Tag Archives: astrophotography

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

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.

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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.

SkyWatcher EQ6-R mount

Well, I have finally surrendered to the temptation of getting myself a heavy mount.

Initially I was looking at the Skywatcher NEQ6 Pro but then discovered that the brand new Skywatcher EQ6-R mount is available on a limited product release from an Aussie supplier. Major changes are the belt driven system with zero backlash, PPEC support, newer motor drive with lower periodic error, improved tracking accuracy, 20kg payload capacity and a carrying handle!

skywatcher_eq6r

Basic specs are as follows:

eq6-r-specs

Will be delivered next week so expect more feedback here soon ……

Worm Wheel and Worm for anyone?

I am thinking of making some more worm wheels soon. My new lathe will be set up soon and it will allow me to make the worm wheels much quicker and hopefully more accurate.

If anybody is interested in ordering a specific worm wheel, please let me know and I will see what I can do. Send me your requirements ( starsinphotos@gmail.com ) with the size of the wheel (or the number of teeth. I suggest that you use an ACME thread as it does not bind as easily as a metric thread. I could also make the worm from an ACME threaded rod  (10mm diameter with a 2mm pitch) as shown in my blog.

I will look at your requirements and let you know if I can make it and then we can discuss a price that suits us both.

Updated 19 June 2016:  I have found that nothing is easy. The lathe is not quicker, if anything its harder to get it right. I will have to fine tune the production process before I can go into the business of selling worm gears. 🙂

Tracker 5 April 15-1149 Tracker 5 April 15-1148 Worm detail Jan15-1 2 x 130mm Al disks Tracker progress Jan15-1 IMG_1726

Canon EOS 600D IR filter Replacement Results

A couple of weekends ago, late on a Sunday afternoon I decided that the time was right to open up my 600D. I suppose I was in a hurry and couldn’t wait any longer. The clear glass replacement filter has just been sitting there and I was already prepared with all my tools and silicon, etc.

So I did it.

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Opening the camera up was pretty easy. I used the following websites to guide me along:

http://dslrmodifications.com/rebelmod450d1.html

http://www.lifepixel.com/tutorials/infrared-diy-tutorials/canon-t3i

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A large number of very small and delicate connectors have to be disconnected.

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Eventually the CCD assembly can be removed.

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This is the complete filter and imaging chip assembly, before I took it apart (and almost broke it…)

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The piezoelectric element is removed here..

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And here I was too impatient and broke the IR cut filter. The crack line can be seen from top left to bottom right. I should have ready the instructions in more detail! Take it from me, don’t be in a hurry when you do this. Fortunately there was no damage to the imager chip and after I cleaned all the filter glass fragments off the CCD surface I could start the assembly process again.

The clearglass filter replaced both the IR cut filter and the piezoelectric filter element. I have now modified the camera to a full spectrum camera.

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Pieces of the IR cut filter. This is not the way to do it!

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Inside of camera, looking at the back of the shutter.

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Putting it all together was reasonably easy. The most difficult part was to get the imaging assembly in the correct position to allow the auto focus to work properly.  I will have to make some more adjustments to get the auto focus to be more accurate. It can wait as I mostly use manual focus for astrophotography anyway.

A big sigh of relief when the camera fires up and still works !

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A weekend later and I was testing the camera under an almost dark sky. Nothing spectacular but just confirming that it all works as it should.

Orion Nebula (M42 / M43)

Picture saved with settings embedded.

 

Large Magelanic Cloud (LMC)

Autosave

Coalsack with the Southern Cross and two pointers

Coalsack

And, the evening would not have been complete without a image of Carina.

Carina

Carina Nebula from under a streetlamp

I had to test my new tracker with autoguiding and could not get away to a dark site so I decided to test it in the front garden where I could reach further south towards Carina Nebula. Unfortunately I have a bright streetlamp in front of my house. I tried to shield the light from falling on the camera and lens to avoid the worst effects of the light conditions. I use a modified Canon 350D and got 29 light frames of 30 seconds each, 7 dark frames and 18 bias frames at f/5.6, ISO 800 with a 250mm focal length.  Ideally you would try to get longer exposures than 30 seconds but the sky was so bright that I had to limit the exposure time for each frame.

Picture saved with settings applied.

Building a new Astrophotography Tracker Mount

If you have been reading my blog you will know that I love building things. I almost like it more than using things. So, after my recent experiment with a tracking mount I decided to start again, from scratch, to try and make a more robust, heavy weight mount that will not complain when I load it up with cameras and scopes. I also use the iOptron SkyTracker a lot but you cannot load it up too much.

The previous tracking mount is shown in one of my previous posts, Look at https://starsinphotos.wordpress.com/2014/09/23/diy-autoguider-for-long-exposure-astrophotography-part-2/ . This mounts works surprisingly well but it looks like a dogs breakfast, it’s sensitive to bumps and it is too bulky to transport easily.

My new design will be more solid with a steel based design rather than aluminium. Its harder to machine but the design is relatively simple so it is quite easy to make. I have decided on a few design parameters that will make the design robust and will not require any skilled machining capability (apart from the worm wheel and gear). I will also make a new worm gear combination (130mm diameter with approximately 270 teeth. The previous one I made was not very accurate and it only tracked smoothly for about 3 hours at a time, then I had to “rewind” the RA axis to get to the start of the good section on the work gear. My stepper controller design have buttons for a fast forward and rewind on the RA drive.

The new tracker design is based on a square section of 125mm mild steel U-channel with two pillow block bearings that holds the 20mm steel RA shaft.

s-8604 s-8606

It should be possible to get the steel supplier to cut the U-channel to the correct length when you buy it but I got an offcut cheap and had to spend a few hours to get it nice and square. The U channel and the 20mm rod cost me $10. The two pillow block bearings was a bit more expensive, the two of them cost about $60.

So now I have the RA shaft mounted and it feels VERY solid. I am thinking that I might be able to load my 8″ SCT OTA on to the mount if all goes well. The new 140mm worm gear will fit onto the 20mm shaft on the left (or bottom) side and the camera / scope mount will be on the right (top) side. The stepper motor and worm will be below the U-channel on the bottom.

I am going to try and build the tracker without any ability to adjust for altitude polar alignment. In my opinion, its too hard to get a very solid mount if you add the adjustment elements to the design. This mount will be mounted on a fixed altitude block that is centred on Adelaide (35 degrees south). I will use the Meade tripod legs to make large changes to that and small changes will be made by an adjustable tripod foot consisting of an adjustable pipe flange that can be rotated to make small adjustments on the tripod leg facing south. Azimuth will be adjustable with the Meade tripod head bolt. I may go so far as to include a method for making small adjustments to the azimuth as I have battled with that in the past.

For accurate polar aligment I will keep on using my green laser pointer on a small aluminium bracket that attaches to the RA shaft itself. This implies that I can achieve very good polar alignment with a mount that may not be perfectly square and with bearings that are not fitted very accurately on the mount. It’s legal to use a green laser pointer in South Australia if you have the correct documentation with you.

My existing stepper controller and autoguider works well and I will use it again for this mount.

Update 22 January 2015:

I have now got two new 130mm diameter aluminium “blanks” for the new worm gear. This time I had them professionally machined so that they will be 100% square on the 20mm shaft, unlike last time…..

2 x 130mm Al disks

New tracker components 1

Over the next few days I will cut the worm gear and a new worm. I will post some photos when it is done.

Update 27 January 2015:

Yesterday, I cut the worm gear and it turned out much better than before. I have 279 teeth on this disk and hopefully they will be quite smooth after I have polished them.

Worm gear Jan15-1

Worm detail Jan15-1

The new tracker is slowly coming together now…

Tracker progress Jan15-1

Now for the worm….

I will update this post as the mount gets built over the next few weeks.

Comments and questions are welcome…