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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Observing Session–Jupiter-20180607

The sky cleared again so setup the LX70 refractor to look at Jupiter.  This time was just going to be astrophotography.  I got the adapter for the LX70 and Canon setup.  Once I connected it to the Canon, I realized why there was only one cover since the cover would protect the camera sensor.

Since I didn’t have the finderscope on, it took a little trail-and-error to find Jupiter.  The focus was way off but got dialed in.  The Canon Live View worked good especially using the digital zoom.   I didn’t realize the exposure settings impacted the Live View.  I had to really decrease the shutter speed to get the color of Jupiter to appear.   The digital zoom helped with focusing.   But without tracking, Jupiter continued to move and thus had to move the telescope and never really got a good focus since Jupiter was moving so much.

However, the results were very disappointing.  I took a few pictures and on the Canon screen, Jupiter was very small.  I guess I really don’t understand the focal length configuration of the different telescope when connected to the Canon DSLR.  I guess I have only really tried taking photos of the moon through the ETX90.  Needs more testing.

I think the next step is to test some daytime images to learn the relative photo sizes and then learn more about focal length.  Since I will be testing during the daytime, I might as well try the ZWO camera and then compare the image results between the two cameras and all the telescopes.

So, went in but also dropped the mount retracting the legs.

I created a wiki entry of the Jupiter image.

ClearSkyTonight_20180607_jupiter

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Observing Session–December 10, 2017

We had a series of clear nights so I decided to take the Meade LX70 Refractor out for its first light.  I was going to try to find the Andromeda Galaxy since I had noticed Cassiopeia overhead a couple of nights before. 

I setup the refractor and the first issue I had was getting it to point straight up.  I started to hit the tripod legs.  The next issue was I was looking in the wrong place.  I had used a reference in one of my books to do the star hopping to the Andromeda Galaxy but I got disoriented.  Once I figure out the region of the sky to be looking that solved by problem of the telescope hitting the tripod legs.  I also raised the telescope on it dovetail rail higher.

My next issue was using the finder scope.  I was very happy to have purchased the 90 degree model but still didn’t know where I should be looking.  So, I decided to just start over with the binoculars and find the galaxy first.  It took a while and a lot of misses but finally found the faint fuzzy.  With a more precise area of the sky to look at, I just scanned back and forth through the eyepiece and finally found it.

I tried a number of different eyepieces and the wide angle one was the best.  I was starting to get cold so really didn’t try of the eyepieces much more.  As I was picked things up and noticed that a lot of dew was starting to form.  First time experiencing dew.

Overall, it was both a good and bad experience.  But, I am still learning so that made the experience worth it.

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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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Finder Scope for Meade LX70 Refractor

The Meade LX70 Refractor came with finder scope but realized it would be difficult to use with the telescope was pointed straight up.  I remember purchasing an Orion Right-Angle Finder Scope earlier and it didn’t work out.  So, I found it and it easily fit on the LX70 Refractor.

ClearSkyTonight_finder_scope_1ClearSkyTonight_finder_scope_2

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Purchased Meade LX70 Refractor

ClearSkyTonight_Meade_LX70_Refractor
I purchased a Meade LX70 mount to use with my Lunt solar telescope for the solar eclipse.  I was thinking about my next plans on the telescope models since I now have a reflector in the from of the Light Bridge 10” and a small compound in the ETX 90EC.  I had read before that small refractor is the best for astrophotography but feel that is a long way off.   But, I did some other reading that refractors are better for planetary viewing because they give sharper images then reflectors.  So, I thought it might be a good idea to get a small, cheap refractor to experiment with that type of telescope model.

I had planned to wait until Christmas for a sale but I looked at Meade’s website for the LX70 telescope and noticed the 5” LX Refractor was being discontinued.  So, I checked around on the telescope store website and found one still in stock and purchased it.

It arrived and of course mounted easily on the LX70 mount.  Definitely needed the counterweight unlike the Lunt.

 

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