Tag: Canon EOS 6D

Chasing the darkness in Greece on Crete

This year we made our traditional summer vacation in Greece a bit earlier. The main reason was the cheap plane tickets to Crete. The destination was given, what remained was to specify the precise location. My friends recommended the southeast coast, so I started to search and found a house with a suitable terrace in the abandoned village Chametoulo. According to the light pollution map, the location should be perfect. We arrived at night, parked in front of the village, and moved all our stuff to the house through very narrow, steep streets. The first thing, which struck my eyes, was the presence of several LED powerful street lamps. WHY? Why there are street lamps in the empty village? Who pays for the electricity? Anyway, the terrace was partially covered and protected from the street lamps. On the other hand, it was very dark anywhere you look. I measured the SQM and directly at the zenith reached 21.55, which is a very good value. I started to get excited, but during our stay, my excitement was turned into frustration. It was very windy all the time. Some days it was less windy, but still, the conditions were far from being optimal. Fortunately, I took two rigs with me. The classical 150/600 mm Newtonian, sitting on RST 135 mount. The second one I tried in the winter – the pocket astrophotography rig. Askar F4.5 180 mm refractor, coupled with Canon 6D astro-modified and all this on extremely portable iOptron SkyGuider Pro. The Newtonian was totally unusable in the wind, but tiny Askar had no problems at all and I took roughly 1300 photos with Canon 6D camera.

Here is village Chametoulo during the day:

And here is village Chametoulo during the night:

Here is the double rig. I attached a 20 l canister to the tripod holding the RST 135 and 150/600 Newtonian to minimize the vibration due to the wind, but unfortunately, it didn’t help.

In the end, I managed to capture a couple of galaxies: M101 Pinwheel, M31 Andromeda, but otherwise, I gave up with 150/600 mm Newtonian. The smaller rig based on iOptron SkyGuider Pro performed much better. My primary target was Rho Ophiuchi @180 mm focal length. Then I captured the most interesting nebulae in constellations Serpens and Sagittarius – Lagoon, Trifid, Eagle, and Omega nebulae. Then I moved to the constellation Cygnus and capture it with many different focal lengths. And finally, I made a stop at the constellation Cassiopeia to compose the Heart, Soul nebulae with the Double Cluster NGC 869 and 884.

The Milky Way was not possible to photograph directly from the house, due to the street lamps in the village. I had to take a car and drive a bit to get to the South Coast Viewpoint:

Technical details:

LensSamyang 24 mm f1.4 @ f2.8
CameraCanon EOS 6Da
MountiOptron Skyguider Pro
Exposure16x15s, ISO 1600
Date2021-07-14


IC1805 Heart Nebula and IC1848 Soul Nebula

One of the last deep space objects I captured on Crete are two visually large nebulae. And these are IC1805 Heart Nebula and IC 1848 Soul Nebula. Both are very dim objects, therefore I set the shutter speed of the Canon EOS 6Da camera to 3 minutes and let it capture the light shooting from the constellation Perseus the whole night long. Even NGC 884 869 Double Cluster fit in the field of view.

Technical details:

LensAskar FMA180 F4.5
CameraCanon EOS 6Da
MountiOptron Skyguider Pro
Exposure50x180s, ISO 1600
Date2021-07-12

Cygnus

I went to Crete without a detailed plan on which deep space objects to capture. The primary target was Rho Ophiuchi, which I captured really well. Then I started to think about the next objects. Obviously, if you are in a dark place, you can point your camera nearly anywhere. However, there are some regions full of stars and deep space objects. For example constellation Cygnus, which is sometimes called the Northern Cross. It is located visually on the plane of the Milky Way galactic disk, therefore there are many deep space objects.

Let’s have a look at a wide-field picture captured by a 24 mm lens attached to Canon EOS 6Da:

Let’s zoom a bit by changing the lens to a 50 mm focal length. Here the constellation is perfectly centered:

Let’s zoom further to the central star Sadr by change of the lens to 180 mm focal length:

Let’s keep the focal length 180 mm and let’s have a look at the left star Deneb and very famous North America nebula:

Again, let’s keep the focal length 180 mm and change to perspective to the bottom (eastern) star Aljanah, where the beautiful supernova remnant the Veil nebula is located:

In total, the camera collected 15.5 hours of light and I am happy with the result.


IC1396 Elephant’s Trunk nebula

Elephant’s Trunk nebula is an emission nebula located in constellation Cepheus. I tried to capture this magnificent nebula in 2017 and in 2018, but it never fit in the field of view of my camera-telescope assembly. This time I used a focal length of only 180 mm, combined with a large full-frame sensor. Well, and finally it fits. Moreover, even the B174 dark nebula at the bottom left corner found the spot on the sensor. The picture was taken under a very dark Cretan sky.

Technical details:


Rho Ophiuchi region

Rho Ophiuchi is in my opinion the most beautiful assembly of the nebulae in the universe. Blue, red, and orange colors are combined to create this magnificent cloud complex. The dominant yellow star Antares (Alpha Scorpii) is a red supergiant, one of the largest visible stars. The star Alniyat (Sigma Scorpii) is surrounded by ionized hydrogen gas. Between these two stars is the M4 globular cluster, which I captured on Fuerteventura. The blue nebula is Rho Ophiuchi, also captured by me earlier.

In order to capture the whole beauty, one has to use a relatively short focal length (I used 180 mm), combined with a large sensor area (I used full frame 36×24 mm), and take the shots at a very dark location. This was my primary target during our trip to Crete 2021 and I am very happy that I finally got it framed. However, there is another beautiful nebula called Blue Horsehead in the visual vicinity and if I would turn the camera 90°, I would manage to capture it. So, there is a target for my next expedition.

Technical details:

LensAskar FMA180 F4.5
CameraCanon EOS 6Da
MountiOptron Skyguider Pro
Exposure38x120s, ISO 1600
Date2021-07-07

M8 Lagoon nebula M20 Trifid nebula

Constellation Sagittarius is full of deep space objects. I think we all agree that the most beautiful one is the Lagoon nebula, accompanied by the Trifid nebula. I captured these nebulae already, but with a much longer focal length. This time I used a significantly shorter telescope – only 180 mm to reveal the other deep space objects. The bright star at the bottom left is the star Kaus Bolearis, where the archer has his head. This star is surrounded by the globular clusters: M22 Great Sagittarius cluster on the left and M28 on the top.

Technical details:

LensAskar FMA180 F4.5
CameraCanon EOS 6Da
MountiOptron Skyguider Pro
Exposure50x60s, ISO 1600
Date2021-07-03

iOptron SkyGuider Pro, Askar FMA180 f4.5 review

I made a big step towards ultra-portable astrophotography. On Kythira I first time placed my workhorse Canon EOS 6Da on mini mount Baader Nanotracker and made quite stunning pictures of the Milky Way. I was so excited and started to think about more serious “pocket-size” astrophotography. The requirements were the following: no external batteries, telescope, and camera should have max. 1.5 kg weight, focal length around 200 mm. The camera it’s simple, I simply keep using modified Canon 6D.

The telescope is quite trickier, but I found Askar FMA, which has a 220 mm focal length, which is shortened by included a full-frame reducer to 180 mm. Aperture 40 mm yields for this focal length to speed F 4.5. The scope weighs only 400 g (700 g with the rings and EOS adapter). There is an M48 thread at the front of the telescope, which is very useful to attach the 2” mounted filters, particularly if you live in a light-polluted area.

There are several travel mounts on the market. Probably the most famous is Skywatcher Star Adventurer. I was about to pull the trigger on this mount, but I found another one, which will fulfill my requirements even better – iOptron SkyGuider Pro. iOptron has the same payload (5 kg with counterweight, 1.5 kg without) and has many interesting features:

  • Integrated illuminated polar scope
  • The torque from the motor to the worm gear is transmitted by a belt (this should minimize the backlash),
  • Integrated battery, which can be changed by USB cable
  • ST-4 socket for autoguiding

iOptron is slightly lighter than Skywatcher, so the decision was made. And how does it perform? I must say: VERY WELL! I got a chance to use it at home, so I screwed the IDAS NB1 filter in front of the Askar and captured the center region of Orion and California nebula. The mount is tracking very accurately even without any counterweight and the number of bad photos caused by poor tracking was zero.

The telescope surprised me very positively as well. The connection to the camera is done by T-thread (M42), so I expected significant vignetting on the full-frame sensor, because the diameter of the thread is 42 mm, whereas the diagonal of the sensor is 43 mm. Surprisingly, it vignettes very little, and even flat frames are not necessary. The darker corners can be corrected by dynamic background extraction in PixInsight. The stars are a little bit oval at the bottom corners, but we are here looking at a full-frame sensor. In the end, I am very happy with the price/weight/performance ratio of Askar.

Let’s have a look how heavy is the whole rig:

Tripod2.3 kg
iOptron SkyGuider1.5 kg
Canon EOS 6D0.8 kg
Askar0.7 kg
Total5.3 kg

This can fit into any backpack.

Here are the pictures:

Technical details:

LensAskar FMA180 F4.5
CameraCanon EOS 6Da
MountiOptron Skyguider Pro
Exposure60x60s, ISO 1600
Date2021-02-18

Technical details:

LensAskar FMA180 F4.5
CameraCanon EOS 6Da
MountiOptron Skyguider Pro
Exposure44x120s, ISO 1600
Date2021-02-18

Chasing darkness in Switzerland – Flims Laax

I got a fantastic idea to combine our ski vacation with chasing darkness and creating some spectacular wide-angle astrophotography. I started to search for a hotel, preferably at the top of the mountain, where would be very low light pollution. I found one – Berghaus Nagens in ski resort Flims-Laax. According to the light pollution map, there should be ideal conditions given by the altitude 2000 meters above the sea level, leaving the bright villages in the valley. The hotel has a south-oriented terrace, which should be also optimal to capture the most interesting deep space objects. I knew that to take even the portable telescope together with ski equipment is not feasible, so I took just an astro-modified Canon EOS 6D, two lenses, a tripod, and a portable mount. During our trip to Kythira, I used Baader Nanotracker, which did the job, but I was struggling a lot with polar alignment, so I decided on an upgrade. Specifically, I purchased iOptron Skyguider Pro. It is still very portable, but almost like a real equatorial mount with integrated polar scope.  

So, I booked the hotel, packed ski, previously mentioned astro-equipment, and left for a couple of days towards a new experience. The arrival is quite strict – you have to be at the bottom gondola station between 15:00 and 15:30, to take the lift up. If you miss this gondola, you will not get up. Fortunately, we managed and even first evening we saw few stars in holes between the clouds. The next night the weather improved, but the clouds were still making serious astrophotography nearly impossible. Last two nights the sky cleared and even the Orion arm of the Milky Way was visible by the naked eye. I grabbed a sky quality meter and measured only 21.0, which is not that spectacular. The problem was not caused by the light from the hotel’s restaurant (they switched the lights off at 23:00), but the reason is that we were surrounded by slopes, which have to prepare and the Pistenbullys making the job done have extremely powerful headlights. I can imagine that as soon the ski season is over and the snow melts away, the conditions will be excellent. In the end, I took only two pictures 24 mm and 50 mm of the constellation Orion. Such poor performance can be explained by the extreme weather conditions (freezing -15°C) and my complete tiredness after the whole day of skiing. It’s definitely easier to spend a whole day on the beach and in the evening do some astrophotography because your body is charged by solar power.

Anyway, these few days were mainly about skiing and we enjoined that very much. I cannot imagine a better place for this purpose. One can simply put the ski on at 8:00 be alone on the very well-prepared slopes. Berghaus Nagens is therefore 100% recommendable.

Technical details:

LensSamyang 24 mm f1.4 @ f2.8
CameraCanon EOS 6Da
MountiOptron Skyguider Pro
Exposure46x15s, ISO 1600
Date2021-02-14

Technical details:

LensSigma 50 mm f1.4 Art@ f2.0
CameraCanon EOS 6Da
MountiOptron Skyguider Pro
Exposure44x30s, ISO 1600
Date2021-02-13

Milky Way on Kythira

To capture our home galaxy Milky Way properly was my dream for a very long time. A long time ago I started with Canon EOS 40D with Tokina 11-20 f2.8. Then I changed the rig to Olympus PEN-F with Zuiko 12-40 mm f2.8. A year later I upgraded to Zuiko 8 mm f1.8. Recently I purchased a second-hand full-frame camera Canon EOS 6D and I let it modified for astrophotography. All my previous attempts were based on a single photo strategy, following the 500 rule. Basically, you divide 500 by the focal length of your lens and you get maximal exposure time. Of course, you have to crank up the ISO, use as wide aperture as possible, and a tripod. Photos produced by the above-described methods lack the details or they are very noisy, depends how much you de-noise in post-processing.

However, there is another method, which requires a tracker, which is basically a motor with a gear, which makes a full revolution in one day. By other words, it compensates for the Earth’s rotation. This means, you are not limited by a single picture, but you can make as many pictures as the weather allows. Of course, you have to stack the pictures. Therefore the post-processing is a bit complicated, but the signal to noise ratio can be significantly improved. I purchased Baader Nano tracker for my trip to Fuerteventura, but I was struggling with the equipment (shutter release, polar alignment, and lens) and as soon I got familiar with the setup, the weather got really bad, so the outcome was not as expected.

I got a new opportunity to test this set up on Kythira, where the Milky Way was not spoiled by the light pollution, because in direction south, there was nothing else than the Mediterranean sea. The primary target was the Rho Ophiuchi cloud complex. I have to say that I managed to capture it really well:

LensSigma 50 mm f1.4 Art@ f2.8
CameraCanon EOS 6Da
MountBaader NanoTracker
Exposure80x25s, ISO 1600
Date2020-07-11

After collecting 80 photos of Rho Ophiuchi, I pointed the camera to the east side of the Milky Way and I tried to capture the brightest objects in the sky – Jupiter and Saturn (upper left corner). Can you see the dark cloud at the bottom left corner? This is NGC6726 Nebula and NGC 6723 Chandelier Cluster.

LensSigma 50 mm f1.4 Art@ f2.8
CameraCanon EOS 6Da
MountBaader NanoTracker
Exposure40x23s, ISO 1600
Date2020-07-11

The next day I turned the camera 90 degrees and capture the Milky Way again. At the bottom, there is “a line” of red nebulas. From left to right: Cat’s Paw Nebula, Lobster Nebula, Lagoon and Trifid Nebulae, Omega Nebula, and Eagle Nebula. The brightest object at the top right is Jupiter, making some reflections.

LensSigma 50 mm f1.4 Art@ f2.8
CameraCanon EOS 6Da
MountBaader NanoTracker
Exposure47x25s, ISO 1600
Date2020-07-12

Here is another stack of 40 pictures targeting the core of the Milky Way.

LensSigma 50 mm f1.4 Art@ f2.8
CameraCanon EOS 6Da
MountBaader NanoTracker
Exposure40x25s, ISO 1600
Date2020-07-12

Later on, the Milky Way started to submerge into the Mediterranean Sea, so I changed the composition slightly, to capture the constellation Scutum. I also changed the post-processing technique and left bit of the green color. 

LensSigma 50 mm f1.4 Art@ f2.8
CameraCanon EOS 6Da
MountBaader NanoTracker
Exposure47x25s, ISO 1600
Date2020-07-12

I also took a different lens with me – Samyang 24 mm f1.4. This lens is theoretically very fast, but I experienced very ugly stars if it’s fully opened. The reasonable aperture starts at f2.4, but at f2.8 the sharpness is very good, except in one corner. Here is a stack of 55 pictures, 60 second each:

LensSamyang 24 mm f1.4 @ f2.8
CameraCanon EOS 6Da
MountBaader NanoTracker
Exposure55x60s, ISO 1600
Date2020-07-17

Or here is another wide-angle picture, which is a stack of 60 samples, each 24 second long:

LensSamyang 24 mm f1.4 @ f2.8
CameraCanon EOS 6Da
MountBaader NanoTracker
Exposure60x24s, ISO 1600
Date2020-07-13

The last picture I would like to post here is made by the smartphone Xiaomi Mi 10 Pro. The camera has a night mode, but for astrophotography, one would need something better. Google Pixels has a special feature for it. Moreover one can install a non-official port of the Goggle Camera App to third-party Android phones. So I purchased the holder for the phone, placed on a tripod, and pressed the shutter button. The camera collected photons for 3 minutes and made multiple shots and stacked them automatically. The result is, however, not impressive and I have to conclude that smartphones cannot replace the DSLR or mirrorless cameras. There is Milky Way visible in the picture, but it lacks details and stars are elongated. The conclusion: for my next expedition I still cannot leave the camera at home and take only the smartphone.


Chasing darkness on Fuerteventura

This year was a special year. The pandemic outbreak ruined my first attempt of darkness chasing on the Canary Islands in May. I didn’t give up and as soon the restrictions were released, I purchased plane tickets to Fuerteventura again. We rented a house via AirBnB on the south side of the island, in the middle of nowhere, where the light pollution supposed to be minimal (measured SQM 21.2).

The island lies on the 28th parallel, which makes the core of the Milky Way pretty up in the sky. And this was exactly my primary astrophotographic target. I packed recently astro-modified Canon 6D, nifty-fifty 50 mm f1.8 lens and headed south. The aim was to capture the Antares region together with the core of the Milky Way and in the end, I somehow managed.  However, the lens disappointed me a lot, because it suffers from comatic and chromatic aberrations, combined with astigmatism. The stars in the corners are not round, even if the lens is slowed down to f 3.5. I was trying nearly every evening to recapture the Milky Way, but I was fighting with the weather (it was very windy) and with the equipment (polar alignment, shutter release, drained batteries), but I somehow managed to generate at least one decent picture of the desired target. Lessons learned – I need a better 50 mm lens.

Technical details:

LensCanon EF 50 mm f1.8
F-stop2.8
Focal length50 mm
MountBaader NanoTracker
CameraCanon EOS 6D Astro modified
Exposure14x20s, ISO 1600
Date2020-07-22

I also packed 150mm Newtonian, together with my new mount Rainbow Astro RS135. This mount is simply excellent and very portable. I still have Avalon M-Zero, but it is significantly heavier, therefore if I travel with Avalon, I have to order a second suitcase and to travel with two suitcases is not that convenient. Rainbow Astro occupies only half of my luggage, so there was a space for some T-shirts. I must say, that the Avalon is a better mount for tracking and there is no need to do a meridian flip, but the portability is for me more important. The primary target was the Lobster nebula, but I managed to capture some DSOs around Antares and in the core of the Milky Way (Lagoon, Trifid, M4, M6, M7, M24, IC4304)

The conclusion: the weather was much better than in La Palma last year. Every night was cloudless, but it was windy. Fortunately not every day, so in the end, it was a quite successful trip.


Samyang 24 mm f 1.4 review

I have been searching for a wide lens for my recently astro-modified, second hand Canon 6D. This means the lens should be suitable for a full-frame sensor 36 x 24 mm. The requirements on lenses are very tough for astrophotography because you photograph the stars – pinpoint sources of the light. The design/manufacturing flaws of the lenses are revealed on every astrophoto and optical aberrations spoil the good shot. Astrophotography of the Milky Way needs a lot of effort. Specifically, you have to travel to reach the dark sky and if you do so, you want to make nice pictures. In my opinion, the lens is the most important piece of equipment for astrophotography, because nowadays you can buy second hand Canon 6D, which is still very good and relatively inexpensive.

All the lenses are very sharp and aberration-free in the center of the picture, but the more you go off the axis, the aberrations start to pop up. There are many kinds of optical aberrations. Very nice article about the most common aberrations is on Lonely Speck.

Last year I purchased Samyang 14 mm f2.8, which is a great lens for the money, but the corners are not perfect and the stars are strongly deformed in every corner. I assumed that almost twice more expensive Samyang 24 mm f1.4 will perform much better and I also assumed that it’s easier to make a 24 mm lens compared to 14 mm. Moreover, f1.4 is a brilliant convincing argument. On the other hand, Samyang 24 mm doesn’t communicate with the camera, which means no EXIF of aperture and manual focus. This makes the lens a one-trick pony, suitable mainly for astrophotography and not that practical for regular photography.

Before I take this lens to the dark site, I decided to test it from my light-polluted home. The equipment: Canon 6Da, Baader Nanotracker, and of course, Samyang 24 mm f1.4. The main aim was to find the best aperture/sharpness ratio. Most of the lenses get sharper if slowed down. So I kept the exposure time 20 s, ISO 800, and was systematically changing the aperture from 1.4 to 2.8.

Here are the results of uncropped and uncorrected (no flats, no bias, no darks, and no noise reduction) pictures:

F1.4

F2.0

F2.4

F2.8

And the winner is…. obviously, the largest aperture (the smallest F number) collects the most of the light, but it vignettes strongly and honestly, the stars are ugly even in the center – this is totally unusable for serious astrophotography. The situation is not much improved by slowing the lens down to F2.0. At F2.4 the situation is significantly improved but at F2.8 the star roundness is acceptable almost everywhere, except the left corners.

Let’s have a look to the upper left corner – there the stars are the worst.

F1.4

F2.0

F2.4

F2.8

Conclusions

Samyang 24 mm F1.4 should be slowed down to at least to F2.4, to offer decent quality of the stars on a full-frame sensor. At F2.8 the quality is even slightly better, but at the top-left corners are the stars still elongated by astigmatic aberration. I expected better star quality, but in the end it’s not so dramatic, because the right side is not perfect, but acceptable. At least I know which side of the camera I should turn towards the ground if making a portrait picture of the Milky Way.


Chasing darkness in Greece – Karpathos

Like every summer, I packed the telescope, mount, camera and many accessories and flew to Greece. This time we went to Karpathos, the island not spoiled by massive tourism and light pollution. Long story short, the skies were amazing, but every single night, except one, was extremely windy. It was a torture – to see millions of stars and not be able to photograph them. There is no surprise that Karpathos is beloved by windsurfers and kite surfers. In the end I captured only the Iris Nebula and the Double Cluster. I talked to locals and they told me that the wind should stop at the end of September, so probably I picked the wrong time.

On the other hand I was able to do a wide angle astrophotography of the Milky Way. SQM reached 21.5, galactic core was so bright and I think the photos of the Milky Way are quite decent. This time I changed the setup and purchased Canon EOS 6D, which is one of the best cameras for this purpose. Moreover, there are many second hand 6Ds, because mirrorless mania arrived. 6D combined with Samyang 14 mm f2.8 offers excellent performance for this purpose.