In most cameras (an exception would be a pinhole camera) a lens is used to focus the incoming light onto an image sensor - either the photographic film (light sensitive chemical emulsion) or CCD chip (digital photocell). Most lenses are rigidly coupled to the front of the camera in such a way that the focal plane is parallel to that of the image sensor.
This means that the "slice" of focus (whose depth/thickness is dependent on the aperture and lens) is parallel to the image sensor. This parallel slice of focus is for most cameras and their users simply the way it is, and is a very powerful creative tool on its own. For example, by using a large aperture (i.e. a low f-stop), a narrow focal slice is created meaning that the areas on either side of the slice are blurred. The image below demonstrates this perfectly.
In contrast, a narrow aperture (or high f-stop) produces a broad focal slice. This is useful for landscape photos where you'd like as much of the photo to be in focus as possible. The image below was shot at f/10.0 which produces quite a broad focal slice, but even narrower apertures like f/22.0 or f/32.0 will produce images where almost all the visible image is sharply focused. A pinhole camera (which doesn't have a lens, but just a pin-prick size hole for the light to enter) has a very narrow aperture (my pinhole camera has an f-stop of 177! and practically everything is in focus.
The Lensbaby Composer (as well as the Lensbaby Muse and Control Freak) is a creative lens system that creates a circular "sweet spot" of focus surrounded by a circular blurred zone. Furthermore, the lens can be tilted allowing the "sweet spot" (think of it as a circular focal spot) to be angled versus the image sensor.
In the Composer model, this is achieved using a ball and socket design. Aperture is controlled by using metallic discs with varying size holes in them which are placed over the lens optic. Like traditional lenses, the aperture also controls the depth of the focal spot. So a large aperture gives lots of blur, and a small aperture gives little blur. Before we look at some actual Lensbaby images (I think in this case the pictures will speak a 1000 words), I should also mention that Lanesbaby is a lens system, with interchangeable optics. This means that different lenses can be plugged into the lens body allowing for different visual effects. Below is an image of the Lensbaby Composer from the side showing the unit tilted, and also 4 of the optics I own (from left to right: Single Glass Optic, Plastic Optic, Pinhole/zone plate optic, Double Glass Optic). Other optics are also available. I will cover all the optics in more detail in a future post.
So, onto some sample images! The image of the tree below has the lens centered (no tilt), and uses a f2.8 aperture (maximum blur). As you can see the center of the image is focused, with a radial blur extending outwards - almost like a motion blur. You can see a bigger version of the image by clicking the link above.
In the daisy image below, the daisy in focus is off-center. This is achieved by tilting the lens so that the "sweet-spot" is centered on the daisy. As you can see the whole of the daisy is focused, and not just a slice of it! Had this photo been taken with a normal lens by changing the aperture, the whole of the daisy could have been in focus, but the focal slice would have crossed the entire image. Here we see the rest of the image is blurred.
The orange daisy is another example of the creativity offered by the Lensbaby system.
The Lensbaby system also allows the addition of screw-on macro lenses, allowing for close-up shots. As a photomacrographer myself, this is a great option. I will share my experiences using these accessories in a future post.
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