Lesson 7 - Photography

DSLR Camera

Digital Single-Lens Reflex camera

• Uses a mirror system to capture images

• One of two professional types of cameras (DSLR & Mirrorless)

Wide-Angle Lens

(14-35mm)

• Expansive field of view

• Ideal for landscapes

• Causes “fish-eye” view = distortion

Standard Lens

(35-85mm)

• Offers view closest to human vision

• Used in LP photography

Macro Lens

(a variety of lengths - most commonly 90-105mm)

• Achieves 1:1 or greater magnification ratio

• Close-up, detailed photo of small subjects

• Used in LP photography

Telephoto

(85-100mm+)

• Magnifies distant subjects

• Good for wildlife & sports

Exposure

The total amount of light that reaches the camera’s sensor determining how bright or dark an image appears

• Controlled by Aperture, Shutter Speed & ISO

Aperture

The adjustable opening of the camera lens

• Measured in f-stops (ex. f/11)

• Larger opening = more light entering, shallow depth of field (less in focus)

• Smaller opening = less light entering, deeper depth of field (more in focus)

F-Stops

The size of the aperture… basically how much light you are letting into the camera

• Based on fractions ( f/11 = 1/11)

• The larger the f-stop number is, the smaller the aperture is going to be…

  • 1/4 is a lot bigger than 1/16

• Larger f-stops (f/32) can sometimes cause a loss of contrast in photos… ridges might look less crisp or lighter in color

• Small f-stops (f/4) can help when photographing prints on transparent materials… they can focus on the foreground & blur / lighten any debris or additional prints on the opposite side of the material

Focal Point

The focus point of the image - the subject of your photo

Depth of Field (DoF)

The distance between the closest & farthest objects in a photo that are in focus

• Larger aperture (smaller f-stop, f/2.8) = Shallower DoF

• Smaller aperture (bigger f-stop, f/16) = Deeper DoF

• DoF can also depend on lens size… a 200mm lens will have a smaller DoF than a 24mm lens even with the same f-stop

Shutter Speed

The duration a camera sensor is exposed to light - how long the shutter is open measured in seconds or fractions or seconds

• Fast shutter speeds are better for photographing moving objects but will not let in as much light as slower shutter speeds

• We don’t have to worry about moving objects but the shutter speed is important for exposure…

  • Slow shutter = more light, Fast shutter = less light

  • Ex. Photographing a fluorescent print in a dark room = slower shutter speed to compensate for lack of light

ISO

A camera setting that control the sensor’s sensitivity to light - allows photos to be taken in varying lighting conditions

• A higher ISO number makes the sensor MORE sensitive to light

  • Low light environment = use higher ISO #

  • Bright environment = use lower ISO #

• Higher ISO numbers can cause photos to have more “noise” - they will look blurry or grainy

• The DCS5 has ISO presets for different lighting conditions…

  • Visual = 200, Fluorescent = 500, UV = 800, IR = 200

White Balance

White balance is the process of removing unrealistic color casts - not usually a big deal for LP photography since everything ends up in greyscale anyway

PPI

Pixels per Inch

• The pixel density of each inch of a digital image

• Higher PPIs indicate a higher quality photo that is sharper and more detailed

• Resolution refers to the total number of pixels & is very important = need higher resolution screen to view minute details when zooming in

  • The closer the photo (filling the frame) = the better the resolution

DPI

Dots per Inch

Lossy vs. Lossless Compression

Lossy Compression

• ex. JPEG, JPG

• Loses pixel data after editing and re-saving to reduce file size - quality is reduced each time the image is opened

• JPGs can start off with high resolution equal to TIFS & etc.

• If a lossy compression format photo is submitted, we must convert it to lossless as fast as possible

Lossless Compression

• ex. TIF, RAW, NEF, PNG, BMP

• Reduces file size without losing any pixel data - quality remains high

• Our cameras (DCS5 & D700) are set to take photos in their NEF format (aka RAW)

Extension Tube

Can be added to a lens to increase the focal length and therefore be able to take a photo closer to the subject / more zoomed in

DCS5 Light Sources

FLS (Forensic Light Source)

• Controlled by DCS5 software

• Has range of visible light wavelengths and IR wavelengths

• Can use with any light guide

• Stronger light than halogen

Polytec Halogen

• Controlled manually

• Has dimmer

• Has red, blue, green, yellow & daylight filter

• Emits white light and IR light at the same time

• Can use with any light guide

UV Handheld Light

• Used only for UV photography

• Can easily maneuver to control light angle and intensity

• Controlled manually

8×4

• Has UV wavelength and a range of visible light wavelengths (can use multiple at once)

• Can be controlled on the DCS5 software or manually

• Can be used for fluorescent, visible or UV photography

• Has polarizing filter