Astronomy and DSLR Astrophotography Blog

Dark nebula is a nebula in the galaxy which absorbs the light from the background. There are two types of them in general – one can be seen because they block the light of the emission nebulas in the background. One of the most spectalular of them is Horsehead nebula in Orion. The others block the light which comes from the stars behind them and those are best seen where the density of the stars is the highest – in the Milky Way. Dark nebulas consist of cold materia in the space, which is not hot enough to transmit the light.

In the night from 23th to 24th August I have gone to Bohor to take some photos of Elephant’s trunk, but I had to end taking photos about at midnight because the object passed the meridian and I couldn’t track it anymore. I had to make quick decision which object to capture the rest of the night and I choose the dark nebulas B334, 336-7 in Aquila, near Altair. I had no internet and I hadn’t a clue how this nebula looks like. Some of dark nebulas are really breath-taking and impressive (who doesn’t know Horsehead). Well, mine isn’t so spectacular, but I am pretty satisfied with the result. The next day I have checked the google image search for this nebula and found nothing, which means that I am one of the first who decided to “burn” his CMOS sensor on this object for some hours After all, that counts as well …

Here you go:

Dark Nebulas B334, B336, B337 @ photo: Primož Cigler

Some technical data about the exposure, equipment and so on:

Object: B334
Date and Location: 23. 8. 2009, Oslica, Bohor
Exposition: 26 x 5min
Camera: Canon 350D, Baader mod., ISO 800, RAW
Optics: Orion Optics Europa 20cm f/4.5
Mount: Vixen GP-DX SS2K
Autoguiding: SW 80/400 with QHY5
Processed in: Iris, Ps

astrophotography astrophotography, camera, canon, constellation, dark nebula, deep-sky, galaxy, milky way, nebula, stars

I think it’s not right always showing just the best works you produce. Sometimes it’s also good to represent worse pictures to show the world you also have troubles with everything and to encourage those who are not so good at astrophotography yet. I had a disaster last Thursday, capturing the Rho Ophiuchi region.

Last week we had some clear skies out here and on Thursday I decided to go to the near hill named Bohor to caputre the Rho Ophiuchi region, which is a large cloud of colorful nebulas, a part of Milky Way. June is the only month when this region is accessible to photograph from our latitude because it comes the highest on the night sky – about 20 degrees. Se we had clear skies, warm weather, no moon – perfect astrophotography conditions. I packed my mount Vixen GP-DX with SkySensor 2000 PC to the case with all the accessories and went to the Bohor to take some shots. I arrived there 2 hours before the astronomic night, prepared everything, aligned the mount, focused my modified Canon 350D with Canon 70-200 f/4.0 IS L lens and waited for the night. I started shooting at 23.45 LT. After first two shots I saw that everything works OK and went into the car, watching a movie for two hours. When  the film finished I was planning to take some darks and then to go home but when I checked the destination folder for images on my laptop I immediately noticed that something had gone wrong – THERE WERE JUST 6 PICTURES!!! OMG, I was awake till 4 a. m., getting just 6 frames. There was noting else to do, I had about half and hour till the dawn so I packed up the mount and everything and went home.

Nevertheless, on Sunday I decided give it a try and I processed the image. Honestly, I suspected to be worse, but it’s far from that I was planning to do. So here you have, Rho Ophiuchi nebula, not so perfect:

Rho Ophiuchi region @ 6 x 5min, ISO 800, RAW. Author: Primož Cigler

I hope that next time I will show something more attractive. And which are yours most common troubles you are dealing with?

Thanks for reading!

astrophotography, personal astrophotography, canon, deep-sky, images, milky way, nebula, stars

In this part we’ll take a look at some telescope specifications. It’ pretty common question what’s the best telescope for astrophotography. The answer? Such a telescope doesn’t exsist. There are several different telescopes available on the market and every serves its own purpose.

The Newtonians, for example, are very handy and good instruments for astrophotography, though they need to be collimated very precisely and often. On the other hand ED and APO refractors are better, but they are much more expensive. The SCTs are compact and provides longer focal lengths but they are rarely well-made.
So the question is what telescope to choose for deep-sky astrophotography with DSLR camera?

There are several different answers, depending on our object to be captured. Let’s start with the largest: wide-field images of the sky. If you are planning to capture the wide-field images of the night sky you don’t need the telescope but the lens. This is because telescopes are optical instruments with longer focal lengths and that means smaller field of view (FOV) whereas the lenses has a really wide range of focal lengths, from 4mm up to 1200mm and more. The most common target in this range of objects is the Milky Way. This kind of astrophotography is especially appropriate for beginners because the auto-guiding is not necessary and most of the cameras already comes with “kit” lenses which have wide field of view.
One of my images of Milky Way in Cygnus taken with 50mm lens:

Mosaic of Milky Way taken with 50mm lens

Next step are large deep-sky objects. For this objects I recommend the middle-sized APO and ED refractors (80-120mm) or telephoto-lenses. If we have a good mount we still don’t need auto-guiding at this focal length but in most cases it’s better to use it if possible. The most common objects in this range are constellations, detailed locations of Milky Way, large nebula complexes (Orion) and bright comets. The next picture represents Comet Holmes as it was seen 8th January, 2008, taken with Canon EF 70-200 f/4.0 lens:

Comet Holmes with Canon EF 70-200 f/4.0 at 200 mm

Next are middle-sized deep-sky objects. The best focal lengths for them are from 1000 mm to 2000 mm. Newton telescopes and larger refractors has the most appropriate specifications for imaging this type of objects. The auto-guiding is really necessary here because just the best mounts can slew accurate enough to assure the pin-point stars at these magnifications. In this range we find almost all the object from Messier’s catalogue and the brightest NGCs. One of my pictures taken with Orion Optics Europa 8″ f/4.5 are Pleiades.

The last type of object, accessible to amateur astrophotographers, are smaller deep-sky object. They are mostly galaxies and planetary nebulas. Because they are small, we need long focal length to capture the details inside them. The SCTs and other catadioptric telescopes are the most appropriate for these objects.

So, now you know which objects are in the range of your equipment. I hope that you enjoyed reading.

astrophotography APO, astrophotography, camera, deep-sky, images, mount, nebula, telescope, tutorial

I have decided to publish step-by-step how-to tutorial for astrophotography beginners. It’s International Year of Astronomy and I am pretty sure that there is a lot of people who are interested in astronomy and astrophotography, but they don’t know where to start.

Weekly I will publish articles guiding you trough the process of astrophotography – from equipment to the imaging tips and processing of images on the computer. Each article will cover specific part and every single of them is important for good results.

There are several different types of objects up there and they require different type of equipment, capturing, processing. In this tutorial I will focus on deep-sky astrophotography with DSLR camera and with amateur equipment in range up to 5.000$. If you are beginner – don’t be afraid! There is a possibility to start astrophotography with much lower budget and get stunning results. You just need to be patient and don’t give up.

Contents:

• Part I: Choosing an Object
• Part II: Camera Settings
• Part III: The Telescope

Don’t forget that we all learn from mistakes. With patience and enthusiasm everything is possible. Enjoy the Universe and Clear Skies!

NGC6888 - The Crescent Nebula @ Primož Cigler

astrophotography astronomy, astrophotography, deep-sky, equipment, guide, images, milky way, nebula, stars, tutorial

A lot of astrophotograpers decide to make a modification of their cameras. The reason is that filter in front of CMOS or CCS sensor blocks almost all the H-α part of spectrum due to balancing the colors for daylight photography. But this is not suitable for astrophotography because almost all the nebulas consist of the Hydrogen and this light is cutted off just some millimeters in front of the sensor. If we remove that filter then we get much better response of the red color.

Since the Canon Rebel is the most common camera used between enthusiastic astrophotographers I’ll try to suggest some good links of step-by-step tutorials which guide you thought the process.

1. Canon Digital Rebel (300D) Modification
   Good tutorial with sample images before and after modification. For Rebel (300D).
2. ash’s Modified Digital Rebel XT Page
   Very nice tutorial for modification of Rebel XT (350D). I have done modification of my Rebel XT with this guide and he survived the operation!
3. Canon Digital Rebel XSi (450D) Modification
   Good guide with pictures and everything well explained for Rebel XSi (450D).
4. Canon Digital Rebel (300D) Peltier Modification
   Guide how attach Peltier cooling element into Rebel. Works good for long-exposure astrophotography.
5. Another Digital Rebel XT (350D) Modification
   Just another Digital Rebel XT mod. Maybe someone finds it useful.

For the end I am presenting one of my images after the modification. The Veil Nebula, NGC 6992:

The Veil nebula (NGC 6992) @ Primož Cigler

equipment 300D, astrophotography, camera, canon, digital, filter, images, links, nebula, rebel, tutorial, veil

Yesterday I haven’t written a post because I was travelling. I am on holidays now, so I’ll publish just one deep-sky astrophotography:

M42 (Orion nebula) @ Primož Cigler

Orion nebula is reflection nebula in constellation Orion (the hunter). It is located approximately 1300 ly from us. It’s just the brightest part of very large nebula complex which stretches between almost all the brightest Orion’s stars and consists of Barnard’s Loop, Horse-head nebula, Flaming-tree nebula and M42, M43 and NGC1977:

Orion Complex (M42, M43, NGC1977, Horse-head, Flaming-tree nebulas @ Primož Cigler

The first picture was taken with a telescope Orion Optics Europa 8″ @ f/4.5 with Vixen GP-DX mount and auto-guided. The conditions were bad (light pollution on the South, half of moon, bad transparency and seeing). The camera was unmodified Canon 350D. The picture was taken on 18th of December 2007 and it’s the combination of 39 times 3 min exposures and 10 times 20 s exposures (for core details).

The second picture was taken with a lens Canon EF 70-200L IS USM f/4.0 at 200mm and f/4.5 with modified Canon 350D piggy-backed on Vixen GP-DX without auto-guiding. The exposition was 25 times 3 min. The picture was taken on 8th of January 2008.

That’s all for today, thank you for reading and watching!

astrophotography astrophotography, constellation, deep-sky, images, milky way, nebula, Orion, stars