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# Lens calculator - Calculating the object size / field of view (FOV)

The object size G is usually the object range to be detected which must be viewed by means of the camera.

'Classic',
G=B* (g / f´-1)
Extended calc. of
width, height & diagonal
Using
imaging scale
Using opening angle

## Calculating the object size or FOV using entocentric standard lenses

Calculate the field of view given the working distance, sensor size and lens focal length.

G = B * (g / f'-1)

Note: Even when using the drop-down lists own values can be entered. Please use the first entry "user def."!

 Sensor size : User def. (mm) 1/4" 3.2 mm 1/3" 4.8 mm 1/2.5" 5.7 mm 1/2" 6.4 mm 1/1.8" 7.2 mm 2/3" 8.8mm 10.5 mm 1" 12.8 mm 1.2" 14.2 mm 15.3 mm 4/3 17.9 mm APS/C 23.7 mm KB 36.0 mm Line .5K 14µm Line 1K 10µm Line 1K 14µm Line 2K 10µm Line 2K 14µm Line 4K 7µm Line 4K 10µm Line 6K 7µm Line 8K 7µm Line 12K 5µm Focal length: User def. (mm) 2.8 3.2 4.8 6 8 9 12 16 17 23 25 35 50 60 75 85 100 125 150 Working distance in mm: Calculated object size (FOV):

## Calculating the object size (height, width, diagonal) using real sensor dimensions

Note: Even when using the drop-down lists own values can be entered. Please use the first entry "user def."!

 Sensor pixel count in X direction: User def. (px) 240 px 320 px 480 px 512 px 640 px 800 px 1024 px 1200 px 1280 px 1400 px 1600 px 2048 px 2452 px 3200 px 4096 px 4872 px 6144 px 8192 px 12288 px Sensor pixel count in Y direction: User def. (px) 240 px 320 px 480 px 512 px 640 px 800 px 1024 px 1200 px 1280 px 1400 px 1600 px 2048 px 2452 px 3200 px 4096 px 4872 px 6144 px 8192 px 12288 px Pixel size in µm: User def. pixel size in µm 1 µm 1.7 µm 2 µm 2.2 µm 3 µm 3.45 µm 4 µm 4.4 µm 5 µm 5.3 µm 6 µm 7 µm 8 µm 10 µm 14 µm 20 µm Focal length of lens: Userdef. (mm) 2.8 3.2 4.8 6 8 9 12 16 17 23 25 35 50 60 75 85 100 125 150 Working distance in mm: Calculated sensor dimensions: Calculated sensor ratio: Object size / FOV X: Y: Diagonal:

Attention: Calculated object sizes of several millimetres can indeed be realised by means of entocentric lenses (incl. close-up rings), but often hardly useful. Normal objects with close-up rings in retro position provide an alternative for better image quality. In case of smallest image details and large magnifications please use macro-lenses which are specially designed for these applications.

Further details on optical calculations can be found in chapter Optical basics.

## Calculating the object size using the reproduction scale (macro & telecentric lenses)

Also for macro lenses and telecentric lenses it is possible to calculate the field of view using the imaging scale and sensor size.

Object size G = sensor size B / imaging scale ß

Note: Even when using the drop-down lists own values can be entered. Please use the first entry "user def."!

 Sensor size: User def. (mm) 1/4" 3.2 mm 1/3" 4.8 mm 1/2.5" 5.7 mm 1/2" 6.4 mm 1/1.8" 7.2 mm 2/3" 8.8mm 10.5 mm 1" 12.8 mm 1.2" 14.2 mm 15.3 mm 4/3 17.9 mm APS/C 23.7 mm KB 36.0 mm Line .5K 14µm Line 1K 10µm Line 1K 14µm Line 2K 10µm Line 2K 14µm Line 4K 7µm Line 4K 10µm Line 6K 7µm Line 8K 7µm Line 12K 5µm Imaging scale of lens: Calculated object size (FOV) in mm:

## Calculating the object size from opening angle

The field of view at a given working distance can also be calculated using the aperture angle of the optics.

 Opening angle of lens: User def. (degrees) 5 degrees 10 degrees 15 degrees 20 degrees 25 degrees 30 degrees 35 degrees 40 degrees 45 degrees 50 degrees 60 degrees 70 degrees 80 degrees 90 degrees 100 degrees 120 degrees Working distance in mm: Field of view (object size):

Note:

Further details on optical calculations can be found in chapter Optical basics.