Just calculate the predicted temperature drop from the weather forecast and schedule timed refocusing sessions accordingly and you should be fine.

This can be added to Ekos... so it's just if temperature diff is above a certain threshold, then refocus? It records temperature on connection and if that exceeds the threshold , then autofocus?

Could a simple model, like a fixed focus-shift pr. temperature, also work, such that one does not need a full refocus but just some minor (semi-continuous) adjustments based on the temperature difference alone? Just a crazy idea...

I'd prefer a full refocus since minor (semi-continuous) adjustments need calibration by the user and the differences may vary per night.

I can do autofocus when temperature is above threshold... rest would take a lot of time

Oh, that would be great ! ... Can we chose the threshold (depending on ones F/D or focal length) ?

- Marc

I agree, that would be a great addition to the capabilities of EKOS. Even more if at the same time both values (temperature and focus) would be added to the FITS header, that would make it much easier to derive a temperature dependence for those that want to do this....

I was wondering if anyone knows what's that status of this? Will a "refocus if the temperature difference is more than X degrees" feature come to an Ekos near us soon?


Wouter

Hello all,
just seen this and there is an Autofocus if Delta Temp is bigger than a certain amount of degrees.

I have recently purchased a ZWO EAF and I have a Pegasus PPA (Pocket Powerbox Advance). I dont have a temperature sensor on the ZWO EAF but I do have on the PPA.
Which temperature is used for this condition?

The issue is that the ASI EAF has got a temperature channel which is clearly wrong (28C degrees at room temperature vs 20C read by PPA).

It shouldn't matter that much that the temperature reading of the ZWO EAF is off. You are only interested in delta temp, i.e. you want to refocus whenever the termperature drops by more than 1.5 or 2 degrees. Whether you start out at 28 degrees (the ZWO reading is probably thrown off by the heat the ZWO itself is generating) or at 20 degrees should be largely irrelevant.

Thanks for the quick reply. I was thinking the same logic but the ZWO EAF temperature was constant all morning long so I thought it was a wrong reading. I
will check tonight again to see what value I get as my fridge isnt big enough

Considering that the temperature sensor for the ZWO EAF costs only $10, I would consider just buying one and be done with it.
optcorp.com/products/zwo-eaf-sensor-zwo-temperature-sensor