Interview for

By Aileen Wessely. Originally published in German at

Hello Sylvain, thank you for taking the time to have an interview with us. First, tell us a little about you: Who are you, what are you doing?

I’m astrophotographer and landscape photographer. I’m passionate about astronomy since childhood. I had my first telescope at the age of 12. In 2006 I bought a DSLR for astrophotography. It made me discovering the world of traditional, daytime, photography and my love for nature and hiking brought me to landscape photography. Now, when the sky is clear and there is no Moon I go shooting deep sky objects. The remaining time I go hiking in the mountains for landscape photography.

Why astronomy? What fascinates you about stars and nebulae?

That’s a very good question ! In fact, I don’t really know. I think I’ve been always fascinate by what’s beyond… Beyond a forest, beyond a mountain… Beyond what my yes can see. The immensity of the universe offer a large number of possibilities. When we look at a galaxy through a telescope with the eyes, all we can see is a faint blurry spot. It’s far from the vision a photo can offer. This faint spot is constituted by billions of stars. Recent discoveries tell that most star have planets, some of them could be habitable. How much civilization could there be ? And it is just an example.

Unlike most other photographic genres, astronomy only has one sky we all look up to with only one point of view. Do you feel these limitations? Are there things in astrophotography that make up for it?

Sometimes I feel this limitations, asking myself what will I do when I will have photograph every object I can do. But if you consider that I need an entire night for only one photo, I still have a lot of work ! The most important limitation, for me, is the artistic aspect. Astrophotography is very technical and there is a very little place for artistic consideration. You cannot play with depth of field as all objects are seen as if they were at the infinity and compositions are somewhat simple. Most of the time, it consist of placing the object in the center of the frame. I try to play with compositions by placing the subject off-center, following the rule of third, and counterbalancing with something else. A small galaxy in the vastness of a star field (, a nebula among dust (, for example. Deep-sky imaging can be specialized. I made what we call wide field imaging. I use short focal length to shoot wide part of the sky. Well, it should be considered in the astrophotographic point of view, the focal length I use are 387mm and 530mm which are pretty long for traditional photography. Some astrophotographs use filters to make false-color imaging, others use long focal length, several meters, to make detailed images of small object like galaxies and planetary nebula. Progress in digital imaging allow us to make images that were not possible even with professional observatories 10 or 15 years ago. We rediscover some part of the sky.

How do you prepare a shoot? How do you choose your motifs?

I choose my motifs depending on the season. You cannot shoot Orion in summer because it’s not visible. Spring is the galaxy season, summer is for nebulae in the Milky Way. The target must be visible during a large part of the night. I also use astronomy software like Carte du Ciel, or Microsoft WorldWide Telescope to choose the target, to see how I can do the framing and to check its visibility. Other photographer are good sources of inspiration. When the new moon is approaching I begin to watch the weather. When the sky is clear I put all the gears in my car and I go to one of my astronomy spot, in the mountain, where’s there no light pollution.

Probably the used equipment in astrophotography is much more important than in lots of other genres. What hints can you give to beginners?

Yes, equipment is important and it can quickly become expensive. The quality of the sky and the experience of the astrophotgrapher can make a big difference too. But you can begin with a relatively cheap telescope. A 150/750 Newtonian telescope on an equatorial mount and a cheap DSLR is a good way to begin in deep sky imagery. This is the equipment with which I began. It can be progressive : you start to buy the telescope for some hundreds euros and you acquire experience in astronomy observation. I think it is preferable to have a solid experience in general astronomic observation before starting astrophotography. Then you can try photos with the DSLR you already have, or buy a cheap one. All you need at this step is a T2 ring and a photographic adapter. After that and if you’re still addict to imagery, you will certainly change the equatorial mount for a better one because this is the most important gear in the imagery chain. Then you will modify your DSLR to remove the IR-cut filter, add an autoguiding system, change the cheap Newtonian by a high-end apochromatic refractor, change the DSLR by an expensive CCD-camera… Well if you still have money. Don’t forget that, like in other genre, equipment does not make all the job. It need fine tuning. Processing represents a good portion of the time to make an image. The sky is also very important. It will be way more difficult if you leave in a city and you’re not ready to drive hours to reach a place where the sky is dark enough.

What about post-production? What role does it play in your works?

Processing is very important in astrophotography. Almost as much as the acquisitions. But, like in other genres, you will never make a good image with bad acquisitions. Raw exposures are ugly. Very noisy. Details are buried in the noise. Colors are bad, especially with a modified DSLR. Basically, the technique is to make several, tens, exposures of the same object along the night. We apply calibration images on each exposure and we stack them. Stacking drastically decrease noise. We use specialized software for it such as Iris or PixInsight. Once we have the stacked image, we process it by adjusting colors, removing gradient, increasing the dynamic, reducing noise again, etc. The final processing can be made with traditional software like photoshop. I spend hours for the processing. I start it generally the day following the night I was outside making the acquisitions. Then I leave the picture a few days without touching it, to step back and see if my processing is good or not. Most of the times I made adjustments. Sometimes I remake the processing entirely. An image can contains a lot of information : faint objects in the background, details in the highlights. It’s hard to show all this things but it is the more interesting part of the processing job.

Are you inspired by other astro photographers and exchange with them or is it more a genre of lone warriors, each one looking through his own telescope alone?

Other astrophotographer are good source of inspiration. I like browsing their website to find new target and to see how they make. Sharing tips and tricks and critics through forums is very helping. It happens I met an astrophotographer in the field, sometimes fortuitously, but I’m often alone. If I’m not alone I’m with other amateur astronomer who don’t make photos, only visual observation. The loneliness feeling is dominant but sometimes I feel privileged to be crazy enough to spend entire nights alone in the dark.

Last question: What are your dreams and plans for the future?

I have already realized some dreams in astronomy, like using a powerful refractor telescope under some great sky in the Alps, where I live. A dream would be to put it on the platform of the VLT, the Very Large Telescope in Chile. In the next years, I would like to travel to Chile or Namibia to discover the southern sky. The Atacama desert is the best place on Earth for astronomy. I dream of making a great mosaic shot of the entire Orion constellation. I wish to get more opportunities to go out and make more astrophoto. I started to film some of my astrophoto adventures with timelapse sequences. Also I would like to get more inspiration for landscape photography