Lens filters can enhance photographs by modifying light entering the camera lens. They come in various types, including screw-on and drop-in filters. Choosing the right size, type, and filter factor is important to avoid negatively impacting image quality. Common filters include UV filters for protection, polarizing filters for reducing reflections, and color balancing and neutral density filters for exposure control. Filters also have uses in black and white photography to enhance contrast between tones through effects on sky, foliage, and other elements. Proper understanding and application of filters can improve photographic results.
2. • can enhance colors, add special effects and
reduce reflections
• can protect lenses for capturing scenery in
extremely difficult lighting conditions
• are often necessary to modify the light before
it enters the lens
• at the same time, lens filters can actually hurt
photographs if they are not properly used
Lens Filters
3. Notes on Choosing a Filter for a
Camera Lens
Lens filters generally come in two varieties:
1. Front filters – more flexible = can be
used on virtually any lens diameter;
may also be more inefficient to use
since they may need to be held in front
of the lens. On the other hand, filter
holder kits are available that can
improve this process.
5. Notes on Choosing a Filter for a
Camera Lens
Lens filters generally come in two varieties:
2. Screw-on filters – can provide an air-
tight seal when needed for protection,
and cannot accidentally move relative
to the lens during composure.
Disadvantage: a given screw-on filter
will only work with a specific lens size.
7. Notes on Choosing a Filter Size for a
Camera Lens
Screw-on filter
- expressed in terms of its diameter, which
corresponds to the diameter usually listed
on the top or front of your camera lens
- listed in millimeters and usually ranges
from about 46 to 82 mm for digital SLR
cameras
9. Notes on Choosing a Filter Height for a
Camera Lens
• the height of the filter edges may also
be important
• ultra-thin and other special filters are
designed so that they can be used on
wide angle lenses without vignetting
(the reduction of an image's brightness
or saturation at the edges compared to
the image center)
• but may also be much more expensive
13. Types
1. Circular screw-on filters
• most common
• mounts directly on the lens filter thread
• e.g. UV/Clear/Haze filters, circular polarizers,
neutral density and color filters
15. Types
2. Square filters
• a popular choice for landscape and other
photography
• a filter holder directly attaches to the lens
filter thread and can hold one or more filters
• the most popular sizes are 3×3 and 4×4
• can be stacked together in certain situations,
which can negatively impact image quality and
add reflections.
17. Types
3. Rectangular filters
• another popular choice, primarily among
landscape photographers
• mounted just like square filters via a filter holder
system
• unlike square filters, they have more room to
move up and down
• the most popular size is 4×6, although larger and
smaller filter sizes are also available
19. Types
4. Drop-in filters
• these filters are used inside long telephoto
lenses, due to the large size of the front lens
element
• only clear and polarizing filters are used for
drop-in filters
21. Filter Factor
• filters change the dynamics of the
light entering the lens and usually
require you to alter your exposure to
compensate for this fact which is
called Filter Factor
• each filter has a specific filter factor
22. Filter Factor
1. UV filter
• transparent filters that block ultra-violet light
to reduce the haziness that is noticeably
apparent in some daylight photography
• doesn’t affect the majority of visible light, so
it’s a perfect form of lens protection and it will
not alter your exposure
24. Filter Factor
2. Polarizing filter
• can be used to darken overly light skies as it
increases the contrast between clouds and the
sky
• like the UV filter, the Polarizer reduces
atmospheric haze, but also reduces reflected
sunlight
• most typical function: to remove reflections from
water and glass
• two types: linear and circular
26. Filter Factor
3. Color Balancing filter
• use this to affect a change in your light
sources and to compensate for the various
differences in the photographed color of light
27. Filter Factor
3. Color Balancing filter
• 85B (warm-up/orange filter) enables you to
shoot in the daylight when the white
balance/color temperature is set for tungsten.
Without the 85B filter, your image will have a
blue color cast to it
30. Filter Factor
3. Color Balancing filter
• 80A (cool-down/blue filter) enables you to
shoot under tungsten light when the color
temperature/white balance is set for daylight.
Without the 80A, your image will be
abnormally warm/reddish orange
32. Filter Factor
4. Neutral Density filter
• reduces the amount of light entering the lens
• is helpful when the contrast between the
highlights and shadows is too great to get a
quality exposure
• can enable greater motion blurring and image
detail by allowing a large aperture and/or a
slow shutter speed to be used
34. Filter Factor
5. Soft Focus filter
• reduces the sharpness of an image, but only to an
extent that is barely noticeable
• useful in shooting close up shots of people’s faces
• with the help of a little diffusion; imperfect skin
conditions are replaced by silky smooth skin
• you can use soft focus filters while photographing
landscapes or monuments as well
36. Filter Factor
6. Filters for B&W Photography
• there are specific filters for B&W photography
that lighten similar colors and darken opposite
colors, thereby enhancing the monochromatic
look
37. Filter Factor
5. Filters for B&W Photography
Red filters
• are a favorite among landscape photographers and are
often used to add drama
• in nature photography, this will increase the contrast
between red flowers and green foliage
• will deepen a blue sky and make white clouds pop out
• can also decrease the effects of haze and fog
• in some cases, depending on its strength, a red filter
could even turn the sky black
40. Filter Factor
5. Filters for B&W Photography
Orange filters
• increase contrast between tones in textures
such as tile or bricks, making it a good choice
for general use and urban or abstract
photography
• it also helps to decrease haze and fog, but it’s
effects on the sky and clouds are subtler than
the red filter
42. Filter Factor
5. Filters for B&W Photography
Yellow filters
• subtler than orange filters, making it a ‘classic’
choice for beginners just starting to explore
using filters with black and white photography
• helps to darken the clouds slightly, and it also
separates light green foliage from the darker
shades of green
44. Filter Factor
5. Filters for B&W Photography
Green filters
• lighten dark green foliage and boost light green
foliage
• have a more specific use and are not as
commonly used as the other filters, but these are
extremely useful for nature photographers
• may lighten the sky, so landscape photographers
should take note of this when using it
46. Filter Factor
5. Filters for B&W Photography
Blue filters
• not as commonly used in black and white
photography because they lighten the sky and
darken highlights or colors that are seen as
light
• can draw attention to haze and fog, which can
enhance the mood of the photo if needed
48. Conclusion
Photographic filters
• are used to achieve image enhancement effects that
can change the tone and mood of your photographs
• inject slight, but noticeable alterations to your image
• unlike editing softwares, you can immediately see
the difference to your image in the viewfinder when
you use a filter
• the effects of filters are more pronounced when
working in B&W, as the monochromatic tonal scale
reacts much differently, and also with greater
dramatic affect
49. References:
• Lens Filters | Camera Lens Filters Explained. Retrieved from
http://www.exposureguide.com/lens-filters.htm
• Choosing a Camera Lens Filter. Retrieved from
http://www.cambridgeincolour.com/tutorials/camera-lens-filters.htm
• Lens Filters Explained. (2011, September 8). Retrieved from
https://photographylife.com/lens-filters-explained