Digital magnifier?

Discussion in 'Digital Photography' started by Bruce W.1, Jan 3, 2009.

  1. Bruce W.1

    Bruce W.1 Guest

    Does anyone know of a reasonably priced video magnifier that connects to
    a PC using USB?

    I'd like to magnify a variety of things like knife edges, gemstones,
    surface-mount electronics, and insects. So a magnification range of 10x
    to 70x would be good. And I'd like to capture these images with my PC.

    Thinkgeek.com has this nifty microscope:
    http://www.thinkgeek.com/gadgets/electronic/9955/
    however at high magnification it needs to be right next to the subject,
    i.e. one or two inches away. The focal length is too short. I'd like
    some room to work and solder.

    My local library has a Magnisight Explorer, which works up to 70x from
    five inches away:
    http://www.magnisight.com/?page=manualFocus
    It's wonderful but does it not connect with USB, and it's price is
    pretty steep too.

    Are there any zooming USB microscopes out there with a long focal length?

    Thanks for your help.
    Bruce W.1, Jan 3, 2009
    #1
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  2. Bruce W.1

    Paul Furman Guest

    Bruce W.1 wrote:
    > Does anyone know of a reasonably priced video magnifier that connects to
    > a PC using USB?
    >
    > I'd like to magnify a variety of things like knife edges, gemstones,
    > surface-mount electronics, and insects. So a magnification range of 10x
    > to 70x would be good. And I'd like to capture these images with my PC.
    >
    > Thinkgeek.com has this nifty microscope:
    > http://www.thinkgeek.com/gadgets/electronic/9955/
    > however at high magnification it needs to be right next to the subject,
    > i.e. one or two inches away. The focal length is too short. I'd like
    > some room to work and solder.
    >
    > My local library has a Magnisight Explorer, which works up to 70x from
    > five inches away:
    > http://www.magnisight.com/?page=manualFocus
    > It's wonderful but does it not connect with USB, and it's price is
    > pretty steep too.
    >
    > Are there any zooming USB microscopes out there with a long focal length?


    Long focal length macro is fancy and I don't think you will find it in a
    consumer product. But, when those links talk about 70x magnification
    that means from screen size to actual object so it's hard to judge
    exactly what lens spec is involved. A 1:1 macro lens on a 12mp 35mm crop
    frame DSLR will magnify a 24mm wide object to 4256 pixels - on a 150dpi
    monitor, that's 28" wide or 711mm or 30x magnification the way they
    state it. With a 72dpi monitor, that's 62x magnification. A 100mm macro
    lens will do that with about 5 inches clear. That won't give a full
    pixel live preview though but maybe gives some basis for figuring out
    what you need: an HD video camera can output a 1920 pixel wide live
    feed, use a long lens & closeup lenses on that... or probably that much
    quality isn't needed & a small 480x768 live view feed from a digicam can
    be enlarged to fill your screen.

    --
    Paul Furman
    www.edgehill.net
    www.baynatives.com

    all google groups messages filtered due to spam
    Paul Furman, Jan 4, 2009
    #2
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  3. Bruce W.1

    tony cooper Guest

    On Sat, 03 Jan 2009 18:50:43 -0500, "Bruce W.1" <> wrote:

    >Does anyone know of a reasonably priced video magnifier that connects to
    >a PC using USB?
    >
    >I'd like to magnify a variety of things like knife edges, gemstones,
    >surface-mount electronics, and insects. So a magnification range of 10x
    >to 70x would be good. And I'd like to capture these images with my PC.
    >
    >Thinkgeek.com has this nifty microscope:
    > http://www.thinkgeek.com/gadgets/electronic/9955/
    >however at high magnification it needs to be right next to the subject,
    >i.e. one or two inches away. The focal length is too short. I'd like
    >some room to work and solder.
    >
    >My local library has a Magnisight Explorer, which works up to 70x from
    >five inches away:
    > http://www.magnisight.com/?page=manualFocus
    >It's wonderful but does it not connect with USB, and it's price is
    >pretty steep too.
    >
    >Are there any zooming USB microscopes out there with a long focal length?
    >
    >Thanks for your help.


    Build your own:
    http://www.instructables.com/id/Build-a-USB-Digital-Microscope-in-60min-and-15/


    --
    Tony Cooper - Orlando, Florida
    tony cooper, Jan 4, 2009
    #3
  4. On Sat, 03 Jan 2009 18:50:43 -0500, "Bruce W.1" <> wrote:

    >Does anyone know of a reasonably priced video magnifier that connects to
    >a PC using USB?
    >
    >I'd like to magnify a variety of things like knife edges, gemstones,
    >surface-mount electronics, and insects. So a magnification range of 10x
    >to 70x would be good. And I'd like to capture these images with my PC.
    >
    >Thinkgeek.com has this nifty microscope:
    > http://www.thinkgeek.com/gadgets/electronic/9955/
    >however at high magnification it needs to be right next to the subject,
    >i.e. one or two inches away. The focal length is too short. I'd like
    >some room to work and solder.
    >
    >My local library has a Magnisight Explorer, which works up to 70x from
    >five inches away:
    > http://www.magnisight.com/?page=manualFocus
    >It's wonderful but does it not connect with USB, and it's price is
    >pretty steep too.
    >
    >Are there any zooming USB microscopes out there with a long focal length?
    >
    >Thanks for your help.


    What you need is a telescope, not a microscope.

    w.
    Helmut Wabnig, Jan 4, 2009
    #4
  5. Bruce W.1

    jaf Guest

    http://search.ebay.com/search/searc...=compare&copagenum=1&coentrypage=search&fgtp=



    John


    "Bruce W.1" <> wrote in message news:uRS7l.12262$...
    > Does anyone know of a reasonably priced video magnifier that connects to a PC using USB?
    >
    > I'd like to magnify a variety of things like knife edges, gemstones, surface-mount electronics, and insects. So a magnification
    > range of 10x to 70x would be good. And I'd like to capture these images with my PC.
    >
    > Thinkgeek.com has this nifty microscope:
    > http://www.thinkgeek.com/gadgets/electronic/9955/
    > however at high magnification it needs to be right next to the subject, i.e. one or two inches away. The focal length is too
    > short. I'd like some room to work and solder.
    >
    > My local library has a Magnisight Explorer, which works up to 70x from five inches away:
    > http://www.magnisight.com/?page=manualFocus
    > It's wonderful but does it not connect with USB, and it's price is pretty steep too.
    >
    > Are there any zooming USB microscopes out there with a long focal length?
    >
    > Thanks for your help.
    jaf, Jan 4, 2009
    #5
  6. Bruce W.1

    Dave Bell Guest

    Dave Bell, Jan 4, 2009
    #6
  7. Bruce W.1

    Paul Furman Guest

    Paul Furman wrote:
    > Bruce W.1 wrote:
    >> Does anyone know of a reasonably priced video magnifier that connects
    >> to a PC using USB?
    >>
    >> I'd like to magnify a variety of things like knife edges, gemstones,
    >> surface-mount electronics, and insects. So a magnification range of
    >> 10x to 70x would be good. And I'd like to capture these images with
    >> my PC.
    >>
    >> Thinkgeek.com has this nifty microscope:
    >> http://www.thinkgeek.com/gadgets/electronic/9955/
    >> however at high magnification it needs to be right next to the
    >> subject, i.e. one or two inches away. The focal length is too short.
    >> I'd like some room to work and solder.
    >>
    >> My local library has a Magnisight Explorer, which works up to 70x from
    >> five inches away:
    >> http://www.magnisight.com/?page=manualFocus
    >> It's wonderful but does it not connect with USB, and it's price is
    >> pretty steep too.
    >>
    >> Are there any zooming USB microscopes out there with a long focal length?

    >
    > Long focal length macro is fancy and I don't think you will find it in a
    > consumer product.


    A quick google for 'microscope working distance' shows that long
    distances like almost an inch are called 'Extra Long Working Distance'
    http://www.microscopyu.com/articles/formulas/formulasworkingparfocal.html
    So, if you need 5-inches clear, a microscope is not the right tool.

    It would be simple to mount a webcam (with it's lens removed) onto an
    old 35mm macro lens with an aperture ring for manual adjustment. This
    would magnify several times more than I outlined below and would be a
    bit of a waste of the glass because it only uses a small percent of the
    center of the image projected but it should work fine. I've got an old
    bellows lens for example, a Spiratone Macrotel 150mm f/4.5-f/22 which
    I'd sell for probably $50 or less (not sure, I'd give it away frankly)
    it is small, about 1-3/4" dia by 2-1/4 long and a Logitech web cam with
    a sensor about 7mm wide that I paid a little over $100 at radio shack
    for a couple years ago... better low light performance than the cheapest
    ones. 1.3MP Logitech Quickcam for Notebooks Pro. It would need to be
    mounted very very firmly as shake can be very noticeable with that kind
    of focal length & magnification. This setup with the 1:1 macro described
    would magnify 7mm wide to whatever your screen size at 960x720 so
    anyways on a 17-inch monitor it would be about 60x magnification. The
    bellows lens will focus to any distance, at some point the quality will
    be crap but it's just a matter of the distance you mount the webcam from
    the lens. It should look fine at 1:1.


    > But, when those links talk about 70x magnification
    > that means from screen size to actual object so it's hard to judge
    > exactly what lens spec is involved. A 1:1 macro lens on a 12mp 35mm crop
    > frame DSLR will magnify a 24mm wide object to 4256 pixels - on a 150dpi
    > monitor, that's 28" wide or 711mm or 30x magnification the way they
    > state it. With a 72dpi monitor, that's 62x magnification. A 100mm macro
    > lens will do that with about 5 inches clear. That won't give a full
    > pixel live preview though but maybe gives some basis for figuring out
    > what you need: an HD video camera can output a 1920 pixel wide live
    > feed, use a long lens & closeup lenses on that... or probably that much
    > quality isn't needed & a small 480x768 live view feed from a digicam can
    > be enlarged to fill your screen.
    >



    --
    Paul Furman
    www.edgehill.net
    www.baynatives.com

    all google groups messages filtered due to spam
    Paul Furman, Jan 4, 2009
    #7
  8. Bruce W.1

    tony cooper Guest

    On Sun, 04 Jan 2009 11:25:36 -0800, Paul Furman <>
    wrote:

    >Paul Furman wrote:
    >> Bruce W.1 wrote:
    >>> Does anyone know of a reasonably priced video magnifier that connects
    >>> to a PC using USB?
    >>>
    >>> I'd like to magnify a variety of things like knife edges, gemstones,
    >>> surface-mount electronics, and insects. So a magnification range of
    >>> 10x to 70x would be good. And I'd like to capture these images with
    >>> my PC.
    >>>
    >>> Thinkgeek.com has this nifty microscope:
    >>> http://www.thinkgeek.com/gadgets/electronic/9955/
    >>> however at high magnification it needs to be right next to the
    >>> subject, i.e. one or two inches away. The focal length is too short.
    >>> I'd like some room to work and solder.
    >>>
    >>> My local library has a Magnisight Explorer, which works up to 70x from
    >>> five inches away:
    >>> http://www.magnisight.com/?page=manualFocus
    >>> It's wonderful but does it not connect with USB, and it's price is
    >>> pretty steep too.
    >>>
    >>> Are there any zooming USB microscopes out there with a long focal length?

    >>
    >> Long focal length macro is fancy and I don't think you will find it in a
    >> consumer product.

    >
    >A quick google for 'microscope working distance' shows that long
    >distances like almost an inch are called 'Extra Long Working Distance'
    >http://www.microscopyu.com/articles/formulas/formulasworkingparfocal.html
    >So, if you need 5-inches clear, a microscope is not the right tool.
    >

    As someone who distributed Zeiss operating microscopes to surgeons
    for 30 years, I have to disagree. The working distance is set by the
    objective lens. For laryngeal and neurosurgery, a 400mm (almost 16")
    working lens was standard. While operating microscopes and bench
    microscopes are two different things, the point is that a 150mm,
    200mm, 250mm 300mm, or 400m objective lens provide standard working
    distances. These working distances are used in surgery.



    --
    Tony Cooper - Orlando, Florida
    tony cooper, Jan 4, 2009
    #8
  9. Bruce W.1

    Paul Furman Guest

    Paul Furman wrote:
    > Paul Furman wrote:
    >> Bruce W.1 wrote:
    >>> Does anyone know of a reasonably priced video magnifier that connects
    >>> to a PC using USB?
    >>>
    >>> I'd like to magnify a variety of things like knife edges, gemstones,
    >>> surface-mount electronics, and insects. So a magnification range of
    >>> 10x to 70x would be good. And I'd like to capture these images with
    >>> my PC.
    >>>
    >>> Thinkgeek.com has this nifty microscope:
    >>> http://www.thinkgeek.com/gadgets/electronic/9955/
    >>> however at high magnification it needs to be right next to the
    >>> subject, i.e. one or two inches away. The focal length is too
    >>> short. I'd like some room to work and solder.
    >>>
    >>> My local library has a Magnisight Explorer, which works up to 70x
    >>> from five inches away:
    >>> http://www.magnisight.com/?page=manualFocus
    >>> It's wonderful but does it not connect with USB, and it's price is
    >>> pretty steep too.
    >>>
    >>> Are there any zooming USB microscopes out there with a long focal
    >>> length?

    >>
    >> Long focal length macro is fancy and I don't think you will find it in
    >> a consumer product.

    >
    > A quick google for 'microscope working distance' shows that long
    > distances like almost an inch are called 'Extra Long Working Distance'
    > http://www.microscopyu.com/articles/formulas/formulasworkingparfocal.html
    > So, if you need 5-inches clear, a microscope is not the right tool.
    >
    > It would be simple to mount a webcam (with it's lens removed) onto an
    > old 35mm macro lens with an aperture ring for manual adjustment. This
    > would magnify several times more than I outlined below and would be a
    > bit of a waste of the glass because it only uses a small percent of the
    > center of the image projected but it should work fine. I've got an old
    > bellows lens for example, a Spiratone Macrotel 150mm f/4.5-f/22 which
    > I'd sell for probably $50 or less (not sure, I'd give it away frankly)
    > it is small, about 1-3/4" dia by 2-1/4 long and a Logitech web cam with
    > a sensor about 7mm wide that I paid a little over $100 at radio shack
    > for a couple years ago... better low light performance than the cheapest
    > ones. 1.3MP Logitech Quickcam for Notebooks Pro. It would need to be
    > mounted very very firmly as shake can be very noticeable with that kind
    > of focal length & magnification. This setup with the 1:1 macro described
    > would magnify 7mm wide to whatever your screen size at 960x720 so
    > anyways on a 17-inch monitor it would be about 60x magnification. The
    > bellows lens will focus to any distance, at some point the quality will
    > be crap but it's just a matter of the distance you mount the webcam from
    > the lens. It should look fine at 1:1.


    OK I pulled it out & played a little. at about 1:1 I have to put the
    webcam about 7 inches behind the lens and the focus point is about
    20-inches in front of the lens. With a 50mm lens the glass almost
    touches the subject, with an 80mm lens it's about 4 inches away and less
    magnification, maybe 1:2. Those are all on the longest bellows extension
    I can manage which is about 7 inches but you could make a cardboard tube
    of any length though the longer it is, the darker it gets. A larger
    aperture helps brightness but then you get shallow depth of field so
    higher ISO performance helps: better model of webcam.

    You can search ebay for 'bellows lens' and maybe find something around
    100mm or 105mm but those tend to be kind of rare and expensive like $400
    or more. An obsolete 100 or 105 macro lens should work fine, like this:
    http://www.mir.com.my/rb/photography/companies/nikon/nikkoresources/preAI70/micro105mm.htm
    for under $200 and while you don't need a bellows (cardboard tube will
    work), a bellows can be bought for $30-$100 used, maybe more if it
    includes a focusing rail which would also be very handy. It's difficult
    to find the right focus distances otherwise and the bellows makes it all
    adjustable with a built in mount screw. So we are looking at around $400
    for a decent setup. Like I said, not something you will find as a common
    consumer product.

    PS removing the lens on my webcam removes the infrared filter which may
    or may not be a good thing for your purposes... probably no harm, maybe
    useful. It makes ugly color photos. You could get an IR filter for the
    front of the lens.

    PPS you won't get this out of a compact digital, for example a Panasonic
    FZ20 has a 36-432mm lens but that's stated as '35mm equivalent' so the
    real focal length at 432 eq. is 27mm and we already determined you
    really need about a 100mm lens in real terms. My 150mm bellows lens
    would work but the bellows extension needed is so long that it's going
    to be quite dark so something in the range of 80-100mm is optimal for
    your needs... maybe a little different but somewhere in that ballpark.
    It's possible that a zoom lens marketed with the term 'macro' will work
    but maybe not sharp enough. The little webcam has such a high pixel
    density that it is probably more demanding on the quality of the lens
    than a 35mm camera and those 'macro' zooms aren't designed to be sharp
    at full 1:1 magnification.


    >> But, when those links talk about 70x magnification that means from
    >> screen size to actual object so it's hard to judge exactly what lens
    >> spec is involved. A 1:1 macro lens on a 12mp 35mm crop frame DSLR will
    >> magnify a 24mm wide object to 4256 pixels - on a 150dpi monitor,
    >> that's 28" wide or 711mm or 30x magnification the way they state it.
    >> With a 72dpi monitor, that's 62x magnification. A 100mm macro lens
    >> will do that with about 5 inches clear. That won't give a full pixel
    >> live preview though but maybe gives some basis for figuring out what
    >> you need: an HD video camera can output a 1920 pixel wide live feed,
    >> use a long lens & closeup lenses on that... or probably that much
    >> quality isn't needed & a small 480x768 live view feed from a digicam
    >> can be enlarged to fill your screen.


    --
    Paul Furman
    www.edgehill.net
    www.baynatives.com

    all google groups messages filtered due to spam
    Paul Furman, Jan 4, 2009
    #9
  10. Bruce W.1

    Paul Furman Guest

    tony cooper wrote:
    > Paul Furman wrote:
    >
    >> A quick google for 'microscope working distance' shows that long
    >> distances like almost an inch are called 'Extra Long Working Distance'
    >> http://www.microscopyu.com/articles/formulas/formulasworkingparfocal.html
    >> So, if you need 5-inches clear, a microscope is not the right tool.
    >>

    > As someone who distributed Zeiss operating microscopes to surgeons
    > for 30 years, I have to disagree. The working distance is set by the
    > objective lens. For laryngeal and neurosurgery, a 400mm (almost 16")
    > working lens was standard. While operating microscopes and bench
    > microscopes are two different things, the point is that a 150mm,
    > 200mm, 250mm 300mm, or 400m objective lens provide standard working
    > distances. These working distances are used in surgery.


    Yeah but how much do those objectives cost?

    http://www.lowpowermicroscopes.com/
    "Low power microscopes also have much longer working distances, as much
    as 100mm, and even more if used with bottom reduction objective lens.
    This allows room to get tools such as soldering irons under the
    objective for doing microscopic work."

    Hmm, OK $250 for a complete microscope with USB webcam, not bad at all:
    http://www.stereomicroscopes.com/001a000m.html
    640x480 isn't much but well there's examples to judge from. The working
    distance is about 4 inches max.


    --
    Paul Furman
    www.edgehill.net
    www.baynatives.com

    all google groups messages filtered due to spam
    Paul Furman, Jan 4, 2009
    #10
  11. Bruce W.1

    tony cooper Guest

    On Sun, 04 Jan 2009 13:23:04 -0800, Paul Furman <>
    wrote:

    >tony cooper wrote:
    >> Paul Furman wrote:
    >>
    >>> A quick google for 'microscope working distance' shows that long
    >>> distances like almost an inch are called 'Extra Long Working Distance'
    >>> http://www.microscopyu.com/articles/formulas/formulasworkingparfocal.html
    >>> So, if you need 5-inches clear, a microscope is not the right tool.
    >>>

    >> As someone who distributed Zeiss operating microscopes to surgeons
    >> for 30 years, I have to disagree. The working distance is set by the
    >> objective lens. For laryngeal and neurosurgery, a 400mm (almost 16")
    >> working lens was standard. While operating microscopes and bench
    >> microscopes are two different things, the point is that a 150mm,
    >> 200mm, 250mm 300mm, or 400m objective lens provide standard working
    >> distances. These working distances are used in surgery.

    >
    >Yeah but how much do those objectives cost?
    >

    That wasn't my point and isn't my concern. My disagreement is over
    the statement "a microscope is not the right tool" based on the
    working distance being over 5".

    In an earlier post I suggested using a modified webcam because I
    understand the OP is looking for a minimal investment solution.


    --
    Tony Cooper - Orlando, Florida
    tony cooper, Jan 4, 2009
    #11
  12. Bruce W.1

    Paul Furman Guest

    tony cooper wrote:
    > On Sun, 04 Jan 2009 13:23:04 -0800, Paul Furman <>
    > wrote:
    >
    >> tony cooper wrote:
    >>> Paul Furman wrote:
    >>>
    >>>> A quick google for 'microscope working distance' shows that long
    >>>> distances like almost an inch are called 'Extra Long Working Distance'
    >>>> http://www.microscopyu.com/articles/formulas/formulasworkingparfocal.html
    >>>> So, if you need 5-inches clear, a microscope is not the right tool.
    >>>>
    >>> As someone who distributed Zeiss operating microscopes to surgeons
    >>> for 30 years, I have to disagree. The working distance is set by the
    >>> objective lens. For laryngeal and neurosurgery, a 400mm (almost 16")
    >>> working lens was standard. While operating microscopes and bench
    >>> microscopes are two different things, the point is that a 150mm,
    >>> 200mm, 250mm 300mm, or 400m objective lens provide standard working
    >>> distances. These working distances are used in surgery.

    >> Yeah but how much do those objectives cost?
    >>

    > That wasn't my point and isn't my concern. My disagreement is over
    > the statement "a microscope is not the right tool" based on the
    > working distance being over 5".
    >
    > In an earlier post I suggested using a modified webcam because I
    > understand the OP is looking for a minimal investment solution.


    Here's a real simple one for under $100, which could have a webcam
    mounted on it somehow:
    http://www.microscopeworld.com/MSWorld/detail.aspx?ID=50

    --
    Paul Furman
    www.edgehill.net
    www.baynatives.com

    all google groups messages filtered due to spam
    Paul Furman, Jan 4, 2009
    #12
  13. Bruce W.1

    J. Clarke Guest

    Paul Furman wrote:
    > tony cooper wrote:
    >> On Sun, 04 Jan 2009 13:23:04 -0800, Paul Furman
    >> <>
    >> wrote:
    >>
    >>> tony cooper wrote:
    >>>> Paul Furman wrote:
    >>>>
    >>>>> A quick google for 'microscope working distance' shows that long
    >>>>> distances like almost an inch are called 'Extra Long Working
    >>>>> Distance'
    >>>>> http://www.microscopyu.com/articles/formulas/formulasworkingparfocal.html
    >>>>> So, if you need 5-inches clear, a microscope is not the right
    >>>>> tool.
    >>>>>
    >>>> As someone who distributed Zeiss operating microscopes to
    >>>> surgeons
    >>>> for 30 years, I have to disagree. The working distance is set by
    >>>> the objective lens. For laryngeal and neurosurgery, a 400mm
    >>>> (almost 16") working lens was standard. While operating
    >>>> microscopes and bench microscopes are two different things, the
    >>>> point is that a 150mm, 200mm, 250mm 300mm, or 400m objective lens
    >>>> provide standard working distances. These working distances are
    >>>> used in surgery.
    >>> Yeah but how much do those objectives cost?
    >>>

    >> That wasn't my point and isn't my concern. My disagreement is over
    >> the statement "a microscope is not the right tool" based on the
    >> working distance being over 5".
    >>
    >> In an earlier post I suggested using a modified webcam because I
    >> understand the OP is looking for a minimal investment solution.

    >
    > Here's a real simple one for under $100, which could have a webcam
    > mounted on it somehow:
    > http://www.microscopeworld.com/MSWorld/detail.aspx?ID=50


    Here's a bunch of USB eyepiece cameras
    http://www.sunrisedino.com/index.php?main_page=index&cPath=2. Google
    shopping has more than a thousand hits ranging from 50 bucks to around
    2000.

    Read all the fine print--I don't vouch for any of them, although I
    suspect that the Zeiss are pretty good <grin>.



    --
    --
    --John
    to email, dial "usenet" and validate
    (was jclarke at eye bee em dot net)
    J. Clarke, Jan 4, 2009
    #13
  14. Bruce W.1

    tony cooper Guest

    On Sun, 04 Jan 2009 14:20:36 -0800, Paul Furman <>
    wrote:

    >tony cooper wrote:
    >> On Sun, 04 Jan 2009 13:23:04 -0800, Paul Furman <>
    >> wrote:
    >>
    >>> tony cooper wrote:
    >>>> Paul Furman wrote:
    >>>>
    >>>>> A quick google for 'microscope working distance' shows that long
    >>>>> distances like almost an inch are called 'Extra Long Working Distance'
    >>>>> http://www.microscopyu.com/articles/formulas/formulasworkingparfocal.html
    >>>>> So, if you need 5-inches clear, a microscope is not the right tool.
    >>>>>
    >>>> As someone who distributed Zeiss operating microscopes to surgeons
    >>>> for 30 years, I have to disagree. The working distance is set by the
    >>>> objective lens. For laryngeal and neurosurgery, a 400mm (almost 16")
    >>>> working lens was standard. While operating microscopes and bench
    >>>> microscopes are two different things, the point is that a 150mm,
    >>>> 200mm, 250mm 300mm, or 400m objective lens provide standard working
    >>>> distances. These working distances are used in surgery.
    >>> Yeah but how much do those objectives cost?
    >>>

    >> That wasn't my point and isn't my concern. My disagreement is over
    >> the statement "a microscope is not the right tool" based on the
    >> working distance being over 5".
    >>
    >> In an earlier post I suggested using a modified webcam because I
    >> understand the OP is looking for a minimal investment solution.

    >
    >Here's a real simple one for under $100, which could have a webcam
    >mounted on it somehow:
    >http://www.microscopeworld.com/MSWorld/detail.aspx?ID=50


    I am much more impressed by someone who comes up with a Rube Goldberg
    device built on the cheap than I am with high magnification shots
    through a purpose-built microscope. If duct tape is involved, I like
    it.


    --
    Tony Cooper - Orlando, Florida
    tony cooper, Jan 4, 2009
    #14
  15. Bruce W.1

    tony cooper Guest

    On Mon, 05 Jan 2009 00:03:17 -0600, Richard J Kinch
    <> wrote:

    >tony cooper writes:
    >
    >> As someone who distributed Zeiss operating microscopes to surgeons
    >> for 30 years, I have to disagree. The working distance is set by the
    >> objective lens. For laryngeal and neurosurgery, a 400mm (almost 16")
    >> working lens was standard. While operating microscopes and bench
    >> microscopes are two different things, the point is that a 150mm,
    >> 200mm, 250mm 300mm, or 400m objective lens provide standard working
    >> distances. These working distances are used in surgery.

    >
    >True, but the working distance of a compound microscope is by definition
    >limited to something less than the objective focal length. Otherwise it is
    >a telescope! And since NA is likewise a function of focal length, it also
    >limits working distance for a given clear aperture in the microscope
    >objective.
    >
    >Operating microscopes are basically low-magnification reflected-light
    >stereo types. As indeed they must be, since one cannot transmit high NA
    >light to a surgical field. Essentially a classy pair of loupes.


    Going back to the OP's post, he was looking for a device for
    photography of "...a variety of things like knife edges, gemstones,
    surface-mount electronics, and insects. So a magnification range of
    10x to 70x would be good."

    When you consider this, the term "low-magnification" covers what he
    wants to do. Operating microscopes do magnify in this range. At
    their magnification range, he'll be able to photograph a sugar ant.
    He isn't, seemingly, interested in determining the color of the ant's
    eyes.

    We tend to drift, in these threads, from the original question or
    comment. In this case, away from the fact that there is no limitation
    of a 5" working distance.






    --
    Tony Cooper - Orlando, Florida
    tony cooper, Jan 5, 2009
    #15
  16. Bruce W.1

    Paul Furman Guest

    Paul Furman, Jan 5, 2009
    #16
  17. Bruce W.1

    tony cooper Guest

    On Mon, 05 Jan 2009 01:01:23 -0800, Paul Furman <>
    wrote:

    >tony cooper wrote:
    >>
    >> If duct tape is involved, I like it.

    >
    >Here you go:
    >http://edgehill.net/Misc/photography/1-3-09-webcam-macro/pg2pc7


    That's a bit too professional looking, but the blue tape is
    encouraging. People who come up with their own devices impress me
    more than people who buy devices.


    --
    Tony Cooper - Orlando, Florida
    tony cooper, Jan 5, 2009
    #17
  18. Bruce W.1

    Paul Furman Guest

    tony cooper wrote:
    > On Mon, 05 Jan 2009 00:03:17 -0600, Richard J Kinch
    > <> wrote:
    >
    >> tony cooper writes:
    >>
    >>> As someone who distributed Zeiss operating microscopes to surgeons
    >>> for 30 years, I have to disagree. The working distance is set by the
    >>> objective lens. For laryngeal and neurosurgery, a 400mm (almost 16")
    >>> working lens was standard. While operating microscopes and bench
    >>> microscopes are two different things, the point is that a 150mm,
    >>> 200mm, 250mm 300mm, or 400m objective lens provide standard working
    >>> distances. These working distances are used in surgery.

    >> True, but the working distance of a compound microscope is by definition
    >> limited to something less than the objective focal length. Otherwise it is
    >> a telescope! And since NA is likewise a function of focal length, it also
    >> limits working distance for a given clear aperture in the microscope
    >> objective.
    >>
    >> Operating microscopes are basically low-magnification reflected-light
    >> stereo types. As indeed they must be, since one cannot transmit high NA
    >> light to a surgical field. Essentially a classy pair of loupes.

    >
    > Going back to the OP's post, he was looking for a device for
    > photography of "...a variety of things like knife edges, gemstones,
    > surface-mount electronics, and insects. So a magnification range of
    > 10x to 70x would be good."
    >
    > When you consider this, the term "low-magnification" covers what he
    > wants to do. Operating microscopes do magnify in this range. At
    > their magnification range, he'll be able to photograph a sugar ant.
    > He isn't, seemingly, interested in determining the color of the ant's
    > eyes.
    >
    > We tend to drift, in these threads, from the original question or
    > comment. In this case, away from the fact that there is no limitation
    > of a 5" working distance.


    The OP *does* want about 5 inches working distance (more than 2 anyway):

    >>> Bruce W.1 wrote:
    >>>
    >>>>> ...however at high magnification it needs to be right next to the subject, i.e. one or two inches away. The focal length is too short. I'd like some room to work and solder.
    >>>>>
    >>>>> My local library has a Magnisight Explorer, which works up to 70x from five inches away...




    --
    Paul Furman
    www.edgehill.net
    www.baynatives.com

    all google groups messages filtered due to spam
    Paul Furman, Jan 5, 2009
    #18
  19. Bruce W.1

    tony cooper Guest

    On Mon, 05 Jan 2009 18:10:56 -0600, Richard J Kinch
    <> wrote:

    >tony cooper writes:
    >
    >> In this case, away from the fact that there is no limitation
    >> of a 5" working distance.

    >
    >Since NA is a function of the working distance, and since NA is the whole
    >point of having a microscope, there is thus indeed a limitation to working
    >distance.


    OK, I spent 30 years working with Zeiss Operation Microscopes and I've
    never come across "NA" as an abbreviation in this field. The working
    distance (objective distance) is one of the factors that determine the
    field of view and the magnification. What is "NA"?

    Note, though, that the meaning of "there is no limitation of a 5"
    working distance" is a completely different statement than "there is
    thus indeed a limitation to working distance". Completely different
    meaning. That doesn't even take into consideration that there was
    additional context.



    --
    Tony Cooper - Orlando, Florida
    tony cooper, Jan 6, 2009
    #19
  20. Bruce W.1

    Mark Thomas Guest

    tony cooper wrote:
    > On Mon, 05 Jan 2009 18:10:56 -0600, Richard J Kinch
    > <> wrote:
    >
    >> tony cooper writes:
    >>
    >>> In this case, away from the fact that there is no limitation
    >>> of a 5" working distance.

    >> Since NA is a function of the working distance, and since NA is the whole
    >> point of having a microscope, there is thus indeed a limitation to working
    >> distance.

    >
    > OK, I spent 30 years working with Zeiss Operation Microscopes and I've
    > never come across "NA" as an abbreviation in this field. The working
    > distance (objective distance) is one of the factors that determine the
    > field of view and the magnification. What is "NA"?


    Same here - I don't claim that level of experience but I've had a lot to
    do with both low- and hi-power scopes (I own a lovely old Olympus ECE)
    and had not encountered the term either, so I had to look it up:

    http://www.micrographia.com/tutoria/micbasic/micbpt06/micb0600.htm

    The way it got tossed into this conversation left me a little confused
    also.. As Doug said, it's all about money and "NA" is *not* the whole
    reason - it's whether the op can get *enough* quality given what he
    wants to do.
    Mark Thomas, Jan 6, 2009
    #20
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