Tag: Samyang 24 mm f1.4

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


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.


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.


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.