Optimize Lens Settings

Adjusting Zoom

ClosedWHAT IS ZOOM?

With a Zoom lens, it is possible to simulate the effect of changing the distance between the camera and the finish line. This makes objects appear smaller or larger and changes the amount of the finish line in the camera view.

To adjust the zoom value for a manual lens, simply turn the ring that adjusts the Zoom setting.  Large numbers make the image appear nearer (larger), small numbers make it seem as if the image is further away. When using a remote control lens, use the Remote control icons in the Hardware Control window.

Zoom in or out to optimize the view of the camera. The view should be wide enough to see all the important parts of an object crossing the finish line, but tight enough to cut out undesired content at the top and bottom of the image and maximize the resolution of objects of interest.

See this video for more information.

Adjusting the Iris

ClosedWHAT IS THE IRIS?

The amount of light reaching the image sensor is also dependent on the size of the opening in the lens (iris). By default, the Auto Iris function is enabled in FinishLynx. When a remote controlled lens is connected to the camera, the software will automatically open and close the iris to adjust with varying light conditions based on the current Gain.

For manual lenses without remote iris, it is adjusted by turning the ring on the lens that has a spread of numbers from the sequence: f1, f1.4, f2.8, f4, f5.6, f8, f11, f16, f22. Not all these numbers may appear, especially from either ends of the list. However, it is always true that as the numbers get LARGER, the amount of light reaching the image sensor gets SMALLER.

ClosedWHAT IS GAIN?

The value of the Gain setting is a reflection of the amount of first level electronic boost that is given to the signal by the software. If the iris is left unchanged, in low light the gain value will be higher than in bright light.

There are two methods of setting the Gain in the Camera Settings:

  • Auto Gain Control (AGC) - Set automatically by FinishLynx. Depending on the light conditions, the Gain value will change automatically in the range between 1 and the Maximum Gain Sets the ceiling value for AGC. based on the current Brightness setting.
  • Manual - Set by the Operator. The gain will remain at the fixed value and the image will be lighter or darker if the light conditions change.

With a remote controlled lens, you should let the software control the iris.

With a manual lens, you should adjust the Iris until the value of Gain is in the lower third of the range - an ideal value is around 40. If the initial value is close to 150, you should open the Iris (lower number). If the initial value is close to 0, you should close the Iris (higher number).

NOTE: With AGC and Auto Iris enabled, the Brightness level is the guiding parameter. See Adjust Camera Settings for details.

 

Adjusting Focus

When using a remote control lens, use the Remote control icons in the Hardware Control window to adjust the focus. On a manual lens, the focus adjustment is a ring on the lens which has distances marked on it. The operator should be able to get nearly the correct focus by determining the distance between the camera and a point one third of the way up the finish line and setting the focus adjustment to that distance.

Adjust camera focus so that the focus indicator number , situated left above the alignment image, has reached a number as high as possible. Horizontal lines in the background image being scanned should look as sharp as possible.

ClosedWHAT IS DEPTH OF FIELD?

Everybody understands the difference between an image which is in focus and one which is not; however, an operator will also have to consider the “depth of field” – sometimes known as depth of focus.

Depth of Field is defined as the distance in front of, and behind the point of precise focus where the image is also focused. In other words, even though a lens is precisely focused in the middle of the track (Lane 3), the area of sharp focus will extend a certain distance in front of this (lanes 1 & 2), and a certain distance behind (lanes 4, 5, 6, 7 & 8). 

Obviously an operator would like as much of the image as possible to be in focus, and there are certain steps that can be taken to increase the Depth of Field.  The smaller the iris – the greater the Depth of Field. However, precisely because the depth of field is largest when the iris is smallest, the operator should try to FOCUS the camera with the iris as large as possible. Once the camera has been focused, the settings should be changed to make the depth of field as big as possible.

  • To set focus for varying light conditions and low depth of field:
  1. Open the Iris as much as possible.
    1. Disable the Auto Iris function if needed, by unchecking the box in the Camera Settings.
  2. If the image is overexposed...
    1. Increase the Frame Rate.
  3. Set focus by turning the focus ring. When using a remote control lens, use the Remote control icons in the Hardware Control window.
  4. Return Rate and Iris to initial values.
TIP: Placing two dark lines a few inches apart across the finish line can aid in finding the correct focus. When the camera is not focused, two close lines will blur into one; as the focus improves the space between the lines will become more evident.