Why are image-orthicon television cameras not widely used?

Image-orthicon television cameras are not widely used primarily due to their high cost. The technology behind image-orthicon cameras involved complex electronics and expensive materials, which made them less economical compared to other available imaging technologies. As advancements were made in the field of imaging, less costly alternatives such as charge-coupled devices (CCDs) and other types of cameras became more accessible and affordable, thus leading to a decline in the use of image-orthicon cameras. These alternatives often offer similar or improved performance at a fraction of the operational cost, making them more appealing for both commercial and medical applications.

The other factors related to fixed gain, very fast discharge time, and complexity of use have not significantly contributed to the decline in the use of image-orthicon cameras. While these characteristics may affect performance or usability, it is the economic factor—the high cost—that ultimately plays a decisive role in their reduced prevalence in the market.