Where do I put the auto-focuser temperature probe?

[rnobleeddy]

I assume this will turn out be obvious, but on a refractor with a dew heater wrapped around the outside of the lens, where do people place their auto-focuser temperature probe? 

I guess I want to measure the lens cell temperature, but I guess if I place this in contact with the dew heater strap, it'll be pretty constant, whereas presumably the lens cell dissipates heat according to how cold it is? So maybe I just put it anywhere else?

[Doug64]

Hi

I just place mine by the focuser, I then have my software auto focus after filter change or 1 degree drop in temp

Doug

 

[Richard_]

I keep mine near the housing of the auto focuser just as Doug says, as placing it near the objective lens is a no go due to the heater bands. 

See attached picture, showing the temperature probe (silver rod) near the blue housing of my Pegasus Focus cube auto focuser. 

As an FYI, in my image capture software (NINA) I include HFR and duration as criteria to perform an auto focus.  Temperature seems somewhat stable throughout the evening at my location and I don't often see a trigger to refocus due to temperature. This may differ for you 🙂

[The Lazy Astronomer]

I'd do away with the probe all together and base a refocus trigger solely on a change to measured star size (or filter change).

I have a probe on mine anyway, but I've literally never used it for refocus purposes, all it does now is provide me information about the ambient temp, so I know exactly how cold I'll be when l go back out to pack up after a session 😁