Macro with Canon 24mm f/2.8 and Nikon 105mm f/2.8

Discussion in 'Nikon' started by Rita Ä Berkowitz, May 30, 2005.

  1. I had a chance to put a 24mm lens in front of the 105mm and found that I got
    slightly better distance between the lens and the subject. The
    magnification is greater than the 50mm f/1.4 and the date on the penny
    almost fills the frame. This shot was taken at a 45* angle and as you can
    see there is considerable perspective distortion on the date. Is this going
    to be normal with any wide-angle lens reversed? I also feel my depth of
    field is even shallower than the 50mm. In conclusion, I feel this
    combination isn't worth using.

    http://www.geocities.com/ritaberk2003/eBay/Penny_24mm.jpg




    Rita
     
    Rita Ä Berkowitz, May 30, 2005
    #1
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  2. Rita Ä Berkowitz

    Paul Furman Guest


    Wow the perspective looks backwards! How could that be?

    I'm curious if you tried the 50mm reversed on the end of the 70-200
    probably not great I'd guess.
     
    Paul Furman, May 31, 2005
    #2
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  3. I didn't consider that fact. You're right, the bottom of the date should be
    bigger since it was closer to the lens. LOL! Maybe it's the Nikon
    screaming in pain from not wanting to be mated with a Canon?
    I haven't gotten around to it since I need to get some rings. I have a
    Canon 20mm that I'm guessing has a 72mm filter mount. I might have an
    easier time getting that on there than the 50mm, but I'm afraid the 20mm is
    going to be terrible. I haven't had too much time to play with this stuff.
    My priority is getting my fiber optic flash mounted on the 50mm. I'm still
    playing with lighting issues and I think the fiber is the only answer.

    http://www.geocities.com/ritaberk2003/eBay/Fly.jpg



    Rita
     
    Rita Ä Berkowitz, May 31, 2005
    #3
  4. Rita Ä Berkowitz

    Stacey Guest

    DOF is ONLY affected by magnification and fstop using the same size format.

    Try it stopped down..

    The distortion is porbably the angle and magnification you shot this at..
     
    Stacey, May 31, 2005
    #4
  5. Rita Ä Berkowitz

    Ed Ruf Guest

    If you took a few seconds to check, it was shot at f/32 according to the
    exif data.
     
    Ed Ruf, May 31, 2005
    #5
  6. I'm fairly sure you must have posted the shot upside down. Turn it over
    and it makes perfect sense.David
     
    David Littlewood, Jun 8, 2005
    #6
  7. Rita,

    (1) The perspective distortion is an inevitable result when using a
    non-shift lens; it is simply a factor of the angle made between the
    plane of the sensor and the plane of the subject. If you were able to
    use a shift lens (or a large format camera with built-in movement) you
    could keep the two plane parallel and eliminate the "distortion".
    Otherwise you will get the same effect whatever lens or combination you
    use. (Actually, it's a misnomer to call it distortion, it's simply a
    true reflection of the fact that something further away forms a smaller
    image.)

    BTW, you have (I'm virtually certain) shown the picture upside down.

    (2) DOF is a function of magnification, so you will get similar results
    however you achieve it. You say the 50mm shot you took had lower
    magnification, so a larger DOF is of course expected; a 50mm lens with
    extension tubes to get the same magnification would give you the same
    DOF. The only way to get out of this is to make the plane of sharp focus
    coincide with the plane of the subject, using a tilt lens (or a large
    format camera with movements that work the same way).

    You may now have some understanding of why professional studios doing
    product shots prefer to use large format cameras with full movements!
    However, there are (or used to be) bellows which had movements on the
    front standard which could provide a limited amount of facility in these
    respects - IIRC Novoflex used to make some. Not the cheapest bellows
    around though. Try Googling.

    David
     
    David Littlewood, Jun 8, 2005
    #7
  8. Rita Ä Berkowitz

    BC Guest

    Regarding DOF; if you stop down your 105mm (which I assume is mounted
    directly to the camera) you will likely have severe vignetting. Try
    stopping down reverse-coupled 24mm instead while leaving the 105mm wide
    open. The reason is that the 105mm lens is far more tolerant of stop
    shift than the 24mm. You might get even better results with a
    non-macro lens attached to the camera, such as a 105mm/2.5.

    Brian
     
    BC, Jun 8, 2005
    #8
  9. SNIP
    Maybe, or maybe it's just the direction of the main light.

    Bart
     
    Bart van der Wolf, Jun 8, 2005
    #9
  10. Rita Ä Berkowitz

    Deedee Tee Guest

    I hate to differ, but probably stopping down the reversed lens will
    not reduce vignetting (on the contrary, it does increase it in all the
    setups I tried, although I don't have the combination of lenses
    mentioned above). Normally you stop down only the lens mounted
    directly on the camera, and leave the reversed lens wide open. The
    general rules-of-thumb are:
    1 - use a direct mounted lens of high focal length (if you use a zoom,
    you can increase it until you see no vignetting in the final picture).
    2 - as you stop down either the direct mounted or the reversed lenses,
    vignetting increases, so you may not see vignetting in the viewfinder
    or preview screen, but still get it in the final picture. However,
    likely you cannot shoot with lenses wide open because DOF is
    insufficient. Learn the properties of your setup by experimenting.
    3 - the front lens element of the reversed lens should be as wide as
    possible to reduce vignetting, so you should use a reversed lens as
    fast as possible. 50mm f/1.4 or 1.8 is usually excellent in this
    respect, and also cheap. If you use a direct mounted lens with a large
    front lens element (e.g., a tele), as a rule of thumb the front lens
    element of the reversed lens should be at least as wide. So it is
    counterproductive to mount a very fast lens or a very high focal
    length on the camera body unless you have another lens with a
    correspondingly wide front element to reverse on top of it.
    4 - the two lenses should be mounted together at the smallest possible
    reciprocal distance. Increasing the distance between the two lenses
    will increase vignetting. So it can be a problem to mount a reversed
    lens onto a macro lens that has a deeply recessed front lens element.
    (If you mount two lenses sufficiently far from each other, you will
    end up with a telescope or microscope, but this is another story.)
    5 - I always get better results with macro lenses, bellows and
    extension tubes than with added reversed lenses. Even a macro lens
    with telemultiplier is far better than one with a reversed lens on
    top.
    6 - a reversed lens mounted on extension tubes or bellows (without a
    direct mounted lens on the camera body) usually works great at
    magnifications above 1:1.
    7 - some camera bodies will produce vignetting when used with very
    long bellows, extension tubes or when projection-mounted on
    microscopes or telescopes. This vignetting is produced by the camera
    lens mount or by internal mechanisms of the camera, and is completely
    different from vignetting caused by added reversed lenses. With these
    extreme setups, some SLR camera bodies will produce vignetting in the
    viewfinder but not in the final pictures, others in both.

    My personal conclusions: reversed lenses mounted onto a camera lens
    are a great solution for cameras without removable lenses or for
    occasional use, but not for frequent work. Equipment that has been
    designed specifically for high magnification photography almost
    invariably works better. However, there is a lot of fun involved in
    experimenting, so by no means let this discourage you.
     
    Deedee Tee, Jun 9, 2005
    #10
  11. Nope. That's the strange part since I shot it as you see it. The bottom of
    the penny is in fact closer to the lens. I've all but given up using the
    24mm. Thanks for all the great info, Dave.



    Rita
     
    Rita Ä Berkowitz, Jun 9, 2005
    #11
  12. Rita Ä Berkowitz

    BC Guest

    I've tried numerous combinations with a short lens reverse-mounted to a
    longer one. Without exception, stopping down the short lens results is
    less vignetting and less aberration than stopping down the long lens.
    As I've stated before, the reason is due to different degrees of
    tolerance for extreme stop shift in the two lenses. When you actually
    try ray-tracing various combinations (in addition to trying them
    experimentally) the conclusion is painfully obvious. When I get a
    chance I'll post some examples.

    Using proper reversed-lens technique will give you a much larger
    effective aperture to work with than you could ever dream of with most
    dedicated macro lenses. Perhaps your poor image quality is due to
    stopping down the wrong lens?

    Brian
    www.caldwellphotographic.com
     
    BC, Jun 9, 2005
    #12
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