Do optical zooms 15X or higher reduce image quality?

Discussion in 'Amateur Video Production' started by HS Crow, Sep 11, 2005.

  1. HS Crow

    HS Crow Guest

    I'm looking to buy my first camcorder and I like the idea of an
    optical zoom in the 20X or greater range, but I'm wondering how a high
    zoom factor effects the image quality. I will be using the camcorder
    on a tripod so shake is not an issue. My budget is roughly $600. Are
    there any issues I should look out for when choosing a camcorder with
    a large zoom factor?
     
    HS Crow, Sep 11, 2005
    #1
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  2. Sure. Given your budget, it will be a lens which will not be very
    light-sensitive, and the further you zoom in, the worse it gets.
    If you would want a lens with that zoom-range, having a constant maximum
    aperture of say f2.8, it would set you back a nice Mercedes :)

    cheers

    -martin-
     
    Martin Heffels, Sep 11, 2005
    #2
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  3. HS Crow

    Doc Guest

    These huge "digital zoom" numbers you see listed on camcorders are complete
    snake oil, just like the massive magnification numbers listed on consumer
    telescopes. I don't have the numbers in front of me but there's a
    mathematical limit to the magnification a given optical instrument can
    yield. You can't continually magnify ever larger an image that's coming
    through a given lens. My Sony TRV-240 Digital8 has 25x optical zoom and
    theoretically has 700x digital zoom, but from what I can see, the digital
    zoom is a complete waste of circuitry. Even at the higher end of the optical
    zoom you lose image clarity. When you get into the digital zoom it gets
    nothing but worse. Looking at the moon fully zoomed in, you can't even
    discern what you're looking at. It's just a big white field with fuzzy grey
    blotches at points.
     
    Doc, Sep 11, 2005
    #3
  4. HS Crow

    Hal Lowe Guest

    There are many issues to check out besides zoom factor, especially if
    your budget is limited. So, make a list of the features that are most
    important to you, including zoom, and find the camera that best meets
    those features. Use the zoom to break any ties you may find.

    Anyway, here's a camera that may be of some interest to you:

    Panasonic PV-GS35. It has a 30x optical zoom, S-video connector
    (out), mic input, accuate color (see Videomaker October issue), 1000x
    digital zoom (although I don't generally recommend using digital
    zoomes) etc.

    NOTE: I have a "Shopping Quick-Help" section on my Digital Photography
    page, so you may want to give that a look. It may help you figure out
    with features: http://www.halowe-graphics.com/photo.html

    Okay the price for the GS35 is $500 USD, but you should be able to
    find it for less.
    http://www.pricegrabber.com/search_attrib.php/page_id=47/vendors[]=PAN

    B&H lists sells it for $429.95, but there are better prices. Make sure
    to check out the seller ratings before ordering (anything).

    Hope this has been helpful and best of luck on your search!

    Hal Lowe

    http://www.halogos.com (logo t-shirts, mugs, etc.)
    http://www.halowe-graphics.com/photo.html (digiPhoto)
    http://www.1and1.com/?k_id=7391019 (web hosting)
    http://www.halowe-graphics.com/tinc?key=0TmhZVQ5&formname=web_email
     
    Hal Lowe, Sep 11, 2005
    #4
  5. HS Crow

    HS Crow Guest

    Thanks for the replies.
    I should have stated that the optical zoom figure is of course not the
    only factor that I'm basing my purchasing decision on. Also, I'm
    completely ignoring the digital zoom factor as I'm aware of their
    serious limitations.
    I was going to buy a lower-end 3CCD Panasonic (GS120, GS75), which
    typically have a 10X zoom. But, because I want to experiment with
    very close-up nature shots, I figured a larger zoom ratio might be
    very useful. I did notice that the Panasonic GS35 has a 30X zoom, has
    had pretty good reviews and is in my price range.
    I guess it's a case of I won't know the answer until I buy something
    and try it out.
    I suppose I was concerned that a 30X zoom on a $500 camcorder might
    not be that useful, if the lens isn't up to it!
     
    HS Crow, Sep 11, 2005
    #5
  6. Not necessarily. Sounds like MACRO ability is more important
    to you than large magnification at long distance.
     
    Richard Crowley, Sep 11, 2005
    #6
  7. HS Crow

    HS Crow Guest

    Not necessarily. Sounds like MACRO ability is more important
    I hear you, but some of the things I want to shoot aren't so
    accessible, hence I thought the need for a zoom. What sort of
    distances do MACROS allow you to shoot from?
     
    HS Crow, Sep 12, 2005
    #7
  8. In that regard, you might probably be better of with a doubler.

    cheers

    -martin-
     
    Martin Heffels, Sep 12, 2005
    #8
  9. Some can focus as close as an inch. Some can
    almost focus on their own front glass! Of course
    when you get that close, lighting is a problem.
     
    Richard Crowley, Sep 12, 2005
    #9
  10. HS Crow

    Jimmy Guest

    What are you using for a lens now? You can get a set of close-up lenses
    that will get you as close as you want and will fit a lens you already have.
     
    Jimmy, Sep 13, 2005
    #10
  11. ...
    Focus "distance" is measured from the *sensor* (film or chip surface), not
    the lens front.

    FYI, my Sony TRV-240 will (in the absence of anything else to focus on)
    focus on the surface dust on the UV filter screwed onto the front of it's
    lens!
     
    Richard Amirault, Sep 13, 2005
    #11
  12. This does not appear to be a universal standard.
     
    Richard Crowley, Sep 13, 2005
    #12
  13. HS Crow

    HS Crow Guest

    I don't currently have a camcorder, I'm asking a few questions here to
    help me choose my first model, see initial post for details.

    How does the add-on lens thing work? Can you add a close-up lens to
    most camcorders in the $500+ range? Do they tend to be proprietary?
    What sort of price range are the low to mid price lenses? It's a
    whole new world to me.
     
    HS Crow, Sep 13, 2005
    #13
  14. It is in fact the official standard in photography.

    For that very reason, many cameras (not necessarily the least
    professional) have a mark on the body to help you locate the film
    plane.

    The mark is a circle with a line through it. The line is coplanar with
    the film plane.

    HTH,
    Gino
     
    Gene E. Bloch, Sep 14, 2005
    #14
  15. HS Crow

    Jimmy Guest

    I have for example, a 50mm lens that has threads on the front where the
    lens cover goes. Most lenses have these for filters. This is also where you
    would attach the close-up lens set. It can be one or more that would give
    you a combined magnification factor of each lens. They come in sets like
    1,2,4 where you can combine to get from 1 to 7. Others sets are available.
    Google for 1,2,4 close-up lenses.
     
    Jimmy, Sep 14, 2005
    #15
  16. Apparently "shooting distance" means film-plane to subject, and
    "working distance" means front-glass to subject. I was thinking
    of "working distance" because it sometimes isn't clear exactly
    where the "film-plane" actually is in small camcorders.

    Thanks for the clarification.
     
    Richard Crowley, Sep 14, 2005
    #16
  17. Thanks for *your* clarification!

    For _practical_ reasons, obviously the working distance is the
    important one - especially in extreme macro modes, since it can be
    pretty hard to get that picture of the mosquito or whatever, when
    you've only got a few millimeters of clearance to deal with. Not to
    mention not knowing where the film plane is. And besides that, no
    one is really measuring these days - we're focussing by eye or by
    autofocus...

    Gino
     
    Gene E. Bloch, Sep 14, 2005
    #17
  18. HS Crow

    Pete D Guest

    I have a D8 (TRV-320) that I use for videoing rock climbers, 25x zoom,
    bloody awesome with inbuilt image stabilization.
     
    Pete D, Sep 14, 2005
    #18
  19. HS Crow

    Pete D Guest

    You have got to be kidding, my TRV-320 see the moon superbly, must be
    something wrong with your machine.
     
    Pete D, Sep 15, 2005
    #19
  20. HS Crow

    davesvideo Guest

    The poster was refering to the digital zoom function, which is a
    pretty useless concept. Full optical zoom with the cheap lens system of
    the 320 is going to cause some provlem, but obviously not serious for
    your purposes.

    Dave
     
    davesvideo, Sep 15, 2005
    #20
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