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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LX70 Refractor and Canon DSLR

I decided to do some research on the options to connect my Canon DSLR to the Meade LX70 Refractor.  I had a special adapter for the ETX 90EC that allows the Canon to connect along with a T-mount adapter.  So, I first searched for adapters for the LX70 but didn’t find any.  I did find that Meade sold a camera adapter that connected to a DSLR and then went in the 1.25” eyepiece holder.  This sounded like a great idea because I could then use it will all my telescopes.

I did some more research and found a great article about taking lunar photos through a telescope.  The article mentioned three ways.  One way was afocal photography which I was aware of.  The camera adapter would enable eyepiece-projection photography.  This was interesting because it actual uses an eyepiece so would allow for different magnifications.  But the drawback in the images are dimmer.

The third option was prime-focus photography.  I guess this is what I am doing with the Canon and ETX.  The article mentioned you could buy adapters for many telescopes so started doing that research.  I found a number of options including adapters that already had the T-mount.  But, then I had a thought.  There was a part in the box for the LX70 Refractor that I didn’t know what it was.  I took the T-mount adapter and tried to screw it on to the mysterious adapter.  It worked.  I then put in on the diagonal and it all works.  I added the Canon and tried to focus on a distant power pole.  I couldn’t get focus similar to what happened on my Lunt.  I guess it was time to research extension tubes.

But, then I had a thought.  The diagonal was removable so I took it off and added the DSLR and adapter to the back of the refractor and it all worked.  I was able to get a focused.  So, guess I already have everything I need to use the DSLR with the LX70 Refractor.

ClearSkyTonight_LX70_Refractor_DSLR_4ClearSkyTonight_LX70_Refractor_DSLR_1ClearSkyTonight_LX70_Refractor_DSLR_2ClearSkyTonight_LX70_Refractor_DSLR_3

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Observing Session–October 24, 2017

The night before was clear but I forgot to take out the ETX to cool before getting back from walking the dogs.  But tonight I took it out during dinner.  I connected the Canon after dinner and looked for Saturn.  It was in the southwest and was almost behind the tree.  I moved the tripod and took some images.  I struggled trying to remember the settings on the Canon and accidently erased the memory card.  Opps!! 

But, I did get images of Saturn and the Moon.  I looked at the images on the computer and Saturn was blurry but the moon wasn’t that bad.

ClearSkyTonight_7419_20171024_moon

Full image located at https://clearskytonight.com/wiki/October_24,_2017

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Total Solar Eclipse on August 21, 2017

I went to Madras, Oregon to view the total solar eclipse at Oregon Solarfest

I setup a couple of cameras.  The first was using a solar filter over a telephoto lens on my Canon.  I took a couple of shots during the first contact phase.  The main effort was using the Lunt and ZWO to try to capture totality.  The last was using the Canon to record a video during the event pointed at the horizon.  The results are located in the articles wiki for astrophotography events for the total solar eclipse

The video of using the Lunt and ZWO didn’t turn out.  The still images are great but the video needed some different type of exposure settings.  The view from the Canon was fine but the video of the event using the Canon was great.  Like I read, it was great to record the surroundings and our reactions to the event.

The total solar eclipse itself was incredible to see with my own eyes.  I am sure with more practice I could figure out the exposure settings but it was just incredible to experience though way too short.  I was also amazed by the temperature change.  Didn’t expect that.

Lastly, here are some news videos for the place we camped and nearby:

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Canon Astrophotography Settings

I recently attended the Table Mountain Star Party.  With the dark skies, I was able to try to take some night sky photos of the Milky Way.  I read the book Photography: Night Sky: A Field Guide to Shooting after Dark by Jennifer Wu and James Martin.  One of the chapter is the book is Stars as Points of Light.  I used this chapter as guidance to set my Canon T3i.  I created an article explaining my camera settings to take a night sky photo.

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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.

 

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