Searching a lens for an imaging system can appear like a complicated task. So breaking down the selection into workable pieces is necessary. Pieces like the field of view, working distance, resolution, and depth of field are all significant that come directly from what should be done for an effective application of imaging lenses.
Key Points to Remember While Selecting Imaging Lenses
Field of View (FoW)
The key here is to make sure you determine the field of view that lets you match it with lens specifications. The complexity is that most sensors in machine view cameras are rectangular. This directs to the lens field of view likely to be stated in 3 different ways: horizontal FoW, vertical FoW or diagonal FoW. Due to this, you should always ensure to consider the whole region that the object being imaged will follow through. A 6-inch x 1-inch object will need a distinct lens than a 6 by 6-inch object.
Working Distance Range
One more important specification in imaging lenses is the range of working distance you can work inside. It is imperative to understand that working distance is always described as the object distance being viewed or imaged and the front area of the lens; it does not involve the lens length itself. Thus, if you are working within a stiff package size, it is necessary to know the system length that you may have, which is the working distance + lens length + camera length.
Now the basics of each imaging system are knowing the resolution requirements and matching a lens to that requirement. The best method to consider the resolution you want is to find out the smallest element you need to undertake. Once you have identified this, you must link it to the FoW that you have identified you will require. This is due to requiring to resolve 0.1 mm specifics with a 4×3 mm FoW is a much lesser resolution need than needing to resolve 0.1 mm specifics with a 400×300 mm FoW will be.
Depth of Field
Finally, it is essential to know what field depth you need for imaging lenses. The field depth is the length that the lens can resolve over the working distance you focus on. This is necessary if the object you are seeing has any top part that you wish to image through—consider the contents on a circuit board. Generally, lenses have a particular depth of field that includes a resolution or contrast below the specified working distance. Thus, it is good to ask the lens provider about the needed field depth with the specifications you identify.
Finding the basic specifications of the imaging lenses makes your lens selection much simpler and lets you assess lenses that you have resolved. Thus, you can ensure finding one that is the best performing in your application or give you expensive over-performance.