56

It would be wrong to think that increasing ISO results in no "physical" change in the camera at all. The problem with ISO is that people often call it sensitivity. That is really a misnomer...sensitivity is a fixed attribute of any given sensor, and it cannot be changed. Sensitivity is really more synonymous with the quantum efficiency of the photodiodes, ...


30

So I first shoot with ISO 1600 and shutter speed set to 1/125 second and then I shoot with ISO 3200 and shutter speed set to 1/250 second. The amount of light should be identical and indeed both shots look properly exposed and exposed the same way. The amount of light is not identical. You let twice as much light into the camera at 1/125 second than at 1/...


27

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

It's very important to realize that it is not the high ISO setting itself that results in noisy image, it's that fact that using a high ISO setting means you capture very little light. Light is made up of photons which are randomly emitted by a lightsource. When the light levels are low or the exposure time very short then the number of photons you get will ...


23

A few things you can do to improve your results. Use ISO 5000 or 6400. The way Canon DSLRs handle the ISO settings between the full-stop settings (100, 200, 400, 800, etc.) means ISO 5000 is cleaner than ISO 4000 and even ISO 2000 on most Canon cameras. The +1/3 stop settings (ISO 125, 250, 500, 1000, 2000, 4000, etc.) should be avoided if noise is a ...


15

The base ISO of all Canon cameras is ISO 100. This is the ISO with the lowest gain, without any in-camera magickry to achieve the setting (like ISO 50, which mucks with the actual exposure settings behind the scenes). There is a lot of conjecture and misunderstanding about Canon's ISO settings because they use a "real/push/pull" model for ISO settings, ...


11

The long exposure Noise Reduction takes a "dark frame" after the real shot, and then uses the noise pattern from that image to reduce the noise generated by the sensor. That's why the exposure takes twice as long as this NR were disabled. Long time exposure can increase the sensor temperature, and increased temperature also means more noise. So you should ...


10

Reduce it, yes. For example, the Canon 5D Mark III is 2/3 stops better than the Canon 5D in high ISO performance, although their sensors are the same size, because it is seven years newer. Of course, past performance is not necessarily indicative of future results, but I see no reason for incremental gains not to continue to be made. Eliminating it ...


10

For some sort of photography high ISO is very important. At some point the picture quality does not matter as much as having at least taken a photo, even if it is very noisy. News journalists or street photographers, who want to capture the moment do not have the time to light up the scene. Therefore they accept the noise to get the shot. High ISO is also ...


8

I'm not even going to try to supplant jrista's very informative and well written answer. He covers the bases of the physics in the camera's imaging pipeline very well. I would like to add an observation that may shed some light on the relationship between stars and noise. If all the stars in the universe were equally bright as viewed from the surface of the ...


8

I believe it may be a flaw in your testing. Raising ISO should not be getting you a higher signal to noise ratio (or usable dynamic range). You are raising the noise floor, without any corresponding increase in dynamic range at the bright end. Thus you should be left with overall lower dynamic range. It would not be possible to go the other way. Is it ...


7

It already happened! On film, or early digital, high ISO meant 400, on latest full frame cameras it means 6400. Problem is that each time it happens, 'High ISO' gets redefined to be even higher, or in another words, high ISO always means "so high that current tech makes it noisy". As noted by Tony, there are eventually, physical limitations as to how far it ...


7

ISOs lower than 100 on the A7 are not "real" in the sense that they don't lower the gain on the sensor, they just instruct the camera to increase exposure time as if the sensitivity was lower. The net result of this is reduced highlight headroom. If you shoot RAW there is nothing really to be gained from any ISO setting less than 100.


6

Noise is the difference between what the sensor measures and what it should have measured. If you take a photo with the lens cap on (or with some other means of completely blocking any light from entering the lens), you'd expect to get a frame where every pixel is entirely black. In reality, you'll get an image where the pixels vary slightly from one to the ...


6

Beyond the sensationalist title, I think what you are asking is simply - Are my results typical? To which I'd answer, yes your results are typical and expected. I don't often try to shoot in the woods, in November, right before sunset, handheld, but if I did - I would be well aware that I am pushing the capabilities of my equipment no matter if I have a f/...


6

Yes Here comes the definition of Circuitry, from whatdigitalcamera.com CCD and CMOS sensors differ in terms of their construction. CCDs collect the charge at each photosite, and transfer it from the sensor through a light-shielded vertical array of pixels before it is converted to a signal and amplified. CMOS sensors convert charge to voltage and ...


6

The moon is really a special case, because it is mostly grey. So you can remove chroma noise by just picking a channel (green, usually). This also removes some of the chromatic aberrations on the edges (when they are sharp, which isn't he case here). You can also average the three color channels: copy the image to obtain three layers, and using the channel ...


5

You could try using Registax. Generally, Registax is used for astrophotography, particularly of the planets in our solar system. Registax uses the concept of superresolution to stack hundreds or thousands of frames, discard the worst, keep the best, then interpolate the information from all of those frames in such a way that it enhances detail and resolution....


5

I know that you asked for a non-command-line solution, but I think that this one is simple enough to post. Moreover, I noticed the "no CLI" only after I wrote it, so... maybe could be useful for someone else. There is an example doing exactly that (although for a different objective --- long exposure without ND filters) that I think it is what you need in ...


5

Except for dark frame subtraction, which helps get rid of (non-random) pattern noise,no noise reduction is done at the pre-demosaiced level. There are simply too many variables that come between the raw sensel data and a rendered image. However, there are a couple of demosaicing algorithms (LMMSE and IGV) that are optimized to deal with noisy data, and many ...


5

darktable has a "raw denoise" module that does noise reduction before the demosaic step. In practice, it is rarely better than the other modules that work on the demosaiced image. Most noise reduction options in raw development software work between the demosaic step and the sharpening.


5

The best way to deal with noise in the situation you describe is to use a form of dark frame subtraction. If your camera doesn't offer such a built in feature, take a few frames during your session with the lens cap on (using the same ISO, and shutter time). Then use an application in post processing to subtract the dark frame from each segment from the ...


5

This is going to be a really quick example of how to do it. You'll have to be a bit more precise when you do it yourself. Add a Hue/Saturation Adjustment Layer by clicking on this icon beneath your Layers Palette: Now, you can either reduce the saturation of the master (all colors) or select colors individually. In your case, you'd have to do red and ...


5

For #1 and #2. Doubling exposure and stacking two exposures are going to be similar, but not exactly the same. Doubling exposure means you get twice as much signal, for a single unit of read noise. Taking two exposures means you get the same total signal as doubling exposure across both shots, but you end up with two units of read noise. Depending on how ...


5

You're the victim of typical indoor light and small sensor. It's darker indoors than what you think. The DC-FZ82 has a crop factor of 5.6. To put this into context, even entry-level DSLRs and mirrorless cameras have a crop factor of 1.5 - 1.6, and professionals use cameras with crop factor 1 (or even smaller than 1!). The amount of light collected is ...


4

Changing the ISO setting does invoke a change in the camera, it alters the on chip amplification. The voltages produced by incoming light are amplified prior to digitization. The reason for this is that the analogue signal picks up noise on its way to the ADC (analogue to digital converter). By amplifying a weak signal first, the effects of this noise are ...


4

Adding some info to Akram's answer. You could use try some of the filters from G'mic (a "plugin pack" for the Gimp which has a lot more filters than just noise removal ones). Here's its website and download page. For a tutorial: Noise reduction with G'Mic . An excerpt: Anisotropic Smoothing is the best solution for pure noise reduction, it can be found ...


4

You are correct that there is no free lunch. Software NR works by looking for sharp edges and trying to identify what is detail and what is noise, but at a very fine level, they can't be distinguished. What you will normally see with light NR is a reduction in fine detail, but gross detail is maintained. The more you turn up NR, the more gross the detail ...


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