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 narrowband 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 – a one-shot color camera + a 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 chasing the darkness 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 was 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 the 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 of 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 a 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 the 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 the Canary Islands, where the nebula rises 27° above the horizon. Therefore, this nebula was the primary target of my expedition to Fuerteventura. Unfortunately, the weather didn’t cooperate 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 a spiral arm of our galaxy located in the constellation Sagittarius. The region is heavily populated by the stars, which makes you think how big our home galaxy Milky Way is. I captured it already a few years back, but it would be a pity not to recapture this magnificent star cloud again with a slightly shorter focal length and under the 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 the constellation Ophiuchus. The light from the stars is partially absorbed by the gas, which makes the blue reflection nebula visible. A smaller reflection nebula called IC 4603 is located on the right. The picture shows just a small frame of the significantly bigger nebula, called the 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 a significantly shorter focal length, like 130 – 200 mm.

The picture was taken under the dark skies of Fuerteventura and it’s a stack of 73 pictures, 3 minutes each, which makes the 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 the 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 when I was again in the 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 the 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, the Lagoon nebula (right side) is an emission nebula – a 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, the second one with 630 mm and now I used a 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 the 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 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. A 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 the constellation Serpens. I revisited this cluster after four years. Such a 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 a different coma corrector and camera. Moreover, this time I dedicated significantly longer integration time, specifically I was collecting the photons 2.7 hours, which were 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

M98 M99 Galaxies

Messier 98 (left bottom) and 99 (right) are galaxies visually located in constellation Come Berenices. These galaxies interacted with each other long time ago, but it’s long time forgotten, because currently, the distance between them is 1.3 million light years.

Technical details:

TelescopeNewton 150/600 mm
Aperture150 mm
Focal length630 mm
MountAvalon M-Zero
AutoguidingZWO 174MM, Guidescope 30 mm
CameraZWO 071 Pro @-10°C
CorrectorExplore Scientific HR
FiltersAstronomik L-1 - UV IR Block Filter
Exposure140x180s, Gain 94, bin 1x1,
Date2020-03-24

M44 Beehive Cluster

Messier 44, sometimes called Beehive cluster, is visually one of the biggest open cluster, which can be observed from northern hemisphere. Previous picture, taken 3 year ago, was done with focal length 1000 mm. Now I changed the strategy and used only 630 mm. I think this was a good idea and whole cluster is perfectly framed.

Technical details:

TelescopeNewton 150/600 mm
Aperture150 mm
Focal length630 mm
MountAvalon M-Zero
AutoguidingZWO 174MM, Guidescope 30 mm
CameraZWO 071 Pro @-10°C
CorrectorExplore Scientific HR
FiltersAstronomik L-1 - UV IR Block Filter
Exposure76x180s, Gain 94, bin 1x1,
Date2020-03-46

M95 M96 M105 NGC 3384 and NGC 3389 Galaxies

Well, the weather was so bad very long time or the Moon was up and shining. I had almost no opportunity to capture something this year. Finally the sky cleared up and galactic season started (the spring). I was so excited that I wanted to capture as many deep space object at possible. Therefore I took the telescope with the shortest focal length I have (630 mm), pointed the telescope into the constellation Leo and captured 5 bright galaxies in one shot. M95 is the one at bottom left, M96 in middle and M105 the brightest at top right corner.

Technical details:

TelescopeNewton 150/600 mm
Aperture150 mm
Focal length630 mm
MountAvalon M-Zero
AutoguidingZWO 174MM, Guidescope 30 mm
CameraZWO 071 Pro @-10°C
CorrectorExplore Scientific HR
FiltersAstronomik L-1 - UV IR Block Filter
Exposure76x180s, Gain 94, bin 1x1,
Date2020-03-18

M48 Open Cluster

Telescope is out after long time. My main targets for this night are some galaxies in constellation Leo, but I have to wait for these galaxies to cross the meridian (line splitting west and east). By browsing in planetarium software I found one object, which can fill the gap – it was the open cluster M48. Open cluster usually don’t need super dark skies, therefore I can capture them during the evening, when there is still strong light pollution. My previous picture was taken by much longer focal length, therefore the cluster covered nearly whole field of view. This time the background if filled by many stars, which are not members of this cluster.

Technical details:

TelescopeNewton 150/600 mm
Aperture150 mm
Focal length630 mm
MountAvalon M-Zero
AutoguidingZWO 174MM, Guidescope 30 mm
CameraZWO 071 Pro @-10°C
CorrectorExplore Scientific HR
FiltersAstronomik L-1 - UV IR Block Filter
Exposure76x180s, Gain 94, bin 1x1,
Date2020-03-18

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.

Karpathos offers other beauties, for example very beautiful beaches, mountains, delicious food friendly people and many more.

Our house Elaeon with remarkable dark skies – SQM 21.5
Olympos
Apela beach
Avalon M-Zero and TS 6" Newtonian
Avalon M-Zero and TS 6″ Newtonian at Elaeon