alangston2
what does amperture and focal length mean with lens and what is the best wide angle lens for close-ups picture
Answer
In (simplified) photographic terms Focal Length is the measurement of the distance between the optical center of a lens focused at infinity and the plane where the image is focused. This helps to define the lens in terms of it's angle-of-view. The shorter the focal length the larger (wider) the angle-of-view, so a short focal length is called a Wide Angle lens. If the angle is close to that which human beings normally see it is generally referred to as a "normal" lens. If the angle-of-view becomes smaller than a "normal" view it is commonly referred to as a telephoto lens.
Aperture is a measurement of the diameter of the lens in relation to the focal length. Most photographic lenses have either a fixed aperture or a variable aperture using a mechanical Iris type Diaphragm to change the size of the opening. This allows the user, or a computer in the camera, to adjust the amount of light coming through the lens. This is one of the two major controls for the amount of light reaching the film/sensor. The other control is the shutter speed. The aperature selected IS NOT the depth of field, it does effect the depth of field and can effect the image quality. Depth of field is widely misunderstood and would be a topic requiring many pages to explain. In a nutshell, wider/larger apertures (lower F numbers) mean less depth of field and narrower/smaller (higher F numbers) mean more depth of field.
In general, wide angle lenses can focus "closer" than telephoto lenses because it is easier mechanically to make a "short" lens focus closer than a long lens. (To get a lens to focus on an object that is closer the lens must be moved FURTHER from the plane of focus). These distances can be quite small in a wide angel lens and very large in a telephoto lens.
If by "close-ups" you mean high magnification or Macro photography, using wide angle lenses is seldom attempted because the wide angle of view results in a smaller image size, thus partially defeating the purpose. In 35mm photography typical Macro lenses would be in the 45mm-105mm focal lengths. Usually, longer focal lengths are better for macro work because it allows the photographer to have a greater working distance from the subject. See the exception below.
Special wide angle close up lenses such as 18mm-35mm length have generally been designed for specialized copy work. This allows cameras to be mounted on vertical copy stands and remain relatively close to flat art material so that large subjects can be processed without requiring photographers to climb step ladders to compose the images.
Hope this helps:
Email me if you need additional information...
In (simplified) photographic terms Focal Length is the measurement of the distance between the optical center of a lens focused at infinity and the plane where the image is focused. This helps to define the lens in terms of it's angle-of-view. The shorter the focal length the larger (wider) the angle-of-view, so a short focal length is called a Wide Angle lens. If the angle is close to that which human beings normally see it is generally referred to as a "normal" lens. If the angle-of-view becomes smaller than a "normal" view it is commonly referred to as a telephoto lens.
Aperture is a measurement of the diameter of the lens in relation to the focal length. Most photographic lenses have either a fixed aperture or a variable aperture using a mechanical Iris type Diaphragm to change the size of the opening. This allows the user, or a computer in the camera, to adjust the amount of light coming through the lens. This is one of the two major controls for the amount of light reaching the film/sensor. The other control is the shutter speed. The aperature selected IS NOT the depth of field, it does effect the depth of field and can effect the image quality. Depth of field is widely misunderstood and would be a topic requiring many pages to explain. In a nutshell, wider/larger apertures (lower F numbers) mean less depth of field and narrower/smaller (higher F numbers) mean more depth of field.
In general, wide angle lenses can focus "closer" than telephoto lenses because it is easier mechanically to make a "short" lens focus closer than a long lens. (To get a lens to focus on an object that is closer the lens must be moved FURTHER from the plane of focus). These distances can be quite small in a wide angel lens and very large in a telephoto lens.
If by "close-ups" you mean high magnification or Macro photography, using wide angle lenses is seldom attempted because the wide angle of view results in a smaller image size, thus partially defeating the purpose. In 35mm photography typical Macro lenses would be in the 45mm-105mm focal lengths. Usually, longer focal lengths are better for macro work because it allows the photographer to have a greater working distance from the subject. See the exception below.
Special wide angle close up lenses such as 18mm-35mm length have generally been designed for specialized copy work. This allows cameras to be mounted on vertical copy stands and remain relatively close to flat art material so that large subjects can be processed without requiring photographers to climb step ladders to compose the images.
Hope this helps:
Email me if you need additional information...
What camera and lens is best for long distance action close ups?
Q. I want to be a wildlife photographer so i need a camera that can focus fast and take pictures fast. E.g an owl flying down to perch on a tree branch.I also need a lens that will give me highly detained photos.
Answer
For wildlife photography you will want a camera with lots of autofocus points and a high burst rate. For wildlife and sports I use the Canon 7D (18mp, 8fps, 19 af points). If you like Nikon, the D7000 is a great choice (16mp, 6fps, 39 af points). For lenses, you will ideally want L series lenses with image stabilization and a fast focusing motor (USM for Canon). I'm not familiar with Nikon lenses, but the same basic rules apply. If you're on a budget, get the best quality lens you can afford that has image stabilization and USM. USM = Ultra Sonic Motor.
Usually I recommend better lenses before a better camera body, but in this case the body is just as important for getting that perfect shot.
I hope this helps. Good Luck.
For wildlife photography you will want a camera with lots of autofocus points and a high burst rate. For wildlife and sports I use the Canon 7D (18mp, 8fps, 19 af points). If you like Nikon, the D7000 is a great choice (16mp, 6fps, 39 af points). For lenses, you will ideally want L series lenses with image stabilization and a fast focusing motor (USM for Canon). I'm not familiar with Nikon lenses, but the same basic rules apply. If you're on a budget, get the best quality lens you can afford that has image stabilization and USM. USM = Ultra Sonic Motor.
Usually I recommend better lenses before a better camera body, but in this case the body is just as important for getting that perfect shot.
I hope this helps. Good Luck.
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