46

The vast majority of night sky photos have been boosted in post to achieve their brightness. This is more true for cameras with smaller sensors than for cameras with larger sensors, but in general, even if you shoot the night sky at ISO 3200, you are going to need to boost exposure to get one of those nice, bright single-frame Milky Way shots. There are a ...


45

Whenever light passes a boundary, it diffracts, or bends, due to the wavelike property of light interacting with that boundary. An aperture in an optical system, typically circular or circle-like, is one such boundary. How light interacts with the aperture is described by the point spread function (PSF), or how much and to what degree a point source of ...


43

@Michael Clark and @Itai have provided good answers. A few more thoughts from the perspective of the enthusiastic amateur: Tracking technology isn't perfect and sometimes its better to work within the practical limitations of the tracking available rather than push it too far Very long exposures may not play well with high levels of light pollution. There's ...


41

Stars don't show up voluntarily on a photo. You need to tweak them a bit using photo editing tools on a computer. Best if you use RAW file format, and RAW-processing software to do this. JPEGs can be tweaked to show more stars, but with a lot less working room and result being of lesser quality. The likely JPEG image you get with the exposure settings you ...


34

What makes the difference on partially and fully visible moon? In a word: shadows. I cannot understand why the IQ is extremely diminished when doing the same with an almost fully visible moon. The second image does appear to suffer from lower sharpness and overall quality. However, even if the technical image quality factors were equal, most importantly,...


34

1) To capture more stars, go somewhere where there is less light pollution. If you can't see the north star, you aren't going to get much. I can't see the north star from my front yard, so attempting to shoot stars is hopeless. 2) If a longer shutter speed resulted in plain white, then the light pollution overwhelmed the image.


33

Because the distance from Earth to each of the other planets varies due to orbital mechanics, the size of each planet as seen from Earth can vary significantly. Which planet is the largest and the order of relative sizes changes frequently. For example, right now as of April 1, 2018 the following are the angular sizes of the planets as viewed from Earth: ...


32

To achieve what you're thinking of you would have to know what the noise was. If you knew what the noise was then you could just remove that to get clean images.


26

Your exposures are very different. Ignore the quantity of images that you captured for a moment... and just compare the the single exposure settings (for reasons I'll describe in a moment). Top: 13 seconds at f/5 using ISO 1000 Bottom: 60 seconds at f/5.6 using ISO 6400 These are very different exposures. If you wanted the top photo to have an "...


24

Normally Jupiter is easily the largest seen from Earth, but depending on orbits, it could sometimes be Venus (next time in September, and then next in 2020). This site will answer about details relative to exact date: https://www.timeanddate.com/astronomy/planets/distance


24

They are not uniform but they all show the same bright-dim-bright pattern. One explanation is that this is a composite picture of several exposures and that the middle exposure(s) was/were dimmed a bit to compensate for a brighter subject (booster separation).


22

With regard to reasonably bright stellar objects: technically, yes. With regard to dimmer objects like those that make up most of what we mean when we say "The Milky Way": practically speaking, no. In addition to the phase of the Moon, which determines the overall amount of light falling on the atmosphere above a specific location on the Earth's surface, ...


19

Johann3s' answer is good, and covers all the basics. When it comes to the milky way, which is a form of ultra wide field night sky astrophotography, you want to use the highest ISO you can get away with, the longest exposure you can get away with, at the fastest aperture your lens supports. Here is a little bit more detail. The Technicalities Which ISO to ...


19

Image stacking works to reduce noise because the noise is random — or at least, ideally so — while the stars are (famously) constant. That means that (once you've corrected for rotation) the stars will be in every photo. But noise — at least, the kinds of noise that this can correct for — is already random fluctuations... maybe there in one image, and not ...


19

In principle, there's no difference between a camera lens and a refractor telescope. While focal distance is related with the magnification of the image, in astronomy, resolution is related to aperture (not the F-ratio, but the area where light enters). So, if you increase your focal distance, without increasing your aperture, then you are not increasing ...


18

When it comes to night sky photography and stacking, there is no real substitute for actual SNR (Signal to Noise Ratio). You can virtually improve SNR by stacking hundreds of very short exposures (like stacking 720 10-second exposures), but the result will never quite be the same as if you stack say forty 3-minute exposures. Stacking a bunch of 30 second ...


18

It is firstly because we can now. Bulb photography can indeed shoot exposures of minutes to several hours, depending on the camera. Using a film camera, astrophotography is done with very long exposures and those cameras have no time limit since they do not need power to operate. A digital camera can be used in the same way but most mirrorless limit bulb ...


18

The main advantage of stacking is to average out the randomized Poisson distribution "shot noise" that can be a problem in low light images such as astrophotography. Another advantage for stacking comes in using dedicated monochrome imaging sensors while alternating color (or specialized astronomy related) filters over the entire sensor for each exposure and ...


18

You need more than an ND filter and a polarizer. You need a solar filter specifically designed for imaging the sun. The danger to your eyes and camera are very real if you are pointing the unprotected or underprotected camera at the sun. Most ND filters and polarizers only block visible light. The sun emits very high levels of UV and infrared radiation as ...


18

I can tell 3 common reasons for weird/fake colors in astrophotography: Chromatic aberration makes some starts appear white in the center, but their borders blue or red, depending what of those two are out of focus. Demosaicing algorithms tends to fail for bright white objects against a dark background, and you see red or blue in one border of some stars. ...


17

Shoot when there is no moon in the sky. e.g. Near the "New Moon" or "Last Quarter Moon" if shooting after sunset. Get away from urban light pollution. I've generated a simulated field of view (using Sky Safari Pro) for your Nikon & 50mm lens (the blue box is the field of view) and approximated your section of the sky: You can see a few faint objects ...


16

I have tested RPi HQ Cam for astrophotography over last month and it works quite well. First, sample images: Canon FD 200/2.8 lens, 42 minutes exposure time (not a high quality glass, and not long enough exposure time to get rid of all noise) WO SpaceCat 250/f4.9 scope, 290 minutes exposure time Few more images here: https://terramex.neocities.org/astro/...


15

Everyone talks about shortest focal length and lower aperture when shooting Milky Way, and this guy does it with f5 How is that possible? It is possible to shoot at f/5 because he is also shooting at ISO12800. A single image at that ISO would be extremely noisy, but stacking 100 images at that ISO allows the random noise from each image to be averaged out. ...


14

For focusing on stars, I suggest using a Bahtinov mask, which uses purposely-created diffraction spikes to determine correct focus. Bahtinov mask by Justin Dolske, from Flickr. CC BY-SA-2.0 This image montage is an example of a Bahtinov mask on a telescope focusing on the star Betelguese. The center image is correctly focused; the other two images are ...


14

@vsis already said this, but I'm going to be more explicit: It's all about the brightness. Most astronomical objects worth looking at are dim. The more light your optical system "gathers," the more objects will be available for you to see and photograph. When amateur astronomers get together to talk about whose is bigger, the most important ...


13

Photographing Milky way while a full moon is up? No. Can't be done. Photographing other stellar objects then? Yes, with reservations. The problem is the amount of particles in atmosphere. Air pollution, dust and water/humidity. Particles in air reflect the light from moon practically blanketing the whole sky with thin haze. Quite similar to what light ...


13

Some possible reasons, arranged in the likely order of influence, for the lack of clarity in the example photo: 1) The optical limits of your lens. The EF 100-300mm f/4.5-5.6 was released as a budget telephoto zoom lens in 1990 at the dawn of the EOS era. Compared to the current EF-S 55-250mm f/4-5.6 STM, at the longest focal lengths and widest apertures ...


13

Experimentally (on my EOS 70D), this is the beginning of the exposure, and not the end. But: this seems truncated to the second it depends how accurate is the time of the camera (before doing this I carefully set the time on my camera, but I doubt I can do better than half a second) ... not speaking of clock drift if it hasn't been set recently IMHO a ...


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