UV filter applied on CCD/CMOS (Nikon D80) ?

Discussion in 'Nikon' started by Lorenzo Sandini, Oct 22, 2008.

  1. Hello,

    First post from a DSLR newbie, please bear with me.

    I got a Nikon D80 with a Nikkor 18-55VR objective, and I bought a Sigma
    18-200 for convenience. A friend of mine suggested I buy some Hoya
    filters as well, at least a UV filter for taking photos in bright
    sunshine. He insisted that I could keep it on all times as a protector
    as well, it wouldn't affect the quality of the pictures in other conditions.

    So I went shopping, and the seller told me the CCD sensors on modern
    DSLRs were already coated with an anti-UV layer, and UV filters were
    therefore useless, or recommended for film cameras only. I trusted him
    and bought a simple lens protector.

    I could not find any information relevant to the existence of UV-filter
    coatings on CCDs. Any definite answer ?

    Thank you.

    Lorenzo
     
    Lorenzo Sandini, Oct 22, 2008
    #1
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  2. Lorenzo Sandini

    J. Clarke Guest

    If you googling "uv photography" the third hit was
    http://www.naturfotograf.com/UV_IR_rev00.html, which will tell you
    more than you wanted to know about UV and digital cameras.
     
    J. Clarke, Oct 22, 2008
    #2
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  3. I wouldn't go out to the usenet without one.
    Lens has always sounded like "lentil" (lens culinaris) to me, so I
    prefer to use objective (as in "objektiivi" in finnish). But for my
    first appearance in here I'll accept the criticism as contructive.
    According to what I read here and there, I certainly agree, and I am
    taking recommendations for my next lens (ooh look, I wrote lens). again,
    I am only a beginner...
    Aaaah, friends. What would we do without 'em ? Well, next sunshine will
    be in 6 months or so, so plenty of time to make my mind. (Greetings from
    Finland btw)
    A welding shop would be an interesting place to take photos, thank you
    for the recommendation. Now that I have a lens protector (see ? I wrote
    lens again), I really need to find hostile places :)

    <long snip>

    Thank you for your answer, I'll probably keep the lens protector where
    it is needed, and take photos without whenever I can. As for UV light,
    I'll remember this the next time I'll climb the K2 or the Everest.

    Lorenzo
     
    Lorenzo Sandini, Oct 22, 2008
    #3
  4. Welcome aboard!
    The seller is more correct than your friend. 30 years ago, I wouldn't
    have said that.

    Like most of today's dSLR's, the D80 has built-in UV filtration. Fuji
    briefly made a specialty dSLR that was UV and IR sensitive, and some
    older dSLR's were more sensitive to UV, but for the vast majority of dSLR
    owners a UV filter is only useful as a protector.

    Most modern film is also UV insensitive. Unless you are using tungsten
    balanced color film or traditional black and white film, you don't need
    a UV filter with film.

    Furthermore, both of your lenses also have coatings and optical cement
    which block most UV. This is true of the vast majority of lenses made
    in the last 25 years.

    Using any filter can impact image quality. Every air-glass surface
    results in some light loss and increased risk of flare. Unlike clear
    protectors, UV filters also filter out some additional visible purple
    and indigo light. You can see this by placing a UV filter on a bright
    white sheet of paper.

    If you use a top-quality multicoated UV filter like a Nikon L37c, under
    many circumstances you will only detect the difference by "pixel
    peeping" each shot and doing a side-by-side comparison. A cheap,
    uncoated UV _or_ clear filter will cost you at least 9% of your light,
    plus greatly increase the chance of flare.

    I do own some very old lenses, and do use UV sensitive film at times.
    As a result, I own B+W 010 MRC UV filters, but usually shoot without
    a filter.
     
    Michael Benveniste, Oct 22, 2008
    #4
  5. Lorenzo Sandini wrote:
    []

    I have no problems with the term objective.

    David
     
    David J Taylor, Oct 22, 2008
    #5
  6. Lorenzo Sandini

    * Guest

    Hmmm, you arrogant arsehole! The OP is in Finland, so English isn't his
    first language. Objective is technically correct, as is lens. However lense
    is not the common spelling of lens. It is sort of correct, but not the
    accepted version. As for "freaking"

    intr. & tr.v. freak·ing, Slang

    To experience or cause to experience frightening hallucinations or feelings
    of paranoia, especially as a result of taking a drug. Often used with out.
    To behave or cause to behave irrationally and uncontrollably. Often used
    with out.
    To become or cause to become greatly excited or upset. Often used with out.

    So how can a lens "freak out"???

    I bet Lorenzo speaks better English that you speak Finnish! The Internet,
    and usenet are global. What will you do next correct the 90% of the English
    speaking World that uses the word colour, instead of the USA variant color?
     
    *, Oct 22, 2008
    #6
  7. Lorenzo Sandini

    Don Stauffer Guest

    Floyd L. Davidson wrote:
    ..
    ..
    In optics terminology the main imageforming lens of a camera is
    frequently termed an "objective" lens. This differentiates it from any
    lenses in the viewfinder, rangefinder, etc.
     
    Don Stauffer, Oct 22, 2008
    #7
  8. Convenience, yes. High quality ... not so much. If your glass
    is good enough and fast enough for you, more power to you.
    Not needed. Digital cameras have white balance, and on Auto mode
    it'll at best countercorrect your filter. (This may be useful
    if you need to e.g. dampen an overabundance red light during
    a concert, but you'll know when you'll be inthat situation.)
    It's called a front cap, or (during shooting) a lens hood.

    Unless it's flying mud, sand, saltwater and so on, then
    you'll want a good, multi-coated protector. Why multicoated
    and so on?
    a) Each element in the optical path --- even air over longer
    distances --- can and will degrade the image quality to some
    degree.
    b) digital sensors are good mirrors. There's a reason why
    lenses with a mostly protective first element don't have a
    flat glass there (this is corrected by the other elements) ---
    reflections from the sensor back on the sensor aren't good for
    image quality. Well-coated protectors reflect much less light.

    Especially in high contrast images you'll probably see
    reflections from the brighter parts in the darker parts.

    c) Light reaching the protector at an angle should not be
    'smeared' over the whole image, that reduces contrast.
    Well-coated protectors do have less effect in that
    situation.
    A lens hood will improve your images, as stray light can be
    prevented from reaching the lens. (Of course, it's somewhat
    complicated to get a good lens hood for a superzoom.)

    -Wolfgang
     
    Wolfgang Weisselberg, Oct 22, 2008
    #8
  9. Lorenzo Sandini

    ASAAR Guest

    The bear has left the room, replaced by your freaking *bull*! :)

    Did you notice that what you quoted has the OP saying that the
    18-200 lens was made by Sigma, not Nikon? But in your never ending
    quest to find ways to provide help that is larded with smugness,
    condescension and superciliousness, you've once again attained your
    lens . . . uh, objective.

    Well, yes, if one knows how to properly use it, and knows enough
    to be able to filter the nonsense it can sometimes dredge up. Many
    agree with your advice, but several (found on the first google
    search results page) didn't. Here's one :
    http://www.graphyphoto.com/labels/U...efits and the Cost to Contrast and Color.html

    Google can indeed be a friend, or rather, point you towards
    useful, friendly advice. But it also does little or nothing to
    shield you from false friends. The OP did himself a favor by asking
    his question here instead of first trying Google, since this smaller
    community does a good job of 'filtering' out those false friends
    that would intentionally or unwittingly provide bogus information.
     
    ASAAR, Oct 22, 2008
    #9
  10. Lorenzo Sandini

    John A. Guest

    "Freaking" is also a bowdlerism, if you want to get technical. :)
     
    John A., Oct 22, 2008
    #10
  11. As long as it's not used subjectively? :)

    That said (the devil made me do it!), is what we know about CCD sensors
    in this context applicable to CMOS sensors as well? I'm about to order a
    Nikon D90, and I'm wondering if there are any practical (as versus the
    obvious deep technical and economic) aspects that will be different.
     
    Blinky the Shark, Oct 22, 2008
    #11
  12. Lorenzo Sandini

    Pboud Guest

    You Bastard... The closest thing I've got here is the rockies.. It's
    just not the same..

    :p

    P.
     
    Pboud, Oct 22, 2008
    #12
  13. Blinky,

    I see no reason for any significant difference if, as Floyd said, it's the
    anti-alias filter which (happens as a side effect) to filter out much of
    the UV. I've seen nothing to suggest that the spectral responses of the
    imaging sensors are significantly different. Of course, there are bound
    to be slight differences between different sensors.

    I've seen some purple flowers reproduce differently on digital to their
    apparent colour (to me), but I've never systematically investigated
    whether the errors can be changed with extra UV filters.

    Enjoy the D90 - I would love to be able to afford one, but the D60 is more
    my level right now!

    Cheers,
    David
     
    David J Taylor, Oct 22, 2008
    #13
  14. Lorenzo Sandini

    Eric Stevens Guest

    You got him in one!


    Eric Stevens
     
    Eric Stevens, Oct 22, 2008
    #14
  15. Lorenzo Sandini

    Doug Jewell Guest

    The effect you are talking about is caused more by the UV
    fluorescents in the paper. White paper has UV fluorescents
    added to it, to make it appear brighter and whiter than it
    really is. Fluorescants mostly respond in the upper blue
    spectrum which can be observed when they glow bluish under a
    blacklight. When you put the UV filter over it, you are
    blocking the UV light reaching the paper, which means the
    fluorescants won't glow, hence the paper appears duller, and
    with a slight colour shift toward red - not because the UV
    filter is changing the visible light reflecting off the
    paper, but because it is changing the invisible light that
    is hitting the paper and hence the fluorescing.

    Fluorescants are also added to laundry detergents to make
    your clothes look brighter and whiter too.

    To see what impact a UV filter has on visible light, look at
    a rainbow, or other spectrum generating device such as a
    prism. Personally, with my Hoya super-multi-coated UV's, I
    can't observe any difference in the visible spectrum.
    Cheaper UV's may have an effect.

    Everything else you said about UV's though is pretty much
    spot on - they do degrade image quality and their only real
    function on digital is as a front element protector.
    I use them whenever I'm operating in snapshot mode, in
    hostile places (such as high wind days), or if there is a
    high chance of anything touching the front element (eg when
    the kids are around - peanut butter fingerprints are damned
    hard to get off). In most cases though, I leave them off.
     
    Doug Jewell, Oct 22, 2008
    #15
  16. Lorenzo Sandini

    Guest Guest

    |
    | I got a Nikon D80 with a Nikkor 18-55VR objective, and I bought a Sigma
    | 18-200 for convenience. A friend of mine suggested I buy some Hoya
    | filters as well, at least a UV filter for taking photos in bright
    | sunshine. He insisted that I could keep it on all times as a protector
    | as well, it wouldn't affect the quality of the pictures in other conditions.
    |
    | So I went shopping, and the seller told me the CCD sensors on modern
    | DSLRs were already coated with an anti-UV layer, and UV filters were
    | therefore useless, or recommended for film cameras only. I trusted him
    | and bought a simple lens protector.
    |
    | I could not find any information relevant to the existence of UV-filter
    | coatings on CCDs. Any definite answer ?

    The UV protection on the sensor is probably, or at least should be, a more
    conservative level of UV blocking. It needs to be certain that it has no
    impact on visible light at all. When I worked with film, I had four grades
    of UV protection filters for different situations. The strongest level had
    some very slight yellow appearance to it, because it was affecting blue light
    a small amount. But that strongest one was most effective at preventing a
    blue cast on snow. I doubt that the built-in UV protection on a digital
    camera will be as effective as the strong UV filter I had.

    I just recently moved into digital after a long pause from doing photography
    at all. I went ahead and got a UV filter for my new camera, even though I
    knew it didn't need it for basic UV protection. I got it more for the purpose
    of having an extra level of physical protection. I couldn't use my filters
    that I have in my film equipment because it was a new size (everything I have
    is 52mm, 62mm and 72mm, but kit lens on my new Canon 450D needs 58mm). I did
    make sure it was a better brand (I recommend B+W, Hoya, and Tiffen) and is
    "super multi coated" to minimize how much it would affect photos.

    In cases where the sunlight would be directly impacting the front of the lens,
    whether in the shot or not, then I would most likely be removing the filter,
    unless I am intentionally trying to create a lot of reflection effects (that,
    too, can be interesting when done in an artistic way).

    If you are new to photography I highly recommend the protective filter as a
    way to protect the lens from YOU. After some time handling the camera, you
    will be less likely to damage the lens by accident, and can then use the
    filter as needed (less so with digital).

    Post processing software can also be used to correct things in photos that
    were hard or even impossible with film. The blue cast/tint of snow on a
    clear sky day can be removed partially or completely by most software that
    has color corrections. So even that isn't much of a worry anymore.

    Actually, I'm looking at doing something a bit radical with digital photos.
    I know that the blue range of light (approximately 400nm to 500nm) does have
    variations within it. For example blue sky has more of the shorter part of
    the blue range than of the longer part. My idea is to use a fairly deep
    yellow filter more commonly used for contrast in black and white photography
    that blocks the shorter 2/3 of the blue range, say about 400-470nm. Then to
    compensate for the reduction in overall blue level, I will post process the
    photos to re-enhance the blue. The theory is that this will leave the sky
    darker than it otherwise would. It's an experiment that remains to be done.
     
    Guest, Oct 22, 2008
    #16
  17. Lorenzo Sandini

    Eric Stevens Guest

    Floyd, you have a short memory. I wasn't referring just to your post
    which attracted the attention of *. I was thinking of our brushes in
    the past. You _are_ an arrogant arsehole and * rightly picked that on
    sight.


    Eric Stevens
     
    Eric Stevens, Oct 23, 2008
    #17
  18. In fact, my present DSLR is a D60, and I do really like it. There were
    just a few things about the D90 that pulled me in. Should have it around
    the first of next week.

    Ironically, I already have the 18-105 kit lens. I one last month as a
    walking-around lens for the D60. When I bought that last spring, I got
    the two-lens kit (18-55 and 55-200 VRs). When the 18-105 came out, I
    thought that a very appealing range, since it starts where the kit lens
    pair does, and goes 50mm further than the wider of those two. Figured
    that would save some lens changes. That was all before I decided to pick
    up a D90. So now I'm getting a body-only D90 kit. At least I didn't get
    hosed on costs, buying lens and then body separately -- I got a new 18-105
    for $199 from a rental house I've gotten to trust, because they got some
    D90s for rental but didn't want to rent the lenses.

    As for moving from D60 to D90, one thing that will take some getting used
    to is the D90 apparently not having a shooting menu on the main LCD, with
    ISO, AF type, AF area, exposure comp, flash comp, flash mode and so on (I
    elaborate for folks not familiar with the camera) there and *easily
    accessible for changing*. I know "everyone" loves the body-top b/w (grey
    and greyer) LCD -- but I find them hard to read compared with full color
    LCD panels. Also, the body-top display is much smaller than the rear LCD,
    which can't help. I'll be very disappointed if I find the D90 shooting
    menu, up there, useless except under certain ambient lighting conditions.

    Sure, I've done my homework, and know that there are dedicated (or at
    least programmable) hard buttons for that array of settings, and that
    certainly makes them accessible. But if I can't read where they're set on
    the little grey-grey display, I'm boogered.
     
    Blinky the Shark, Oct 23, 2008
    #18
  19. Lorenzo Sandini

    ASAAR Guest

    The D90 provides that capability unless I'm misunderstanding what
    you mean. The main difference between the D60 and D90 is that the
    D60's LCD display is always on, unless (I think) you press the
    shutter or bring your eye to the viewfinder. With the D90, the LCD
    is off while shooting, but is turned on while in shooting mode by
    pressing the [INFO] button. Page 10 of the D90's manual shows two
    views of the LCD display and page 11 identifies the 37 camera
    settings that are displayed, and the LCD shows the changed settings
    as you make them. Pressing the [INFO] button a second time enables
    the Quick Settings Display which shows settings for (and lets you
    change, using the multi-selector) Long exposure noise reduction,
    High ISO noise reduction, Active D-Lighting, Picture Control, Fn
    button assignment and AE-L/AF-L button assignment, as well as
    providing Tip displays for these six additional settings.
     
    ASAAR, Oct 23, 2008
    #19
  20. That's about right, yes.
    I was just reading up on buttons, knobs and wheels (at Ken Rockwell's
    site) and discovered this. I am a happier shark, now. :)
    Which all sounds just like what I'm used to with the D60. This is very
    good news. I'm no luddite, but familiarity does have its plusses.

    Thanks!
     
    Blinky the Shark, Oct 23, 2008
    #20
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