Tag Archives: LR4

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

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“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

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

VicSouth Desert Spring Star Party

I joined the crowd of amateur (and probably a few professional) astronomers at a star party in Nhill, about half way between Adelaide and Melbourne. There must have been about 100+ telescopes out there and it was quite an experience.

I did not take a telescope along but I did try out my home built tracker under the dark skies. Refer to https://starsinphotos.wordpress.com/2014/10/03/diy-autoguider-for-long-exposure-astrophotography-part-4/.

The following image of the Large Magellanic Cloud (LMC) was taken with a Canon 600D and a Canon EFS 60mm f/2.8 lens at ISO 800 on the tracker, using autoguiding. The image is made up of 23 lightframes of 1 minute each with two dark frames. Stacked in DSS and then processed in Photoshop CS2 and LR4.

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I will post more images here as I get them processed over the next week or two.

DIY Autoguider for Long Exposure Astrophotography (Part 4)

I tried the upgraded autoguiding tracker again on Wednesday and the results improved quite a bit. I used a 250mm lens to image the LMC. The following is a photo of the PDH graph showing the tracking error. The error is a small fraction of pixel. It has improved a lot since the previous test where the typical tracking error was ±3 pixels.

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The resulting images of the LMC are not great due to the light polution but the tracking is starting to show promise.This is a single image (no darks or flats) taken at 60mm, f/2.8, 120 seconds and ISO 800 showing some round stars. Some cropping, levels and stretching was done with Lightroom 4.

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This is the setup I used:

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I used a Canon 18-55mm lens for the guide webcam. Tracking accuracy will improve a lot if I increase the focal length for the guiding, maybe use a 18-135mm. The zoom works well on the guide camera to find a suitable guide star.

The advantage of this mount is that it can take a bit of weight. I tried to mount an Orion EON 80mm on and it did not complain too much. Maybe I will need to modify a bracket to make sure the camera mount ball head cant slip with the 80mm scope. I will try that next.

Here is the latest version of the Arduino sketch:  Stepper Motor sketch (pdf download)

Sketch

Milky Way and Small Magellanic Cloud

After a  number of cloudy, wet and cold winter months we had a clear night on 3/4 August to take the cameras out for a few photos. The moon only set at about 11:15pm so it was quite a wait in the cold. This was the coldest night in Adelaide for something like 125 years! It did not bother me too much as I was dressed as if I was going to Antartica. Luckily there was no dew and that made everything easier.

I used the Canon 600D on the iOptron SkyTracker on my photographic tripod.

This image is of the Milky Way with a 60mm prime lens at f/3.2 and ISO 800. I used 11 light frames of 60 seconds each with 3 dark frames. The image is showing the Sagitarius region with the Lagoon nebula (M8) at the lower right and the M6 cluster in Scorpius at the lower left. This is a very rich star field and larger apertures will reveal incredible detail. It is also the location of the centre or core of the Milky Way Galaxy.

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The next wide field image is of the Milky Way with a 11-16mm Tokina lens at 14mm and f/3.2 and ISO 800. I used 9 light frames of 60 seconds each with 2 dark frames.

MW 14mm

I also took a quick image of the Small Magellanic Cloud with a 60mm prime lens at f/3.2 and ISO 1600. I used 11 light frames of 60 seconds each with 2 dark frames.

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Images was stacked with DSS and stretched in PS CS2 and finished up in LR4.

I think that I need to make my exposures longer than 1 minute to get more detail. I don’t like to raise the ISO level higher as it will also increase the amount of noise.  I will try and get to 3 minutes per frame next time. It just makes it harder to get the tracking done well so that the stars don’t turn out to be lines! This should be easy with the Tokina 11-16mm lens but when using the longer focal lengths it will be a bigger challenge.

Carina Nebula (NGC 3372)

The Carina Nebula is about 300 light years across, twenty times the size of the Orion nebula. It is 9000 light years away but it stretches across 2 degrees of sky (about the width of 4 Moons).  Two million years ago, the Carina Nebula was a huge dense and dark molecular cloud. The dark dust lanes are the remains of that cloud.  Also see “The Great Nebula in Carina“. Carina Nebula 1 1200 This image of the Carina nebula was taken with my recently modified Canon 350D.  The 350D camera is now quite an old model and it is not supported by the latest Windows operating systems. This means that I have to use old software to assist me with the focussing of images such as this.  For this image I used Astro Photography Tool (APT) version 1.93  (www.astroplace.net). I am quite happy with the performance of the 350D. It now outperforms my 600D for astrophotography, especially when deep space objects is imaged. I will try to stage a comparison between the results of the two cameras in a future post. The image above was created with 17 subs of 30 seconds each with five darks. I obviously used the modded 350D and a Canon EF-S 55-250mm lens at 250mm, f/5.6 at ISO 800. I tracked the sky with iOptron SkyTracker on a Meade tripod. The full resolution image is available at http://astrob.in/74776/0/

Edit on 10/03/2015:  This image made it into the Australian Sky & Telescope gallery in the April 2015 issue.