How To Do Astronomical Photography

For us simple mortals, taking pictures of Saturn’s rings is something we’re a bit far away from. When we hear astro photography we imagine those amazing images of nebulae of thousands of colors, we imagine solar explosions or craters on the dark side of the moon. And yes, those images would fall into this category, but to get them we need to have pockets full of money and be willing to spend it to get them, or be lucky enough to be sent to the International Space Station.

How To Do Astronomical Photography

Then you’ll say that what’s the point of reading, what’s the interest in something photographic that I’ve already denied you. Well, you won’t be able to photograph Neptune nebulae or rings (without previous extra investment) but if I tell you that you can get incredible images of the sky without having to invest too much, you get more excited, right? Let’s see how? Let’s see what?

Basic Material

Camera with manual controls, interchangeable lenses (Reflex/Evil) and mode

  • Bulb
  • Tripod
  • Telephoto lens
  • Remote Trigger
  • Basic Concepts

Before you start, you’ll need to be clear about the following concepts:

Diaphragm Opening

It regulates the entry of light into the target and the depth of field. Since we will generally have little light, it is more likely that we must work with large openings to capture it (low values of f).

Speed

The time when the camera shutter is open. The longer it stays open, the more light it will have.

Long Exposure Photography

Do you know those images of night cities full of lines created by cars passing at full speed with the lights on? Well, that’s done with long exposure photographs, which are those taken at very low speeds so that the shutter is open long enough to capture the evolution of motion.

ISO: Another aspect to consider is the sensor’s sensitivity to light, which is determined by ISO. The higher the ISO, the more sensitivity (ideal for low-light situations) but at the same time loss of sharpness. On the other hand, the lower the sensitivity, the higher the image quality.

Bulb: It is one of the modes of your camera, usually marked with the letter B, and allows you to keep the shutter open for an indefinite time, beyond the maximum allowed by your camera. With this system, the obturator is opened and closed manually by tightening the obturator.

Where Do I Start?

Although it seems to you that with what you have you can not do great tricks, the truth is that with patience, imagination and perseverance you can get fantastic images, even without a telephoto lens, although if you are encouraged by the subject, without one you will be a little left with the desire.

Star

While it may seem that photographing stars at such a distance is not worthwhile, you can get fantastic images thanks, for example, to the rotational motion of the earth.

Since the stars in the night sky are generally not very bright for our camera, to photograph them we work with long exposures (our shutter remains open certain seconds to be able to capture enough light).

Star Photography

There are two ways to photograph stars for the simple mortal: with the static camera on a tripod and with the camera placed in some artifact that imitates the movement of the earth so that it is annulled leaving the stars visually static (on top of a telescope that imitates the rotational movement of the earth, or some other system). You will most likely simply use a tripod, at least to begin with.

If you want to portray the movement, ideally you should do everything possible to work at very slow speeds. That is, lower the ISO to maximum or close the diaphragm (high f-values).

If, on the other hand, you want to portray the stars in a static way, and you don’t have external help (telescope, rail…) you must do everything possible to reduce the shutter time as much as possible (fast speeds). You can do this by opening the diaphragm or by increasing the ISO to values such as 2000 or 4000 as long as you maintain good image quality (that depends on each camera).

In General

These are the recommendations for photographing stars:

Well-charged batteries (keep the shutter open for a while, check, repeat, etc., wastes a lot of battery)

Tripod (essential)
Remote trigger to avoid vibrations
Manual focus (infinity)
Manual mode to control aperture, exposure time, and ISO
Perform various tests. You can make the first overexposed to contemplate the landscape and choose the best frame. Then rectify the exposure
Checks histogram to rectify if times or opening is necessary
Magnify the image 100% on the screen and check that you have focused and exposed correctly.
Repeat, check, repeat and infinite patience

Sun

If darkness is not your thing, the star king can be a great photographic opportunity too, since alone or accompanying some beautiful landscape, can be a great protagonist of the image. The ideal, if you want to get the sun moderately close, is to have a telephoto lens of approximately 200mm. Or, evidently, a telescope. If you don’t have either, don’t worry, you can get wonderful images by playing with the sun and the environment, especially when it approaches the horizon line where it looks bigger.

Sun Photo

Always Use A Tripod

Reduce vibrations with a remote trigger or with your camera’s self-timer
Keep the mirror of your camera open if you work with a SLR that has this option, this way you will avoid the movement it generates when it opens and closes.
Keep the ISO as low as possible to achieve the best possible sharpness

Focus On Manual

the cameras are easily lost when focusing on infinity, since you have a certain amount of time, do it yourself to ensure the focus. Close the diaphragm approximately halfway to have a greater depth of field and good sharpness (e.g. f/11 if the maximum is f/22).

Take your time to compose the scene.

Predicts where the sun will rise or set, you can use applications such as Photopills
Do different exposure tests (the best way to measure in this case is to under-expose a point to the edition obtained in point).
Activate your camera’s Histogram to check and/or correct the image in situ.

Moon

Another great astronomical classic. In this case you will face darkness, in fact, the darker the better, the more contrast and the more the moon will highlight.

With the moon we have more limitations when trying to integrate it into the environment because, when it is best seen, it is when it is darkest. Therefore, in this case, if we want to portray the moon as a motif in itself is essential a telephoto lens.
If the sky is clear and the moon is full, it may emit enough light to capture surrounding elements. These images are very artistic, dreamlike and suggestive.

Moon

Tripod. Even more essential than when we photograph the sun due to lack of light. A tripod will allow you to have a sharp image at low speeds and with the ISO at a minimum.

  • Remote shutter (or in its defect automatic shutter of the camera)
  • If your camera has this option it blocks the mirror to avoid trepidations.
  • ISO for maximum image sharpness.

Consider the lunar phases. If you want to photograph the lunar orography, the best thing is to do it in the lunar quarters because the light falls laterally increasing the contrast and textures of the surface of the moon.

Focus On Manual

To achieve a good depth of field and the highest possible sharpness, work with medium diaphragm apertures.

One More Step, The Telescope

For anyone who loves stars, the next logical step is to get a telescope and attach the camera to it in one way or another. There are several techniques that can be complicated to infinity.

Parallel Photography

It is based on attaching the camera above the telescope using the camera’s own optics. If it has a motorized equatorial mount, the camera will correctly follow the apparent movement of the stars and neutralize it.

Photograph to primary focus: In this case, through an adapter, we attach the body of our optics to the telescope, taking advantage of its higher resolution.

Projection Photography: Similar to the previous one but adds a separator that emphasizes the magnification, thus being able to bring us closer to celestial objects.

Logistical Considerations

Look for a place away from the light pollution of cities, that is safe and where you can settle down without disturbing or being disturbed and of course it is safe, as you will probably go home well into the night.
It’s daytime to settle in comfortably before the lights go out.
Look for a way that’s easy to get back, don’t get lost or fall you or your precious camera.

  • Take a flashlight and enough batteries.
  • Mobile and batteries fully charged
  • Don’t go alone and if you go, let someone know where you’re going to be. It’s better to prevent

Patience And More Patience

Obtaining images of the night sky with all its elements can be as rewarding as it is frustrating, because there are many aspects to take into account and it is not easy to expose or compose in these lighting conditions. Nevertheless, you will see that the sorrows disappear when you get a good image. In life nobody gives you anything, and in photography even less! So you know, to practice, to correct, to progress and to be better every day.

What? You feel like trying? I’m sure that if you haven’t worried too much about this type of photography until now, it’s because you haven’t thought about the amazing results you can get at.¬†Ah, if you thought it was interesting, please share it so that someone else can benefit from the information. Thank you and see you next time.

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