Micro / Macro question?

Discussion in 'Digital Point & Shoot Camera' started by Dr. Leonard H. McCoy, Mar 28, 2008.

  1. I need to photograph small objects at a distance of 2-4 inches (5-10 cm) from
    the lens. I want a magnification of ~50 to 100.

    Photomicrography (using microscopes) is limited in the working distance from
    the objective; it needs to be <1 inch. Photomacrography is limited in the
    magnification; typically <10.

    I'd like a solution that terminates with filter threads (any size can be
    adapted) so I may attach a digicam.

    Suggestions?

    If there is a better forum in which to ask this question, just point the
    way...

    Thanks.
     
    Dr. Leonard H. McCoy, Mar 28, 2008
    #1
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  2. Hi Doc,

    Seems like your solution would be an 'industrial' type microscope, not the
    ones used in medicine. These usually go to the magnification and the working
    distances you need. The better ones will zoom and have a ring-type
    illuminator. A camera will usually attach with a 'C' mount. If you want to
    use a P&S camera, make sure that a 'C' mount can be attached to it.
    A stereo microscope with a camera tube will let you view the image through
    the right lens, while using the left one for the camera. Fancier ones will
    even have a third objective lens, allowing taking photographs while having
    full stereo vision. Hope this helps.
     
    Happy Traveler, Mar 28, 2008
    #2
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  3. You are mixing a lot of different technologies.

    Let's try again.

    What is the size of the object to be photographed? Is it two
    dimensional? Is it important to keep the entire depth in focus? How much
    depth is there? Is the surface shiny or flat? Is there a lot of detail?
    What type of camera are you using or do you have available? Digital?
    Lenses? Lighting? Does the subject move? How will the results be viewed?
    In a book, a large print as video etc.
     
    Joseph Meehan, Mar 28, 2008
    #3
  4. Sorry I hit send too soon. It is not clear if you know or are asking
    about Macro vs Micro. In the traditional sense Macro is anything recorded
    on the light sensitive material at life size or smaller to about half to
    quarter life size. Micro is used for anything recorded larger than life
    size. Those terms don't have a lot of meaning in the digital world with
    the changes in sensor size, but from a technical view, I would guess they
    still apply.
     
    Joseph Meehan, Mar 28, 2008
    #4
  5. Dr. Leonard H. McCoy

    TRoss Guest

    I think what you're looking for is a stereo or stereo zoom microscope.
    It's sometimes called a dissecting microscope. You'll also need an
    eyepiece adapter for your camera ... or buy an eyepiece camera.

    What are you trying to photograph?


    TR
     
    TRoss, Mar 28, 2008
    #5
  6. What is the size of the object to be photographed?

    ~50 micron
    They are roughly spherical in shape.
    Not sure. Not important. Suspended, submerged in clear water, so of high
    contrast.
    No. Confirming presence and number will be sufficient.
    Have Canon P&S A95 digital.
    researchers.
     
    Dr. Leonard H. McCoy, Mar 29, 2008
    #6
  7. Dr. Leonard H. McCoy

    Paul Furman Guest

    1 millimeter = 1,000 microns so if they were closely spaced, 100 of them
    could be counted in a screen sized mm wide strip (ballpark scope).

    7.18 x 5.32 mm sensor so the 1mm wide frame would be about 7x.... but
    that's not how things are stated in photography, the "7x" in camera
    speak is a completely different number, anyways it would be a job for a
    microscope mounted camera.

    The Nikon Multiphot system
    http://www.microscopyu.com/museum/multiphot.html
    .... goes up to 40x which means a 24x36mm sensor capturing 40x life size.
    1/40th of 36mm is .9mm... round that off to 1mm so that would work for
    your purposes with a DSLR, but you don't need to make huge beautiful
    prints at that size so probably something much less powerful is needed.

    Re-reading your original question....

    Hmmm, so you need a longer focal length to keep further from the
    subject. That is odd because extreme closeups are usually done with
    short focal length lenses, like the Multiphot above uses 19mm at 1:40
    and 120mm at 1:1. To use longer focal lengths would require a very long
    tall bellows.
     
    Paul Furman, Mar 29, 2008
    #7
  8. Hmmm, so you need a longer focal length to keep further from the
    But since the subjects are submerged, longer working distance is necessary.
    For example...? Can you give me an idea of what lens (backward?) and what
    bellow length? Just a ball park idea...
     
    Dr. Leonard H. McCoy, Mar 29, 2008
    #8
  9. From "The Science of Imaging: An Introduction" by Graham
    Saxby,

    Photomacrography is the making of an image that is larger
    than the object using conventional camera technques.

    Photomicrography is te technique of imaging through a
    microscope.

    Generally though, macro has become more broad in meaning and is
    now commonly used for 1:4 ratios on zoom lenses rather than only
    at 1:1 or more.

    But the basic difference is the use of a compound
    microscope (micro) rather than a generic camera lense
    (macro).
     
    Floyd L. Davidson, Mar 29, 2008
    #9
  10. You want to look at a web cam mounted on a dissecting
    scope. That combination will give you the lense to
    subject distance you need and allow both optical and
    through the camera viewing (and you will soon enough
    determine that optical viewing is great for the initial
    setup, while through the camera viewing is essential for
    photography).

    This web site has a large selection of articles
    describing virtually all aspects of photomicrography.
    For you purposes be sure to read the ones involving
    dissecting microscopes, but for a general overview
    you'll want at least scan through some of the others
    too.

    http://www.microscopy-uk.org.uk/mag/libindex3.html
    To get the magnification you need, that is not within
    reason.
     
    Floyd L. Davidson, Mar 29, 2008
    #10
  11. Dr. Leonard H. McCoy, Mar 29, 2008
    #11
  12. Dr. Leonard H. McCoy

    Paul Furman Guest

    I think it's a microscope job but I'll try to make an educated guess for
    an SLR setup. A regular 200mm lens needs about 200mm of
    extension/bellows to reach 1:1 and a typical bellows is about 200mm, so,
    I'm not sure, say you start with a 200mm macro lens already at 1:1,
    another 200mm of extension brings it to 1:2 which is still a 12mm wide
    field of view and you want to see about a 1mm frame. Well, if that's a
    10MP image, 3,000 pixels across & 3 pixels is enough to resolve an
    object & you can crop to 750 pixels wide field of view of 3mm... not
    rteally enough detail. I'm not sure the working distance of this setup
    but would guess at least 4 inches. The Canon 65mm MPE goes to 1:5 and
    probably has a working distance considerably less than 2 inches so maybe
    an in between focal length, 100mm macro lenses are common but I think
    you'd need something designed for more magnification: something more
    like a microscope lens, not a 35mm still lens:

    Here's that Multiphot setup with what looks to be about 400mm of
    extension (twice the size of a normal bellows):
    http://www.naturfotograf.com/images/U020812490.jpg
    Here's the lenses which go with it:
    http://www.naturfotograf.com/lens_spec.html
     
    Paul Furman, Mar 29, 2008
    #12
  13. Dr. Leonard H. McCoy

    Anyoldiron Guest

    Hi there,

    If it can be done, then the people at Brunel Microscopes will know:
    http://www.brunelmicroscopes.co.uk/

    I have several of their IMXZ 'scopes with digital cameras for field of views
    ranging from 50mm diameter down to around 1mm. At 1mm you will easily be
    able to count/detect 50um particles.

    A
     
    Anyoldiron, Apr 2, 2008
    #13
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