If you’ve had Level I Thermographic Applications training course you most likely heard the mantra of “Focus First!” from your instructor, and with good reason! Of all of the camera settings that can be adjusted by the camera operator, focus is by far the most important. Focus is essential to both image quality and temperature measurement.
Consider the images above. The image on the right is of much higher quality. While it’s fairly easy to discern that the object in either image is a house, the right hand image is crisper, and there is more detail because the focus is so sharply adjusted. Most customers will notice image quality immediately, and the image on the left just wouldn’t be helpful to help illustrate thermal anomalies clearly.
Reviewing the next set of images above, one can determine that each contains a box used to measure the maximum apparent temperature of the detected anomaly. In the left hand image, the focus is sharp and thus the detector elements are getting a clear representation of the amount of thermal energy being emitted from the surfaces within the area box. This allows the detector to more reliably measure that energy and assign a temperature value to it. In the right hand image, our focus is marred. This effect reduces the clarity of the energy being projected onto the detector elements, resulting in a faulty measurement.
Clear, sharp focus is essential in thermal imaging. It can be the difference between success and failure. Remember and adopt the mantra of “Focus First!”, and use this tip to help you Think Thermally®.
Think Thermally, www.thesnellgroup.com The Snell Group, a Fluke Thermal Imaging Blog content partner