46

This is a featured called Long Exposure Noise Reduction. To cancel out noise the camera will close the shutter and take an equally long exposure again, this time capturing a black image with only the electrical noise on it. This information is then used to reduce the noise on the original exposure. In the camera settings you can disable the Noise Reduction ...


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 ...


33

Considering the relatively long exposure time, I would say this is an airliner flying over. You can see how the lights flash on alternate wings. The central line is likely some other, steady light on the undercarriage.


29

You've got the sun almost in the frame. This is causing huge amounts of veiling flare — light bouncing all around, reducing contrast. You'll get better results from a different angle, or at a different time of day. Did you have a lens hood? If so, positioning the camera so the hood can better do its job would help. And, yeah, it probably isn't doing you any ...


26

Noise is a fact of life when it comes to astrophotography, with the exception being stacked deep sky photos taken on a tracking mount (more in a moment). Your photo is actually very low noise, in the grand scheme of wide field, single-frame astrophotography shots that I have seen...but it also lacks saturation. I think it really comes down to a matter of ...


26

Use the ambient light to illuminate the waterfall. Use a fairly powerful flash to illuminate your human subject. The quick duration of the flash will freeze her, especially if she remains fairly still over the long exposure. The narrow aperture you will need to properly expose with the flash will also give better depth of field so that the water fall is also ...


25

What you are looking for is a ND (Neutral Density) filter. To illustrate, here is an example of a photo taken in daylight in a street with a ND1000 filter. The filter allowed a shutter speed of 6 seconds. With no filter, with the same aperture and ISO, the shutter speed would have been approximately 6/1000 = 0.006 seconds (no "ghosts" effect). Contrary to ...


23

From a functional standpoint, yes, you could essentially achieve the same effect with multiple stacked filters as a single high-density filter (say a 10-stopper.) There are a variety of concerns to be aware of, however, regarding stacking multiple filters. Filter quality: The Lee "Big Stopper" 10-stop ND filter is pretty high quality glass filter There are ...


22

Camera sensors (see this article for an overview) consist of a very large number of individual sensor elements, each of which can be regarded as a bucket that collects photons. These buckets have a maximum number of photons they can capture before they become full, which is called being saturated (this is when the highlights clip). This maximum capacity is ...


20

You can merge multiple short exposure photos into a single long exposure image. There are a lot of tutorials on the net, for example: https://www.youtube.com/watch?v=nAuQWfS3pLg Basically, he opens the sequence of photos in photoshop as layers in a single picture, then "auto-align layers", "convert to smart object" and "stack mode" - "mean". Image ...


20

To reduce the processing time for long exposures, you want to turn off Long Exposure Noise Reduction. However, you may not want to give up the benefit of LENR. Long Exposure Noise Reduction (LENR) is Canon's nomenclature for in-camera dark frame subtraction. When you take a photo the camera will expose the image normally and then use the same settings to ...


19

Look up Long Exposure Noise Reduction in your camera's manual. Depending on the model, you may or may not be able to continue taking photos. Some models do the processing immediately after the exposure. Some allow you to continue to take exposures, and then do the processing. This feature uses dark frame subtraction. The idea being that if you expose a ...


18

that purple haze is probably a color cast caused by the glass itself; the welders glass often isn't neutral color. you should be looking at solar filters, or very dark (and probably stacked) ND filters. Thousand Oaks sells solar filters, to name one company.


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 ...


17

Absolutely you can. Many square filter holders are specifically designed for this: The Lee Filters systems (Sev5n, 100mm) have optional front threaded rings designed to hold a polarizer in front of the ND filter(s). The NiSi 70mm and 100mm square filter holders feature a specially-made thin polarizer filter meant to stack behind the ND filters, closest to ...


16

You wanted to use the effect of long exposures. What effects of long exposure are visible in your image? Lights are blown out. For the street lamp on the right, it seems to be ok. But the neon sign is rather ugly. The name of the restaurant is hard to read. So the long exposure doesn't work on lights close to you. The fountain becomes a closed curtain, ...


15

If anything, the longer the exposure, the less detail you will get, because it gives things more time to move. Even when you're looking at a "still" landscape scene, the tree branches may be moving a bit, water will be rippling, clouds will be slowly scudding across the sky... A few of my all-time favorite photos are technically marred because of this. They'...


15

As a general rule, exposure time depends directly on the amount of available light. So if you measure the time needed for some exposure at early dawn, it would probably be bigger than the time needed after the sun rises. Assuming you want to capture the atmosphere and colors of a sunrise or sunset, the amount of light would probably be too much for a really ...


15

(There are people here who know a lot more about this than I do, but since there is no reply yet I'll give it a shot.) There are two questions here: How did Michael Wesely do it? And could we do the same with a digital camera? Digital camera I'll start with the calculations for a digital camera, it's the simplest: From an exposure table we can pick a ...


15

The Olympus OM-D EM-5 can display the cumulative collection of light in a long exposure. But there is another way to test long exposure that takes much less time and works with almost any digital camera. Start out by setting your camera to the highest ISO setting it has, open the aperture of your lens as wide as it will go and start with short exposures ...


14

Well, perhaps you should have gone out after all :) The noise is thermal noise, which will become noticeable as your sensor heats up during a long exposure. In astrophotography, it's quite a common problem. Some ways to reduce such noise: cool sensor down, e.g. by shooting in the cold weather. Note that cold also negatively affects battery life. set the ...


14

Yes it is possible with all DSLRs. The 30s limit of all non-Olympus DSLRs is for timed exposures, meaning you dial in the time ahead of time and the exposure takes up to 30s (or 60s for Olympus). All DSLRs also have a bulb mode which you press the shutter to start the exposure and let go when you are done. This can also be done with a remote control which ...


14

Light Trails This style of photography is often referred to as light trails. Photoshop is not necessarily needed. Effects like this can be achieved on a single photograph without multiple exposures. 1. You need darkness for this style. Even though the photo may end up looking light, absolute darkness is needed do this sort of photography. Usually this ...


14

Obviously, there was still way too much light getting onto your sensor despite the tiny aperture. Methods to avoid that: First, make sure your ISO setting is as low as possible. Use Tv (shutter priority) mode instead of manual, then choose the shutter speed you want and let the camera adjust everything else to get normal exposure. If that is not possible (...


14

Apart from using an ND filter, you might be able to achieve the desired effect by taking multiple photos and then blending them in post processing. Either an automatic blend with "ghost removal" might work, or layering the images and manually masking/unmasking selectively (in effect "painting out" the people). All of this pretty much requires a tripod for ...


14

If the camera is on a tripod, and we assume little or no camera movement, then there are two possibilities. Most likely, at 3", your brother is not going to stay perfectly still and there will be some subject movement. You could fix that in part by using flash during the exposure to freeze the foreground subject. And also, it's presumably fairly dark, ...


14

Is it usually safe to leave the camera strap on the camera body itself for long exposure shots? It's fine. If you're concerned about wind catching the strap and causing blur (or even flying up into the shot) you can roll it up and secure it with a rubber band or zip tie. But if there's enough wind to move the strap, there's probably enough wind to shake the ...


14

I just try to see if there's any stable surface available nearby and try to use it That's the basic idea. Be careful to watch for slight slippage. Also note that vibrations can also affects the stability, including when you trigger the shot - make sure you use a timer so that the vibrations of your touching the camera can subside. I'd use the 10 seconds ...


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