LS4000 depth of focus problem--Nikon LS5000 also, or other alternatives?

Discussion in 'Scanners' started by Gary L Hunt, Mar 17, 2004.

  1. Gary L Hunt

    Gary L Hunt Guest

    My Nikon LS4000 has always suffered from the widely reported "narrow depth of
    focus" problem, which means that in most cases it is impossible to get the
    entire slide (or even most of it) in critical focus without resorting to glass
    slide mounts. The description of the LS5000 sounds to me as though it is pretty
    similar mechanically and optically. Is there any reason to suppose this problem
    is less severe with the new model?

    And a related question--does the "grain dissolver" diffuser on the Minolta 5400
    improve its performance in this respect? My old Polaroid 4000 SprintScan was
    never as sharp as the LS4000, but its focus uniformity was very good indeed. With
    the Nikon, I wind up having to manually focus it most of the time on a compromise
    setting.

    Gary Hunt <>
     
    Gary L Hunt, Mar 17, 2004
    #1
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  2. "Gary L Hunt" <> wrote in message
    news:...
    SNIP
    > And a related question--does the "grain dissolver" diffuser on the Minolta

    5400
    > improve its performance in this respect?


    No, and Yes...

    Technically it affects neither resolution* nor depth of field (lens aperture
    and distance is unchanged). However, the first giveaway with
    out-of-critical-focus is the different rendering of the grain structure,
    especially in the corners.
    Since graininess is reduced, lack of critical focus is harder to spot.

    * It does modify contrast depending on density, so that may affect the
    tonality, depending of grain/dye-cloud structure.

    Bart
     
    Bart van der Wolf, Mar 17, 2004
    #2
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  3. On 16 Mar 2004 22:57:32 -0800, (Gary L Hunt) wrote:

    >My Nikon LS4000 has always suffered from the widely reported "narrow depth of
    >focus" problem, which means that in most cases it is impossible to get the
    >entire slide (or even most of it) in critical focus without resorting to glass


    Maybe I'm just not discerning enough but in over 6000 slides in the
    last few weeks, I've never noted this problem.

    >slide mounts. The description of the LS5000 sounds to me as though it is pretty
    >similar mechanically and optically. Is there any reason to suppose this problem
    >is less severe with the new model?


    I haven't seen any problem. OTHO ask me again in another year of use.
    <:))
    I'm currently running a whole series of problem negatives through that
    require adjustment of the analog gain, color correction, and are super
    dense (under exposed). So far, it has make all but one look like new.

    >
    >And a related question--does the "grain dissolver" diffuser on the Minolta 5400
    >improve its performance in this respect? My old Polaroid 4000 SprintScan was
    >never as sharp as the LS4000, but its focus uniformity was very good indeed. With
    >the Nikon, I wind up having to manually focus it most of the time on a compromise
    >setting.


    In over 6000 slides I've not had to touch the focus once.

    Roger Halstead (K8RI & ARRL life member)
    (N833R, S# CD-2 Worlds oldest Debonair)
    www.rogerhalstead.com

    >
    >Gary Hunt <>
     
    Roger Halstead, Mar 17, 2004
    #3
  4. Gary L Hunt

    Gary L Hunt Guest

    I don't think it's a matter of how discerning you are but rather what uses you
    are making of the scans. If I look at them on the monitor, or make smaller
    prints from them, it's not noticeable. And no one else has ever admitted to
    noticing it on my enlargements (which are never larger than 11x17 or so).
    But if I use the default focus point (in the center), I can see it very clearly
    in the corners and edges, although some slides are MUCH worse than others.
    (Home-mounted cardboard slide mounts are the worst for me.) And of course
    it's partly annoying because I know it's not an optical limitation--if I mount
    the slide in glass, then the whole image is sharp. I'm reluctant to archive
    scans where all parts of the image are not equally usable for future printing.

    Roger Halstead <> wrote in message news:<>...
    > On 16 Mar 2004 22:57:32 -0800, (Gary L Hunt) wrote:
    >
    > >My Nikon LS4000 has always suffered from the widely reported "narrow depth of
    > >focus" problem, which means that in most cases it is impossible to get the
    > >entire slide (or even most of it) in critical focus without resorting to glass

    >
    > Maybe I'm just not discerning enough but in over 6000 slides in the
    > last few weeks, I've never noted this problem.
     
    Gary L Hunt, Mar 18, 2004
    #4
  5. On 17 Mar 2004 16:39:48 -0800, (Gary L Hunt) wrote:

    >I don't think it's a matter of how discerning you are but rather what uses you
    >are making of the scans. If I look at them on the monitor, or make smaller
    >prints from them, it's not noticeable. And no one else has ever admitted to
    >noticing it on my enlargements (which are never larger than 11x17 or so).
    >But if I use the default focus point (in the center), I can see it very clearly
    >in the corners and edges, although some slides are MUCH worse than others.
    >(Home-mounted cardboard slide mounts are the worst for me.) And of course
    >it's partly annoying because I know it's not an optical limitation--if I mount
    >the slide in glass, then the whole image is sharp. I'm reluctant to archive
    >scans where all parts of the image are not equally usable for future printing.
    >

    That would explain the difference.
    All of the slildes are either Kodak paper mounts (from Kodak), or I
    use plastic mounts. Although I do have to admint some of those Kodak
    mounts that are 50 years old and have been through a projector or two
    a few hundered times... or more <:)) are't all that straight. Then
    again those slides are only saved for reference and possibly small
    prints at 2000 or 2400 dpi and not 4000.

    Roger Halstead (K8RI & ARRL life member)
    (N833R, S# CD-2 Worlds oldest Debonair)
    www.rogerhalstead.com

    >Roger Halstead <> wrote in message news:<>...
    >> On 16 Mar 2004 22:57:32 -0800, (Gary L Hunt) wrote:
    >>
    >> >My Nikon LS4000 has always suffered from the widely reported "narrow depth of
    >> >focus" problem, which means that in most cases it is impossible to get the
    >> >entire slide (or even most of it) in critical focus without resorting to glass

    >>
    >> Maybe I'm just not discerning enough but in over 6000 slides in the
    >> last few weeks, I've never noted this problem.
     
    Roger Halstead, Mar 18, 2004
    #5
  6. In article <>, Roger Halstead
    <> writes
    >
    >I haven't seen any problem. OTHO ask me again in another year of use.
    ><:))
    >I'm currently running a whole series of problem negatives through that
    >require adjustment of the analog gain, color correction, and are super
    >dense (under exposed).


    Why do your negatives need analogue gain adjustment? Negatives usually
    don't have enough dynamic range to cause a problem with exposure. Super
    dense negatives are usually extremely over-exposed, not under-exposed.

    Are you sure you are not talking about slides?
    --
    Kennedy
    Yes, Socrates himself is particularly missed;
    A lovely little thinker, but a bugger when he's pissed.
    Python Philosophers (replace 'nospam' with 'kennedym' when replying)
     
    Kennedy McEwen, Mar 19, 2004
    #6
  7. On Fri, 19 Mar 2004 18:51:34 +0000, Kennedy McEwen
    <> wrote:

    >In article <>, Roger Halstead
    ><> writes
    >>
    >>I haven't seen any problem. OTHO ask me again in another year of use.
    >><:))
    >>I'm currently running a whole series of problem negatives through that
    >>require adjustment of the analog gain, color correction, and are super
    >>dense (under exposed).

    >
    >Why do your negatives need analogue gain adjustment? Negatives usually
    >don't have enough dynamic range to cause a problem with exposure. Super
    >dense negatives are usually extremely over-exposed, not under-exposed.
    >
    >Are you sure you are not talking about slides?


    I'm sure I am talking about slides, but the guy you are answering was
    talking about negatives...I think.

    There are two posts mixed in there<:))

    Roger Halstead (K8RI & ARRL life member)
    (N833R, S# CD-2 Worlds oldest Debonair)
    www.rogerhalstead.com
     
    Roger Halstead, Mar 25, 2004
    #7
  8. Gary L Hunt

    ThomasH Guest

    Re: LS4000 depth of focus problem--Nikon LS5000 also, or otheralternatives?

    Roger Halstead wrote:
    >
    > On 16 Mar 2004 22:57:32 -0800, (Gary L Hunt) wrote:
    >
    > >My Nikon LS4000 has always suffered from the widely reported "narrow depth of
    > >focus" problem, which means that in most cases it is impossible to get the
    > >entire slide (or even most of it) in critical focus without resorting to glass

    >
    > Maybe I'm just not discerning enough but in over 6000 slides in the
    > last few weeks, I've never noted this problem.


    Same here. I think that is gossip and rumor, which as always
    might have something true in its origin: Maybe some of the
    LS4000 were misaligned or maybe some of the users tried to
    scan (too) warped film?


    >
    > >slide mounts. The description of the LS5000 sounds to me as though it is pretty
    > >similar mechanically and optically. Is there any reason to suppose this problem
    > >is less severe with the new model?

    >
    > I haven't seen any problem. OTHO ask me again in another year of use.
    > <:))
    > I'm currently running a whole series of problem negatives through that
    > require adjustment of the analog gain, color correction, and are super
    > dense (under exposed). So far, it has make all but one look like new.
    >


    Exposure problems and foremost color balance handling: yes,
    this are the problems which I also experience with NikonScan.
    Vuescan is of great help here.

    Scan of negatives with NikonScan is also very troubled.
    Especially, I notice from the histograms that NikonScan
    never maps darkest gray to 0. All histograms seem to
    indicate an offset of approx. 25%!

    Thomas

    > >
    > >And a related question--does the "grain dissolver" diffuser on the Minolta 5400
    > >improve its performance in this respect? My old Polaroid 4000 SprintScan was
    > >never as sharp as the LS4000, but its focus uniformity was very good indeed. With
    > >the Nikon, I wind up having to manually focus it most of the time on a compromise
    > >setting.

    >
    > In over 6000 slides I've not had to touch the focus once.
    >
    > Roger Halstead (K8RI & ARRL life member)
    > (N833R, S# CD-2 Worlds oldest Debonair)
    > www.rogerhalstead.com
    >
    > >
    > >Gary Hunt <>
     
    ThomasH, Mar 25, 2004
    #8
  9. In article <>, Roger Halstead
    <> writes
    >On Fri, 19 Mar 2004 18:51:34 +0000, Kennedy McEwen
    ><> wrote:
    >
    >>In article <>, Roger Halstead
    >><> writes
    >>>
    >>>I haven't seen any problem. OTHO ask me again in another year of use.
    >>><:))
    >>>I'm currently running a whole series of problem negatives through that
    >>>require adjustment of the analog gain, color correction, and are super
    >>>dense (under exposed).

    >>
    >>Why do your negatives need analogue gain adjustment? Negatives usually
    >>don't have enough dynamic range to cause a problem with exposure. Super
    >>dense negatives are usually extremely over-exposed, not under-exposed.
    >>
    >>Are you sure you are not talking about slides?

    >
    >I'm sure I am talking about slides,


    I thought you must be.

    > but the guy you are answering was
    >talking about negatives...I think.
    >

    I wasn't answering anyone - I was asking you a question about what you
    wrote. Negatives were introduced in the thread in your post - up till
    then it had been only Gary's question about focus across glass-less
    mounted slides. Did you reply to the correct article? ;-)

    >There are two posts mixed in there<:))
    >

    Not in the section I quoted: 5 lines comprising two sentences separated
    by an emoticon - all written by you and posted on 17th March 2004 at
    18:11:07GMT (13:11:07 EST). That is the first place in the entire
    thread that underexposed negatives were super dense, consequently
    requiring analogue gain adjustment, was mentioned.
    --
    Kennedy
    Yes, Socrates himself is particularly missed;
    A lovely little thinker, but a bugger when he's pissed.
    Python Philosophers (replace 'nospam' with 'kennedym' when replying)
     
    Kennedy McEwen, Mar 28, 2004
    #9
  10. On Sun, 28 Mar 2004 13:02:17 +0100, Kennedy McEwen
    <> wrote:

    >In article <>, Roger Halstead
    ><> writes
    >>On Fri, 19 Mar 2004 18:51:34 +0000, Kennedy McEwen
    >><> wrote:
    >>
    >>>In article <>, Roger Halstead
    >>><> writes
    >>>>
    >>>>I haven't seen any problem. OTHO ask me again in another year of use.
    >>>><:))
    >>>>I'm currently running a whole series of problem negatives through that
    >>>>require adjustment of the analog gain, color correction, and are super
    >>>>dense (under exposed).
    >>>
    >>>Why do your negatives need analogue gain adjustment? Negatives usually
    >>>don't have enough dynamic range to cause a problem with exposure. Super
    >>>dense negatives are usually extremely over-exposed, not under-exposed.
    >>>
    >>>Are you sure you are not talking about slides?

    >>
    >>I'm sure I am talking about slides,

    >
    >I thought you must be.
    >
    >> but the guy you are answering was
    >>talking about negatives...I think.
    >>

    >I wasn't answering anyone - I was asking you a question about what you
    >wrote. Negatives were introduced in the thread in your post - up till
    >then it had been only Gary's question about focus across glass-less
    >mounted slides. Did you reply to the correct article? ;-)
    >
    >>There are two posts mixed in there<:))
    >>

    >Not in the section I quoted: 5 lines comprising two sentences separated
    >by an emoticon - all written by you and posted on 17th March 2004 at
    >18:11:07GMT (13:11:07 EST). That is the first place in the entire
    >thread that underexposed negatives were super dense, consequently
    >requiring analogue gain adjustment, was mentioned.


    My apologies,

    I didn't recall the wording and the post wasn't on my
    server...However, I went back thorough the <Sent Messages> and lo and
    behold, there it was.

    Bout the only excuse I can think of at the moment is a plain old
    fashioned "brain fart". I have no idea as to why I said negatives,
    unless I was thinking of what I have to do after I get through the
    slides.

    I am going through a bunch of problem slides that are "old", warped,
    discolored, scratched, and dirty. I'm definitely not using the SF-210
    for these. They are strictly one-at-a-time.

    Again, my apologies.

    Roger Halstead (K8RI & ARRL life member)
    (N833R, S# CD-2 Worlds oldest Debonair)
    www.rogerhalstead.com
     
    Roger Halstead, Mar 29, 2004
    #10
  11. Re: LS4000 depth of focus problem--Nikon LS5000 also, or other alternatives?

    On Thu, 25 Mar 2004 17:40:42 GMT, ThomasH <> wrote:

    >Roger Halstead wrote:
    >>
    >> On 16 Mar 2004 22:57:32 -0800, (Gary L Hunt) wrote:
    >>
    >> >My Nikon LS4000 has always suffered from the widely reported "narrow depth of
    >> >focus" problem, which means that in most cases it is impossible to get the
    >> >entire slide (or even most of it) in critical focus without resorting to glass

    >>
    >> Maybe I'm just not discerning enough but in over 6000 slides in the
    >> last few weeks, I've never noted this problem.

    >
    >Same here. I think that is gossip and rumor, which as always
    >might have something true in its origin: Maybe some of the
    >LS4000 were misaligned or maybe some of the users tried to
    >scan (too) warped film?



    Basing on the LS-8000, I'd say the problem is overstated.
    But still real. I do a fair amount of fussing with film in holders
    and occasionally have to re-load film a few times before
    it's flat enough to scan well. 35 mm in strips is generally
    no problem. Old slides that have curved or domed in their
    mounts can be a b*tch.


    >> >slide mounts. The description of the LS5000 sounds to me as though it is pretty
    >> >similar mechanically and optically. Is there any reason to suppose this problem
    >> >is less severe with the new model?

    >>
    >> I haven't seen any problem. OTHO ask me again in another year of use.
    >> <:))
    >> I'm currently running a whole series of problem negatives through that
    >> require adjustment of the analog gain, color correction, and are super
    >> dense (under exposed). So far, it has make all but one look like new.
    >>

    >
    >Exposure problems and foremost color balance handling: yes,
    >this are the problems which I also experience with NikonScan.
    >Vuescan is of great help here.
    >
    >Scan of negatives with NikonScan is also very troubled.
    >Especially, I notice from the histograms that NikonScan
    >never maps darkest gray to 0. All histograms seem to
    >indicate an offset of approx. 25%!



    Try scanning your negatives as positives, and inverting
    them in NikonScan. Look up "dane kosaka LS-8000" on
    google for a nice site describing the technique.



    rafe b.
    http://www.terrapinphoto.com
     
    Raphael Bustin, Mar 29, 2004
    #11
  12. Re: LS4000 depth of focus problem--Nikon LS5000 also, or other alternatives?

    >
    >Exposure problems and foremost color balance handling: yes,
    >this are the problems which I also experience with NikonScan.
    >Vuescan is of great help here.
    >
    >Scan of negatives with NikonScan is also very troubled.
    >Especially, I notice from the histograms that NikonScan
    >never maps darkest gray to 0. All histograms seem to
    >indicate an offset of approx. 25%!
    >

    It does if you tell it to, Thomas. :)

    However the default setting results in a black level which depends on
    the density of the film base - that is what defines the black point on a
    negative. The autoexposure will adjust this to ensure that the CCD
    level is matched but not saturated in any of the colour channels and,
    once inverted, the saturation level becomes peak black. Consequently
    the film base level is therefore offset from this level by an amount
    dependent on the density of the film base itself - which varies from
    film type to type. I have never seen this get above 10 percent
    (histogram black level=25).

    There are two simple solutions to this.
    First, set a global adjustment to the exposure that brings the black
    level to 0 for the film type you use and then save that as the default
    user setting or a specific film type setting. This approach has the
    disadvantage that the film base can be a slightly different density
    depending on the processing used, even on the same film type.
    Consequently you might find that some blacks are actually clipped and
    you need to rescan at preview level to get acceptable results. The
    advantage of this technique is that you get a few percent extra in
    dynamic range due to increased exposure and better use of the full CCD
    dynamic range. Since negatives don't actually have anything like the
    density range that the scanner can cope with, what actually matters is
    the improved signal to noise ratio, which is dominated by shot noise on
    the illumination itself. In practice the difference is almost
    negligible - a 10% increase in exposure improves the SNR by around 3%,
    so hardly a big deal. Even at your extreme 25% level, this is only
    going to improve things by 5%, which is pretty negligible.

    Second approach is just to define a black level on the curves window and
    save that as a user default or film type setting. The advantages and
    disadvantages of this approach are pretty much complementary to the
    first solution.

    Given the marginal disadvantage of operating the CCD close to
    saturation, I prefer the latter, since I can make minor adjustments to
    the black point without getting another preview on the rare occasions
    that I just throw film at the scanner without checking which type it is
    and choosing a setting I have previously created.

    I haven't had NikonScan transfer an image into Photoshop which did not
    have a good black level, (or histogram distribution for that matter)
    since the day I bought the LS-4000 and started using it.

    As for your problems on colour balance - once you get a default setting
    that gives good blacks, find or create a test negative with good whites
    and grey content - a colour chart is a good start. Then use the eye
    droppers in the curves window to determine the white point from the
    white areas of the image - you might need to make a few adjustments to
    the final levels to give you a safe margin, depending on your preference
    settings. Then use the gamma dropper to determine slope correction in
    each colour channel from any of the grey sections. Store these with
    your defaults for that film as well. Perfect colour balance (or at
    least matching the colour of the light the image was shot under) every
    time thereafter.
    --
    Kennedy
    Yes, Socrates himself is particularly missed;
    A lovely little thinker, but a bugger when he's pissed.
    Python Philosophers (replace 'nospam' with 'kennedym' when replying)
     
    Kennedy McEwen, Mar 29, 2004
    #12
  13. Gary L Hunt

    nikita Guest

    Re: LS4000 depth of focus problem--Nikon LS5000 also, or other alternatives?

    "I think that is gossip and rumor".

    Well, if you mean the wellknown fact of the narrow depth of focus in
    the Nikonscanners, then you're dead wrong.

    Nikonscanners have always been suffering from this problem. In the
    same way as glassless enlargers always have. Some people never noticed
    that.....but the fact was clear. You don't have to
    go that close to see that the structure and sharpness of the grain is
    blurring away. The depth of focus is helped just a little bit by
    stopping down to a smaller f-stop but the lens>filmplanedistance is so
    narrow that the problem is still there. A glasscarrier with two
    glasses was the only real solution. This was not just an issue with
    larger filmformats – even the smaller 35 mm had this. Coldlight
    sources helped, but not much. It just hold it more stable but any
    curvation was creating problems. Again, the only real solution was
    glass on both sides of the film.

    This is also a problem in cameras – more than you ever can imagine.
    But it's hard to make a distinction between that and bad
    lenscorrections. Even my Leica M cams have problems, especially as the
    rearlens of the wideangels are so close to the filmplane, they're real
    wideangels and of no retrofocusdesign. But the grain will always be
    sharp allover when printing with glass. So, one tend to accept that
    unsharpness as a bad lenscorrection, but many times it could be a bad
    flatness of the film in the camera. It's also wellknown fact that is
    just take a single bit of your hair between the lensmpount and lens to
    screw up focus accurance when using a wider lens.

    The Nikonscanners use a weaker lightsource. The working f-stop has to
    be larger. What does that tell you ? There IS a great problem with
    focus allover the film with Nikonscanners. It's not hard to check that
    out in real world. It doesn't get better with the crappy
    filmstripholders made by Nikon. The scanner itself is fantastic, but
    it's sad to see what takes it downhills.

    nikita
     
    nikita, Mar 29, 2004
    #13
  14. Gary L Hunt

    ThomasH Guest

    Re: Dealing with negs on LS4000... [depth of focus problem]

    Raphael Bustin wrote:
    >
    > On Thu, 25 Mar 2004 17:40:42 GMT, ThomasH <> wrote:
    >

    [...]
    > >>

    > >
    > >Exposure problems and foremost color balance handling: yes,
    > >this are the problems which I also experience with NikonScan.
    > >Vuescan is of great help here.
    > >
    > >Scan of negatives with NikonScan is also very troubled.
    > >Especially, I notice from the histograms that NikonScan
    > >never maps darkest gray to 0. All histograms seem to
    > >indicate an offset of approx. 25%!

    >
    > Try scanning your negatives as positives, and inverting
    > them in NikonScan. Look up "dane kosaka LS-8000" on
    > google for a nice site describing the technique.
    >
    > rafe b.
    > http://www.terrapinphoto.com


    Thanks for this tip! It was entirely unknown to me!
    I will give it a try.

    This example unveils though, or confirms rather, a dilemma
    which we have with Nikon: rigid structures and inability to
    move. This "negative scan bug" can be obviously handled
    *using Nikon Scan* only, even on a user interface level.
    The more easy would it be to apply it in the software
    internally. And yet, after several years of waiting we are
    not getting any solution from Nikon.

    I have my own collected list of bugs and weaknesses of
    NikonScan, such as the thumbnail positioning problem and
    exposure problem, of which I posted several examples to
    the web.

    I also was a few times (especially in the beginning) on phone
    with Nikon, directed a few times to Level 2. All this talk,
    as good and nice it is, remains worthless if the software will
    not be fixed. My purchase of a Canon camera was initiated by
    this unspeakable example of arrogance and ignorance presented
    by the software department of the (former) undisputed First
    Diva in Photography, now dragging behind Canon on the base of
    nostalgia... This web page:

    http://www.marginalsoftware.com/LS8000Notes/three_easy_ways.htm

    reassures me that I am not alone in dealing with this problem.
    Photo Magazines resort to the usual approach "Praise the Lord
    and all Products made by its Sheep" and somehow... fail to
    discover *any* problem with NikonScan. Good that we have web.
    We can now address the issues and present them to thousands of
    users by ourselves :) Let me guess now: in this particular
    case Nikon will not fix the software anyway...

    Thomas
     
    ThomasH, Mar 30, 2004
    #14
  15. Gary L Hunt

    ThomasH Guest

    Re: LS4000 depth of focus problem--Nikon LS5000 also, or otheralternatives?

    Kennedy McEwen wrote:
    >
    > >
    > >Exposure problems and foremost color balance handling: yes,
    > >this are the problems which I also experience with NikonScan.
    > >Vuescan is of great help here.
    > >
    > >Scan of negatives with NikonScan is also very troubled.
    > >Especially, I notice from the histograms that NikonScan
    > >never maps darkest gray to 0. All histograms seem to
    > >indicate an offset of approx. 25%!
    > >

    > It does if you tell it to, Thomas. :)
    >
    > However the default setting results in a black level which depends on
    > the density of the film base - that is what defines the black point on a
    > negative. The autoexposure will adjust this to ensure that the CCD
    > level is matched but not saturated in any of the colour channels and,
    > once inverted, the saturation level becomes peak black. Consequently
    > the film base level is therefore offset from this level by an amount
    > dependent on the density of the film base itself - which varies from
    > film type to type. I have never seen this get above 10 percent
    > (histogram black level=25).


    You are correct, my fault. I misspoke by calling this value
    on the histogram as a percentage value! It is indeed approx.
    10% on the 0..255 scale used by Nikon.

    Thomas
     
    ThomasH, Mar 30, 2004
    #15
  16. Re: LS4000 depth of focus problem--Nikon LS5000 also, or other alternatives?

    In article <>, ThomasH <>
    writes
    >Kennedy McEwen wrote:
    >>
    >> >
    >> >Exposure problems and foremost color balance handling: yes,
    >> >this are the problems which I also experience with NikonScan.
    >> >Vuescan is of great help here.
    >> >
    >> >Scan of negatives with NikonScan is also very troubled.
    >> >Especially, I notice from the histograms that NikonScan
    >> >never maps darkest gray to 0. All histograms seem to
    >> >indicate an offset of approx. 25%!
    >> >

    >> It does if you tell it to, Thomas. :)
    >>
    >> However the default setting results in a black level which depends on
    >> the density of the film base - that is what defines the black point on a
    >> negative. The autoexposure will adjust this to ensure that the CCD
    >> level is matched but not saturated in any of the colour channels and,
    >> once inverted, the saturation level becomes peak black. Consequently
    >> the film base level is therefore offset from this level by an amount
    >> dependent on the density of the film base itself - which varies from
    >> film type to type. I have never seen this get above 10 percent
    >> (histogram black level=25).

    >
    >You are correct, my fault. I misspoke by calling this value
    >on the histogram as a percentage value! It is indeed approx.
    >10% on the 0..255 scale used by Nikon.
    >

    Well, I take it back in any case Thomas.

    I just remembered some very fogged negatives that I have, very fogged
    indeed, and the base level is around 74 on RGB, but over 130 in the red
    channel!

    Having said that, the suggestions I gave to adjust the black level still
    worked although, with the seriously reduced dynamic range of the images,
    that simply shifted the white point as well - resulting in further
    compression due to the system gamma applied. IMO, the best solution was
    still to use the second option.

    It seems to me that scanning as a positive and then inverting it in
    software would only work in a linear gamma space - although I suppose
    that some folks might consider the artificially stretched shadows and
    compressed highlights that would result from implementing that method in
    normal gamma work space to be preferable to correct gamma.
    --
    Kennedy
    Yes, Socrates himself is particularly missed;
    A lovely little thinker, but a bugger when he's pissed.
    Python Philosophers (replace 'nospam' with 'kennedym' when replying)
     
    Kennedy McEwen, Mar 30, 2004
    #16
  17. Re: Dealing with negs on LS4000... [depth of focus problem]

    On Tue, 30 Mar 2004 17:13:22 GMT, ThomasH <> wrote:


    >Thanks for this tip! It was entirely unknown to me!
    >I will give it a try.
    >
    >This example unveils though, or confirms rather, a dilemma
    >which we have with Nikon: rigid structures and inability to
    >move. This "negative scan bug" can be obviously handled
    >*using Nikon Scan* only, even on a user interface level.
    >The more easy would it be to apply it in the software
    >internally. And yet, after several years of waiting we are
    >not getting any solution from Nikon.
    >
    >I have my own collected list of bugs and weaknesses of
    >NikonScan, such as the thumbnail positioning problem and
    >exposure problem, of which I posted several examples to
    >the web.


    <snip>

    I've used a number of scanner drivers over the years.

    In the overall scheme of things NikonScan isn't bad at all.

    It has its quirks and idiosyncracies, but it's generally stable
    and gets the job done. It has all the tools I need or expect,
    and they work pretty much as I'd expect them to.


    rafe b.
    http://www.terrapinphoto.com
     
    Raphael Bustin, Mar 31, 2004
    #17
  18. Gary L Hunt

    Gary L Hunt Guest

    Re: LS4000 depth of focus problem--Nikon LS5000 also, or other alternatives?

    (nikita) wrote in message news:<>...
    > "I think that is gossip and rumor".
    >
    > Well, if you mean the wellknown fact of the narrow depth of focus in
    > the Nikonscanners, then you're dead wrong.
    >

    .....>
    > The Nikonscanners use a weaker lightsource. The working f-stop has to
    > be larger. What does that tell you ? There IS a great problem with
    > focus allover the film with Nikonscanners. It's not hard to check that
    > out in real world. It doesn't get better with the crappy
    > filmstripholders made by Nikon. The scanner itself is fantastic, but
    > it's sad to see what takes it downhills.
    >
    > nikita


    I don't know about the "weaker lightsource", but I do believe the scanner
    lens is probably faster (i.e. less DOF), probably in order to speed up
    scan times. (It's the fastest by far of the 3 slide scanners I've owned.)
    I love most everything about it--except for having razor-sharp slides in
    the middle that are visibly blurry at the edges and corners.

    There's at least one pretty decent Web page illustrating the DOF problem
    (http://members.austarmetro.com.au/~julian/photography/ls2000-focus.htm)
    whose results agree very closely with my own experience. If you walk the
    autofocus point around over a slide, it's common for the range of settings
    to vary by 30-50 "points" or more, and the DOF is maybe about +/-10 for
    critical enlargements. If you pick a compromise point for focusing (e.g.
    about halfway between the middle and the edge), the central focus is good
    over most of the image--but the extreme edges are never in focus, at least
    for my cardboard mounted slides. For lots of subjects it doesn't matter.
    For landscapes, it does.

    The new LS-9000 has some kind of diffuser built into it, evidently in
    recognition of this problem, but the LS5000 does not, it turns out. So I'm
    still looking for a fast, accurate, auto-feeding, does-everything-but-
    make-bread slide scanner with enough DOF for my cardboard-mounted slides.
    (Not holding breath.)

    Gary Hunt <>
     
    Gary L Hunt, Apr 6, 2004
    #18
  19. Gary L Hunt

    nikita Guest

    Re: LS4000 depth of focus problem--Nikon LS5000 also, or other alternatives?

    Gary,

    the "weaker lightsource" is LEDs intensitylevels compared to more the
    common halogen or whatever used in most other filmscanners. So,
    faster/short scantimes in combo with weaker light source means an even
    faster lens.....
    The lightsource itself is terrific. And it's very gentle with the
    film.

    Anyway, IF the grain – and the structure of it – is clearly visible,
    It's also very disturbing when the grain in some areas of the picture
    is halfway into a decent focus while others are razorsharp. Like a bad
    use of the treshold value when sharpening with USM. The eye will see
    that as we're focusing at the grain as well as the rest of the
    "picture sharpness". A slightly blurred grain looks crappy and sloppy.
    Sure, different outputs will mask this more or less. But the fact is
    still there; it's very difficult to get the whole frame sharp with the
    Nikonscanners. Even when using the "compromise focus point method" it
    mostly fails to deliver. It depends so much on where in the
    filmstripholder/autofeeder (or whatever in use) the filmframe is
    located. It's not an equal corner to corner situation over the frame.
    Then add differences in air humidity. In dry areas of the world, film
    will curve with a lot of strenght. This easily bends the filmholder
    differently in the weak parts. In the outer end of the holder it
    pushes the filmplane more. In such situation the compromise
    focusingpoint is justy a dream. The trial and error method is kind of
    frustrating.....

    The glass on both side is the optimal, but a workaround with 35 mm
    darkroomenlargers has been to mount a longer focal lenght than
    normally used. Instead of 50 mm a 60, 75 or 80 gives a better depth of
    focus at the filmplane. It's more narrow at the "paperside" of the
    lens like a camera with a longer lens – but larger on the other side.
    Just look at a telelens; When focusing the lens moves much more in and
    out from the filmplane than a wideangel......

    Nikon might play with THAT in mind when building the next generation
    of filmscanners. But I doubt that we will see a new generation in the
    near future. It's amazing that Nikon haven't taken this as a problem
    allready.

    As for diffusers, it's not a solution for this problem. It is when it
    comes to deal with the character of the harsh LEDs as a lightsource in
    some ways perhaps. It would be better if we could get the sharpness
    back than hiding the differences between sharp areas>>blurred..

    nikita
     
    nikita, Apr 6, 2004
    #19
  20. Re: LS4000 depth of focus problem--Nikon LS5000 also, or other alternatives?

    In article <>, Gary L
    Hunt <> writes
    >
    >I don't know about the "weaker lightsource", but I do believe the scanner
    >lens is probably faster (i.e. less DOF), probably in order to speed up
    >scan times.


    Nope, the lens is the same speed as the LS-4000. The LS-5000 is twice
    as fast as its predecessor (20sec v's 38sec) because it uses a double
    CCD - the same technique as the LS-8000 used for its high speed mode,
    but with two lines instead of three. Hopefully it does not suffer from
    the same mechanical resonance which made that (default!) option unusable
    in the LS-8000.
    --
    Kennedy
    Yes, Socrates himself is particularly missed;
    A lovely little thinker, but a bugger when he's pissed.
    Python Philosophers (replace 'nospam' with 'kennedym' when replying)
     
    Kennedy McEwen, Apr 6, 2004
    #20
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