Category Archives: Astronomy

Polar Alignment Made Easy

I may have just found a great solution for achieving very good polar alignment with any telescope mount.

There is this little piece of software called “SharpCap” ( http://www.sharpcap.co.uk/ ). It’s a very clever piece of software that uses a webcam or an astronomy camera to assist with focusing, stacking, polar alignment and much more.  Unfortunately SharpCap does not support DSLR cameras as a video source. It supports some of the available astronomy cameras such as ZWO, QHY, etc.  If you want to use SharpCap you have to have a camera that is supported. I was on my way to purchase a ZWO camera to do this when I read a forum post on Cloudy Nights ( https://www.cloudynights.com/topic/545643-sharpcap-polar-alignment-experiences/ ) where someone mentioned that they are using another piece of software to allow them to use a DSLR as a webcam and that SharpCap actually processes the DSLR image seamlessly.

“SparkoCam” ( http://sparkosoft.com/sparkocam ) is providing the capability to use your Canon or Nikon DSLR as a regular webcam. When installed, SharpCap will recognise SparkoCam as a virtual webcam and process the DSLR live view images directly. No need to purchase a separate camera to work with SharpCap.

The process is quite simple, install the DSLR on your mount pointing towards the celestial pole. You would obviously do a basic mount alignment to get the camera view close to the pole, at least to within about 5 degrees. Now activate SharpCap and follow the instructions to get to an accurate alignment. This process will work with a tracking mount as well as a manual equatorial mount.

I have everything installed now and will test under the stars as soon as possible. It is raining outside at the moment, as can be expected….

Orion Nebula M42

The Orion Nebula must be one of the greatest objects in the night sky. At about 1,344 light years away it’s not close but it is visible to the naked eye as a fuzzy patch in the middle of Orion’s sword.

This nebula is difficult to photograph because of the large dynamic range in the image. The Trapezium is a group of bright stars that illuminate the nebula and the difference in brightness between these stars in the centre and the fainter clouds on the outside makes it hard to image and process the nebula in all its glory.

This image was taken at Rabbiter’s Hut in the Adelaide Hills on a dark night and processed from 5 light frames and 2 dark frames of 5 minutes each. I used the Orion ED80 (500mm focal length) and Canon 600D (modified). The Skywatcher EQ6-R was tracking on its own without any guiding but I do make an effort to get the polar alignment as accurate as practically possible.

Processing was normal with DSS and Lightroom 4.

Orion Nebula M42

Orion Nebula M42

Rosette Nebula

Now that was a perfect long weekend!

New moon and dark skies far from the city lights for two nights.

I took a lot of photos with the new EQ6-R mount, Canon 600D (modified) camera, an Orion ED80 EON and a Meade 8″ SCT. There will be a lot of processing required over the next few weeks to get all the photos out. I experienced a lot of problems but that is par for the course by now.

The first photo is the Rosette Nebula. About 5,000 light years away and visually it’s about three times larger than the Orion Nebula.  Its is not bright and require a large telescope to see it under dark skies. If you want to take a photos of it, it is a great target, not too difficult and it is located high in the sky this time of year, just east of Orion.

This image was processed from 22 light frames and 6 dark frames of 2 minutes each. I used the Orion ED80 (500mm focal length) and Canon 600D (modified).

Processing was different this time. I had a lot of noise in the light frames and tried processing each individual frame in LightRoom 4 for noise reduction before I stacked all of them in DSS and processed further in LR4. What do you think?

Picture saved with settings applied.

  Rosette Nebula

“First Light” for EQ6-R

I used the new laser alignment tool last night and it took me about 2 minutes to achieve polar alignment for the EQ6-R. I then used a 1-star alignment to get the mount setup.

To test, I used my trusty Canon 600D (modified) with a Sigma APO 120-400mm at 400mm and f/5.6 for a single 3 minute exposure. This is not a lens that I would normally use for astrophotography but I wanted a long focal length to test the alignment and tracking.

Well, let’s say that I was not disappointed with the result.The following image of the Carina Nebula is an unguided 3 minutes exposure at 400mm and there is not a trace of star trials, even when zoomed in. Take a look….

Carina Nebula - Test Image

Carina Nebula – Test Image

Polar Alignment Laser for EQ6-R 

I was very exited about trying out the new Skywatcher EQ6-R mount but the weather wasn’t cooperating and then Xmas happened.  When I tried the mount I struggled to polar align in the suburban light conditions through the polar scope. 

I made a plan…. 

Previously I made a laser tool that I used to polar align my homebuilt tracker as well as the iOptron Skytracker. 

The EQ6-R has a handle that is fixed on the RA axis with two bolts.  I made an aluminium plate that replaced the handle and provides a slot for the laser tool. 

Tonight I will test the setup and see if polar alignment is easier. I expect to be able to get close to the SCP very quickly with this setup. 

De-Forking a Meade 8″ SCT OTA

This sound a bit obscene but I promise that no animals, people or telescopes were harmed in the process.

The Meade SCT in question is an 8″  2080 model that I purchased around 1992. I used it quite a bit for a number of years until my interest turned to astrophotography. The specific model do not have a dec motor and the RA motor is running off 240VAC.

img_2775Over time I build an invertor that could work from AC or 12VDC and allowed me to vary the frequency  around the nominal 50Hz and I could therefore do some manual guiding in RA with a set of buttons and with the existing fine controls on the DEC. It worked a treat for a while but anybody that has guided long exposures manually will know that its a very tedious exercise with unpredictable results.

Well, now everything has changed. The new Skywatcher EQ6-R can easily carry the 8″ OTA (Optical Tube Assembly) as well as my ED 80mm and new opportunities becomes available.

I had to de-fork the OTA out of the Meade fork mount to allow me to fit a Losmandy plate to allow for the OTA to be fitted to the EQ6-R. There are a lot of guidance on the web for how to do this but I used the following site:

http://uncle-rods.blogspot.com.au/search?q=getting+deforked

Its remarkable easy and took no time at all.

Loosen two bolts on one of the arms first.

img_2778

Then remove three small bolts from each side of the tube. Take care to work on a soft surface and have someone assist you to make sure you don’t scratch the tube surface.img_2779

And its off!img_2780

Now to mount the Losmandy DM8 kit into the existing holes on the OTA.img_2783

10 minutes later…img_2784 img_2785 img_2786

And now the amazing Meade 8″ OTA can be used on a very capable and accurate mount. A big change for me and there should be some new images soon.

img_2788With my luck it will probably be cloudy and rainy for a month now ….

Unpacking the SkyWatcher EQ6-R mount

The EQ6-R has arrived on Thursday and I unpacked it that night. No surprises there….

Here are some photos of the process:

img_2751 img_2753 img_2754 img_2755img_2756 img_2757 img_2758The handle makes it easy to lift the mount head with one hand.img_2759 img_2762The adjustments bolts look quite solid, at least 15mm on the main altitude bolt and 12mm on the other three.img_2766 img_2767Saddle takes Vixen and Losmandy.img_2768 Probably not many changes visible here on the cable panel except for the power connector that is now a solid screw on type.img_2769 img_2770Synscan loaded with version 04.37.03.

img_2772 img_2773 img_2774Waiting for the weekend now and a mounting plate for my Orion ED 80mm EON and also a Losmandy DM8  dovetail plate for my Meade 8″ SCT.