Dew spot on ASI071 window

arie

Hi, last night I shot M16 in Ha 7Nm. 5x20min TEC -20, LNR

M16 Ha 5x20min.jpeg

Sub frame #6 failed because a dew spot had developed on the window's outside.

Despite that the anti-dew option was tagged in the ASCOM driver.

What is it that this anti-dew function provides, if still dew can develop on the windows outside?

When I wiped it of it immediately fogged up again.

Atmospheric conditions were fairly humid, towards slight ground-fogg.

My telescope did not fog up with no anti-dew ribbons installed.

I just ordered your anti-dew ring to stick on the camera, hoping that this will prevent re-occurence.

I am very pleased with the result btw.

This proves that Ha is possible with this OSC camera.

Regards

Arie

Sam@ZWO

thanks for your feedback

I think we need to enhance the power of the heater which maybe not powerful enough

arie

I think so too, Sam.

The outer edge of the window was clean, but a round spot of +/-2cm developed in te middle after 2 hours in operation at TEC -20.

I can imagine that the super cold sensor draws heat from the window glass sufficiently to cause it to dew-up in certain circumstances. The installed heater was not powerful enough to counteract this process. You could consider a heater in 3 steps. L-M-H

I do hope that with your additional accessory the window will become warm enough.

Support@ZWO

arie wrote:
I think so too, Sam.

The outer edge of the window was clean, but a round spot of +/-2cm developed in te middle after 2 hours in operation at TEC -20.

I can imagine that the super cold sensor draws heat from the window glass sufficiently to cause it to dew-up in certain circumstances. The installed heater was not powerful enough to counteract this process. You could consider a heater in 3 steps. L-M-H

I do hope that with your additional accessory the window will become warm enough.

thanks, for your advice. L-M-H，is very good idea.