OldSchool-WI Loc: Brandon, Wisconsin 53919

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We all know that each camera manufacturer offers a stream of camera models, year by year. Each the greatest since the invention of "white bread?" But mostly they add software for noise reduction so you can grasp at higher ISO over the previous year's model. The dynamic range of your sensor is fixed, but you can either maximize the potential or ignore good photo technique and contract that range. Within limits each sensor exhibits a dynamic range------AS DID EACH FILM. But I have yet to see the range given in a manual by a manufacturer. It is up to the customer or maybe some critic/reviewer to comment, but normally they are bent on nonsense comparisons of software differences. I have many Bayer sensor bodies including a Sony four color Bayer and three successive models of the revolutionary FoveonX3 stacked sensor.

But it is a fact that noise reducers degrade the images and certainly one must keep the dynamic range from blowing out the highlights or submerging the shadows when shadow detail is important to the overall composition. And as ISO is pushed up, the photo degrades. But that is just good-smart photography. And that also applied to film. Yet the technical capabilities of each film---were well known and public, while now with sensors----it is up to the buyer and the buyer should be wary.-------ew

fantom Loc: Colorado

The question asks if DR affects noise. PHRubins' last sentence, in the post I was referring to, seems to have answered the question quite clearly and concisely and people can now comfortably move on to other topics without dwelling on the why, if they so desire.

OldSchool-WI Loc: Brandon, Wisconsin 53919

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With digital sensors, noise is relative to how closely optimal exposure is reached for a particular sensor. And any noise reduction is synthetic and degrading---but might save an otherwise worthless noisy picture.(of course also applies to post processing) For over ten years good cameras have offered noise reduction within a camera body. But the manuals for those cameras say don't use NR if you can help it--it degrades the image. And often those cameras have three or more grades of noise reduction. I presume cell phones are nearly all such fooling around with the noise pixels? So---be a photographer and get your exposure maximizing for the sensor. (Heaven-forbid--even use a meter if you still have one?) No mumbo-jumbo and speaking in tongues. (abbreviations)---------------

selmslie Loc: Fernandina Beach, FL, USA

I think that we have been talking past each other because we are looking at a different view of DR.

There is no question Bill Claff's standard for DR is absolutely correct if you define DR as the number of stops between the maximum raw value and the noise floor.

But I have been thinking of a different manifestation of DR that is independent of noise. In that version I have been assuming that a 14-bit raw file can cover only 14 stops and a 12-bit raw file only 12 stops.

I ran another test with the Nikon Df. I exposed a blank target ISO 100 spot metered to set an exposure for Ev+0. Then I collected a series of exposures by changing the shutter speed to go from Ev+4 through Ev-10 to see what would happen to the raw values over 14 stops. I read the results with RawDigger and I got the following:



The 12-bit results are perfectly aligned with the 14-bit values but their values are consistently two stops lower than the 14-bit values. The 12-bit values stop recording at around Ev-7 but the 14-bit values continue to record for several more stops.

But if you examine the numbers in the attached spreadsheet you will see that after Ev-5 the both sets of raw values get a bit squirrely. Beyond Ev-5 the change from one stop to the next is no longer close to 1 stop for either bit depth. By that crude measure the Df seems to have a reliable Df of about 9 stops for the 14-bit raw file but only about 7 stops for the 12-bit raw file.

Raw values for 12- and 14-bit capture over 14 stops.xlsx
Attached file:
(Download)

TriX Loc: Raleigh, NC

It seems to me this is a plot of the linearity of your camera, which is quite good until you get down to where that old bugaboo, noise (and perhaps non linearities or quantization errors of the A/D), intrudes

OldSchool-WI Loc: Brandon, Wisconsin 53919

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Totally absent in this technical discussion is that film emulsions were more than the straight lines within the exposure range of digital. There were characteristic curves which played a major part in the quality of the rendition. And those were quite known and public for every emulsion.---------------

SuperflyTNT Loc: Manassas VA

It is improvements to the sensors themselves that result in lower noise. It has nothing to do with software. Yes many cameras have high ISO noise reduction settings that are based in the firmware but the only work on JPEG’s and have no affect on raw images.

Ysarex Loc: St. Louis

We know you're sensitive about the super sh*ty low-light performance of those Foveon cameras. So you're trying to imply that the superior low-light performance of today's modern cameras is all just synthetic software that degrades the image.

Why don't you break out one of those triple stacker Foveon super cameras and set the ISO to 6400 and show us what it can do? Surely you can oblige us with a demo? No noise filtering though!

In the meantime here's an ISO 6400 shot from my Fuji X-T4 (APS-C sensor). I made one adjustment and reduced the image size by about 25% to match the size of an image from a Sigma SD1 -- keep it fair.

Oh and there's no luminance noise filtering applied in camera or in the processing software. You are looking at hardware performance (I know how to maximize sensor exposure). I've seen what you get from those Foveon sensors at higher ISOs, so I'm going to go to bed now laughing until I fall asleep. I'll check back in the morning to see that super triple stacker ISO 6400 Foveon sensor photo.

(Download)

OldSchool-WI Loc: Brandon, Wisconsin 53919

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Semantics?-----Software, firmware, sensor "Bayor filters array"-----are'nt they all related? Someone programs a "program"---i.e. Bayer filter to assemble the side by side color pixels or for that matter the three stacked layers of the revolutionary FoveonX3?------------------The more NR----the more synthetic?

Whether NR is applied in camera is not a given--as to raw files. There is not a straight manufacturer's answer I can find with a google search including DPhoto. Only opinions from contributors like here on UHH. Yes, one might think that Raw means totally unprocessed raw. But that has no definitive answer with various sensors from manufacturers.

Here from wikipedia: [The camera's sensor is almost invariably overlaid with a color filter array (CFA), usually a Bayer filter, consisting of a mosaic of a 2x2 matrix of red, green, blue and (second) green filters.----One variation on the Bayer filter is the RGBE filter of the Sony Cyber-shot DSC-F828, which exchanged the green in the RG rows with "emerald"[11] (a blue-green[12] or cyan[13] color). Other sensors, such as the Foveon X3 sensor, capture information directly in RGB form (using three pixel sensors in each location). This RGB raw data still needs to be processed to make an image file, because the raw RGB values correspond to the responses of the sensors, not to a standard color space like sRGB. As there is no color filter array, there is no need for demosaicing]---(end wiki).

OldSchool-WI Loc: Brandon, Wisconsin 53919

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Jealousy jealousy. Maybe some day you will advance from consumer level to pro-level Sigma equipment? In the meantime, don't show your ignorance--it is not becoming and oozes out with each of your posts.---------------------Happy new year.

SuperflyTNT Loc: Manassas VA

Oooh! He’s quoting Wikipedia now. First of all it’s Wikipedia. It can be a decent source of data but I certainly wouldn’t rely on it as an authority. Second if all that entry has absolutely nothing to do with the subject at hand.
Oh, and it’s not “semantics”. In camera high ISO noise reduction has no effect on raw files.

Grahame Loc: Fiji

Watching ..............................

OldSchool-WI Loc: Brandon, Wisconsin 53919

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So----------you build cameras and sensors now. Maybe you should read what I wrote---if that is possible?

SuperflyTNT Loc: Manassas VA

I read what you wrote. I don’t need to build cameras and sensors to know how they work.

bclaff Loc: Sherborn, MA (18mi SW of Boston)

Actually, FWIW, for sensors that implement the ISO setting using variable gain between the pixel and the Analog to Digital Converter (ADC), which is almost all our cameras, raising the ISO setting lowers noise and drops the saturation level.
This is why you lose less than 1 stop of dynamic range when you raise the ISO setting 1 stop.
(Dual conversion gain and noise reduction aside.)
The more "ISO invariant" the sensor the less obvious this effect.
This is what PhotonsToPhotos Photographic Dynamic Range Shadow Improvement conveys.
It's also the reason that Input-referred Read Noise drops as you raise the ISO setting.
And the reason that astro-photographers shoot at higher ISO settings.