Meteor observing requires a huge field of view (FoV) as its appearance in the sky cannot be foreseen. In the new era of the time-domain astronomy many telescopes will cover the whole sky with a cadence of a few days. These requirements lead to fast large telescopes with wide FoVs, like the Schmidt cameras that were widely used for meteor observing in the past. Common general-purpose telescopes have small plate scale and employ large integration times, what plays against meteor detection. We present here an estimation of the number of meteors detected as a byproduct of these surveys, with the detailed example of the Test-Bed Telescopes, an ESA project for NEO and space debris surveillance.