Optics Sizing Calculator
Determine the required resolution, shutter time and lens focal length from your product requirements - before you buy a camera and lens.
This machine vision lens calculator helps system integrators, process engineers and buyers pre-size a camera-lens combination for industrial image processing. Based on the field of view (FOV), the smallest product feature to detect, the product speed and the allowed motion blur, the tool computes the required sensor resolution in pixels and megapixels, the maximum exposure (shutter) time needed to avoid motion blur, and, for a range of common focal lengths (6 to 100 mm), the corresponding working distance and depth of field. This lets you determine upfront whether a candidate camera and lens meet the requirements of your inspection task, before investing in hardware.
Product parameters
Speed at which the product moves through the image. Choose its direction relative to the camera under Direction of travel.
How the linear motion appears in the camera image: along the FOV width or along the FOV height above. This sets which image dimension counts towards the minimum frame rate.
Distance from the rotation axis to the point on the object being imaged. Only relevant for rotating objects; leave at 0 for linear transport (e.g. a conveyor belt).
Extra image shared by consecutive frames, so there are no gaps in inspection coverage.
For example due to radiant heat from a hot product, or the available space right next to the object.
Set by the physical installation space — how far away the camera and lens can be mounted from the object at most.
For wide surfaces (e.g. a 4m+ wide fabric or panel line) multiple cameras can be placed side by side, each covering part of the FOV width above. The calculations below then apply per camera.
Camera specifications
A line scan camera has a single row of pixels across the width and builds the image line by line as the product moves past. Suited to continuous webs (paper, film, textiles, steel), very wide products and rotating cylindrical parts.
Filled in when you pick a sensor: the maximum full-resolution frame rate of the Omron Sentech GigE PoE model. USB3 and Camera Link versions are faster. You can change the value.
Results
What's needed
Required resolution: 300 × 240 px (Required megapixels: 0.07 MP)
A camera needs enough pixels across the width and the height. The total megapixel count alone does not tell you whether it fits.
Does your candidate camera work?
OK — sufficient resolution
| Property | This camera | Required | Fits |
|---|---|---|---|
| Pixels across the width | 2.448 px | ≥ 300 px | Yes |
| Pixels across the height | 2.048 px | ≥ 240 px | Yes |
| One pixel on the object | 0,0408 × 0,0408 mm = 0,0017 mm² | ≤ 0,3333 × 0,3333 mm = 0,1111 mm² | Yes |
| Smallest feature (1 × 1 mm) | 24,5 × 24,5 px = 599,3 px² | ≥ 3 × 3 px = 9 px² | Yes |
Shutter time / motion blur
Maximum exposure time: n/a — speed is 0
Calculated for a target blur between 0.5 and 2 pixels (barely perceptible to just noticeable) — in practice, less is always better.
Minimum frame rate
Minimum required frame rate: 0 fps
Field of view in direction of travel (H): 100 mm
Yes — sufficient
Ensures the object doesn't move through the field of view faster than the camera can capture new frames (no gaps in inspection coverage). Enter your camera's frame rate above to check if it's sufficient.
Focal length, working distance & depth of field
| Focal length (mm) | Working distance (mm) | Angle of view | Within working distance | DOF near (mm) | DOF far (mm) | DOF total (mm) |
|---|---|---|---|---|---|---|
| 6 | 71 | 70,3° | n/a — no limit set | 63,3 – 69,1 | 72,9 – 78,7 | 3,9 – 15,5 |
| 8 | 94,7 | 55,7° | n/a — no limit set | 86,9 – 92,7 | 96,6 – 102,4 | 3,9 – 15,5 |
| 12 | 142 | 38,8° | n/a — no limit set | 134,3 – 140,1 | 143,9 – 149,7 | 3,9 – 15,5 |
| 16 | 189,3 | 29,6° | n/a — no limit set | 181,6 – 187,4 | 191,3 – 197,1 | 3,9 – 15,5 |
| 25 | 295,9 | 19,2° | n/a — no limit set | 288,1 – 293,9 | 297,8 – 303,6 | 3,9 – 15,5 |
| 35 | 414,2 | 13,8° | n/a — no limit set | 406,5 – 412,3 | 416,1 – 421,9 | 3,9 – 15,5 |
| 50 | 591,7 | 9,7° | n/a — no limit set | 584 – 589,8 | 593,6 – 599,5 | 3,9 – 15,5 |
| 75 | 887,6 | 6,4° | n/a — no limit set | 879,8 – 885,6 | 889,5 – 895,3 | 3,9 – 15,5 |
| 100 | 1.183,4 | 4,8° | n/a — no limit set | 1.175,7 – 1.181,5 | 1.185,4 – 1.191,2 | 3,9 – 15,5 |
Both the working-distance and depth-of-field values are far-field approximations (working distance >> focal length), adequate for sizing and pre-selection. For working distances under roughly 20× the focal length, or for a final purchase decision, we recommend checking the lens manufacturer's own calculator — principal plane offsets matter more at short conjugates.
Calculated for a target blur between 0.5 and 2 pixels (barely perceptible to just noticeable) — in practice, less is always better.
The angle of view shows the real physical difference between focal lengths: a short focal length (close to the object, wide angle) is more prone to edge distortion and perspective error; a longer focal length (larger working distance, narrower angle) generally gives a flatter, less distorted image — important when the edges of the frame need to be accurate too. If distortion is still a problem, e.g. for dimensional measurement, a telecentric lens removes perspective error almost entirely (constant magnification, no angle-dependent error) — at the cost of a larger, pricier lens with a FOV that can't exceed the lens diameter.
Your input is kept in this browser automatically (local storage, no cookies), so you can pick up where you left off. "Save calculation" gives you a copy to open on another computer or share with a colleague.
* This calculator provides indicative results based on standard approximation formulas. No rights can be derived from them; always verify your final choice with the lens manufacturer or contact us for expert advice.