looking for "cheap" digital camera

Discussion in 'Digital Photography' started by user, Feb 6, 2008.

  1. user

    user Guest

    I need advice.

    I'm looking for a camera for a special "scientific" purpose. Our old things
    are dying.

    I just need to take picture of a fluorescent screen. It's about 8 inches in diameter and
    green and dim. My Canon 30D takes excellent pictures at ISO 800 and a second or so
    exposure. I know that say an XTi would work fine. BUT ... it is in an
    undergrad lab and we would have to worry a lot about theft, or keep it in
    a locked place, a terrible pain. It will be permanently tied down, and could
    be epoxied to a secure tether.

    What I need is:

    manual exposure in the seconds range ... if a small sensor P&S could
    do 10 seconds the small pixels would be OK.

    MANUAL FOCUS because the screen is dim and rather 3D. My 30D can focus on it,
    unreliably.

    Picture quality is immaterial. Megapixels are a minus ... 1 MP would be fine.
    JPEG will do, ideally uncompressed RAW would be better. If lots of pixels,
    downsampled JPEGS would be good too.

    The field of view we need is about 8 inches diameter at about 4 feet, which
    works out to be 10 degrees, so a long zoom or a modest zoom plus lots of
    digital zoom would be needed. Remember, the crap quality from digital
    zoom is OK if a long enough exposure.

    Finally ... having it computer controllable like my 30D is
    would be nice.

    Budget is $600, BUT, cheaper is better because its less likely to be stolen.

    We may have to pay for the manual focus ... its THAT that has me asking
    the question.


    Any suggestions?

    Doug McDonald
     
    user, Feb 6, 2008
    #1
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  2. user

    Paul Furman Guest

    How about a webcam? Fixed focus, low MP, designed for computer control.
     
    Paul Furman, Feb 6, 2008
    #2
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  3. user

    Zhiyong Sun Guest

    I am new to this newsgroup but I think an olympus E410/510 with its kit lens
    (28mm-300mm equivalent) can do the job for you as it has everything you need

    use 2.5' LCD to do live view and focus, you can do just the regular manual
    focus or a 10X magnification, won't miss any focus by this way.
    10m great IQ
    bulb exposure if you want
    Computer controllable but you need the Olympus studio which is about $100 I
    think, you may try it for free of course.
    good high iso (not as good as canon but much better than P&S)

    E410 wtih two lens kit can be had for less than $700. Or just get a E410/510
    body and get a single lens that can do the job. I got a 50mm (100ml equiv)
    F1.8 manual lens for $30.
     
    Zhiyong Sun, Feb 6, 2008
    #3
  4. user

    Martin Brown Guest

    Two thoughts. Find a second hand DC-120 which although a bit crude and
    elderly might be sensitive enough to do what you want and can be
    computer controlled (RS232 so a bit slow). It is also so old and cheap
    now that no-one will pinch it. It is a bit noisy by modern standards and
    has a warm corner of the CCD with extra noise at the 8 & 16s exposures.

    The other is that you should take a look at some of the tethered low
    light monochrome cameras sold for amateur astronomy and industrial use.
    You should not need active thermoelectric cooling for 10-20s exposures
    so you may be able to find something computer controlled via USB with
    manual focus (ie takes M42 or T mount lenses). You don't need very a
    fancy one.

    I suspect $600 will not get you a Mpixel class low light precision
    camera. Closest I could see offhand was the Meade one.

    http://www.buytelescopes.com/product.asp?t=&pid=10340&m=2

    I don't know if it is as good at its brochure claims...

    Regards,
     
    Martin Brown, Feb 6, 2008
    #4
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