OOF and the Beauty of Blur

Nikon D300, Nikkor 50mm f1.4D @ ISO 200, 50mm f1.4, 1/100 sec

Click on photo for larger image view

Lens designers want to attain the best possible image quality and sharp focus performance in their products and the out of focus (OOF) parts of a camera's produced image are not a primary design objective in the manufacture of a lens. However, the OOF blur characteristics were a thing of beauty to Japanese photographers who introduced the term "bokeh" which in Japanese means "blur" or "haze" in the late 1990's. The aesthetic quality of the blur is the amount of background or foreground blur that is controlled (amongst other stuff) by the setting of the lens f-number.

Nikon D300, Nikkor 50mm f1.4D @ ISO 200, 50mm f1.4, 1/60 sec

Click on photo for larger image view

In an optical system the diameter of the entrance is expressed in terms of the f-number which is the focal length divided by the aperture diameter. F22 is mall f1.4 is large (smaller number bigger hole more light) The larger aperture gives a more blurred background. Out of focus highlights assume the shape of the lens aperture diaphragm opening, for example a six sided diaphragm leads to hexagonal blur patches but it is generally held that the better an aperture approximates a round opening and subsequently a more pleasing the blur (bokeh). One photographer famous for his use of bokeh as far back as the early 1980's is American photographer Kim Kirkpatrick.

Nikon D300, Nikkor 50mm f1.4D @ ISO 200, 50mm f1.4, 1/1000 sec

Click on photo for larger image view

Nikon D300, Nikkor 50mm f1.4D @ ISO 200, 50mm f1.4, 1/1250 sec

Click on photo for larger image view

Nikon D300, Nikkor 50mm f1.4D @ ISO 200, 50mm f1.4, 1/4000 sec

Click on photo for larger image view

Spring colour

A mural on a wall of a boat hire place in Mordialloc, Melbourne Victoria.

Nikon D300, 70-200mm 2.8, ISO 200, 86mm, f 2.8 1/4000 sec

Spring flowers by the side of the highway, somewhere in southern NSW

Nikon D300, 70-200mm 2.8, ISO 200, 200mm, f 2.8 1/500 sec

A flower at my Mums place in Bendigo Victoria

Nikon D300, 70-200mm 2.8, ISO 800, 200mm, f 2.8 1/2500 sec

My brothers dog 'Chester' watching me suspiciously

Nikon D300, 105 mm 2.8, ISO 200, 105mm, f 2.8 1/3200 sec

Cacti, again at my Mums in Bendigo Victoria

Nikon D300, 70-200mm 2.8, ISO 800, 200mm, f 3.2 1/1250 sec

Light II

Some more lighting situations . . .

High contrast sun and shadow.

Diffused light through a screen door. This is a merged image made from two shots, one focused on the door, and the second focused on the people outside then manipulated in Photoshop CS4.

This image is high contrast but boosted front light with a SB-900 flash.

Depth of Field

The Nikon 105mm lens, creates a narrow depth of field, generally depth of field is inversely proportional to focal length of a lens. For any given focal length, the depth of field varies directly with the aperture selected. That is, the wider the aperture (e.g. f2.8) the shallower the depth of field. If you use f22 you can maximize depth of field (the width of the focus area in sharp focus). Most lenses are considered to be at its sharpest at about 2 or 3 stops down from widest aperture, that is at f5.6 or f8, so you sacrifice sharpness if you maximize depth of field. Also pleasing bokeh (blurring of the background) is also effected as you widen aperture say to f-stop number f2.8 in a fast lens.

In this image of Hermione's eye you can see the band of sharp focus, the depth of Field (DOF)

D300, ISO 200, f 3.3 1/500 sec.

I have darkened the image so you can see this more pronounced. Interesting heh?

Light

We see things using light, light is all our eyes can really see. Visible light appears to be colourless or white and although we can see this light, white is not considered to be part of the visible spectrum because white light is not the light of a single color, or frequency. It is made up of many color frequencies which is why when sunlight passes through a glass of water and lands on a wall you see a rainbow. If you shine the colours red, green and blue in a light and them overlap, you will see magenta. Mixing light where red and green light overlap, you will see yellow. Where green and blue light overlap, you will see cyan. You will notice that white light can be made by various combinations, such as yellow with blue, magenta with green, cyan with red, and by mixing all of the colors together.

Most colour we see is reflected light, like paint or dye molecules that absorb specific frequencies of light and bounce back, or reflect, other frequencies to your eye. The reflected frequency is the color of the object. There are some rules for light, for instance light travels in a straight line, the farther you are from a light source, the dimmer the light and the angle that a light hits a surface (the angle of incidence) is the same as the angle the light bounces off the surface (the angle of refraction).

The larger and closer the light source the softer the light and the further away the light the harder the light, it will have stark shadows. The character and quality of a photograph can be altered by the character and quality of light, so you need to think about how a scene should be lit, what lighting angles get good results, and what exposure settings will bring out the best detail and shading. A hard light (the light source is further away) will generate dark shadows and the direction of the light can place shadows in unattractive positions of a subject. One solution is to diffuse the light. Diffused light is softer and does not cast strong shadows. An overcast day is perfect for a lot of photography for this reason, the sunlight is diffused by clouds. the down side being that a white sky makes a very ordinary photographic backdrop.

I just got a new lens for my D300 :-)

The AF-S VR Zoom-Nikkor ED 70-200mm f/2.8

This is the standard lens for news, sports and action and environment portrait shooters. It's light weight mechanically and optically precision built and the 70-200mm VR shines for fast action in low light. Its rated as one of Nikon's sharpest lenses ever and its sharp at every aperture. It is famous for its beautiful bokeh (that gorgeous out of focus background look) The 2.8 aperture makes this a 'fast' lens.

I also have:

Nikkor 105mm f/2.8G ED IF AF-S VR

Macro lens for insects, food and tiny stuff. Also one of the best portrait lenses you can get. Again beautiful bokeh.

AF-S Zoom-Nikkor ED 18-200mm f/3.5-5.6G IF DX VR

Good optics and considering the low price and the long focal range, very good all rounder in performance.

Tokina 11-16mm f/2.8 AT-X

The wide angle lens if you're on a budget and the the sharpest ultra wide lens for a DX Nikon camera. It's rated better than the more expensive Nikkor 12-24mm.

Great for landscapes, architecture and anything inside or close range and low light.

Why 2.8 ?

The maximum aperture of the lens can have a significant impact on the types of photos you can take.

Smaller Aperture number (2.8) = Wider Aperture (the hole) = More Light

Larger Aperture number (22) = Narrower Aperture (smaller hole) = Less Light

If you want to take photos indoors without a flash, on overcast days, for sport or anything you need to use fast shutter speeds to freeze motion you need a fast lens (2.8 or better)

You can also get a shallower Depth of Field (DOF) DOF is that amount of your shot that will be in focus. With a large aperture you get a large depth of field, that is most of your image will be in focus whether it’s close to your camera or far away. With a small aperture you get a small (or shallow) depth of field and only part of the image will be in focus and the rest will be fuzzy (bokeh) but this separates the subject from the background (as long as IT is in sharp focus) and give a 3D effect to images and smoothes out busy backgrounds. - see RedBubble Flickr