What Are Camera Lenses Called For Close Ups

Set of three close-up lenses

Optical scheme of close-up photography.

• 1 - Close-upwardly lens.
• 2 - Camera objective lens (fix to infinity).
• iii - Camera.
• 4 - Movie or CCD plane.
• y - Object
• y" - Image

Photograph taken with a 3 diopter achromatic close-up lens: Pentatomidae-hatchlings underneath a royal beech leaf

In photography, a close-upward lens (sometimes referred to as close-up filter or a macro filter) is a elementary secondary lens used to enable macro photography without requiring a specialised primary lens. They piece of work like reading spectacles, allowing a master lens to focus more closely.^[1] Bringing the focus closer allows the lensman more possibilities.^[ii]

Close-up lenses typically mount on the filter thread of the primary lens,^[three] and are frequently manufactured and sold by suppliers of photographic filters. Withal, they are lenses and not filters. Some manufacturers refer to their close-up lenses as diopters, after the unit of measurement of their optical ability.

Close-upwardly lens do not bear on exposure, different extension tubes, which also can exist used for macro photography with a non-macro lens.^[4]

Optical power [edit]

Shut-upwards lenses are ofttimes specified by their optical power in diopters, the reciprocal of the focal length in meters. For a shut-upwardly lens, the diopter value is positive: the bigger the number, the greater the constructive magnification.

Several close-up lenses may exist used in combination; the optical power of the combination is the sum of the optical powers of the component lenses.^[5] For example, a set up of lenses of +1, +2, and +4 diopters can exist combined to provide a range from +1 to +vii in steps of 1.

Working distances and magnifications [edit]

Shut-up lenses change both the maximum and minimum focus distances of a lens. The range tin can be rather pocket-sized.

Working at maximum distance [edit]

Adding a close-up lens to a lens focused to infinity changes the focus point to the focal length of the close-up lens, that is, the inverse of its optical power. This is the combination'due south maximal working distance:

${\displaystyle X_{\text{max}}={\frac {i}{D}}}$

That distance is sometimes given on the filter in mm. A +3 close-upward lens has a maximal working distance of 0.333grand or 333 mm.

The magnification is the focal altitude of the objective lens (f) divided by the focal distance of the close-up lens; i.e., the focal distance of the objective lens (in meters) multiplied by the diopter value (D) of the close-up lens:

${\displaystyle M_{X{\text{max}}}=fD}$

In the example above, if the lens has a 300 mm focal distance, the magnification is 0.3×3 = 0.9.

Given the small-scale size of almost sensors (about 25mm for APS C sensors) a 20mm insect volition almost make full the frame at this magnification. Using a zoom lens makes it like shooting fish in a barrel to frame the subject equally desired.

Working at minimal distance [edit]

When you add a shut-upward lens to a camera which is focusing at the shortest distance at which the objective lens tin focus, the focus will move to a distance which is given by following formula:

${\displaystyle X_{\text{min}}={\frac {X}{DX+1}}}$

X existence the shortest distance at which the objective lens can focus (in meters), and D being the diopter value of the close-up lens. This is the minimal working distance at which you will be able to accept a moving-picture show with the close-up lens.

For example, a lens that can focus at ane.5m combined with a +3 diopter close-up lens will requite a closest working distance of 1.5/(3×1.v + 1) = 0.273 m.

The magnification reached in those conditions is given by post-obit formula:

${\displaystyle M_{X{\text{min}}}=M_{X}(DX+1)}$

M ₁₀ being the magnification at distance X without the shut-up lens.

In the example above, the gain of magnification at X _min will be (iii×1.5 + one) = 5.5.

It is at this 10 _min distance that you lot volition get the highest magnification.

Macro photography with a close-upwards lens [edit]

Close-upward lenses tin make a telephoto lens role as a macro lens with a large working distance. This is useful, for example, to forestall scaring small animals or isolating the subject field from messy surroundings. To apply the filters for animals the size of the animal will decide the working altitude (small snakes 1m to fifty cm, lizards 50–25 cm, small butterflies, beetles 25–10 cm), so it is essential to know what will exist the favorite bailiwick before screwing on a close-up lens. The close-up lenses are most constructive with long focal length objectives and using a zoom lens is very applied to take some flexibility in the magnification. A adept technique for sharp focussing is to take a picture at a long focal length first to take optimal sharpness at the essential details and so zooming out to have the desired size in the frame.

Optical issues [edit]

Some single-chemical element shut-upwards lenses produce images with astringent aberrations but there are besides loftier-quality close-upwards lenses composed as achromatic doublets which are capable of producing fantabulous images, with fairly depression loss of sharpness.

Meet also [edit]

• Deep focus
• Extension tube
• Photographic filter#Close-up and split diopter lenses

References [edit]

1. ^ Meehan, Joseph (2006). The Magic of Digital Close-Up Photography. New York: Lark Books. p. 59. ISBN978-1-57990-652-8. For real close-upward work, some cameras demand help—their own version of reading glasses.
2. ^ Timacheff, Serge (2008). Canon EOS Digital Photography: Photograph Workshop. Wiley. p. 8. ISBN978-0-470-11434-vi. ...a diverseness of accessories increase your creative options. Additional components include Catechism Softmat filters and shut-upward lenses,...
3. ^ Busch, David D. (2009). Digital SLR Cameras & Photography for Dummies (third ed.). Wiley. p. 84. A lot of available add-ons tin assistance you lot focus close, including filter-like close-upwardly attachments that screw onto the front end of the lens,...
4. ^ Busch, David D. (2009). Digital SLR Cameras & Photography for Dummies (tertiary ed.). Wiley. p. 139.
5. ^ Grimm, Tom; Grimm, Michele (1997). The Basic Volume of Photography (4th ed.). Plume. p. 137. ISBN0-452-27825-two. They tin be used alone, or two can be combined.

External links [edit]

• Close focus Close-up lenses technique

Source: https://en.wikipedia.org/wiki/Close-up_lens#:~:text=In%20photography%2C%20a%20close%2Dup,lens%20to%20focus%20more%20closely.

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