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  • magnification X equals just how big?

    Ok, this might be a waste of some peoples time, but I just gotta know. I have some camera's that magnify and on them is listed the numbers 1500X so ordinarily I would assume 1500 times what you were looking at.
    However? I stuck a 6" scale under it, and one inch is all the screen would hold. The screen is 8" tall. Does that mean it is simple an 8X camera?
    David from jax

    ------------------
    Have gun, will travel.
    A serious accident is one that money can't fix.

  • #2
    Well, they aren't 1500 x magnification. The highest useful magnification from the very best optical microscopes is less than that due to the wavelength of light. In the case of a video camera useful magnification is limited by the camera resolution as well as the optics and the size of the screen. If one inch on the rule is projected on the monitor ten inches wide then that is ten times magnification.

    [This message has been edited by Evan (edited 11-30-2004).]
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    • #3
      1" field of view on an 8" screen is 8x magnification.

      Are you talking about a video camera? If the CCD (or other imaging device) were 1/4" diagonal and the display is 8", the magnification of the camera/lens combo is 32x. Add an objective lens of 40x and you now have 32 x 40 = 1280x magnification.

      In any event, it sounds like the 1500x is with a complete system of some sort.

      Den

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      • #4
        I strongly suspect that the "1500X" is just plain and simple sales hype. They will say anything and print anything to get you to buy.

        As for magnification with a video camera, you are on a slippery slope. The image on the sensor (or film in older cameras for that matter) in the camera is usually much smaller than the object itself. Some cameras that have macro or micro capability will have a 1:1 or larger image but these are less common. Shooting through a microscope will provide an image that is definitely larger than the object itself.

        The slippery slope is actually due to the fact that the image can be viewed in a variety of ways. On a 15" monitor it will be one size, on a 21" it will be bigger. If you display it at a higher resolution on the same monitor, it will be smaller. If it is compressed by the viewing software it will be smaller. If the software expands it, it will be larger, but not have any additional resolution (you are magnifing the blur). If you print it on paper, the size depends on the paper size and any zooming or cropping you do.

        There are just too many variables to know what the final "magnification" will be. And there is really no actual final magnification as it can still be displayed differently.

        What Evan said about the maximum magnification possible with the best available microscope if true. Actually it is understated. Some microscope lenses can do 1000 X or more but again, you are just magnifing the blur. No real increase in resolution is possible and it is due to the properties of visible light. That's why electron microscopes were invented.

        Paul A.
        Paul A.

        Make it fit.
        You can't win and there is a penalty for trying!

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        • #5
          Actually there are two cameras, one split screen to view the two camera locations at the same time. The screen is 8" tall, but I never messured the 1/2 screen.
          Here is a picture of the screen with two separate items.



          ------------------
          Have gun, will travel.
          A serious accident is one that money can't fix.

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          • #6
            Recollection from my old SLR days aprox 56x is considered "nekkid eye view" (NEV) so for the sake of easy math we'll call it 50x.

            So, it comes out to 30 times NEV, that is the LENS multiplication-it does not take into account the 8" monitors field of view or whether yours is a macro or micro type lens or how far away the ruler was from the lens in relation to focal field.

            If you get up to the screen to where it fills your full "human field of view" (and with my 15" monitor my eyeball is less than 2" from the screen) looking at 1" that is spread out to 8" sounds about like 1500x.

            And BTW, I had a 1600x a 2400x zooms and macro and micro lenses and a few nice SLR cameras some 25+ years ago.

            Don't let the fact that your viewing on a screen make it seem less than it is because if you are not filling your "full" field of view as when looking through the viewfinder of a camera it will seem like much smaller magnification.

            [This message has been edited by inspectorsparky (edited 12-01-2004).]

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            • #7
              You cannot magnify an object that is one thousand five hundredth of an inch (0.00067") to one inch in size with optics and actually resolve features at the 0.00067 size. The laws of physics don't permit it as you are then trying to look at something at less than a wavelength of light. Can't be done with light.

              Note that a wavelength of light is a lot smaller than that but diffraction and chromatic abberation effects come in to play much before that.

              [This message has been edited by Evan (edited 12-01-2004).]
              Free software for calculating bolt circles and similar: Click Here

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              • #8
                We used to have a microscope that had a 1000x maximum magnification but the objective lens needed to be immersed in an optical quality oil bath to achieve the max magnification. I think it was an American Optics piece. We couldn't find anything to do with it so we sold it. We still have an AO piece that will do dark field and a bunch of other stuff with a nice precision stage, but we don't really have a use for it either so we'll probably off it one day as well. The Bausch & Lomb Stereozoom 7 is staying though. I love that thing. With 10X eyepieces on 1X zoom it's awesome for removing metal splinters! If they're really small, just zoom in a bit.

                To really be able to judge absolute size through magnification, you need to have optical calibration standards (some look like reticles on a rifle scope) and follow well documented procedures in the setup of the item to be viewed. Then it can be accurate down to th emicron level.

                I love nice optics. It's good to have a wife who worked in microscopy and high tech inspection/quality for many years.

                John

                ------------------
                Pursue Excellence and the rest will follow.

                [This message has been edited by Excitable Boy (edited 12-01-2004).]
                Pursue Excellence and the rest will follow.

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                • #9
                  Ultimate magnification with microscopes and telescopes ultimately depend on your pupil diameter - this is the limiting factor. Those old Bushnell crap telescopes that sold at Christmas advertised as 450X were in reality for most people rarely above 75-120x because of average pupil dilation of 2-10mm (approximate - I am going by memory here so don't quote me)..

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                  • #10
                    OOOOPS!

                    I got to thinking today (while a little more sober!!!) and I had 1600mm and 2400mm telephoto zoom lenses......

                    SO.... put "mm" everywhere I typed "x".

                    DOHHH!!!

                    The 56mm (that I rounded to 50) division is still correct.

                    MMMMMMM BEER!!!!

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