Camera Defects Policy
Ophir-Spiricon, LLC (OSL) is a supplier of laser beam analysis tools that employ commercial-industrial solid-state cameras. OSL attempts to supply cameras with as few pixel defects as possible. OSL tests for and corrects defective pixels that may have an adverse effect when used for its intended purpose. OSL does not guarantee that a supplied camera will be defect free, or that they will remain defect free during its normal lifetime and under normal use.
It is not uncommon for modern megapixel camera imagers to develop point defects as they age, even when not subjected to abuse. Imagers without windows often experience point defects at rates typically greater than imagers with their cover glass left in place. Point defects can also appear more frequently when operating at higher rather than lower ambient temperatures, and higher relative humidity. Such defects can occur even when the camera is in storage and not being used.
Cameras supplied by OSL will be certified for use in laser beam analyzer applications. When defects occur, the ability to make certain measurements under certain conditions may be compromised. However, depending upon the nature of the defect, most measurement can still be performed without loss of accuracy. In some instances the effects of defects can be eliminated or significantly reduced by adjusting the manner in which the camera is being employed.
Ophir-Spiricon, LLC offers a camera recertification service. This service can help to extend the useful life of your camera and correct some point defects that may show up over time. This service can not correct cameras with serious laser damage or imager degradation. Whenever possible OSL will restore the camera to our "as new" level of certification; and if not possible, we will indicate to the user how to avoid areas of the imager that may not perform to "as new" standards.
Defects, Solutions and Workarounds
The following list contains examples of typical camera point defects that may occur over time, and suggested methods of compensating for them if they are troublesome:
|Defect type||Description of the Problem||Recommended Solution
See Note 1 below
|Bright Pixel||Pixels with this defect will indicate being illuminated even when no signal is present. These are the most troublesome when attempting to make accurate peak fluence and peak fluence location measurements because they represent a false signal. Most other measurements are not adversely affected by this type of defect. This type of defect is screened for during our regular camera inspection process. All pixels that exceed a set limit are corrected, if possible, before the camera ships. See Note 1 below. Our QA department will often reject cameras if the pixel can not be corrected and it exceeds our acceptance criteria.||
|Twinkling Pixel||This is an intermittent version of the Bright Pixel defect. These often appear as the camera warms up. May disappear if the camera is run in cooler environments. Usually predicts a pixel that will soon be a permanently bright pixel defect.
These are the hardest to detect and as such may get past our camera inspection process.
|Same as above.
If returned to OSL to be corrected please send a full frame data file showing the pixel as it is malfunctioning. This will aid in our ability to find and fix it.
|Dark Pixel||Dark pixels have low responses compared to the amount of illumination that they receive. Isolated instances of these types of defects do not pose a serious beam analysis problem and they are generally not in need of correcting.||This type of defect will not significantly impact a beam measurement result unless the beam is very very small and the defect falls inside of the beam profile. Reposition the camera to remove the defective pixel from the measurement region.|
|Dead Pixel||Dead pixels have no response at all and may output a raw pixel value of zero (0) counts. This type of defect is screened for during our regular camera inspection process. All pixels that exceed a set limit are corrected, if possible, before the camera ships.||This type of pixel may create a warning message when performing Ultracal operations. Ignore the warning and proceed as in the Dark Pixel case described above.|
|Dark Clusters||These dimmer than normal clusters involving about a dozen or fewer pixels are often caused by dust particles and can usually be removed by cleaning of the imager. Sometimes these can be very difficult to impossible to remove. In the latter case they are may be melted into imager
If this is the result of laser damage then imager replacement is the only solution.
|These usually do not cause serious measurement problems and can be treated with the Dark Pixel workaround described above. They can sometimes be dislodged with very gentle puffs of dry air. If you return a camera to be re-certified we have a few special methods for cleaning these, but success is not 100% guaranteed.|
|Regions of non-uniform response||When large areas of an imager yield reduced signal levels this usually indicates laser damage. Long term exposure to ultraviolet radiation or overexposure to high laser power or peak energies are common causes.||This type of degradation is not repairable and either the camera or the camera imager must be replaced.|
Note 1: The following camera models can be re-certified and can have bad pixels corrected:
GRAS20, SP620, L11058, L230, Pyrocam III, Xeva
Each of the above cameras will have a maximum number of pixels that can be corrected. Once this limit is exceeded the camera imager or the camera must be replaced in order to meet OSL "as new" certification standards. If a large cluster of defective pixels appear, then bad pixel correction may not be able to repair the defect. The following cameras do not have, or have very limited, bad pixel correction capabilities:
SCOR20, SP503, FX50, FX33, FX33HD
The initial release of the SP503U and SP620U cameras did not have the ROI feature enabled. Those cameras that do not have the ROI feature enabled will need to be returned for upgrading both hardware and firmware, and the latest version of software will need to be installed, which is available at;