Terrible Noise/Pixelation With D300 - Active-D Lighting

<p>Hi,<br /><br />Here is the full-sized JPG, converted from 14-bit RAW by Capture NX 2.1.0:<br /><br /><br /><a href="http://www3.telus.net/public/svalmont/_3001150.jpg">Full res photo</a> <br /><br /><br />As you can see after zooming in, water reflections and darker trees show an unacceptable amount of noise and pixel smearing.<br /><br />I used the Nikkor 16-85mm VRII lens with the following settings:<br /><br /><br />F11<br />ISO-200<br />1/50 sec<br /><br /><br />Can anyone tell me why this is happening? My photo guru friends are at a loss, although the RAW converter and resolving power of the lens have been brought up as suspects.<br /><br />Thanks,<br /><br />Calvin</p>

 

<p>Perhaps you could post a crop that shows exactly what you are referring to. For me, that looks just fine at 100%.</p>

<p>Joel, what if you were to go to 200%?<br /><br />Looking at the reflection of the dark green trees near the center, do you see pixels and black dots rather than a clean and clear water surface?</p>

<p>Flat, gray lighting and no use of the usual sharpening and curve adjustments in post will certainly make for a drab image, as shown. But I'm not seeing pixelation or noise - just a somewhat awkward exposure and some softness (which could be any number of things). There's also a green smudge of lens flare near the bottom center-left (was the hood on the lens? if not, that might account for some of the lack of contrast).<br /><br />Is there any chance that you're looking at the image on a display that's producing some funky 6-bit banding effects or other artifacts?</p>

<p>Calvin, I'm not sure what you are referring to as "noise". Your image looks very clean in the water, sky and shadows. Maybe it would be helpful for you to describe your specific concerns about this image.<br>

Dick</p>

<p>Matt, can you please zoom in on the reflection of the dark green trees at center-left? That is where the strange noise is most apparent.</p>

<p>I did have my lens hood on although I'm not sure I know which smudge of lens flare you're referring to. And I've confirmed the issue is visible on several different monitors.</p>

<p>Your camera is set to boost saturation, i doubt that is a problem, but if you use a raw converter, why bother with the in camera saturation setting?</p>

<p>Since you took the shot in manual mode was it way under exposed before you put it through the RAW conversion process? If so, theres you answer.</p>

<p>Richard, it's the water reflections that seem filled with noise when you zoom in close. I don't see clean green and brown but rather pixelated patches that are sprinkled with black dots.</p>

<p>Thanks Galen, but the photo never appeared underexposed.</p>

<p>Just for those who don't want to have to open that whole file, here's a thread-friendly 100% crop from the area that (I believe) Calvin's referring to.</p><div></div>

<p>Wow. Thanks, Matt! That's precisely what I'm referring to.</p>

<p>Calvin, I switched from my small laptop to a 24 inch iMac and I now see what you mean. It is in the trees, the dark reflections and the wood of the dock on the right. I can't explain this, but maybe someone here will.<br>

Dick</p>

<p>To me, it looks like typical chroma noise that results from trying to boost shadow detail in s scene dominated by a bright area (the sky, in this case). I'm guessing that this is a result of having the Active D-Lighting set to "High" (which I see, in the EXIF data, is the case). </p>

<p>I see the stuff that the OP is talking about. This is possibly a combination of pixel peeping and maybe a bit underexposure in the dark areas of a high dynamic range photo. (I'm not somewhere where I can really look at the RGB curves right now.)</p>

<p>The noise doesn't really look all that unusual to me. Point the camera at a clear blue sky and you'll probably see something similar. But if you post the RAW file somewhere it can be downloaded it, I'd be happy to check it out for you.</p>

<p>I never bother to shoot 14-bits because I don't see any difference with 12-bits for my applications.</p>

 

<p>Thanks, guys! I'll try disabling ADL tonight and let you know.</p>

<p>just curious, calvin: how long have you had your D300?</p>

<p>I agree that active D lighting being set to high isn't a good idea. When shooting raw I leave D lighting off as it can always be added later in Capture NX or NX2.</p>

<p>Hopefully something derogatory is not headed my way, William.</p>

<p>I'm a true newb. I've had the D300, and coincidentally been off full-auto mode, for about two and a half weeks.</p>

<p>Was it underexposed to begin with?</p>

<p>It wasn't, Ryan.</p>

<p>If you zoom in beyond 100% magnification you will begin to see pixels and artifacts with any photo. This is normal. It's not like TV or the movies where they can zoom in effortlessly and magnify photos while retaining full detail. That's fiction.</p>

<p>Photos can be resampled to higher resolution, but this is a different process from increasing onscreen magnification beyond 100%.</p>

<p>Don't worry, Lex. I don't expect a fictional level of detail.</p>

<p>D-Lighting and Active D-Lighting aren't the same thing. You <em>can</em> indeed apply classic D-Lighting after the fact in NX. But Active D-Lighting essentially plays with the nature of the exposure at the time it's taken. It's the camera's way of altering the exposure to avoid clipping. When you put it on "High," it gets very aggressive, and tries to compress more of the prospective image's info into the middle part of the curve. Something always has to give... and when you essentially increase gain on those shadowy areas, some chroma noise always shows up.<br /><br />However: I guarantee that if you applied a wee bit of NR in post, and made a print (say, an 8x12) you'd never even see it. As Lex points out - zooming in past 100% doesn't shows you anything meaningful, but can get you worried about nothing of consequence.</p>

<p>Here's an example of the differences between onscreen magnification and resampling. All photos straight from my D2H at highest ISO, 6400, which is extremely noisy. I left the flaws intact to show the distinct effects of image degradation from both magnification and resampling.</p>

<p>The second and third photos were each resampled *downward* to 25% of original size.</p>

<p>#2 was then magnified using the usual onscreen magnification tools of the pixel peeper until it reach the same 500x500 pixel size as the original. This is an example of what you will also see on the digital camera's built in LCD review screen at maximum magnification. The jaggies and pixel artifacts are clearly visible.</p>

<p>A screen capture was made. #3 was resampled downward to 25% of the original size using the Lanczos algorithm; then resampled upward back to 500x500. While the image is obviously badly degraded, it does not show jaggies, stairstepping and sharp edged pixel artifacts because the resampling algorithm does not merely magnify the existing pixels.</p><div></div>

<p>I must admit I never bother much with photos I have not photoshopped at least to (a) reduce noise (b) optiimise contrast / tone © optimise color and (d) sharpen. Often I will also then use the local contrast filter which greatly aids image clarity and apparent sharpness. <em>Then</em> I feel I can look to see how good the image is.<br>

So often, really ordinary if not cruddy images have come up tops after this basic processing that I believe no digital camera is really capable of turning out usable shots straight out of the camera. As a result every photo of mine that I want to keep gets this treatment to get it to the point where its decent. (I am presently mainly using a D200 and am pretty happy with performance although photos straight out of the camera need this work over - just as with every other camera I have owned or tried.<br>

BTW I especially find that many cameras struggle with images like this one - with lots of fine detail in branches and twigs. Of course to add insult to injury somethimes lenses will also produce CA which is noticeable in this type of image - although I think yours have avoided this fault. Honestly though I think I would not worry until I had processed the image properly and then only I did not like the result in successive images.<br>

In your specific photo there is a fair bit of blurring (which I might be inclined to put down to focus error or camera shake (one one fiftieth of a second is not all THAT fast) My camera will also sometimes produce surprisingly large amounts of noise under some conditions but not often enough to worry me. it just happens. Most times it does not.</p>