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Macrophotography

Macrophotography. FDCC - January 2012. Macrophotography. Strict definition - From life size to limit of unaided visibility Loose definition - about 1/3 life size to limit of unaided visibility. Magnification. Magnification is usually represented as a ratio: Life size = 1:1

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Macrophotography

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  1. Macrophotography • FDCC - January 2012

  2. Macrophotography • Strict definition - From life size to limit of unaided visibility • Loose definition - about 1/3 life size to limit of unaided visibility

  3. Magnification • Magnification is usually represented as a ratio: • Life size = 1:1 • Half life size = 1:2 • Twice life size = 2:1 • A lens’ magnification is based on a full-frame sensor/film camera • On a crop camera, the perceived ratio is magnified • Canon 1.6 crop = 1.6:1 ratio • Nikon 1.5 crop = 1.5:1 ratio

  4. Curvilinear Distortion • The outer surface of all distal lens elements are curved • This curvature results in slightly different focal distances to the sensor plane • For objects feet or more away, this has no discernable impact on focus • However, for macrophotography it can have a dramatic impact on focusing • Focus on center, periphery is out of focus • Focus on periphery, center is out of focus • Dedicated macro lenses are corrected for this phenomenon

  5. Tools of Macrophotography • Conventional lenses with macro capabilities (i.e., close focusing) • Dedicated macro lenses • Extension tubes • Bellows • Macro ring flash • Macro rail Kenko extension tube set Nikon Micro 105mm f/2.8 VR Sigma 150mm f/2.8 Macro Zeiss 50mm f/2 Makro-Planar T* Nikon bellows Nikon E-TTL ring flash Canon MP-E 65mm f/2.8 1x to 5x magnification Velbon Macro Rail

  6. Conventional Lenses • Many conventional lenses have macro capabilities that provide up to 1:2 (half life size) magnification • Generally, they tend to suffer optical distortions at macro settings • However, they are typically inexpensive Sigma 17-70 f/2.8-4.5 Macro

  7. Dedicated macro lenses • Usually provide 1:1 magnification to infinity focus • Have high-quality lens elements specifically designed for high magnification • Tend to be extremely sharp • Many portrait photographers use macro lenses • Fixed focal length • Substantially more expensive Pentax 100mm f/2.8 Macro with hood Tamron 60mm f/2 Macro

  8. OLD macro lenses • Usually provide 1:2 magnification to infinity focus • Have high-quality lens elements specifically designed for high magnification • Tend to be extremely sharp • Many portrait photographers use macro lenses • Fixed focal length • Substantially less expensive • Some require mount adapter Pentax 100mm f/4 Macro SMC Takumar

  9. Extension tubes • Fit between camera body and lens • Have no optics • Increase the distance of the lens to the sensor, thus increase magnification • Lose infinity focus • More expensive ones maintain electrical communication between camera and lens • Maintains autoexposure, focus and TTL flash Kenko extension tube set

  10. Bellows • Similar to extension tubes, but variable extension • Do not maintain electrical communication between camera and lens • Lose autofocus, autoexposure and TTL • Generally not used today Nikon bellows

  11. Macro Ring Flash • Magnification reduces the amount of light that strikes the sensor, thus flashes are often needed • Shoe-mounted or pop-up flashes cannot illuminate a macro subject because the lens impedes the light path • Macro ring flashes mount on the end of the lens to provide flash illumination • Some provide E-TTL, while others do not Sigma EM-140 Ring Flash

  12. Macro Ring Flash • Conventional flashes can be used with brackets and diffusers • Need off-camera cable to preserve E-TTL • Allows for diffused light source Delta Flip Flash Bracket II

  13. Aperture Diffraction • Aperture diffraction occurs when the aperture is very small • The result is softness of the image • This phenomenon is magnified with macro photography • The greater the magnification, the more diffraction • Thus, the optimal aperture for most dedicated macro lenses is around f/11 for crop sensor cameras • Larger apertures have thin focal plane, thus have narrow depth of field • Smaller apertures have diffraction, thus the image is soft

  14. Purchasing Macro Lenses • Optically, all dedicated macro lenses will be about the same • The differences in prices include: • Brand name • Fast autofocusing (ultrasonic motors) • Internal focusing (lens does not change length) • Included accessories • Lens hood • Case • Tripod collar

  15. Macro Technique • Moving object • Monopod or free-hand • Rails often of little use • Manual focus • Focus on a point, then move towards that point • Repeat • Stationary object • Tripod • Mirror lock-up • Manual focus • Rails help significantly

  16. Focus stacking • A lack of depth of field is the principal problem with macro photography • Focus stacking is the process of taking several shots at different focal planes, then using the in-focus regions of those images to make a single image that’s in focus throughout • Avoid changing the lens’ focus as this also changes the magnification • Helicon Focus is a software package that provides this technique • Focus rails are excellent for stacking

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