Hot answers tagged

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 ...


34

It looks like there are parallel light trails below each streelamp -- going down, then right, then down some more (ASCII art): / | | | \_ \ | And highlighted on the original: I would guess that these are when the shutter button was pressed, tilting the camera, because only bright sources show this effect. This is in addition to the normal, more ...


31

The light you describe as "green" also contains components of "red" and "blue" light. They are much weaker than the green component, but they are there. Once the exposure is bright enough for the green channel to be fully saturated, increasing the exposure further can not increase the value recorded in the green channel to more than 100%. If green is fully ...


27

You could've probably got a decent result just by picking an intermediate exposure. Alternatively, you can try to take a short and a long exposure of the same scene, and combine them digitally afterwards. Here's what I got just by taking your two images above (mouse cursor and all), aligning them (manually, using the Scale tool in GIMP) and blending them ...


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 ...


16

I see two main problems: Too slow shutter speed. Overexposure. The first goes directly to the issue you ask about. You are stuck with whatever lighting there is, so you can only trade off ISO, shutter speed, and f-stop (short of using a different camera with a more sensitive sensor). You did a good job of following the motion. That's why the car looks ...


12

I already have a Nikon D5200 and I I tried so much to get a clear view of the sky and it didn't work so much. The camera you have is a fine one to start with. You should spend some time working on technique before you worry about switching to a different camera. Astrophotography is all about capturing tiny amounts of light compared to daytime photography, ...


11

There's already something that has been invented to collect light for photographs. We call them lenses. In order to collect more light, the front element of the lens must be larger for the same focal length, or have a wider angle of view for the same entrance pupil diameter.


10

Your question boils down to auto vs manual focus. From the methodology you've described, it seems that you are attempting to use autofocus to get a picture of the night sky. That's not a great plan because the objects your camera can focus on in the night sky are pretty small points of light, and autofocus usually only works well under brightly lit ...


9

Clearly there is some artificial light affecting the shot. Look at the top of the distant house too, and you'll see that it, also, has a red tint on the roof. And more importantly, there is a distinct shadow line on both the roof (from the roof next door) and on the trees (from the distant roof) that shows that the external source of light is coming in at ...


9

The dynamic range of cameras is limited and is unable to capture large brightness differences within one shot. For static subjects use Exposure Blending or HDR preferably on a tripod or similar stable base. For exposure blending you take multiple shots of the same composition but with different exposures. Those images then get merged together by using an ...


9

How annoying :-) - I finished marking up a photo and now see that Chris H has done much the same but better. So I'll post this 'for completeness' but with less comment than I otherwise would have. I saw a movement pattern similar to Chris's. This may have occurred in one motion, but the variable brightnesses along each path suggest it may have been a ...


9

The first thing you must realize is that what you are seeing on your monitor is not "the" raw file. What you are seeing is an 8-bit demosaiced preview conversion of the raw file created by Photoshop (or whatever other raw conversion application you are using) based on the current settings. It's just one of many possible interpretations of the full ...


8

Are those other planets or other stars? Or is that a lens effect? Looks to me like a planet and some moons. I don't know where you are, but Jupiter has been very bright in the night sky lately in my neighborhood, and with a long enough lens it's not hard to see some of its moons. Seen through a sufficiently powerful telescope, a planet looks very different ...


8

You're not going to get "color accurate" white balance at night. There's no way to make every object in the scene look the same color it would be if viewed under full spectrum daylight. This is because night scenes typically have a myriad of varying light sources in them. Those various sources are all different temperatures and have different amounts of the ...


8

Digital sensors heat up over long exposures; I've had exposures as short as 6 minutes exhibiting very visible colour distortion in the corners of the frame. Run the chip continually for hours without specialist cooling and the result would likely be an unusable mess.


7

See How does the colour of ambient lighting affect colour rendition?, because that question uses a sodium vapor light as an example. As the answers there explain, sodium vapor lights produce a very, very narrow spectrum of light: CC-BY-SA image from Wikimedia Commons, author Philips Lighting And in fact, this is effectively monochrome. Your only options ...


7

shined a light to focus on foreground beforehand If you focused on the foreground then the most likely explanation is that the stars are blurry because they are out of focus, at f/4 the depth of field is not sufficient to contain both the foreground and the stars (which are effectively at "infinity" or as far away as you can get). I would recommend you try ...


7

SImple answer: not to a measurable extent. Difficult answer: A high ISO-equivalent setting cranks the analog gain up. More gain requires more power per electron (or milliVolt if you prefer), but there's going to be far fewer electrons in each pixel bucket. A low ISO-equiv. setting will apply less gain to more electrons. That said, if you're in ...


7

Although the poster hasn't specified it, this answer assumes this picture was shot on a tripod (it looks too sharp to be hand-held, even holding the camera steady against the window). Many claimed that this is caused by a movement of the camera. However, I believe that it is actually due to the optical stabilization (IS in Canon parlance) trying to ...


7

Why is it that when the green channel clips, it turns into blue? Actually, it turns towards magenta. Look more closely at your picture. When green clips and the other two channels (red, blue) don't, the result is basically lowering green. Lowering green has the same effect on hue as raising red and blue. Red+blue is magenta, so lowering green by itself ...


7

As you edited your question it gives me more room. The same as a parabolic mic, any mirror lens do the exact same thing. It takes parallel rays coming from a distance, and focus them on a smaller spot... the focus point. https://en.wikipedia.org/wiki/Catadioptric_system#Photographic_catadioptric_lenses https://www.google.com/search?q=mirror+lens Ever heard ...


7

Would it be better for me to jump ship to Nikon and start from there or should I continue with Canon and use the few lenses I already own? You're putting the cart a bit before the horse. It would be better for you to stay with your current camera and lenses while you start learning photography in ernest. There's nothing about the EOS Rebel T3 and the ...


6

You need a tripod, set your camera for long exposure, as low an ISO you can set. You need to experiment on the exposure time to get the proper result. Set focus to infinite. Set a 2 second timer and mirror lockup to prevent "shake". Shoot RAW and post process. I suggest finding sites during the day and come back a night when there are less people in the ...


6

They were probably shot close up with a bare on camera flash. The inverse square law is a wonderful thing - get your flash twice as close and it effectively becomes four times as bright. Four times closer and it's sixteen times as bright. Getting a black background is just a case of getting close enough so that the flash is so much brighter than the ambient ...


6

At full resolution, the line gets terrible. Perhaps I've missed something, but it sounds like you want to make the line between the light and dark parts of the wall as sharp as possible, more like the lights on the right hand side of this image than the ones on the left: In that case, as long as your camera is properly focussed in the first place, the real ...


6

All you can do is experiment, really. Nighttime photography has its own peculiar set of problems, especially where film is concerned, and you really can't rely on anything that looks like an easy recipe. Reciprocity failure is a thing, and it's variable with conditions (temperature, mostly) and film age as well as with extended exposure time. I don't know ...


6

You can either use a flash to expose the subject (you won't be able to see them walking into or out of the frame), or you can, as you suggest, take two shots and blend them in Photoshop - a matter of a few minutes work. Making an exposure blended shot would require the subject to stand preternaturally still between shots for a decent effect.


6

You don't need to use the widest aperture. In fact, in many cases, using the widest aperture for astrophotography can result in very poor quality stars. If you are doing wide field untracked imaging (i.e. milky way imaging), then you can usually get away with using maximum aperture, and the larger aperture allows you to use shorter exposures, which reduces ...


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