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 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

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

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

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 f/ Macro

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

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

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

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

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

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

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

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

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

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