The beautiful starry sky is a strange and mysterious existence for many photographers, and most of the enthusiasts who are interested in astrophotography only shoot large-scale works of the Milky Way; however, those countless celestial objects hidden in the night sky, There are many different appearances and their own beauty, which are worth capturing and recording through the camera. In this exclusive interview with the staff of T Hakbang, we specially invited Wang Weihao, a well-known astronomer in Taiwan, who will lead you into the mysterious world of deep space photography through the 50.1 million pixel full-frame camera Sony α1!
about | Wang Weihao
A Taiwanese astronomer, currently working at the Institute of Astronomy and Astrophysics, Academia Sinica. He mainly studies submillimeter wave observations. He is also the author of the well-known book “Hoshino Photography”. He is famous in the amateur astronomy circle for his astrophotography.
Currently operating: personal website / Flickr / Astrobin
What is deep space photography? What’s the difference from general astrophotography?
In fact, astrophotography covers a wide range, and deep space photography can be regarded as the mainstream of astrophotography. As for the photos of the Milky Way combined with the landscape that are often taken by ordinary photographers, it is the so-called “star scene photography”, which usually uses an ultra-wide-angle lens to capture a wide range of starry sky. And “deep sky photography” refers to celestial objects hidden in the night sky, such as nebulae, star clusters and galaxies… etc. These objects are usually very far away from the earth and dim, and must use a telephoto lens or even an astronomical telescope, and pass a certain amount of time. Only the exposure of time can be captured, and the photos will not have ground scenes. This is the so-called “deep sky photography”.
What seasons, places and tips are suitable for beginners to take deep space photography in Taiwan?
In Taiwan, the most suitable seasons for deep space photography are summer, autumn and winter. Although there are many targets for deep space photography in spring, because these targets are relatively small in spring, and the weather conditions in Taiwan are also unstable in spring, it seems that summer, autumn and winter are more suitable for shooting deep space. photography season.
In terms of location, of course, priority is given to places with low light pollution, such as Yangmingshan in the north, Cingjing Farm in the middle, and Kenting in the south. In the deep mountains and old forests, it is more convenient and easy for beginners to temporarily need supplies. As for the shooting know-how, if you have studied the photos of deep space photography, you should find that its exposure time often starts from half an hour, and even works with exposure times of more than ten hours are not uncommon.
As mentioned earlier, the main targets of deep space photography, such as nebulae, star clusters or galaxies… are very far away from the photographer and are dim, so it takes a long time to expose before CMOS can fully record these faint objects. signal, and the image processing method after the event is also very different from the image processing common in general photography; moreover, because the earth will rotate, it has to be assisted by other accessories to make the lens follow the subject. to capture clear images.
The above points do take a lot of time to learn and try for players who have no deep space photography experience in the past.
What are the requirements for cameras and lenses for deep space photography? What advice would you give?
Because the target to be photographed is both distant and dim, as far as the lens is concerned, a large aperture and high image quality are absolutely necessary. It is recommended that the maximum aperture should be at least F4, preferably F2.8, or even F2. In short, the bigger the better. Good, but the premise is that even if the lens is shot at the maximum aperture, it must have a good image quality presentation, so that the image taken can have a certain level. In addition, the first CMOS photosensitive ability of the camera part should be sensitive enough, because deep space photography captures very weak signals, only the camera CMOS has a sensitive photosensitive ability, can it be recorded smoothly. From this point of view, the performance of several Sony α cameras I have used is very good, of which the α1 is currently the top, no one.
Besides cameras and lenses, what other equipment is absolutely indispensable?
The rotation of the earth makes the celestial bodies rise in the east and set in the west like the sun. Therefore, it is necessary to use the assistance of a star chaser or an equatorial mount to allow the camera lens to continue to lock the target while taking a long exposure and move with it. The dragged video works.
For beginners, my suggestion is to start with a star chaser, which is about the size of a bento box and sells from $10,000 to over $50,000. It is relatively cheaper and lighter than an equatorial mount, as long as After installing it on a tripod, and fixing a camera with a lens attached to it, you can start practicing deep space photography. In contrast, equatorial mounts are more professional equipment. Not only are they expensive (about $20,000~$200,000), but they also require more complex operating experience and related knowledge. Therefore, it is recommended to have a foundation in deep space photography. It’s not too late to buy after experience and shooting experience.
A’1 What features can bring obvious help for deep space photography?
In addition to testing the sensitivity of the camera’s CMOS sensor in deep space photography, the display capability of the screen behind the fuselage is also a part of my attention. Taking the whole process of deep space photography with Sony α1 this time, I found that the α1 screen has a very good display effect. Take the following photo of the M31 Andromeda galaxy as an example. The galaxy is about 2.5 million light-years away from the earth. At present, one of the most distant deep-sky objects visible to the naked eye (provided that it can be observed in an environment with very little light pollution), even so, the M31 Andromeda galaxy that can be seen through the naked eye is actually very small, and With the excellent LCD display capability of the α1, when I point the telescope to the direction of the M31 Andromeda galaxy, I can easily confirm the target I want to shoot through the α1’s screen. Coupled with the assistance of the α1’s excellent CMOS sensitivity, it allows me to It can capture the whole picture of the M31 Andromeda galaxy, and even the faint outer spiral arms of the galaxy can be clearly captured. I think α1’s performance in this regard is very commendable.
A’1 of 5,010 Is 10,000 Pixels Enough for Deep Space Photography? In addition, can the image quality meet the requirements of deep space photography?
Because only the sensitivity of the camera CMOS itself is high enough, more image information and lower noise can be recorded in the same time unit, which facilitates the smooth extraction of details of deep-sky objects during post-production. Judging from my actual shooting experience with the α1, I really like the 50.1-megapixel CMOS of the α1. In addition to the excellent sensitivity, the image quality is also quite excellent.
But I want to remind everyone that if you want the 50.1-megapixel CMOS of the α1 to play the best role, the lens must be good enough. The two complement each other. Once the quality is good enough for the α1 connection , I believe that the power of this 50.1 million pixel CMOS can definitely be fully utilized.
use A’1 When shooting deep space photography, which lenses are mainly used?
As far as I am concerned, I mainly use my own and school astronomical telescopes for deep sky photography, such as 1100mm F7 or 250mm F5. As for Sony’s lenses, I don’t have much experience in using them. Most of them use SEL1224GM to shoot the galaxy combined with the landscape. I mainly take photos, but as far as I have seen on the Internet or deep space photography forums, the effects of others using Sony α cameras with Sony lenses, I believe that even if the α1 is connected to the Sony GM series of telephoto lenses, the quality of the pictures will be certain. Also great!
▲▼ In addition to deep space photography, Wang Weihao also takes astrophotography photos of the Milky Way combined with the landscape, and he said that the Sony α camera with the SEL1224GM is an excellent combination for shooting such subjects. (Above: Sony α1 + SEL1224F28GM, 18mm, F2.8, 10s, ISO 3200 (see larger picture); Bottom: Sony α1 + SEL1224F28GM, 12mm, F3.5, 20s, ISO 1600) (see larger picture)
Whether it is an astronomical telescope or Sony’s own lens, I always recommend choosing a lens with good quality and high level (such as the G Master series). Only with the α1’s 50.1 million pixel CMOS can achieve good motion effects, and then shoot high-quality deep space video works.
A’1 of 15 level dynamic range RAW What help does the file bring to deep space photography?
It is undeniable that the α1 has a RAW file format with a dynamic range of 15 levels, which can definitely bring great help to deep space photography. For the most direct example, like the photo below, I used α1 to take the famous M42 Orion Nebula. It is a diffuse nebula located in the south of the belt of Orion, about 1,500 light-years away from the earth. It can generally be seen directly with the naked eye. But if it is observed through a telescope, it can be found that its center is very bright, and its periphery is quite dim, and it belongs to a celestial body with very large contrast.
The general practice of photographing the M42 Orion Nebula is to take a few shots with long exposures (such as 5 minutes) and a few shots with short exposures (such as 10 seconds), and then use the software to stack the images to synthesize them. The concept is actually the same as that of landscape photography. HDR is the same; but thanks to the 15 stops of dynamic range in RAW, I only need to take a few shots with long exposures (say 5 minutes) and stack them together to get a full dynamic range photo of the M42 Orion Nebula.
use A’1 What are the precautions for shooting deep space photography? Advice for beginners?
Beginners who are really interested in deep space photography should get in touch with astrophotography enthusiasts and exchange and learn from each other. Relatively easy. In terms of equipment, since the shooting target is the celestial body in deep space, the camera with high CMOS sensitivity is definitely the first choice, and the pixels should not be too low. For example, the α1 used this time is the camera that I personally recommend!
If the budget is limited, the equipment should be better first and then better. For the Sony α series cameras that I have used in the past few years, I personally think that it is absolutely sufficient for shooting deep space photography. The lens is recommended to go straight to the G Master series, such as SEL100400GM, SEL400F28GM, I highly recommend it, mainly because the excellent optical quality and the use of Sony α series cameras can definitely add points to the image, and I will buy it when I want to be more advanced in the future. It’s not too late for astronomical telescopes.
Finally, if a novice wants to try to take deep sky photography, it is recommended to practice from the two deep sky objects of M31 Andromeda Galaxy and M42 Orion Nebula, especially the M42 Orion Nebula, which can be easily found in the clear night sky in winter, and then buy An entry-level star chaser with α1 and GM lenses can start exploring the mysteries of deep space photography. It’s better to sit up and walk, let’s enjoy its charming charm together!
Learn more about Sony α1 full frame camera: http://go.sony.tw/up3CY16T