High ISO noise vs No high ISO noise??? Comparison

[tim_ziegler]

<p>Guys,<br>

Please take take a look at the two image crops. Both taken a few minutes apart with similar settings, the same high ISO (1,250), same camera (D7000) model, almost same shutter speed (1/80 vs 1/60), similar light level (but not direction). They both are 200% crops of the same eyes. You will notice the eyes are different size and therefore were a different distance from the lens (but that should not make a difference noise wise). The first image is sharp and has very little noticeable noise. The second is reasonably sharp with LOTS of noise! Why? Except for the distance, shutter speed, and slight light level differences these should be the same noise level. Does light direction make all this difference? Or does the slightly lower light level make all the noise happen? Any help you can give me is MUCH appreciated.<br>

<img src="/photo/17983403" alt="" /><br>

<img src="/photo/17983401" alt="" /></p>

 

[georges_pelpel]

<p>I cannot see the photos but you probably answered your own question.<br>

At the same ISO setting underexposed areas will show more noise after exposure adjustment than if they had got enough light to start with.</p>

[steven_clark]

<p>If everything is too dim the camera is probably bringing up the shadows with some mild post-processing and the result is it amplifies the noise with the signal.</p>

[5711]

<p>he is talking about those two shots</p>

<p><img src="http://d6d2h4gfvy8t8.cloudfront.net/17983403-md.jpg" alt="" width="680" height="344" /></p>

<p><img src="http://d6d2h4gfvy8t8.cloudfront.net/17983401-md.jpg" alt="" width="680" height="338" /></p>

<p> </p>

[5711]

<p>first shot:<br /> Model: NIKON D7000;<br />ExposureTime: 1/60 s;<br />FNumber: f/4;<br />ISOSpeedRatings: 1250;<br />ExposureProgram: Aperture priority;<br />ExposureBiasValue: 0/6;</p>

<p>second shot:</p>

<p>Model: NIKON D7000;<br />ExposureTime: 1/80 s;<br />FNumber: f/4;<br />ISOSpeedRatings: 1250;<br />ExposureProgram: Manual;<br />ExposureBiasValue: 0/6;</p>

<p>the shot below is not in focus, the first shot, the eye is not sharp all across either.<br /> you can see that on the hair of the nose and the edge of the eye (lines of any sort give this away real fast).</p>

<p>rendering off focus stuff the high iso starts to look like this real fast.</p>

<p>concerning the autofocus stuff..<br /> use the af-l button on the back.</p>

<p>for shots like this use continues autofocus. keep track of the eye.<br /> try to focus it in a way that the focus point lies in the middle of the eye in the 3d dimensinal room, giving it sharpnes from the aperture before and after the focus point, thus getting the eye in focus.</p>

<p>apart from not beeing really sharp, i think the iso looks alright.<br>

because of sharpness it does look different.</p>

 

[5711]

<p>try it like this</p>

<p>put something infront of the camera, very close, make three shots on tripod with high iso<br /> a small toy as close as possible and the background 5-10 meters away, if possible some stuff in the background but not too plain and not to deistorted, a bookshelf maybe.<br /> good, even light if possible<br /> make a tack sharp image of the figure<br /> one slightly off in focus<br /> one completely off in focus</p>

<p>look what it does to your edges and detail and look at the rendering of the off focus elements.</p>

<p>exactly what happened here in your two photos</p>

[5711]

<p>i had this open in the browser and happened to look at it again right now.<br>

the highlights on the lower shot are completely blown.</p>

<p>on high iso settings this happens really fast.<br>

try to expose for the light, and then correct to fit the scene.<br>

sacrifice detail if you must, but not too much if you want to actually use the shot or sell it.<br>

ruined detail might be a problem then.<br>

exposures can change fast, but it is possible to manage all this with some practice.</p>

<p>how do i know that those shots are out of focus? well..i made quite a number of high iso photos that were out of focus too :D</p>

 

[kari_oinonen]

<p>ADL-setting effects on the input-output mapping "curve". In the second example ADL may have boosted shadows. That would reslut to increased noise as the amplification of shadow areas was bigger.<br>

What was the ADL setting you used?</p>

[5711]

<p><img src="http://d6d2h4gfvy8t8.cloudfront.net/17983769-lg.jpg" alt="" width="1500" height="1175" /><br>

i know there are two reasons why you could hate me.<br /> yes those are files from a canon 1dx and yes this is the keyboared belonging to my mac.<br /> whatever.</p>

<p>what i want to show the OP here is how edges disappear into the off focus zones on iso 100 and on high iso, ..in this case 25.6k...because i can (sorry, i had to :) ).</p>

<p>alright.</p>

<p>what you can see on the high iso shot, is that everything, lines and spaces will become more and more filled with something that looks like huge pixels. the lines are getting more and more rigid in their rendering.</p>

<p>look at the once that are in focus.</p>

<p>look at those slightly out of focus and then look back to the black thing.</p>

<p>you can see that in between this you start to see the pattern of you high iso.</p>

<p>every camera does look different here, especially when comparing nikon and canon.</p>

<p>as kari adds very well, active dlightning or overexposing can also be horrific when it comes to high iso grain</p>

<p>if you, however, under or overexpose the image, the pattern will get more or less noticable.<br /> therefore i do underexpose all my high iso images atleast for -0.3.<br /> alright, blacks might get black and dead space but that is okay with me.</p>

<p>if you overexpose, you will see more agressive noise.<br /> if something is out of focus more, you will get more agressive noise.</p>

<p>maybe do some test shots with one and the same scene.<br /> <br />bracket it for +-5 EV and go for idk..iso 200, 1k,2.5k,highest.<br /> something like this.</p>

<p>your images could look like this because a number of reasons.</p>

<p>out of focus, settzings in camera (active d lightning), wrong exposure</p>

<p>do some tets and let us know.</p>

<p>all the best<br /> cheers</p>

[5711]

<p>you can zoom in to view the images lager</p>

[Wouter Willemse]

<blockquote>

<p>Does light direction make all this difference?</p>

</blockquote>

<p>It can make a huge difference - change direction, and the lighting may become flat, requiring more pushing contrast and a more "aggressive" curve - resulting in more noise (or the alternative, a very flat image). The lower light level also can have some effect - it'll make the image a bit more pushed (esp. shadows, and esp. if something like Active D-Lighting is used), resulting in more noise.<br>

All in all, I find the differences quite pronounced in your examples, but not impossible.</p>

[tim_ziegler]

<p>Thank you all for your responses, I am learning a lot here! Note that I checked and I have Active D off so that is not a concern. I did have to bring up the second (high noise) image a little (exposure setting in Camera Raw) from the original since the eyes were a bit dark and I wanted the examples to be similar. That second image also was very hot on the right and as mentioned, out of focus. I've noticed that very dark images are usually a loss when they are shot at high ISO but these two were not that different from each other. It shocked me when I found out how close the settings were.<br>

I am going to take notes on everyone's advice and most importantly practice what I've learned! I can't tell you how much I appreciate your help. Thank you again for taking the time to respond.</p>

[sjmurray]

<p>Looking at a 16mb image at 200% will give you a false sense of having too much noise. Realistically, how big are you going to print these images? I shoot my D7100 all the time at 3200 and even 6400 iso and at 100% there is obvious noise, but even prints at 10x15 inches are quite acceptable and the noise is not even noticed at normal viewing distances. </p>

[5711]

<p>first, steve...one does see the high iso noise. this just depends on the viewer ;)</p>

<p>on a different matter..high iso exposure.<br /> it is very tricky, tim.</p>

<p>you will always have to sacrifice something.<br /> it is either detail in the black or the light.<br /> with high iso the dynamic range gets smaller and you are limited by that in your photo.<br /> you cannot crank it up till stupidly high iso and hope for iso 200 kind of photos, as the dynamic range is very much smaller.<br /> judging from my images from my d3, i can only guess here, the dynamic range from my shots at iso 2000 is about the half of the dynamic range of an iso 200 shot. the 1dx is something completely different though. however, i rarley push it over 2000iso. <br /><br /></p>

<p>what i do with high iso is, that i try to avoid burned out zones.<br /> i underexpose things.<br /> sometimes you might get one or two stops of iso back by doing so, depeneding on the light, and that will<br /> give you freedom to actually get back the lack in dr due to high iso.</p>

<p>there is a lot to say to this and also a lot to learn.<br /> most of it comes by shooting a lot of photos, and to all the<br /> people writing on the high iso issue i recommented to go to concerts and take photos.</p>

<p>also check out that blog, this guy really knows his stuff and has quite some posts on high iso too:<br /> <a href="http://www.wildlifeinpixels.net/blog/">http://www.wildlifeinpixels.net/blog/</a></p>

<p> </p>

[ShunCheung]

<p>Consider the 2nd image: http://d6d2h4gfvy8t8.cloudfront.net/17983401-lg.jpg<br>

The left side of the image (right eye) is considerably darker than the right side (left eye) of that same image. And it is quite clear that dark side is much noisier. As usual, underexposure leads to noise.</p>

[sjmurray]

<p>Those of us used to shooting film for years and years, are quite used to seeing a lot of grain when using a focusing magnifier when enlarging to make sure the print is really focused, in other words "pixel peeping" equivalent in film. 35mm Tri-X had pretty large grain when normal developers were used, and the grain could be seen quite readily in any print larger than 8x10 or so, but it was part of the medium, and accepted. Below is an example of a shot done on Tri-X (400 iso)and developed in D-76, both the full shot and a 100% crop. Next is a shot done with my D7100 at night when a fire truck came in to the neighborhood to check out a report of a fire (none was found, thankfully). Both the full shot and a 100% crop are presented. The colors and dynamic range of the color shot are rendered quite nicely, even at 12800 iso. You can see why I don't get all excited about a little noise in a 100 or 200 percent view of an image! </p>

[sjmurray]

<p>Those of us used to shooting film for years and years, are quite used to seeing a lot of grain when using a focusing magnifier when enlarging to make sure the print is really focused, in other words "pixel peeping" equivalent in film. 35mm Tri-X had pretty large grain when normal developers were used, and the grain could be seen quite readily in any print larger than 8x10 or so, but it was part of the medium, and accepted. Below is an example of a shot done on Tri-X (400 iso)and developed in D-76, both the full shot and a 100% crop. Next is a shot done with my D7100 at night when a fire truck came in to the neighborhood to check out a report of a fire (none was found, thankfully). Both the full shot and a 100% crop are presented. The colors and dynamic range of the color shot are rendered quite nicely, even at 12800 iso. You can see why I don't get all excited about a little noise in a 100 or 200 percent view of an image! </p><div></div>

[sjmurray]

<p>Digital example. What progress we've made!</p><div></div>

[Landrum Kelly]

<p>Not to contradict anyone above, but don't forget that some post-processing steps can also increase noise. </p>

<p>I shoot a lot at night, and I am still trying to figure out when to expect noise. Some of my under-exposed shots are almost noise-free. Go figure.</p>

<p>--Lannie</p>

[ShunCheung]

<blockquote>

<p>Some of my under-exposed shots are almost noise-free.</p>

</blockquote>

<p>Lannie, underexposure without noise? I would love to achieve such results at higher ISOs. Could you shows us a couple of examples? Maybe that will give us some ideas.</p>

<p>Here is one example from a D750 @ its top ISO setting 12800 (before going into the Hi range). The two kids were playing chess on an iPhone 6 inside a restaurant. The lens is a 50mm/f1.4 AF-S @ f3.5, 1/60 sec. Since the two children were not on the same plane, I tried to stop down a bit to gain some depth of field. The shadow area in the girl's hand vs. the bright phone display provides great contrast.</p><div></div>

[Landrum Kelly]

<p>Well, Shun, I was not really talking about high ISO when I said this: "I shoot a lot at night, and I am still trying to figure out when to expect noise. Some of my under-exposed shots are almost noise-free."</p>

<p>When I shoot in very low light with high ISO (say, 12800) on the D3s, I get substantial noise, but it is manageable with the correct processing and upon viewing at regular, usable sizes. I won't get into those shots here. I use the D3s to shoot hand-held at night in fairly dangerous neighborhoods, so that I can get in and out fast. It can do wondrous things at high ISO, since the pixel density is not great with its twelve megapixels.</p>

<p>The shot I will address here was actually taken <strong><em>on the D800E at low ISO--and on a tripod</em></strong>. That does not address the specifics of the thread, but I still found the results interesting, although others might find them unremarkable, since they were shot at low ISO on a tripod. Even so, the time exposure was long: six full seconds.</p>

<p>In any case, the file in question (shown in what follows) was made at ISO 100, f/11, 6 seconds--on a tripod. It was shot under-exposed--not deliberately, but what did I expect at f/11? Well, let me say that I used f/11 because there were some obvious hot spots due the extremely bright lights shining up onto the water tower. I wanted to bring out the hot spots to some extent, but I knew that some might be blown. (The specifics about that I dealt with in post, by taking the under-exposed NEF raw file and trying varying settings on exposure compensation in Nikon's View NX2 file converter.) In other words, I brought down the ISO to 100 and shot at f/11 (aperture priority) to keep from blowing out too many highlights. (I still blew out some.) The six-second exposure was derivative of these settings: I had no idea how long the shutter would stay open.</p>

<p>I believe, though I am not sure, that the file used in what follows was brought up two full stops in View NX2 (using exposure compensation, of course). (I do not have ACR for this camera, and so bringing it up more than two stops was not possible, I don't think.)</p>

<p>I will try to post eight crops, followed by a ninth posting showing the version showing now on Photo.net</p>

<p>I hope that all of this is not deemed too irrelevant because it was not shot at high ISO. As I said at the outset, <strong><em>I am only addressing the issue of low noise in under-exposed shots, but not on a shot at high ISO.</em></strong></p>

<p>I hope that it might still be of some relevance. I don't really know enough to say.</p>

<p>--Lannie<strong><em><br /></em></strong></p>

[Landrum Kelly]

<p>This is a crop from near the left side, made from the original under-exposed JPEG.</p>

<div></div>

[Landrum Kelly]

<p>Next is approximately the same crop with the JPEG actually used from the same raw file, probably brought up two stops. (It looks like more than two stops to me, but I don't know how that would have been possible using View NX2.)</p><div></div>

[Landrum Kelly]

<p>Here is a crop from near the center, cropped out of the original under-exposed JPEG.</p><div></div>

[Landrum Kelly]

<p>Next is approximately the same crop with the JPEG actually used from the same raw file, probably brought up two stops using Exposure Compensation in Nikon's View NX2.</p><div></div>