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.

MW 60mm

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.

SMC 60mm

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.

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4 thoughts on “Milky Way and Small Magellanic Cloud

  1. Craig

    Hi Theo, those are some amazing photos! As it happened I was out on the same night at Hallett Cove conservation park making a 2 hour star trail stack. It was definitely cold! I’ve only recently got into astrophotography and have done some reading on the subject but I just wanted to pick your brain if possible.

    Next month I’ll be in a darker part of the state and wanted to get some nice single frames of the Milky Way, I own a 600D with the basic 18-55mm lens, a tripod but no tracker. I’m hoping to get some decent shots wide open with ISO 800-3200 and exposures of around 28 seconds. Would dark frames assist in this situation and is there any other advice you could give me to achieve better results (not expecting anything like yours of course!)

    Cheers, Craig.

    Reply
  2. Theo Post author

    Hi Craig,
    Thanks for your comment. I am very critical about my photos and I always see something that I should have done better. With these photos I was stuck on 60 seconds exposures and did not even try to see if I could get away with 2 or 3 minutes. I have done 10 minutes with this setup before and it worked great.
    The 600D is great for astrophotography with quite low noise and the swivel screen makes it easy to see what is going on, especially when you have to focus on live view. I suggest that you look at http://www.magiclantern.fm/ . It is a software add-on that will run on the 600D and it will give you a truck load of additional features for astrophotography. I use the intervalometer, bulb timer for long exposures, focus tools, etc. This software is safe to use on the 600d, I have been using it now for about 2 years without any issue. You can set the camera to take a series of exposures without you having to touch the camera.
    The EFS 18-55mm lens is not a fantastic lens for astrophotography but if you take a few precautions you should get good results. I suggest that you go reasonably wide, around 20 mm, and not on the 18mm point. Also set your aperture at one or two stops slower than the lowest it will go at 20mm. This will prevent lens effects such as aberration or coma. This will cause stars on the edges of the image to smear into streaks towards the centre of the image. It might help to fix the zoom setting with a piece of tape to prevent the zoom point to move when you start. Do the same with the focus ring after you have achieved a good manual focus.
    Here is a good article describing lenses for wide field astrophotography: http://petapixel.com/2014/01/29/picking-great-lens-milky-way-photography/
    Without a star tracker you are limited to short exposures and then stacking them with software such as Deep Sky Stacker. Longer exposures will increase the signal to noise ratio but will also result in start trials. The sweet spot is probably somewhere around 15 seconds, you will have to experiment a bit by taking a photo and zoom into the stars to see if they are starting to trail. The shorter your focal distance, the longer you can go on your exposures. Look at the following site for more information about the “600 Rule” ( http://www.capturingthenight.com/astrophotography-and-the-600-rule/ ).
    I try not to use anything higher than ISO-800 or ISO-1600, preferably lower. Without a tracker you will have to bump up the ISO and deal with the noise later during processing.
    Dark frames will always help. Just keep on taking photos and put the lens cap on carefully for a number of exposures (5 to 10?). Take as many light frames as you can and try not to jump around to a new target every few frames. It really helps to plan beforehand what you are going to do. Check Stellarium ( http://www.stellarium.org/ ) to time your shots with the moon and horizon.
    Remember to set the camera image quality to RAW + L.
    A good YouTube video on the subject by Forrest Tanaka: http://youtu.be/e0JSTF8SGi4 . Also look at his other videos.
    Good luck!
    Theo

    Reply
    1. Craig

      Thanks for the reply Theo. I had a look at Magic Lantern last week but was nervous about it possibly voiding my warranty but I’ll probably just go ahead and get it any way, it would be quite helpful. As for the lenses, I’d love to get one more suited to astro work but they are out of my price range at the moment. I was out taking some car light trail photos tonight and on the spur of the moment decided to have a crack at the Milky Way. Played around with a few settings and this was the best result I got –

      Milky Way

      It was taken in the ‘burbs and next to a road so far from the ideal location but I feel like it turned out okay given it was my first time. Now that I’ve seen your comment I’ll know to try a few different things.

      One last question, I was able to get my focus by using a distant street light but when I got home and tried taking some more shots in the backyard I didn’t have any object to use for focusing. I’ve heard people say to pick out the brightest star in the sky and use that to focus on but when I’m using Liveview all I see is black. I tried using the zoom but that didn’t help either. Is there something I’m missing? I gather from what I’ve read that the Exposure Simulation doesn’t function in low light or bulb mode but haven’t been able to find a workaround.

      Cheers, Craig.

  3. Theo Post author

    Craig,
    Magic Lantern runs from a SD card and installs every time you switch the camera on and does not make any permanent changes to the camera software. But, there is always a chance (very small) that something goes wrong and then you might have a problem with the warranty. Read everything on the Magic Lantern website regarding the process to follow when your camera locks up.
    Focussing is relatively easy with the 600D as it has quite a sensitive sensor, the flip screen and live view. I suggest the following process for focussing:
    a. Identify the brightest star or planet that you can see naked eye. Orient your camera on the tripod so that this star is approximately in view.
    b. Switch on camera in Manual mode with ISO at highest level possible, typically ISO-6400. Don’t use the various modes on the camera, only use the camera on the M setting (MANUAL).
    c. Set camera lens to manual and change zoom to infinity and slightly back.
    d. Switch on live view and try to locate star/planet in the centre of screen. Use focus ring on lens to get it closer to good focus.
    e. Set the screen brightness higher if you can’t see anything in live view. (Menu, 8th tab, at the top)
    f. When you think you have the star/planet in view, zoom in to 5X with the zoom button (not with the lens zoom!) You might have to pan around a bit until you find the star.
    g. Now zoom to 10x and improve focus again.
    h. When you think you have the focus spot on, try and move the focus ring extremely slowly to and fro to see the focus on the screen go both sides of perfect focus. Stop when it is the best focus possible. Movements of the lens focus ring will be very small; you will only touch the focus ring at the end to make a change.
    i. Now lock the focus ring down with tape and point the camera towards your target for the night. Avoid touching the lens if you can. You will probably have to do the process a couple of times during the session to make sure nothing changed. You should not have to change the focus from one target to the next.
    j. Remember to change your ISO back to 800 or whatever you want to use.
    To focus the camera on a short focal length (18 – 25mm) is a lot easier and forgiving than focussing on longer focal lengths. As the image will be a wide field image the focus is not all that critical unless you want to crop the image heavily in post processing.
    Cheers
    Theo

    Reply

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