Noise reduction Software

[felix5616]

what currently is the best nisoe reduction software? are programs like Nik Collection or Topaz worth the money, especially topaz that is a monthly fee

[Wolfman]

If you don't want to pay for a subscription, DXO Photo Lab or DXO Pure Raw are your best bets.

[Jeremy Roussak]

I use LR and Topaz. I find Topaz can be marginally better for very noisy images at very high ISO (40,000 plus) from my A7Riv, but both are pretty impressive.

Jeremy

[digitaldog]

Worth repeating: ISO doesn't cause more noise. ISO does not affect exposure. ISO affects an exposure recommendation. The relative amount of noise changes with exposure. Underexposure leads to more noise. Altering ISO and, thus, the exposure recommendation can come in handy in low-light situations where you may need to increase the ISO setting and this exposure recommendation to avoid camera shake or stop motion with a higher shutter speed. Or if you wish to alter DOF, that wouldn’t be recommended* at a lower ISO setting. This results in less exposure and results in more noise.

*https://www.fastrawviewer.com/blog/mystic-exposure-triangle

Back OT, I use Lightroom Classic / Adobe Camera Raw, but as outlined, that requires a subscription.

[Jeremy Roussak]

To put it another way, a high ISO means that more gain has been applied at the analog-to-digital stage within the sensor electronics. If greater gain is applied (generally because, for whatever reason, not much light has struck the sensor during the exposure), the signal-to-noise ratio will be lower and hence more noise will be visible.

Jeremy

[digitaldog]

To put it another way, a high ISO means that more gain has been applied at the analog-to-digital stage within the sensor electronics. If greater gain is applied (generally because, for whatever reason, not much light has struck the sensor during the exposure), the signal-to-noise ratio will be lower and hence more noise will be visible.

Jeremy

Higher ISO can produce lower noise. It's all about exposure, not ISO. Your higher ISO images are noisy, not because of higher ISO but due to insufficient exposure. Yes: not much light has struck the sensor during the exposure.
Anyone can test this themselves quite easily.

Set up your camera on a tripod, outside on a sunny day. We will not even use your camera meter, just use the good old “Sunny 16 rule.”
Set ISO to 125 and camera to full manual. Set exposure (the only two exposure attributes) to 125th of a second at F16.
1. Take a capture using the above exposure and ISO.
2. Set ISO to 800; change nothing else. The exposure is still 125th at F16.
3. Set the ISO back to 100. Change the shutter to a 500th of a second, nothing else! This is what the meter would have recommended from capture #2. This 3rd image will, of course, be 2 stops underexposed. And it will need to be brightened in the raw converter.

#1 and #2 have identical exposure; the only change is ISO. Both have identical noise!
#1 and #3 have identical ISO, but #3 will be far more noisy because it is underexposed. As #2 would be if the photographer followed the automatic exposure recommendation.
And now we see that an increase in noise has little if anything to do with ISO and everything to do with exposure.
Yeah, sometimes the tradeoff of the capture you need is less exposure and more noise.
Well summed up by the creator of RawDigger here: https://www.fastrawviewer.com/blog/mystic-exposure-triangle.

http://digitaldog.net/files/ISOExposureNoiseReality1.png

[Jeremy Roussak]

#1 and #2 have identical exposure; the only change is ISO. Both have identical noise!

That is no more than assertion, which I don't accept is correct. The image captured at higher ISO will be noisier because more random noise will have been amplified at the analog to digital stage of the sensor. The histogram will be shifted 3 stops to the right, which is likely to have blown the highlights (not because the sensel was saturated, but because the amplification will have resulted in a number greater than can be held in the raw data). It may be that moving the exposure slider to the left by three stops in LR or equivalent will bring #2 back to #1's cleanliness, but only if the highlights are not blown.

#1 and #3 have identical ISO, but #3 will be far more noisy because it is underexposed.

No, #3 will just be dark, having been two stops underexposed. Moving the exposure slider a couple of stops to the right will correct it, if the shadows are not blocked (due to the light falling on the sensel having been too low to be detected), but only at the expense of amplifying the otherwise invisible noise.

And now we see that an increase in noise has little if anything to do with ISO and everything to do with exposure.

No, we see that increasing "ISO" increases the sensitivity of the sensor to whatever light falls on it; and that the output from a more sensitive sensor is affected by random electronic noise to a greater extent than one which is less sensitive.

Jeremy

[digitaldog]

ISO does not affect exposure. ISO affects an exposure recommendation. You (can) control exposure if you wish. Insufficient exposure is the primary source of (excessive) noise, and photographers can control that noise to a point. Increase the exposure, and the shot noise goes down. Decrease the exposure, and the shot noise goes up.

No, we see that increasing "ISO" increases the sensitivity of the sensor to whatever light falls on it; and that the output from a more sensitive sensor is affected by random electronic noise to a greater extent than one which is less sensitive.

No. Setting the ISO speed does not change the sensor's sensitivity to incoming light, as volume control does not change a radio's sensitivity. In both cases, the setting (ISO or volume) controls only the signal processing, while the input stage (sensor, antenna) provides the same input signal and, in this case, exposure to the sensor. That's why when the ISO setting is cranked up, automatic exposure leads to more noise - automatic exposure, in this case, decreases the exposure (that is, the combination of aperture and shutter speed is set to allow less light captured by the sensor). Less exposure, less light, more noise; the relative amount of noise changes with exposure. Underexposure leads to more noise. Optimal exposure, for raw (which differs from a JPEG), a color neg, a transparency is all basic photography 101.

Remember who just wrote this, which has nothing to do with ISO and everything to do with exposure:
”not much light has struck the sensor during the exposure, the signal-to-noise ratio will be lower and hence more noise will be visible.”
Indeed!

Articles on exposing for specifically and only raw:
http://www.onezone.photos

http://schewephoto.com/ETTR/

https://luminous-landscape.com/the-optimum-digital-exposure/

http://digitaldog.net/files/ExposeForRaw.pdf

https://www.fastrawviewer.com/blog/mystic-exposure-triangle

https://www.fastrawviewer.com/blog/red_flowers_photography_to-see-the-real-picture

https://www.rawdigger.com/howtouse/exposure-for-raw-or-for-jpegs

https://www.rawdigger.com/howtouse/beware-histogram

https://www.rawdigger.com/howtouse/calibrate-exposure-meter-to-improve-dynamic-range

And another good read on this:
High ISO doesn't cause noise - http://digitaldog.net/files/ISO.png

[digitaldog]

Once More into the Negatives of the “Exposure Triangle” Dear Friends, Abridged Version:

The triangle model states that noise rises as a result of ISO being increased.
This is tosh, it’s worse than saying that “well, the wind is blowing because the trees are swaying” (in that case, all that’s happened is a mix-up of cause and effect), it’s like saying that the sea is salty because of all of the lox swimming in it (which goes beyond just confusing cause and effect, because here the “cause” is an absolute invention – a salmon swimming in the sea isn’t salty, while lox, a product of brining salmon fillets, doesn’t swim in the sea. It doesn’t swim at all).
The model warns against raising ISO “because of increases in noise”.
Another lie – everything is exactly the opposite; when the exposure is fixed, not only will raising ISO not worsen the signal-to-noise ratio, it may noticeably improve it.
The model says, right in the name, that ISO is a part of exposure, which is absolute balderdash.
The model presents ISO as a part equal to exposure itself (highlighted by the fact that the sides of the triangle are equilateral), which is, again, absolute nonsense.
The model does not at all underscore the leading role of exposure in controlling noise and dynamic range. In fact, the model hides it.
Exposure is much more important, and it needs to be set first so as to be as high as possible, while ISO is set afterwards so as to reach the desired lightness, but without clipping the elements in the highlights that are important to the composition of the scene. In this case, even the simple in-camera histogram isn’t unhelpful, because a mistake towards insufficiently high ISO leads to less, if any, additional noise than a mistake with the exposure due to a premature clipping indication taken “from the JPEG”.
The model suggests that one consider the goal of exposure to be lightness.
Absolute hokum. Lightness only appears as a result of rendering and processing, and all of that happens after exposure. Exposure and lightness are different physical quantities, with different units of measurement – how can they be interchanged?

https://www.fastrawviewer.com/blog/mystic-exposure-triangle

Higher ISO produces lower noise than lower ISO: http://digitaldog.net/files/100vs800iso.jpg

Maybe someone with pull on this forum can ask the owners why it can no longer host images using [img] command ....

[Jeremy Roussak]

Setting the ISO speed does not change the sensor's sensitivity to incoming light
...
Remember who just wrote this, which has nothing to do with ISO and everything to do with exposure:
”not much light has struck the sensor during the exposure, the signal-to-noise ratio will be lower and hence more noise will be visible.”

As was, I think, obvious, when I wrote "sensor" in that sentence I was referring to the combination of sensel array, amplifying electronics and analog-to-digital conversion.

Whether high ISO "causes" noise, as I think for the reasons I've set out earlier is true, or that fact that high ISO was used signifies that the image was underexposed is perhaps merely a matter of semantics.

I maintain my assertion that images shot by a sensible photographer (that is, one who has chosen appropriate shutter speed and aperture for the object being photographed) will have more noise if the ISO is higher; and the ISO will be higher if there is less light.

I shoot hummingbirds in natural light at 1/4000, f5.6, auto ISO. In the early mornings, or when the day is overcast, the ISO will be high and the raw files, noisy; when the sun shines brightly, the ISO will be low and the noise, less pronounced. Hence high ISO = noisy photograph.

Jeremy

[Jeremy Roussak]

Higher ISO produces lower noise than lower ISO: http://digitaldog.net/files/100vs800iso.jpg
Maybe someone with pull on this forum can ask the owners why it can no longer host images using [img] command ....

The image opens fine in a different tab. I don't know why: the software used by this forum is years out of date and there have been many upgrades.

You don't give any indication of the processing you have applied to those two images. In order to get the same appearance, you must have moved the exposure slider to the right in the first and/or to the left in the second, which rather emphasises the point I made earlier.

Jeremy

[digitaldog]

As was, I think, obvious, when I wrote "sensor" in that sentence I was referring to the combination of sensel array, amplifying electronics and analog-to-digital conversion.

I think, obvious, when I wrote that ISO isn't exposure, only what affects the amount of light striking the sensor is (aperture and shutter speed) and I think, obvious, when I wrote that a higher ISO can produce less noise than a lower ISO based on exposure. High ISO alone doesn't produce more noise; it can produce less noise. The examples speak for themselves. How else would you explain the high ISO having less noise than the lower ISO when the differences here were actual exposure, the amount of light striking the sensor?

YES IF you shoot hummingbirds in natural light at 1/4000, f5.6, auto ISO. In the early mornings or when the day is overcast, the ISO will be high, and the raw files will be noisy because you didn't provide optimal exposure. You could not, and I addressed why this is sometimes necessary. But the noise wasn't due to your ISO setting. The noise is due to your inability to provide an optimal exposure.

ASA 1600 film has more grain than ASA 25 film; always. ISO 1600 captures can produce less noise than ISO 400 captures. And the opposite is also true (more noise), NOT DUE TO THE ISO but due to the exposure. Some people keep showing examples of noise in images and provide a high ISO setting as if the two were tied. The noise is the result of underexposure, not the ISO setting.

[digitaldog]

The image opens fine in a different tab. I don't know why: the software used by this forum is years out of date and there have been many upgrades.

Its broken, that's all I can report at this point.

You don't give any indication of the processing you have applied to those two images. In order to get the same appearance, you must have moved the exposure slider to the right in the first and/or to the left in the second, which rather emphasises the point I made earlier.

First, it doesn't matter; the higher noise is due to underexposure, the lower due to optimal exposure, not the ISO (and no, no highlights were clipped that I didn't wish to clip)*. But the processing was a single adjustment category: brightness. NO adjustments in the Adobe ecosystem that can rebuild channel data from existing channel data (a cheat, but a useful one outside of scientific testing). The noise or lack thereof due to exposure is what it is. NO NR was used if that's the question; that would defeat the experiment, which I did describe, and which anyone here can try.

*Lastly, the ISO provides a ‘recommended’ exposure (Aperture + Shutter speed), but the savvy photographer does not need to accept this! Even without the inclusion of ISO, a savvy photographer will often ignore a reflective meter recommendation, for example, a black cat on coal or a white dog on snow. Such a recommendation would produce an overexposed or underexposed capture, despite the ISO setting in those examples.

[Chris Kern]

The image captured at higher ISO will be noisier because more random noise will have been amplified at the analog to digital stage of the sensor. The histogram will be shifted 3 stops to the right, which is likely to have blown the highlights (not because the sensel was saturated, but because the amplification will have resulted in a number greater than can be held in the raw data).

I wouldn't put much stock in that shift in the in-camera histogram.  As far as I know, most if not all cameras base the histogram they display on the embedded JPEG.  In other words, the histogram reflects the way the particular manufacturer's default image processing algorithms modify the raw image capture to produce an output-referred export format.  I presume these days that includes various techniques to reduce noise (probably at the expense of edge acuity) as well as tonal changes  (including compressing the dynamic range to open up shadow detail and avoid blowing out highlights) that would otherwise be made by post-processing the raw file in external software.  If you know precisely what a camera is doing to the raw capture to produce the JPEG, I guess the histogram is useful.  But as been said in these forums many times, what we really need is a histogram that is based on the raw data, not those that have been transmuted into a JPEG.

(Edited: corrected "JPEG" to "histogram" in the first sentence.)

[digitaldog]

I wouldn't put much stock in that shift in the in-camera JPEG.  As far as I know, most if not all cameras base the histogram they display on the embedded JPEG.  In other words, the histogram reflects the way the particular manufacturer's default image processing algorithms modify the raw image capture to produce an output-referred export format. 

Absolutely spot on. The only truly raw histograms I am aware of are some Phase One's. Everything else is a rendered JPEG removed from the raw data reality.

Old, but still true:
Everything you thought you wanted to know about Histograms
Another exhaustive 40-minute video examining:
What are histograms? In Photoshop, ACR, Lightroom.
Histograms: clipping color and tones, color spaces, and color gamut.
Histogram and Photoshop’s Level’s command.
Histograms don’t tell us our images are good (examples).
Misconceptions about histograms. How they lie.
Histograms and Expose To The Right (ETTR).
Are histograms useful and if so, how?

Low rez (YouTube): http://www.youtube.com/watch?v=EjPsP4HhHhE
High rez: http://digitaldog.net/files/Histogram_Video.mov

Lastly, and going full circle with C1/LR/ACR: NONE provides a raw Histogram! That’s the Histogram of the rendered raw. It tells you nothing about exposure. You need a raw Histogram for that information, so go directly for RawDigger. https://www.rawdigger.com/howtouse/beware-histogram

[digitaldog]

Another great article from the makers of RawDigger and FastRawViewer:

How to Trash a Good Shot in One Step...
Not sure how? It really is very simple - just rely on the JPEG histogram. The one on the back of your camera will do, or one derived from a JPEG by some viewer, or (sometimes) even by a RAW converter.

The JPEG histogram indicates, again, severe overexposure in the red channel. Naturally, you will start decreasing the exposure. But the shot is already underexposed by nearly 2 stops in RAW! Just look at the RAW histogram...

https://www.fastrawviewer.com/raw-histogram-for-culling#:~:text=You%20can%20use%20a%20RAW%20histogram%20to:,the%20best%20shot%20of%20a%20bracketed%20series.

[Jeremy Roussak]

I wouldn't put much stock in that shift in the in-camera histogram.

I very seldom place the slightest reliance on the in-camera histogram. The histogram produced by applications such as Lightroom has, I think, rather more utility and it was that to which I was referring.

Jeremy

[digitaldog]

I very seldom place the slightest reliance on the in-camera histogram. The histogram produced by applications such as Lightroom has, I think, rather more utility and it was that to which I was referring.

Jeremy

Copy and paste; nothing here has anything to do with any histogram from raw data that isn't a raw histogram*, only some current rendering of it:

“The histogram will be shifted 3 stops to the right, which is likely to have blown the highlights (not because the sensel was saturated, but because the amplification will have resulted in a number greater than can be held in the raw data).”

The histogram may or may not be shifted 3 stops to the right, depending on the current rendering in a raw converter. Even less likely in Adobe raw converters, which can create highlight data in one clipped channel from another unclipped channel. IOW, the Adobe Histogram in Adobe Camera Raw and Lightroom Classic often hides actual highlight clipping in the raw data; so a less useful untruth!

*You want to see the clipping of raw, highlight, or otherwise, you need RawDigger to do that.