Every lens has a focal length which is a physical property of the lens. Once the lens is made, this cannot be changed. The field of view associated with a lens will be a function of the area projected by the lens that is captured by the camera. For 35mm film photography, this area is 36mm by 24mm. Note that if you change the area captured, the field of view also changes.

You can equate your 35mm format focal length to focal lengths in larger formats with our Lens Conversion Chart.

The fixed f3.5 on all Minoxes except the Plastic ones (5.6 I don't know that this is equal to) is actually the same as a f12.5 on the 35 mm format --- I found this out by trial and error -- It would be a useful piece of information to include as many 35mm buffs may try Minox 8 X 11 thinking that the F3.5 is the same as on 35mm--- I did until I found under exposure on my Minox lll, if you know ahead of time that f12.

The M2 does not change the focal length of the 35mm lens. Users have complete control over the backfocus to fine-tune this setting. You can use the full 36mm x 24mm frame size of still film lenses, and also frame 18mm x 24mm film lenses. The M2 mounts directly to the standard lens on your camera. There is not currently a version that connects directly to camera bodies.

I want JAlbum to open [enter browser here] instead of Firefox when I select "View album". I am using Linux. If this FAQ didn't help you, please ask your question at the JAlbum forum , but search through the forum first using the forum search tool.

Question: I get an error code returned in the status row when trying to upload an album through FTP. What's wrong Answer: Check out the meaning of the code at some site that lists FTP error codes . A common cause is "Invalid file name" where the remote server is more picky about some special characters in the file name than your own system. Renaming some files is then the recommended solution. Question: I want JAlbum to open [enter browser here] instead of Firefox when I select "View album".

Measured TRV900 focal length Jake Socha (jjsocha midway uchicago edu) Sept. 25, 2001 When I assume that the widest angle is at 4.3 mm, the estimate for the max zoom is 48 mm, instead of the [Sony] listed 51.6. When I use the zoom as the reference, the wide point is estimated at 4.6 mm. Both answers are about 7 % off.

The focal length is a basic optical property of any lens, and the most important one to a photographer. The simple way to think of the focal length is to think of it as a numerical value, expressed in millimetres, which represents how much of a given scene (the coverage area) a lens can take in. Focal lengths for Canon SLR lenses range from ultra-wide (14mm) to incredibly long telephoto (600mm and 1200mm). The typical range of an affordable lens or lenses is from 28mm to 105mm or so.

Focal length is a simple measure in millimeters of the path light takes before its focused in the eyepiece and is important to know when determining the magnification power. Focal ratio is the ratio of focal length to aperture. Long focal ratios (e.g. f/16) yield narrower fields of view, but with higher-contrast images desired by planetary observers. Shorter focal ratios (e.g.

The focal length of a mirror is equal to the focal ratio times the diameter of the mirror. For example, a 1-meter telescope that is f/8 would have a focal length of 8 meters.

Object size and camera format determine magnification. Magnification and working distance determine lens type. Please refer to the lens calculators for fixed focal lengths and the respective charts for zoom systems and Precise Eye systems.

The focal length is approximately 50 mm on all the current Lensbaby Lenses. Our Lensbaby Wide Angle Telephoto Accessory Lenses screw onto the front of the Lensbaby and changes your focal length to either 30mm or 80mm respectively. webstore

In many digital 35mm SLRs, the size of CCD chip is smaller than conventional 35mm frame. This causes effective focal length of the lens to become longer. For example, the size of CCD on Nikon D1 is 1.5 times smaller than a regular 35mm frame increasing effective focal length by 1.5. As a result, 200mm lens would behave like a 300mm lens. Angle of view is thus smaller requiring for extra flare protection. It is a benefit of digital cameras with their smaller exposure latitude.

Focal length is the measurement of the lens view. A wide-angle lens has a short focal length and a telephoto lens has a longer focal length.

Focal length is the distance from the bottom of the lens to what you are looking at. The focal length decreases with the stronger lenses. Viewing area is the size of the lens you are looking through, which also decreases with increased strength.

The focal length of a telescope is the distance (usually expressed in millimeters, or mm) from the telescope's main optical element (main lens or primary mirror) to the point where light rays are brought to a focus. Focal length is an important telescope specification because it determines, among other characteristics, the magnifying power of the telescope.

In short, it tells you how much from the scene you will see using that particular lens. It is called Field of View and is expressed in degrees. Example: 4mm 1/3" lens will give you 63 degrees of horizontal field of view while 8mm 1/3" lens will give you 34 degrees a field of view. Click here to find out exact numbers.

length is placed far from the workpiece so there is less chance for it to damage - for a longer lifetime. However, the laser power density reaching the workpiece decreases. When cutting thin material (5mm and less) one should use 5" focal length since the spot diameter is smaller.

I’d sit down with your photos and think about what focal lengths you tend to use most and where there are gaps. Maybe you want an extreme wide angle, for example. If so there’s no point getting another telephoto.

Prime lenses generally afford higher optical quality than zooms, except in the case of really expensive pro zoom lenses. However prime lenses mean you have to walk around more - you can’t simply adjust the zoom setting to get the framing you need.

The magnification is fixed, so there’s no need to calculate this property. What’s left to calculate is the working distance (WD) that results for a given lens extension or spacer between the lens and the camera. For any of our Double Telecentric lenses, the change in WD is inversely proportional to -(the square of the magnification) times the (spacer length), or: NOTE: If you are using a cs-mount camera without a 5mm c-mount adapter, this is the same as using a negative 5mm spacer.

It doesn't; it is subject distance that affects perspective. However, a longer lens provides more subject magnification at a given distance, so you can get farther from your subject without having the image be too small. By moving back, you make the magnification ratio between the front and back of your subject smaller, because the distance ratio is closer to one.

With an interior environmental portrait made with a wideangle lens the important factor becomes the lens to subject distance. If the subject is kept central in the image and the head is placed approx. 1.3 (5 feet) from the camera it will be relatively free of distortion. Obviously any limbs nearer the camera will increase in apparent size. This is often seen in fashion shots.

Answer: Focal Length is usually dictated by height, wearers 5ft 7’’ and below are usually best with a 330mm Focal Length/Working Distance and wearers 5ft 10’’ and above are best with 500mm Focal Length/Working Distance. There is a 420mm Focal Distance/Working Distance for wearers that need a more variable working distance where they perform a variety of procedures in different positions. This particularly applies to Field Surgeons and Veterinarians.

There is no set focal length that works for a specific format -- a range of focal length lenses are usually suited to a format. For 35mm negatives, try a Componon-S 50 or an Apo-Componon 40. Medium format negatives work well in the range of 60 to 100mm lenses, depending on the specific negative size. 4x5 negatives require nothing shorter than a 135mm lens, although 150mm is the "standard" size. 8x10 shooters would do well with the Componon-S 240 or the G-Componon 300 or 360.

A1. Use the following formula to calculate your new focal length using the Navitar SSW065 or HDSSW065 Wide-angle ScreenStar Conversion Lenses Consider that your current focal length is 1.18-1.80" and you place a Navitar SSW065 Wide-angle ScreenStar Conversion Lens in front of the projector's standard lens, your new focal length will be: Note: When the focal length ranges between two numbers, as in the example above, multiply each number by 0.

A 50mm lens produces an image of a distant object on the film that is the same size as would be produced by a pinhole 50mm from the film. See also Q5 below.