Dew Point?

I have a question about the dew point... if the temperature doesn't fall below the dew point, will optics not dew up? For example, if the forecast low is -14 and the dew point is -16, will dew not form because the dew point temperature isn't reached? Am I interpereting dew point correctly? Any meteorologists out there?

Thanks!

Acutal Dew will not form until dewpoint is reached. You can however dew them up with your breath.
Remember too that the projected low will not necessarily match your location. Dew point is also subject to pressure and humidity changes. Very dry air is less likey to reach dew point.
"Dewpoint: the temperature air would have to be cooled to in order for saturation to occur. The dewpoint temperature assumes there is no change in air pressure or moisture content of the air."
Floyd

As you approach the dewpoint, another critical part is how much your equipment is radiating heat to the atmosphere, thereby reducing its actual temp below the dewpoint. That is typically what happens here in the south on low humidity nights. As long as there is a slight breeze it helps prevent the dew, but as the humidity levels rise, there is nothing that will stop it, unless you agressivly attack with dew heaters from the very beginning
Another reason to live out west in the more arrid environs.

Walt

It's always something, isn't it? If it's not dew, then it's clouds, full moon, mosquitoes, too cold, too windy, light pollution, bad seeing, etc., etc., etc. A very frustrating hobby... :C

I have a degree in meteorology but I am not practicing, instead switched to air quality and engineering.

The other posters are correct that radiation to outer space will cool your equipment to several degrees colder than the official temperature. Thus creating dew or frost on solid surfaces.

The official air temperature is taken in a well ventilated box that is shielded from radiation effects.

Same thing with frost on gardens, you should provide protection if the official temp gets below 38F or so, because the ground will be colder.

Mike Ratcliff