Until recently I had not encountered any problems with condensation with this setup, however I make sure the camera is powered up before turning on the peltier cooler.
It had been quite a warm day and the scope had warmed up sitting in the garage so after setting up I turned the cooling on and promptly forgot, messing around checking alignments etc.
I was also working on an Ardunio set up to monitor temp and humidity and pass the information to BYE and had this working quite nicely. Then the camera quit, the humidity had gone up to around 95% it was dripping wet, the USB connector was flooded. Luckily it dried out and no damage has been done.
My Arduino project then expanded to include a temperature sensor attached to the camera casing, and a relay to shut off the cooling if the camera case temperature dropped close to the dewpoint, testing so far has been good.
The device uses all standard parts from an Ardunio kit: Arduino Nano, DHT11 temp/humid sensor, LCD display, lm35 temp sensor attached to the camera and the Ardunio power relay (the peltier runs at around 4amps). It connects to a USB port on the laptop and gets power from there.
The program sends a simulated Mbox string to BYE, displays Humidity, Temperature, Dewpoint and Camera Case temperature on the LCD.
Pictures attached, if anyone is interested I would be happy to send the code (I am not a programmer so its probably not elegant - but it works)