the some magic way to
turn on the analog gain?

When you scan in 8-bit what do the histograms look like?

What I'm getting at is that when you've turned everything off you
should get "comb" histograms (there will be visible gaps). As I
learned the hard way, this is due to gamma being applied but it's a
pretty good indication that nothing else has been done to the data.

A totally smooth histograms from an 8-bit scan usually indicates that
the image has undergone some processing. For example, using ICE will
produce a smooth histogram even though all else has been turned off.

Don.

 

[stuart]

When you scan in 8-bit what do the histograms look like?

What I'm getting at is that when you've turned everything off you
should get "comb" histograms (there will be visible gaps). As I
learned the hard way, this is due to gamma being applied but it's a
pretty good  indication that nothing else has been done to the data.

A totally smooth histograms from an 8-bit scan usually indicates that
the image has undergone some processing. For example, using ICE will
produce a smooth histogram even though all else has been turned off.

comb-like, yes, but the gaps don't go all the way to the baseline just
about 10% down.

You're right about having to turn off the scanner. There is no way to set
the exposure back to default except by leaving NikonScan and turning
the machine off. I've also found I can't use Analog Gain unless I've
taken a preview (makes sense actually) because the sliders are greyed out.
And another thing - although the pictures I make seem independent of the
Analog Gain setting, when I press the ">Settings" button on the picture
frames in the NikonScan applet window the correctly chosen Analog Gain
is listed.

Very strange!

stuart

 

[Don]

comb-like, yes, but the gaps don't go all the way to the baseline just
about 10% down.

That's normal. It's the result of applying gamma which "stretches" the
dark (left) side of the histogram resulting in these gaps.

OK, since you have a "comb histogram" that means it is a raw scan so
we can (probably) eliminate something else being turned on
inadvertently.

You're right about having to turn off the scanner. There is no way to set
the exposure back to default except by leaving NikonScan and turning
the machine off.

I learned that the hard way! I've lost weeks of testing because of
that and had to repeat it all... :-(

And another thing - although the pictures I make seem independent of the
Analog Gain setting, when I press the ">Settings" button on the picture
frames in the NikonScan applet window the correctly chosen Analog Gain
is listed.

Settings button actually saves current values so pressing it simply
may be just reloading some old values. These values might just happen
to be the same (i.e. correct) as what you chose recently because
you've been repeating the same test.

I don't really use settings because it's yet another thing I would
have to keep in my mind i.e. re-check all values every time I would
use them. Instead, I just base everything on manual settings because I
start from a known state.

Very strange!

Maybe you should re-install!? If you do, there is a catch, of course!
You have to run the Reg Cleaner program otherwise some settings will
be kept even after you uninstall.

Also, this is grasping at straws, but did you make sure you have the
latest firmware in the scanner, and the latest version of NikonScan
for the scanner?

I'll think some more in the meantime, but that is mighty weird!

Don.

 

[stuart]

Settings button actually saves current values so pressing it simply
may be just reloading some old values. These values might just happen
to be the same (i.e. correct) as what you chose recently because
you've been repeating the same test.

I don't really use settings because it's yet another thing I would
have to keep in my mind i.e. re-check all values every time I would
use them. Instead, I just base everything on manual settings because I
start from a known state.

No what I mean here is that when I use NikonScan in standalone mode (and
running it as a PhotoShop plugin is no better) the scanned picture
appears in a frame in the standalone applet and this frame has an area
in the upper left named >Settings. Pressing this opens an area showing
the settings presumably used during the scanning.

Maybe you should re-install!? If you do, there is a catch, of course!
You have to run the Reg Cleaner program otherwise some settings will
be kept even after you uninstall.

Also, this is grasping at straws, but did you make sure you have the
latest firmware in the scanner, and the latest version of NikonScan
for the scanner?

I'll think some more in the meantime, but that is mighty weird!

Don.

Well I first installed NikonScan2.5 which came bundled with the machine.
But that seemed buggy - I lost the thumbnail window! I think I must have
resized it inadvertently to zero, and then not been able to open it again.
I reinstalled that several times, but obviously the parameters are were
saved somewhere. I'll play around with it over the weekend.

Thanks

stuart

 

[Mike Engles]

in a previous thread I had asked a few questions concerning
exposure when scanning negatives. I was advised to try
scanning "raw", i.e. turn off the autoexposure and adjust
the exposure using the analog gain.

Well, I've tried it and I must be missing something, because
I can't get it to work.

I disabled autoexposure in three places in Preferences, exited
NikonScan and then turned off the scanner. After some minutes
I turned the scanner back on, entered NikonScan fed my strip
of 4 negatives into the scanner and after the thumbnails had
been scanned I chose the one I wanted to scan and pressed
Preview. The picture came up (a bit too light) and the histogram
showed the intensities off to the right of the graph. I adjusted
the analog gain to -0.4 and pressed the redraw button and
immediately got a darker preview and a better positioned
histogram (according to the help this is merely simulated).
I pressed Preview and the picture and histogram looked good.
But when I pressed scan I got the original light picture. I've
tried adjusting Analog Gain between 0 and -2.0 but it seems
to have no effect on the *scan* although the preview shows
these changes.

OK, so then I pressed Autoexpose and got a histogram filling
the full scale. Adjusting Analog Gain and pressing redraw
showed changes in the preview and the histogram as before,
pressing Preview also showed the changes and when I press
Scan I got a picture reflecting the changes to Analog Gain.

So at the moment I seem to have a system in which Analog Gain
is only working *after* I've used Autoexposure!

I'd rather not use Autoexposure, because I have the feeling
that the colour balance is being fiddled about with here.

Has anyone else experienced this? Is the some magic way to
turn on the analog gain?

stuart

Hello

Do you have Photoshop 6 or greater?
If so do a scan using autoexposure. Make sure there is no clipping in
the prefs--0%. In Photoshop levels check in options that clipping is set
to 0%. Now in levels hold the alt key down and move the sliders. The
display should go black. If you see any white with the sliders at 0 and
255, then Nikonscan has clipped the image. If all you see is black then,
no clipping has occurred.

First proove that Nikonscan autoexposure clips the output. Personally I
don't think it does.

Mike Engles

 

[Don]

No what I mean here is that when I use NikonScan in standalone mode (and
running it as a PhotoShop plugin is no better) the scanned picture
appears in a frame in the standalone applet and this frame has an area
in the upper left named >Settings. Pressing this opens an area showing
the settings presumably used during the scanning.

I have NikonScan 3.1 here and 2.5 is quite different so I'm not really
sure what that does.

BTW, I only run NikonScan standalone. I don't want Photoshop eating up
resources and complicating things.

Well I first installed NikonScan2.5 which came bundled with the machine.
But that seemed buggy - I lost the thumbnail window! I think I must have
resized it inadvertently to zero, and then not been able to open it again.
I reinstalled that several times, but obviously the parameters are were
saved somewhere. I'll play around with it over the weekend.

You should definitely upgrade to NikonScan 3.1!! It's available for
download from the Nikon site. That's the latest version which still
works with SCSI scanners. Don't forget to run the RegCleaner after you
uninstall 2.5.

Also, make sure you've got the latest firmware. Very important!! Look
for the LS2000_131.exe file.

Finally, while you're at it get the latest manual which is much
improved over earlier versions. The file name is: ns3rmena1.pdf.

Good luck, and let us know how it turns out!

Don.

 

[stuart]

Well, I've found out how to do it.

I had been trying to scan negatives, but I thought "maybe it
works for slides", so I pulled out the film-strip adapter and
pushed in the slide adapter and scanned a slide. And lo and behold
I could adjust Analog Gain and the scanned image showed the
adjustment (this is all without Autoexposure). OK, so I pulled out
the slide adapter and pushed in the film adapter, and again I
could adjust Analog Gain. I'm so surprised that I nearly fall off
my chair. I've been trying to do this for a week with no success
and suddenly it works. Must be a bad contact at the back of the
film adapter.

I try it again about an hour later and it doesn't work. I'm beginning
to get violent, I feel like kicking the scanner *very* hard.

It took me a long time to find that I can adjust Analog Gain without
first using Autoexposure *only* if I insert the adapter into the
scanner *while* NikonScan is running. Up till now I'd always kept
the adapter in the scanner to stop dust getting in and just switched
the scanner on before booting the computer. Then opened NikonScan
in standalone mode and started scanning. Now I pull the adapter
slightly out when I'm finished scanning. And before I start scanning
I open NikonScan and then push the adapter all the way in.

It sounds crazy, and I didn't believe it at first, it's not documented
anywhere, but that's the way *my* scanner works on *my* computer!!!

Anyway I can now scan raw.

Thanks for your help

BTW this is NikonScan3.1.2, Firmware 1.31, Windows2000, Adaptec 2940U
on an ASUS Mainboard with Intel P4

 

[Don]

Well, I've found out how to do it.

I had been trying to scan negatives, but I thought "maybe it
works for slides", so I pulled out the film-strip adapter and
pushed in the slide adapter and scanned a slide. And lo and behold
I could adjust Analog Gain and the scanned image showed the
adjustment (this is all without Autoexposure). OK, so I pulled out
the slide adapter and pushed in the film adapter, and again I
could adjust Analog Gain. I'm so surprised that I nearly fall off
my chair. I've been trying to do this for a week with no success
and suddenly it works. Must be a bad contact at the back of the
film adapter.

Quite possibly. It's the old software person's nightmare. We agonize
over all possible causes failing to notice something obvious like -
the computer is simply not plugged in! ;o)

I try it again about an hour later and it doesn't work. I'm beginning
to get violent, I feel like kicking the scanner *very* hard.

Tell me about it! When my LS-30 was torturing me with Kodachromes I
threatened it with a baseball bat, but it just smiled and kept on
spitting out dark scans with a heavy blue cast!

It took me a long time to find that I can adjust Analog Gain without
first using Autoexposure *only* if I insert the adapter into the
scanner *while* NikonScan is running.

That's because when you change the adapter the scanner sends a "change
adapter" event to the TWAIN driver which re-initializes itself by
reloading all capabilities from scratch. Presumably, a new adapter
making contact also reinitializes the internal scanner memory.

I only use the slide adapter and when I scan strips of film I use the
strip film adapter. The reason is that the adapter keeps the film
flat, which is very important because all film is curved and Nikon -
because of its light source - has a very narrow depth of field.

Anyway I can now scan raw.

Thanks for your help

My pleasure. I'm really glad it all worked out in the end!

Don.

 

[stuart]

Hello

Do you have Photoshop 6 or greater?
If so do a scan using autoexposure. Make sure there is no clipping in
the prefs--0%. In Photoshop levels check in options that clipping is set
to 0%. Now in levels hold the alt key down and move the sliders. The
display should go black. If you see any white with the sliders at 0 and
255, then Nikonscan has clipped the image. If all you see is black then,
no clipping has occurred.

First proove that Nikonscan autoexposure clips the output. Personally I
don't think it does.

I've tried that, and it does clip the highlights. If I autoexpose and
then reduce analog gain I can reduce the highlight clipping, but then
then the shadows are clipped. The problem may well be that I have
overexposed negatives taken with a point and shoot camera many years ago,
so that the clipping is a true representation of the information on
the film.

What worries me now is the colour difference between autoexposure images
and the "raw" images. Subjectively the autoexposure looks better and seems
closer to the colour rendition of the prints. But objectively shouldn't the
raw method be better?

stuart

 

[Don]

I've tried that, and it does clip the highlights. If I autoexpose and
then reduce analog gain I can reduce the highlight clipping, but then
then the shadows are clipped. The problem may well be that I have
overexposed negatives taken with a point and shoot camera many years ago,
so that the clipping is a true representation of the information on
the film.

I forget how many bits LS2000 uses internally but, usually, dynamic
range is not a problem because negatives are compressed to start with.

The problem seem to be that NikonScan doesn't just do autoexposure,
but also seems to uncompress this compressed dynamic range of
negatives. In that it seems to go a bit overboard and that's what
causes the slight clipping. Could be a part of negative inversion
(intentionally or not) because there is no clipping with autoexposed
slides.

Some people, therefore, scan negatives as slides and then invert
manually.

What worries me now is the colour difference between autoexposure images
and the "raw" images. Subjectively the autoexposure looks better and seems
closer to the colour rendition of the prints. But objectively shouldn't the
raw method be better?

What you're seeing is the autoexposure doing a lot of other things
beside exposure. If you take the raw scan and just adjust the black
and white points in Photoshop you should achieve the same effect
(assuming no other features, such as curves, were used in NikonScan).

I haven't done a lot with negatives, other than a few initial tests
(I'm still wrestling with slides) but back then a raw negative scan
was also quite "pale". Looking at the histogram it showed that there
was a lot of room at both ends (the compressed nature of negatives).
The histogram was all "bunched up" in the middle. However, once I
pushed the levels *in* (at both ends) the image "perked up", of
course.

Don.

 

[Mike Engles]

I've tried that, and it does clip the highlights. If I autoexpose and
then reduce analog gain I can reduce the highlight clipping, but then
then the shadows are clipped. The problem may well be that I have
overexposed negatives taken with a point and shoot camera many years ago,
so that the clipping is a true representation of the information on
the film.

What worries me now is the colour difference between autoexposure images
and the "raw" images. Subjectively the autoexposure looks better and seems
closer to the colour rendition of the prints. But objectively shouldn't the
raw method be better?

stuart

Hello

I personally believe that the scanner does not clip, if no clipping is
in the prefs. The clipping you see is that done on the film. I also
think that in the case of negatives, autoexposure is essential. Scans
just do not look right without it. They remind me of prints made from
negatives that have not been processed at the correct temperatue or
time, or the chemicals are exhausted.

Mike Engles