Transcript 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
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
Nikon Micro Sigma 150mm
105mm f/2.8 VR f/2.8 Macro
Macro ring flash
Kenko extension
tube set
Zeiss 50mm f/2
Makro-Planar T*
Macro rail
Nikon
bellows
Velbon Macro Rail
Canon MP-E 65mm f/2.8
1x to 5x magnification
Nikon E-TTL
ring flash
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
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
Tamron 60mm
f/2 Macro
Pentax 100mm
f/2.8 Macro
with hood
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
Kenko extension
tube set
More expensive ones maintain electrical
communication between camera and lens
Maintains autoexposure, focus and TTL
flash
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
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 freehand
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 infocus 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