Sunday, August 30, 2020

Celestron Firstscope Image Through Glass

Celestron Firstscope
Image Through Window Glass Project

NEW! This is the next ultra radical project accomplished with the little telescope that could - the mighty Celestron FirstScope.

Iphone 6 Plus at 1X is a bit overexposed and
unable to fully compensate the exposure. In
this image, the ocular's circular FOV is
apparent.
The night of Sunday August 30th 2020 - A session with the Gibbous Moon and the Celestron FirstScope while staying indoors in comfort!

Introduction
Imaging through window glass is one of the biggest NO-NOs known to astronomers,  both amateur and professional. The glass from a window seriously distorts the image from the telescope and both eyes and camera simply won't see the best image. But hey, what if your telescope is already small and minuscule (2.99" diameter) and optically compromised according to some people? SCT's look through a window of corrected glass all the time. However, house windows are endowed with seriously optically flawed panes of glass. The problem is the glass is not flat and can cause distortions. But what if our telescope s very small and we look through a very small planar section of window glass?

The Proposal
What can we actually expect by using it to image through a glass window indoors? And let's suppose the temperature is cool indoors from air conditioning and the outside is very hot and humid. Incidentally, there is no thermal equilibrium between the telescope and the outdoors or the window glass, there is no telescope drive, the diagonal is compromised in size, and the camera is handheld with no mount. What could go wrong? What could we possibly expect?

Results
Actually, the results are not bad, rather good one might say! Surprise! The best images were taken with the 10mm 62 degree aspheric eyepiece around 20x and a CPL polarizing filter, both from Svbony. A Moon filter did not noticeably change the image and results remained on the overexposed side. The Celestron 6mm orthoscopic eyepiece had a too small exit pupil to be of any real use. The 23mm EP showed a small bright moon with various camera reflections occurring. That image scale was too small and bright in the 12-inch EFL scope, which gives about 12 power. Once again, we have proven aspheric lenses perform superior with this scope. General image processing was applied with Apple Photos on a Mac.

Tips
The trick here was to use two iPhone cameras, one is a 6 Plus with OS 12.4.6 for experimentation and the other is the mighty Xs Max running OS 13.6 with the same 10mm EP and filter but in 2x mode boosting the image to around 40x, just fitting in the FOV to get the best results.

Conclusion
Celestron FirstScope, you have shown the impossible is possible, and in spite of all your deficiencies, we love you!

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