Mars

I have been waiting for this planet very long. It doesn’t mean that Mars hasn’t been visible, it was, but not from my backyard. I live in central Europe, specifically on the 47 parallel. This means that all planets should be 43° above the horizon during the conjunction (when Sun, planet, and observed planet are in one line). Well, this would be true, if the Earth would be spinning perfectly perpendicular to the plane of the Solar System. In reality, the Earth has a tilt, which causes that some years are much better than the others. A better year for a certain planet means that the planet raises a lot above the horizon, a bad year means that it stays close to the horizon.

This year was one of the best years for the planet Mars. The next opportunity will occur in 15 years.

The picture is a stack of 750 best frames, each 7.3 ms long. The focal length of the Celestron C14 telescope was extended from 4000 mm to 6400 mm by the Siebert Barlow lens.

Telescope:Celestron EdgeHD C14
Aperture:354 mm
Focal length:6400 mm
MountGemini G53f
Autoguiding-
Camera:ZWO ASI228MC
Corrector:Barlow 1.6
Filters:UV IR cut
Exposure:3000xRGB (25% used), 7.3 ms, Gain 219
Date:2020-10-25

Chasing darkness of Kythira

Even across the Covid pandemic in 2020, we managed to organize the second trip to chase the darkness. As usual, our summer vacation took place in Greece, this time on the island Kythira. Based on the search on the light-pollution map, I concluded that the best would be the south-west side of the island. I found Vanis house in this location and booked it. The place was fantastic. Westside is obviously optimal for observation of the sunsets – and they were magical.

After the sunset, the Milky Way showed up and it was spectacular. Measured SQM reached 21.5, which means it was one of the darkest locations I have ever been to. My primary target was the Milky Way and I managed to capture it really well. Detailed pictures are in a separate post, but here is the view south during a moonless night.

Milky Way in fron of Vanis House
Vanis House – Waxing Crescent and Milky Way

Besides the Milky Way, I also took my portable Newtonian and captured a few deep space objects. I have to say that our vacation was not just about astrophotography, but also about enjoying the Greek sun, beautiful beaches, tasting delicious food, and simply relaxing. Conclusions: I love Kythira!

View from Vanis House
Avlemonas
Kaladi beach – the most beautiful beach on the island
Paralia Kalami

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.


NGC 253 Sculptor Galaxy

Every time when I chase the darkness in southern lands, I try to capture some deep space objects in the southern hemisphere, which are not visible from Central Europe. One of these objects is the Sculptor Galaxy, which can be found, surprisingly, in the constellation Sculptor (south from Aquarius). Here are some features: it is approximately 11 light-years away from us, it has roughly 90 000 light-years in diameter (similar to Milky Way) and it is characteristic by the intense star formation. This galaxy is sometimes called Silver Coin or Silver Dollar Galaxy, but I pushed the colors into the yellow spectra, therefore it looks like a gold coin.

TelescopeNewton 150/600 mm
Aperture150 mm
Focal length570 mm
MountRainbow Astro RST 135
AutoguidingZWO 174MM, Guidescope 30 mm
CameraZWO 071 Pro @-0°C
CorrectorTS MaxField
FiltersNo
Exposure127x180s, Gain 94, bin 1x1,
Date2020-09-21

NGC 6559 Nebula

If we look in the middle of the night during the summer months (on the northern hemisphere) into the Milky Way’s core, we can find many prominent deep space objects, like Lagoon, Omega, Eagle, or Trifid nebulae. However, there are also not so well known, but also very beautiful, objects. For instance emission nebula NGC 6559, which can be located in constellation Sagittarius. The star-forming region is surrounded by the dark nebula B 91 in the shape of a heart. At the bottom left corner, a part of the Lagoon Nebula is visible.

TelescopeNewton 150/600 mm
Aperture150 mm
Focal length570 mm
MountRainbow Astro RST 135
AutoguidingZWO 174MM, Guidescope 30 mm
CameraZWO 071 Pro @-0°C
CorrectorTS MaxField
FiltersNo
Exposure54x180s, Gain 94, bin 1x1,
Date2020-09-21

NGC 6726 Nebula

NGC 6726 is a reflection nebula located in the constellation Corona Australis. Visually, there is a deep space neighbor, the Chandelier globular cluster NGC 6723. These deep space objects can be also found on my wide-angle picture of the Milky Way in the left bottom corner.

TelescopeNewton 150/600 mm
Aperture150 mm
Focal length570 mm
MountRainbow Astro RST 135
AutoguidingZWO 174MM, Guidescope 30 mm
CameraZWO 071 Pro @-0°C
CorrectorTS MaxField
FiltersNo
Exposure44x180s, Gain 94, bin 1x1,
Date2020-09-13

M22 Great Sagittarius Cluster

Messier 22, sometimes called Great Sagittarius Cluster is a globular cluster, visually located very close to the galactic core of the Milky Way. If we look in this direction by a telescope, the surrounding of this cluster is filled with many stars. The cluster itself contains approximately 100 000 stars and it has roughly 97 light-years in diameter. The region of the sky where is this cluster located is poorly visible from my home, therefore every time I travel south with my portable telescope, I capture some deep space objects in this region. This picture was taken under the dark skies of Kythira.

TelescopeNewton 150/600 mm
Aperture150 mm
Focal length570 mm
MountRainbow Astro RST 135
AutoguidingZWO 174MM, Guidescope 30 mm
CameraZWO 071 Pro @-0°C
CorrectorTS MaxField
FiltersNo
Exposure59x180s, Gain 94, bin 1x1,
Date2020-09-12

IC 1318 Sadr Region

Sadr Region, sometimes called The Gamma Cygni Nebula is a giant cloud of ionized hydrogen, located in the constellation Cygnus (Swan). The picture shows only a part of the whole complex. In order to capture the whole nebula, I would need a telescope with a much shorter focal length of the much bigger sensor of the camera. This is actually my second attempt. The first one from Milos Island was quite nice, but this time I dedicated a significantly longer time for this deep space object. Specifically, the picture is an integration of 405 minutes, which means nearly 7 hours in total.

TelescopeNewton 150/600 mm
Aperture150 mm
Focal length570 mm
MountRainbow Astro RST 135
AutoguidingZWO 174MM, Guidescope 30 mm
CameraZWO 071 Pro @-0°C
CorrectorTS MaxField
FiltersNo
Exposure135x180s, Gain 94, bin 1x1,
Date2020-09-11

NGC6888 Crescent Nebula

Another cloudless night and I decided to test the IDAS NB1 filter again This time on Crescent Nebula, located in constellation Cygnus. The nebulosity was captured well and it’s comparable to the narrow band image I captured a long time ago. However, the bright stars are surrounded by ugly reflections. I am not sure it’s due to the MaxField coma corrector or the filter. Next time I will try with ExploreScientific coma corrector and we will see.

TelescopeNewton 254/1000 mm
Aperture254 mm
Focal length950 mm
MountGemini G53f
AutoguidingZWO 174MM, TS 60/240 mm
CameraZWO 071 Pro @-5°C
CorrectorMaxField coma corrector
FiltersIDAS NB1 Nebula Filter
Exposure103x180s, Gain 95, bin 1x1,
Date2020-08-20

NGC7000 North America Nebula

After capturing the Eagle Nebula, I was searching for another nebula to test the new IDAS NB1 filter and I picked NGC7000 North America Nebula, switched on autoguiding, and went to sleep. The next morning I processed 138 pictures, each 3 minutes long. Well, I must say that this filter is a very good option for astrophotography in light-polluted locations.

Technical details:

TelescopeNewton 254/1000 mm
Aperture254 mm
Focal length950 mm
MountGemini G53f
AutoguidingZWO 174MM, TS 60/240 mm
CameraZWO 071 Pro @-5°C
CorrectorMaxField coma corrector
FiltersIDAS NB1 Nebula Filter
Exposure138x180s, Gain 95, bin 1x1,
Date2020-08-10

M16 Eagle Nebula

Eagle Nebula is probably the most known deep space object, due to one picture from the Hubble Space Telescope. The pillars of creation were detected, where the new stars are born. I already captured this nebula by using narrowband filters and a monochrome camera. This time I used a different approach – one-shot color camera + new IDAS NB1 Nebula Filter. This filter should completely suppress the light pollution from sodium lamps and partially from LED lamps, passing the most interesting wavelength of H-alpha, OIII, and H-beta. In my opinion, it works well even in my light-polluted home.

Technical details:

TelescopeNewton 254/1000 mm
Aperture254 mm
Focal length950 mm
MountGemini G53f
AutoguidingZWO 174MM, TS 60/240 mm
CameraZWO 071 Pro @-5°C
CorrectorMaxField coma corrector
FiltersIDAS NB1 Nebula Filter
Exposure82x180s, Gain 95, bin 1x1,
Date2020-08-09

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.


M4 Globular cluster

Messier 4 (left side of the picture) is a globular cluster located in constellation Scorpius, close to the brightest star of this constellation Antares (right side). This cluster is the closest one to the Solar System, due to its “short” distance 7200 light-years and it contains several tens of thousands of stars. There is another globular cluster on the bottom side of the picture NGC 6144. The star Antares is classified as a red supergiant, with diameter several times bigger than the Sun, which makes it one of the largest know stars. it is only 550 light-years away, which means M4 and Antares are close only visually, but in reality, there is a very long distance between them.
If any brighter star is photographed by the Newtonian telescope, the diffraction cross appears due to the so-called “spider vanes” holder of the secondary mirror. If the spider vanes are not perpendicular to each other (like in my case), the diffraction pattern makes multiple ugly lines. This means I will have to correct it, as soon as I get back from Fuerteventura.

Technical details:

TelescopeNewton 150/600 mm
Aperture150 mm
Focal length570 mm
MountRainbow Astro RST 135
AutoguidingZWO 174MM, Guidescope 30 mm
CameraZWO 071 Pro @-0°C
CorrectorTS MaxField
FiltersNo
Exposure44x180s, Gain 94, bin 1x1,
Date2020-07-23

NGC6357 Lobster Nebula

Lobster Nebula is a HII region (giant cloud of excited hydrogen gas) located in constellation Scorpius. The nebula rises only 8° above the horizon in Central Europe, which means, it is submerged in light pollution caused by nearby towns, villages or cities. The situation is completely different on Canary Islands, where the nebula rises 27° above the horizon. Therefore, this nebula was my primary target of my expedition to Fuerteventura. Unfortunately, the weather didn’t cooperated and strong winds caused bad seeing and didn’t allow me to capture more frames. So, next time it will be better.

Technical details:

TelescopeNewton 150/600 mm
Aperture150 mm
Focal length570 mm
MountRainbow Astro RST 135
AutoguidingZWO 174MM, Guidescope 30 mm
CameraZWO 071 Pro @-0°C
CorrectorTS MaxField
FiltersNo
Exposure40x180s, Gain 94, bin 1x1,
Date2020-07-22

M24 Sagittarius Star Cloud

Messier 24 is spiral arm of our galaxy located in constellation Sagittarius. The region is heavily populated by the stars, which makes you think how big our home galaxy Milky Way is. I captured already few years back, but it would be a pity not to recapture this magnificent star cloud again with slightly shorter focal length and under dark skies of Fuerteventura.

Technical details:

TelescopeNewton 150/600 mm
Aperture150 mm
Focal length570 mm
MountRainbow Astro RST 135
AutoguidingZWO 174MM, Guidescope 30 mm
CameraZWO 071 Pro @-0°C
CorrectorTS MaxField
FiltersNo
Exposure75x120s, Gain 94, bin 1x1,
Date2020-07-21

IC 4304 Rho Ophiuchi Nebula

Rho Ophiuchi is a triple star system (on the left side of the picture) in constellation Ophiuchus. The light from the stars is partially absorbed by the gas, which makes the blue reflection nebula visible. Smaller reflection nebula called IC 4603 is located on the right. The picture shows just small frame of significantly bigger nebula, called Rho Ophiuchi complex, which combines star Antares, globular cluster M4 and many more reflection, emission and dark nebulae. In order to capture the whole complex, one has to use significantly shorter focal length, like 130 – 200 mm.

The picture was taken under dark skies of Fuerteventura and it’s a stack of 73 pictures, 3 minutes each, which makes total integration time 219 minutes.

Technical details:

TelescopeNewton 150/600 mm
Aperture150 mm
Focal length570 mm
MountRainbow Astro RST 135
AutoguidingZWO 174MM, Guidescope 30 mm
CameraZWO 071 Pro @-0°C
CorrectorTS MaxField
FiltersNo
Exposure73x180s, Gain 94, bin 1x1,
Date2020-07-21

M7 Ptolemy cluster

Messier 7, sometimes called Ptolemy cluster, is an open cluster located in between constellations Sagittarius and Scorpius. The cluster is visually located on the galactic plane of the Milky Way, therefore there are many stars in the background. The cluster is badly visible from Central Europe. Much better opportunities to observe or photograph this cluster have astronomers or astrophotographers in southern countries. My last attempt to capture it in Greece was constantly disturbed by the weather, therefore we I was again in South, specifically at Fuerteventura, I didn’t hesitate and recapture this beautiful cluster.

Technical details:

TelescopeNewton 150/600 mm
Aperture150 mm
Focal length570 mm
MountRainbow Astro RST 135
AutoguidingZWO 174MM, Guidescope 30 mm
CameraZWO 071 Pro @-0°C
CorrectorTS MaxField
FiltersNo
Exposure64x180s, Gain 94, bin 1x1,
Date2020-07-21

M8 Lagoon Nebula, M20 Trifid Nebula

These two magnificent nebulae are located visually close to each other in constellation Sagittarius. This means we are looking in direction of the galactic core of the Milky Way. Trifid nebula (up left) is a combination of a reflection nebula (blue part), a dark nebula (brown clouds), an emission nebula (red part) and a star cluster. On the other hand, Lagoon nebula (right side) is an emission nebula – giant cloud of ionized HII gas. Due to very low southern declination, it’s very difficult to photograph these deep space objects from my home place in Central Europe. Therefore every time I travel south, I take the opportunity and recapture these nebulae. My first attempt of M20 was done with focal length 917 mm, second one with 630 mm and now I used gentle focal reducer. Focal length 570 mm allowed me to fit both nebulae into the field of view of APS-C sensor size. The picture is an integration of 213 minutes, taken under dark skies of Fuerteventura.

Technical details:

TelescopeNewton 150/600 mm
Aperture150 mm
Focal length570 mm
MountRainbow Astro RST 135
AutoguidingZWO 174MM, Guidescope 30 mm
CameraZWO 071 Pro @-0°C
CorrectorTS MaxField
FiltersNo
Exposure71x180s, Gain 94, bin 1x1,
Date2020-07-18

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.


M5 Globular Cluster

Messier 5 is a globular cluster located in constellation Serpens. I revisited this cluster after four years. Such spectacular deep space object simply deserves more attention, than I was able to spend four years ago. At that time I used the same telescope, but now I have different coma corrector and the camera. Moreover, this time I dedicated significantly more integration time, specifically I collected 2.7 hours the photons traveling to us 24 500 years.

Technical details:

TelescopeNewton 254/1000 mm
Aperture254 mm
Focal length1060 mm
MountGemini G53f
AutoguidingZWO 174MM, TS 60/240 mm
CameraZWO 071 Pro @-10°C
CorrectorExplore Scientific HR coma corrector
FiltersNo
Exposure54x180s, Gain 95, bin 1x1,
Date2020-05-21