An Ode to an Awesome Couple / Thoughts on Temperature

These folks are so cool, they gave me a very helpful head start in the hobby of astronomy and astrophotography. They are the reason that I was able to obtain the Sky-Watcher EQ6-R Pro equatorial mount. During that time I used the telescope in table-top configuration. On the second night I took it outside, it was less than twenty degrees outside and I was using my BBQ's flat surfaces. The steel flexed a lot and the high gusts of wind were not helpful.


Naturally, I did not get clear images of the moon during that eclipse. It was too cold to play with the settings but I still got off a few shots at different ISO exposure settings as well as shutter speeds. It was some of the longer shutter speeds which enabled me to see the pinkish hue of the eclipsed moon. Anyway, from there I took the OTA out on every clear night I could and did a bit of star hopping. In fact, my first use of the OTA was through a window and it taught me some interesting things.


One would expect a window to be a factor in diminishing image quality, and it is but not the biggest factor. The greatest factor in my opinion is that of temperature, on the OTA, in the room and outside. For example, if it is 20-degrees outside and 74-degrees degrees inside, you will not be able to achieve the sharpest focus. For example, while observing the moon you'll get it to a point where it doesn't get any sharper and you can turn the nob a few degrees and see no change. Whereas, if you take the telescope outside and let it cool down, you will be able to achieve sharper focus.


One idea was to simply open the window. Surely this would eliminate the effects of having a window in front of me. I don't think my window is gold plated or super-coated which means it is indeed possible to view through it, while more well tinted/plated windows are increasingly difficult to look through with a telescope. So, I opened the window and it got worse. The image was distorted and got blurrier, at first I thought it was dew/fog on the lens but nope, it was not.

"...I opened the window and it got worse."

My theories were as follows:

* The corrector plate is being incongruously cooled, thereby changing shape by contracting/shrinking ever so slightly. This, while the primary mirror at the rear of the OTA remains at room temperature.

* The scondary mirror getting cooled incongruously. Less likely, it's kinda buried under stuff and I believe it would take longer than a few seconds of exposure for it to be effected.

Then a third one which was proposed by a coworker and auto-buff is that this was the result of "heat waves." I'm not sure about this, but I'm not sure about eliminating this as a possibility just yet either.


Bottom line, once you bring the OTA outside and it normalizes or equalizes to the ambient outdoor temperature, it does indeed perform better.