Telescope and Camera image size test

I was doing some visual observing with my Meade LX70 refractor. I then tried connecting my Canon T3i and was disappointed with the results. I was looking at Jupiter and could make out some of the bands and the moon with the different eyepieces but the image was way too small on the image with the Canon. So, I did a test some tests. I tested all three of my telescopes (Meade ETX90EC, Meade LX70 refractor, Meade Lightbridge 10”) with my two cameras (Canon T3i and ZWO AS103MC).

The results are in this wiki article called “Image Size Test”.

The first thing that is interesting is of course the difference between the image with the 55 MM camera lens and any of the telescope images. But, the more critical comparison is between the telescopes themselves using the different cameras.

The ZWO camera results is significantly closer image than the Canon regardless of which telescope is used.

When comparing the ZWO images, I was surprised the ETX had a larger image even though it is a small diameter. I will need to do more research. The Lightbridge image is very puzzling. It is a significantly larger diameter and the image isn’t a similar order of magnitude bigger. In fact, the Lightbridge doesn’t look much bigger than the ETX.

Related to the Barlow, the image size is noticeably larger.

Though not related to this test, the blurry images are a problem but again the test was during the day going through a window.

To summarize, interesting results and will need another test using a night time object like the moon.

daylight test 55mmimage size test Capture_00005

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DSLR and Meade ETX-90EC

I experimented with connecting a Canon T3i to an ETX-90EC.  I purchase the necessary T-apdater for the ETX along with the T-mount for the Canon.  The connections all went fine.  I focused in the eyepiece and the flipped the mirror.  I add to refocus for the camera.  The first images were okay.

I looked up in the Canon manual how to get the Live View not to turn off too quickly.  I then read the section on Live View and learned how to manually focus.  It was much better once I learned how to zoom in on the Live View.  The automatic focuser was great but still not sensitive enough.  Later, I found out there are speed settings on the focuser so will have to try that.

Overall, the configuration worked fine and ready to test on astronomy objects.

 

dslr_etx_1dslr_etx_2

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