Luminous Landscape Forum
Equipment & Techniques => Cameras, Lenses and Shooting gear => Topic started by: Dan Wells on December 26, 2008, 06:51:13 pm
-
I just got out for about 4 hours of serious (landscape and macro) shooting with the D3x this morning, and have been looking at the files for most of the afternoon. The easiest comparison I can make is to the 1Ds mk II (note: NOT mk III), as that is the highest-resolution camera I have a lot of experience with (other than the D3x). I am comparing at ISO 100, converting from 14-bit NEFs (in Nikon Capture NX2) and viewing at 100% on screen (unfortunately, my printer is 180 miles away right now, and I'm on my laptop monitor, NOT my calibrated work monitor, because I am visiting my parents for the holidays). There are two apparent differences - first is the incredible sharpness of the D3x. When I've nailed the focus, the D3x looks very darned sharp at 100% without applying any sharpening - because of the AA filter, the Canon never did that. It would PRINT very sharp, but 100% on screen always revealed a slight blur. There is absolutely no noise in an ISO 100 D3x file, even at 100%, which adds to the impression of sharpness - very slight shadow noise in the Canon files adds a slight haze to dark ones - that is simply not there in a D3x file. The second difference is the dynamic range - the D3x has about a stop more range in the highlights, plus at least an extra stop in the shadows, maybe even 1.5 stops extra in the shadows, all of it very clean. This camera, properly handled, should print 24x36 inches with ease from its base ISO of 100 (I get 16x24 out of the Canon, but don't like to go larger than that).
ISO 400 on the D3x is very usable - it looks roughly like an ISO 100 file from a 1Ds mk II in terms of noise - it may have extra dynamic range, which I wouldn't have seen because my ISO 400 tests were on a very dreary, grey day and would have fit easily within the DR of the 1Ds mk II). This is comparing on a per-pixel basis, so the D3x file still has 3/2 the detail in it, due to the increased resolution... I have even fooled around a bit with ISO 3200 (HI 1.0), which looks awful on screen (although quite good considering that it's ISO 3200 - much better than any ISO 3200 film ever looked), but will make a pretty decent 8x10 print with no trouble, and should even print 11x17 with some careful handling. I didn't buy the camera to shoot at ISO 3200, but it's nice to know the capability is there should it be needed. Those unbelievable ISO 100 files are what I bought the camera for, and it is certainly worth its price for its low-ISO performance! There is something highly unusual in the imaging chain of the D3x to get these results - the sensor may NOT be stock Alpha 900 issue (I suspect it isn't - I don't have a lot of Alpha experience, but the test files I've seen are not anywhere near as clean, even at low ISOs) , and if it is, the AA filter in the D3x is extremely unusual, probably made out of pure unobtainium.
Add that performance to a superb rugged and ergonomic camera body with class-leading AF and metering, and the result is a remarkable machine. Yes, it's expensive, but the only way to get better files is three times as expensive and not nearly as rugged.
-Dan
-
Yes, it's expensive, but the only way to get better files is three times as expensive...
I suspect that depends on the photographer and other variables: http://forums.dpreview.com/forums/read.asp...essage=30468356 (http://forums.dpreview.com/forums/read.asp?forum=1037&message=30468356)
-
The second difference is the dynamic range - the D3x has about a stop more range in the highlights, plus at least an extra stop in the shadows, maybe even 1.5 stops extra in the shadows, all of it very clean
The DR of the D3X @ ISO 100 is about ONE stop higher than that of the 1DsMkII; this measured, not estimated. I don't have suitable raw files for conclusive comparisons with different ISOs; if you create some, I can do the measurements.
The D3X appears to be an excellent camera; no need to make phantasy claims.
Btw, digital cameras do not have separate dynamic ranges in the highlights and in the shadows. There is only one dynamic range, everything else is the question of metering.
-
I don't think anyone doubts that the D3x is a superb camera. It looks to be the top of the 35mm heap right now From the tests I've seen, the D3x and A900 are very similar until ISO 800, and past that the Sony lags. The question is whether the D3x is worth 2.5 times the alpha, and that's a decision unique to each shooter. I'm curious to see what an Alpha firmware update brings.
-
It's becoming increasingly difficult to extract more DR and S/N from 35mm sensors. With the D3 and D700, Nikon caught up with Canon and actually surpassed Canon on the noise front. This surpassing was subject to much exaggeration, but after the hype and excitement had settled down it was discovered that these Nikon cameras had about a 1/2 stop DR and noise advantage over the ancient 5D. Furthermore, on the basis of comparison of equal size images, the D3 high-ISO noise is on a par with (or as close as matters) to the 1Ds3.
The initial impression that Canon created with the introduction of the 50D was that individual pixel performance might be close to that of the 40D. In fact, we now know that at the pixel level the 50D is noisier than the 40D. However, at the total image level, it's about the same.
The big question with D3X noise and DR performance is this. Can we expect a higher DR and S/N than the D3 produces, when D3X files are downsized to 12mp?
-
The big question with D3X noise and DR performance is this. Can we expect a higher DR and S/N than the D3 produces, when D3X files are downsized to 12mp?
Ray, I got used to your equalization fanantics (=fanatic antics), but this one surprized me. Your faith in the myth of eliminating noise by downsizing is one thing; but how on earth do you imagine, that the DR would be increased by downsizing? Honestly, do you have an idea, how downsizing is supposed to effect the noise? That is the recipe for lowering the DR
I suggest you to make a test finally, not only talk about it. I did, with one of your 5D shots for the DR measurement (with Jonathan's pattern) and with your #9199, Ratana's Kitchen, in 100%, 75%, 66% and 50%. I do not post the result, a layered TIFF, for it is over 144 MB.
-
I suggest you to make a test finally, not only talk about it. .
I make frequent tests, Gabor. Haven't you noticed? However, my instruments for measuring the results are my eyeballs. I rely upon people like you to provide the mathematical confirmation of what I'm seeing and to raise issues that might not be readily apparent with normal viewing of images and prints.
Dynamic range issues are also subject to exaggeration. The A900's DR advantage in relation to the 5D2, for example, exists only at ISO 100 and, from memory, is only about 1/3rd of a stop, according to DXOMark.
Nevertheless, I confess I'm not totally clear in my mind as to the distinction between DR and S/N. All else being equal, if one were to increase S/N by reducing noise but keeping the signal the same, one would increase DR. It would be theoretically possible to produce a P&S camera with the DR of a Phase DB, if someone were to develop a new way of recording the signal which was essentially noiseless, say a material which was totally insensitive to any radiation other than the frequencies of light, and which was at the same time extremely sensitive to the frequencies of light, more sensitive than current sensors.
-
Gabor,
Perhaps we could shed some light on this issue by stating a principle that a small sensel with an excellent S/N can have the same (or greater) DR as a big sensel with a relatively poor S/N.
Would you go along with that?
-
Ray, I got used to your equalization fanantics (=fanatic antics), but this one surprized me. Your faith in the myth of eliminating noise by downsizing is one thing; but how on earth do you imagine, that the DR would be increased by downsizing? Honestly, do you have an idea, how downsizing is supposed to affect the noise? That is the recipe for lowering the DR
Noise and DR are scale dependent quantities. Any quotation of figures for either that does not take this fact into account are figures without context and meaning. Downsizing eliminates high frequency noise, because downsizing eliminates high frequency everything (noise, detail, etc). The result is that, while noise at a given spatial frequency remains unaffected, the noise as measured by standard deviation of uniform tonality patches is lowered, because of the elimination of high frequency components of noise. Similarly, DR at a given spatial scale is unaffected by downsizing, insofar as the given spatial frequency is still present after downsizing. DR as measured by the std dev noise floor is again increased by downsampling, because the std deviation of noise is an amalgamation of noise at a variety of spatial frequencies, some of which are eliminated by downsampling.
-
Noise and DR are scale dependent quantities. Any quotation of figures for either that does not take this fact into account are figures without context and meaning. Downsizing eliminates high frequency noise, because downsizing eliminates high frequency everything (noise, detail, etc). The result is that, while noise at a given spatial frequency remains unaffected, the noise as measured by standard deviation of uniform tonality patches is lowered, because of the elimination of high frequency components of noise. Similarly, DR at a given spatial scale is unaffected by downsizing, insofar as the given spatial frequency is still present after downsizing. DR as measured by the std dev noise floor is again increased by downsampling, because the std deviation of noise is an amalgamation of noise at a variety of spatial frequencies, some of which are eliminated by downsampling.
Thanks, Emil, for weighing in here. I'm totally mystified as to why Panopeeper is so resistant to this idea that downsampling reduces the perception of noise. It's a phenomenon which is easily visible on one's monitor and on print.
Thanks also for pointing out that DR is also scale dependent. I wasn't sure about that.
-
There is an interesting article (http://blog.dpreview.com/editorial/2008/11/downsampling-to.html) in the editorial blog at DP Review on downsampling and noise.
-
Where did anyone see a measured DR on the D3x - I'd be really interested to see what it is (and I suspect that the lower the acceptable noise, the greater the difference from an older camera like the 1Ds mk II)? Imatest reports four separate DR figures, depending on acceptable noise level (which I like better than DxO's method of reporting only a single figure which corresponds roughly with Imatest's widest and highest-noise figure). Depending on which noise figure you use and how you make the measurement, the 1DsII is between half a stop and 1.5 stops below the Alpha 900 in measured DR, and I would be surprised if the D3x wasn't wider than the Alpha 900 at low noise levels, because the D3x files are so clean (I've never shot an Alpha, but the sample files I've seen are not extraordinarily clean - if anything, they are noisier than I might expect - even the RAWs). As I said earlier, I'm presently viewing files without a calibrated monitor or a printer, but the D3x results are really blowing me away. It will be interesting to compare with better tools right after the first of the year.
-Dan
-
However, my instruments for measuring the results are my eyeballs
There is nothing wrong deciding what you like based on visual inspection. In fact, that is the perfect method.
The usual problem with such comparisons is, that important aspects are not involved. I see very often demonstrations (of incompetence), how low or how high the noise is of a certain camera at a certain ISO, with such specifications like "in a dimly lit kitchen" (and usually noise reduced, downresed, the blackpoint cuts off everything in the really noisy region, etc.).
The A900's DR advantage in relation to the 5D2, for example, exists only at ISO 100 and, from memory, is only about 1/3rd of a stop, according to DXOMark
This is exactly the result of my measurements. However, I am cautios with the A700 and A900 raw files; I can not interpret them properly (nor can ACR).
Anyway, I suggest you to convert for example the #9199 without NR in ACR, pass it to PS and create different downsized versions of it. There are some good spots to measure the noise, like on the side of the huge clay-like planters at the left side. Make a selection on it and look at the statistics under Histograms, Mean and Std Dev.
Please post the result (change of StdDev) here.
-
The result is that, while noise at a given spatial frequency remains unaffected, the noise as measured by standard deviation of uniform tonality patches is lowered, because of the elimination of high frequency components of noise
Like in this example, right? Canon 40D @ ISO 1600; different sizes are in layers. I made it easy for you, you need only to make a selection in PS and look at the standard deviation.
4.5 MB demo TIFF (http://www.panopeeper.com/Download/Noise_ResizingMyth_SmallDemo.tif)
-
There is an interesting article (http://blog.dpreview.com/editorial/2008/11/downsampling-to.html) in the editorial blog at DP Review on downsampling and noise.
That blog post was thoroughly debunked in a couple of threads in the DPR forums:
http://forums.dpreview.com/forums/read.asp...essage=30176643 (http://forums.dpreview.com/forums/read.asp?forum=1000&message=30176643)
http://forums.dpreview.com/forums/read.asp...essage=30190836 (http://forums.dpreview.com/forums/read.asp?forum=1018&message=30190836)
http://forums.dpreview.com/forums/read.asp...essage=30211624 (http://forums.dpreview.com/forums/read.asp?forum=1018&message=30211624)
Gabor, you will find my demonstration of the effect of downsampling in the latter two links.
-
Gabor, you will find my demonstration of the effect of downsampling in the latter two links.
Emil, you will find my demonstration on the effect of downsampling in the TIF I linked to above.
-
Reducing (or increasing) the size of an image can be done in many ways. They will affect noise differently. All this talk about frequencies, etc., is useless without discussing the particular sampling technique used. For example, many of the most common point-sampling techniques will not affect "per pixel" noise at all!
Dynamic range, as it is most commonly defined (or at least as it should be defined) is just the maximum signal (the point of saturation) divided by the root-mean-squared pixel noise in darkness. Only if the noise is changed will dynamic range be changed, since virtually none of these scaling methods affect the maximum signal level. The noise "of an image," i.e., of anything other than an unclipped image taken in pure darkness, is also a relatively meaningless, irrelevant distraction when discussing dynamic range.
If we are talking about camera-level pixel averaging ("binning"), something that few cameras do in a true sense, then if four pixels are binned, the noise will be reduced by a factor of two (the square root of four), and the dynamic range will double. What photoshop, etc., does is quite different and may affect the noise little or not at all. This is most likely why people do not see dramatic reductions in noise (and concomitant increases in dynamic range) when scaling.
-
Emil, you will find my demonstration on the effect of downsampling in the TIF I linked to above.
Your linked file shows several things:
1. The chosen test image has relatively little noise power at high spatial frequency. This is why the "grain size" is fairly large. Downsampling will reduce noise by less than the ratio of linear dimensions, since the downsampling removes only the high frequencies (assuming it is done properly).
2. You downsampled in PS using Bicubic sharper, as near as I can tell by looking at the 50% reduced image, and overlaying the original downsampled in PS CS3 by that method. The sharpening of course enhanced the noise of the reduced image, as would sharpening the unreduced image. As a result, the standard deviation of noise didn't change much at all in the downsampled versions.
3. A straight bicubic 50% downsample reduces the noise standard deviation from about 22-23 in the patches I examined to about 18-19. PS bicubic has the propensity to alias noise into the downsampled result -- that is, noise in the original which is beyond the Nyquist frequency of the target is sampled into the target image. A gaussian blur of radius about 1 or so prior to the 50% downsample does not affect any spatial frequencies of the target image, but dumps the noise power beyond the target Nyquist frequency. By this route the noise standard deviation was reduced to about 13-14 without affecting detail of the downsampled image. Uncorrelated noise would have reduced to about 11 by this method, the fact that it wasn't reduced quite as much is due to the relative lack of high frequency noise, as I mentioned above.
In contrast, the test image I examined had noise power uniform almost out to Nyquist. Resampling by a Lanczos filter using ImageMagick fairly closely reproduced the expected reduction of noise upon downsampling. Details may be found in the links in my initial post in this thread.
-
Reducing (or increasing) the size of an image can be done in many ways. They will affect noise differently. All this talk about frequencies, etc., is useless without discussing the particular sampling technique used. For example, many of the most common point-sampling techniques will not affect "per pixel" noise at all!
Indeed. Nearest neighbor for instance does nothing for noise. Bicubic sharper will reduce the noise via bicubic and then enhance it by sharpening.
Dynamic range, as it is most commonly defined (or at least as it should be defined) is just the maximum signal (the point of saturation) divided by the root-mean-squared pixel noise in darkness. Only if the noise is changed will dynamic range be changed, since virtually none of these scaling methods affect the maximum signal level. The noise "of an image," i.e., of anything other than an unclipped image taken in pure darkness, is also a relatively meaningless, irrelevant distraction when discussing dynamic range.
Noise is not a number, it is a function of spatial frequency. Therefore a S/N ratio can be defined for each spatial frequency, and dynamic range computed for each spatial frequency. In this sense, the noise of an image is quite well defined. When comparing cameras of different pixel counts for noise and dynamic range, the proper and well-defined comparison is to examine the noise, S/N, and DR at a reference spatial frequency. This is roughly what DxO does when they scale results for "print output", under the assumption that the noise is uncorrelated. For a sufficiently accurate raw conversion, which does no or very little noise reduction (unlike Gabor's example), the noise is little correlated until quite close to Nyquist. For instance, the DPP conversions I used in my examples have a rather uncorrelated noise spectrum.
If we are talking about camera-level pixel averaging ("binning"), something that few cameras do in a true sense, then if four pixels are binned, the noise will be reduced by a factor of two (the square root of four), and the dynamic range will double. What photoshop, etc., does is quite different and may affect the noise little or not at all. This is most likely why people do not see dramatic reductions in noise (and concomitant increases in dynamic range) when scaling.
Photoshop bicubic is a rather poor filter for downsampling. It can alias noise into the target image. One way to deal with this is to blur the image slightly before downsampling. But I disagree that the dynamic range, noise, S/N are increased in a meaningful way by downsampling. Pixel peepers may see a reduction in the noise std dev, but that is because the std dev is measuring different aspects of the noise spectrum for the original and the downsampled image. In a proper downsample, the noise at fixed spatial frequency is unaffected. This is shown in the links in my initial post in this thread.
-
1. The chosen test image has relatively little noise power at high spatial frequency. This is why the "grain size" is fairly large
This is the way the Canon 40D works, converted by ACR, NR set to zero. The subject is a grey strip wedge, very uniform.
The noise is lower if converted by DPP (NR set to zero). One could speculate about the reason: if DPP is doing some NR despite NR set to zero (ACR is doing so), or if ACR mistreats the 40D raw data. However, I am using ACR as are most photographers.
2. You downsampled in PS using Bicubic sharper, as near as I can tell by looking at the 50% reduced image, and overlaying the original downsampled in PS CS3 by that method
Of course I did. That is the suggested method for downsampling. Perhaps you choose a method, which is suitable to create a "proof", but I choose the best method for the purpose, namely downsampling with the least loss of details.
Anyway, the difference in noise between "bicubic sharper" and "bicubic" is nothing to be excited about.
As a result, the standard deviation of noise didn't change much at all in the downsampled versions
Oh well... At least I did not select the methods of creating the samples with the goal in mind to prove anything. I did this just like I am doing it normally.
I disagree that the dynamic range, noise, S/N are increased in a meaningful way by downsampling
Well, then where does the myth come from?
Anyway, did someone claim that the noise increases by downsampling? Ray claimed, that the DR increases by downsampling. I find that nonsense, even though the noise can be decreased by downsampling.
-
This is the way the Canon 40D works, converted by ACR, NR set to zero. The subject is a grey strip wedge, very uniform.
The noise is lower if converted by DPP (NR set to zero). One could speculate about the reason: if DPP is doing some NR despite NR set to zero (ACR is doing so), or if ACR mistreats the 40D raw data. However, I am using ACR as are most photographers.
As far as I can tell DPP does not do any significant NR when it is turned off. ACR is just a poor raw converter, especially at high ISO, when it comes to noise and resolution.
Of course I did. That is the suggested method for downsampling. Perhaps you choose a method, which is suitable to create a "proof", but I choose the best method for the purpose, namely downsampling with the least loss of details.
I like to hone a method that gives an accurately resampled image. There are tools in common use, and there are better tools. There is commonly used workflow, and there is better workflow.
Oh well... At least I did not select the methods of creating the samples with the goal in mind to prove anything. I did this just like I am doing it normally.
Yes, and I suggested a major shortcoming of your workflow -- I pointed out that a judiciously chosen gaussian blur before resampling eliminates aliased noise in the downsampled image. Guess you missed that.
Anyway, did someone claim that the noise increases by downsampling? Ray claimed, that the DR increases by downsampling. I find that nonsense, even though the noise can be decreased by downsampling.
You did, implicitly, by posting a file in which the noise at fixed spatial frequency went up after downsampling. And no, the dynamic range at fixed spatial frequency is unchanged with proper downsampling.
-
Ray claimed, that the DR increases by downsampling. I find that nonsense, even though the noise can be decreased by downsampling.
No I didn't. If you have no detail in the shadows and no detail in the highlights, then clearly downsampling will not create detail where non previously existed.
I asked the following question. Can we expect a higher DR and S/N than the D3 produces, when D3X files are downsized to 12mp?
If the D3X were to have the same DR and the same S/N noise as the D3, for example, at the pixel level (which I'd say is unlikely), then one could expect the downsampled D3X image to have at least marginally less noise than the D3, and by virtue of the lower noise resulting from the downsampling, one could also expect a correspondingly greater DR in relation to the D3 image, but not of course in relation to the original D3X image.
Is that now clear? This is how it seems to me, but I'm always happy to be proved wrong. I'm here to learn. .
-
Noise is not a number, it is a function of spatial frequency.
Noise can and is routinely defined as one single number. After all, how much spatial information is there in blackness?
There is sometimes some spatial components to fixed-pattern noise (e.g., "banding"), but that's quite a different thing.
Also, you speak as though you are an authority as to just what algorithms P.S., etc., uses. I suggest in fact you are just presuming.
Thanks.
-
Noise can and is routinely defined as one single number. After all, how much spatial information is there in blackness?
There is sometimes some spatial components to fixed-pattern noise (e.g., "banding"), but that's quite a different thing.
Also, you speak as though you are an authority as to just what algorithms P.S., etc., uses. I suggest in fact you are just presuming.
Prior experience in the LL forum indicate that Emil generally has a pretty good idea about what he's talking about, and that he's good at assimilating information about how things work.
His list of publications seems to indicate that he may know a thing or two about statistics, mathematics, and possibly something about physics.
In other words, I think your mistrust is misplaced.
-
Prior experience in the LL forum indicate that Emil generally has a pretty good idea about what he's talking about, and that he's good at assimilating information about how things work.
His list of publications seems to indicate that he may know a thing or two about statistics, mathematics, and possibly something about physics.
In other words, I think your mistrust is misplaced.
Thanks, but my qualifications are quite robust too, and I design digital camera sensors for a living. I'm not allowed to say for who, though.
Anyway, it's not a matter of trust, it's a matter of the credibility of some of his statements based on their content.
Cheers.
-
If you have no detail in the shadows and no detail in the highlights, then clearly downsampling will not create detail where non previously existed
Removing the lens cap may help.
I asked the following question. Can we expect a higher DR and S/N than the D3 produces, when D3X files are downsized to 12mp?
All right, you did not claim it but asked.
The issue is, tha the dynamic range in photographic sense is not the same as in engineering sense. It involves not only the lack of noise but the presence of details as well; otherwise the dynamic range could be increased by replacing all lower pixel values with a very low constant.
Of course, the level of exectable details is different between the D3 and the D3X due to the different resolution. Thus it is possible to increase the DR while descreasing the resolution (this is, what Emil encodes with "lower spatial frequency"). The problem is, that one could gain the impression in these threads that the image could be "enhanced" by downsizing, and that is the nonsense. The result will always be worse than the original.
by virtue of the lower noise resulting from the downsampling, one could also expect a correspondingly greater DR in relation to the D3 image, but not of course in relation to the original D3X image
Anyone buying a 24 Mpix camera for twice the price of a 12 Mpix camera with the intention of changing that back into another 12 Mpix camera is not fit for photography. This issue does not deserve any discussion.
-
Anyone buying a 24 Mpix camera for twice the price of a 12 Mpix camera with the intention of changing that back into another 12 Mpix camera is not fit for photography. This issue does not deserve any discussion.
Anyone who buys any camera with the intention of making prints only of a specific size in accordance with the native, uninterpolated resolution, is very inflexible.
-
Noise can and is routinely defined as one single number. After all, how much spatial information is there in blackness?
There is sometimes some spatial components to fixed-pattern noise (e.g., "banding"), but that's quite a different thing.
Also, you speak as though you are an authority as to just what algorithms P.S., etc., uses. I suggest in fact you are just presuming.
Thanks.
Noise has a spectral power distribution. The standard deviation is an average over that power distribution, but there is much more information in the power distribution itself. In particular, the power distribution dictates what happens to noise when a linear filter is applied to the image, as is done in resampling an image using any of the common filters -- Bicubic, Lanczos, etc.
The fact that there is no signal in blackness is an issue independent of the fact that there is a spatial frequency distribution of noise still present. I was not referring to fixed pattern noise specifically, though that does indeed show up in the noise power distribution.
I did not and do not claim to be an authority about Photoshop's internal processing. As far as I'm concerned it's a black box that one can perform experiments on. One such experiment is to resample an image and examine the noise before and after (preferably the full power spectrum). My comments were based on the analysis of such exercises, which indicate that PS Bicubic aliases noise into a downsampled image. If you have contrary information, by all means present it.
-
Anyone who buys any camera with the intention of making prints only of a specific size in accordance with the native, uninterpolated resolution, is very inflexible.
Ray, if I downsize an image for printing or for presentation on computer, then I am not doing that in order to make it like it were another camera or in order to compare it to another camera. In other words: I resize it according to the presentation medium, not according to another camera's specs.
-
The issue is, tha the dynamic range in photographic sense is not the same as in engineering sense. Yada yada yada...
Dynamic range "in the photographic sense" is just an arbitrary and personal opinion and is hence useless during critical discussion.
Your main problem is that you want to force others to accept your very own special, undefined "definition" of what noise and dynamic range are. Sorry, that's not good enough.
-
Noise has a spectral power distribution. Yada yada yada
So? I can't summarize noise as X mv or counts, average RMS or sigma or full-width-half-maximum, etc? You think there's so much more information in a what is essentially a Gaussian distribution, for example, that one has to devote pages to it in a publication, or debate endlessly on your ill-defined special theories on a general photography discussion board? You are making me laugh!
-
Dynamic range "in the photographic sense" is just an arbitrary and personal opinion and is hence useless during critical discussion
1. The "detail reproduction" part is not only arbitrary, but subjective as well; we have to live with that.
2. The "noise" part is not subjective, but arbitrary in the sense that the acceptable level of noise has to be declared, but it can not be declared universally.
Therefor, when I measure the dynamic range (only the noise aspect), I create a list of noise levels and the corresponding dynamic ranges per ISO setting; such lists from different cameras and different ISOs can be used for direct comparison.
Following is an extract from such a list, which is going to be incorporated in an Excel chart; this is not sorted yet. It has been measured on the raw channels from the shot of a Stouffer wedge, Canon 40D @ ISO 1600. The first number is the dynamic range, the second is the noise in percentage of the intensity.
6.61 25.2
5.12 13.0
5.24 13.2
6.77 26.5
5.30 13.4
5.41 14.7
6.94 31.2
5.49 15.1
5.59 15.7
7.12 32.0
5.64 15.3
5.75 17.6
7.16 31.7
5.69 16.5
5.80 17.3
-
Ray, if I downsize an image for printing or for presentation on computer, then I am not doing that in order to make it like it were another camera or in order to compare it to another camera. In other words: I resize it according to the presentation medium, not according to another camera's specs.
Nor is anyone else. That would be silly. I can't imagine why anyone would want to produce a print or presentation in order to create the impression the image was taken by a particular camera, unless one were playing a game, "Guess which camera was used for this shot?"
Cameras are tools. It's necessary to know what the strengths and weaknesses of different models and makes of cameras are, so one can choose sensibly in accordance with one's own photographic needs and interests.
It would be a bad decision to buy a particular model of camera for a perceived reason that it produced cleaner images at ISO 3200, if another camera with a higher pixel count could produce equally clean images when downsampled to the same size, but which in addition had the clear advantage of producing higher resolution images when downsampling was not required.
-
By the way, I just realized that I have been conflating the prior two posters as one individual. My apologies for this.
-
1. The "detail reproduction" part is not only arbitrary, but subjective as well; we have to live with that.
2. The "noise" part is not subjective, but arbitrary in the sense that the acceptable level of noise has to be declared, but it can not be declared universally.
No, you have to live with those arbitrary and subjective declarations. The rest of us will continue measuring and comparing camera performance based on normal scientific definitions and standards.
But here's a clue:
"Noise as a percentage of intensity" (not that what you mean is clear) should follow the statistics of shot noise - the fluctuations in the number of arriving photons. Wow, what a discovery! Oh, wait, didn't we get into a "discussion" about some bizarre interpretation of shot noise you were promulgating about a year ago? Right! Never-mind! Of course, this has essentially nothing to do with the performance of the camera, either.
-
So? I can't summarize noise as X mv or counts, average RMS or sigma or full-width-half-maximum, etc? You think there's so much more information in a what is essentially a Gaussian distribution, for example, that one has to devote pages to it in a publication, or debate endlessly on your ill-defined special theories on a general photography discussion board? You are making me laugh!
Setting aside pattern noises (fixed or otherwise), the noise coming off the sensor is highly uncorrelated and indeed close to Gaussian. However, the RAW conversion process and in particular demosaicing (and noise reduction inherent to some converters) make it something quite different, if one looks at the spectral power distribution. A measurement of the standard deviation alone will not dictate what happens to the noise, DR, S/N etc of an image under resampling.
The following three patches have the same noise as measured by the standard deviation:
(http://theory.uchicago.edu/~ejm/pix/20d/posts/tests/Noise/grainsamples.png)
The "grain size" of the noise is related to the shape of the noise spectrum
(http://theory.uchicago.edu/~ejm/pix/20d/posts/tests/Noise/threeFTspectra.png)
and dictates what happens to the std dev under resampling -- "coarse" grain (red) is relatively unaffected by resampling, since it has little noise power near Nyquist.
I'm not sure why you feel the need for condescension.
-
However, the RAW conversion process and in particular demosaicing (and noise reduction inherent to some converters) make it something quite different, ...
The RAW conversion process has little to do with the performance of the sensor or the camera (if RAW is truly RAW). We all know how drastically different the results can be between the various RAW converters.
If you instead want to comment on the relative performance of different RAW converters, then have at it. Indeed, I feel that this is worthwhile, as simple noise results post-conversion (e.g., DPReview plots of JPG noise) can be almost meaningless if one wants to evaluate the performance of the underlying hardware.
But if you want people to accept your methodologies, I suggest defining them mathematically and keeping it simple. If you want to discuss frequency spectra, etc., remember how difficult it is for people to properly read MTF tables, for example. Ideally, you would deliver one figure of merit that represents the over-all performance of that camera+RAW converter.
I'm sorry if I was condescending. As I mentioned, I was confusing you and panopeeper.
-
No, you have to live with those arbitrary and subjective declarations. The rest of us will continue measuring and comparing camera performance based on normal scientific definitions and standards
I'm afraid the rest of you will be a quite small group, as the vast majority of photographers prefers to decide subjectively, if the detail reproduction is good enough for her/him, based on the individual circumstances.
"Noise as a percentage of intensity" (not that what you mean is clear) should follow the statistics of shot noise - the fluctuations in the number of arriving photons. Wow, what a discovery! Oh, wait, didn't we get into a "discussion" about some bizarre interpretation of shot noise you were promulgating about a year ago? Right! Never-mind! Of course, this has essentially nothing to do with the performance of the camera, either.
I think you lost the orientation in the thread.
-
I'm afraid the rest of you will be a quite small group, as the vast majority of photographers prefers to decide subjectively, if the detail reproduction is good enough for her/him, based on the individual circumstances.
I have no problem with people making subjective judgments. I do the same every day. I only scoff at people that insist it is necessary to co-mingle arbitrary and subjective factors in their "scientific" analysis.
-
The RAW conversion process has little to do with the performance of the sensor or the camera (if RAW is truly RAW). We all know how drastically different the results can be between the various RAW converters.
If you instead want to comment on the relative performance of different RAW converters, then have at it. Indeed, I feel that this is worthwhile, as noise results post-conversion can be almost meaningless if one wants to evaluate the performance of the underlying hardware.
I agree with the sentiment that noise performance is best discussed at the level of the RAW data. However, even then I do think it important to keep in mind that noise is frequency dependent, even though it is uncorrelated.
But if you want people to accept your methodologies, I suggest defining them mathematically and keeping it simple. If you want to discuss frequency spectra, etc., remember how difficult it is for people to properly read MTF tables, for example. Ideally, you would deliver one figure of merit that represents the over-all performance of that camera+RAW converter.
For (uncorrelated) noise in the RAW data, I think a good figure of merit is the slope of the noise power spectrum; equivalently the noise at a fixed reference frequency; equivalently the standard deviation at the pixel level divided by the number of vertical pixels in the frame. When the noise is spatially uncorrelated these are all the same thing up to fixed known dimensionless constants. The advantage of such a figure of merit is that it is scale invariant; resample the image and the figure of merit remains unchanged, as indeed it should be for fixed image output dimensions. Noise should be referred to frame size, as one does for resolution, not given as an absolute number at the pixel level. I think we both agree that the scalings involved at the RAW level are trivially performed -- just rescale the pixel level noise by the appropriate power of the pixel count.
Post conversion, however, I don't think one can boil things down to one number. Perhaps a few would do. But now the above three measures of noise are no longer the same -- the slope of the noise power is the same as the noise at a reference scale, provided both are in the linear regime of the power spectrum; but the std dev is very much affected by what the converter did to near-Nyquist data. I think I would prefer one of the first two over the third, since they still refer to fixed output dimensions are relatively immune to what the converter is doing, and add as another figure of merit the "grain size" imparted by the converter perhaps as measured by the point where the spectrum starts to deviate from linearity.
-
I imagine the argument is getting too technical for many of us. We need specific examples of real-world images of the sort photographers make (but of stationary subjects with constant lighting) comparing for example downsized D3X images with full size D3 images, or downsized 50D images with full size 40D images. The processing steps, resampling method and sharpening amounts should also be specified.
If the 50D image has been downsampled using 'bicubic sharper', which I also use when downsampling, then one might expect the downsampled 50D image to have slightly greater accutance than the full-size 40D image. If this proves to be the case, then there is no argument to be made that the 50D image still appears to be slightly noisier, since the whole purpose of the exercise is to trade resolution for lower noise. If the 50D image is still marginally sharper, but also marginally noisier, the trade-off is not complete.
I find the argument that one doesn't buy a camera with a higher pixel count in order to resample the images, disingenuous. One buys a camera to take photos, and the choice of presentation size of such images will depend on many factors such as the size one's printer can handle, the resolution of the projector or display, the degree of objectionable noise apparent if a high ISO was used, the extent of cropping required, and so on. Those who used the first 3mp DSLR that Canon produced (the D30), seemed to have been very happy with the quality of A4 size prints, and even A3 size prints, which of course involved very substantial upsampling. The work of many professionals using 39mp MFDBs will often end up being downsampled to a size suitable for magazine publications.
The lower the camera's pixel count, the more frequently images will be upsampled. The higher the camera's pixel count, the more frequently images will be downsampled.
I happen to be in the situation of owning both a 40D and 50D. Would there be any reason whatsoever, in any circumstances, for me to pick up the 40D instead of the 50D when going out shooting, apart from the trivial reason of being able to fit more images on the card? Is it really necessary for me to go to the trouble of making comparisons at various ISOs and waste ink and paper printing out the results?
-
I imagine the argument is getting too technical for many of us. We need specific examples of real-world images of the sort photographers make (but of stationary subjects with constant lighting) comparing for example downsized D3X images with full size D3 images, or downsized 50D images with full size 40D images. The processing steps, resampling method and sharpening amounts should also be specified.
It's not a perfect example, there are focus and exposure differences, but for noise it's reasonable to use the Imaging-Resource raw files. I did that with the 40D and 50D at ISO 1600. Here they are at native resolution, converted by DPP with default settings for each camera, except for turning off NR:
http://theory.uchicago.edu/~ejm/pix/20d/po...40DhSLI1600.jpg (http://theory.uchicago.edu/~ejm/pix/20d/posts/tests/Noise/E40DhSLI1600.jpg)
http://theory.uchicago.edu/~ejm/pix/20d/po...0DhSLI01600.jpg (http://theory.uchicago.edu/~ejm/pix/20d/posts/tests/Noise/E50DhSLI01600.jpg)
and the 50D resampled to the pixel dimensions of the 40D using PS Bicubic
http://theory.uchicago.edu/~ejm/pix/20d/po...00-downsamp.jpg (http://theory.uchicago.edu/~ejm/pix/20d/posts/tests/Noise/E50DhSLI01600-downsamp.jpg)
I did the same exercise with the Imaging-Resource multitarget images, and had someone run them through Imatest. The downsampled 50D image had slightly higher resolution, but nothing dramatic and perhaps within the error bars. The downsampling mitigated the interpolation artifacts in the 50D image so that they were less objectionable than the 40D at its native resolution. Lanczos is a more accurate resampling filter, and results in slightly less noise than PS Bicubic.
The resampling of the 50D is merely a sideshow IMO, to show using onscreen display the relative noise at equal output size. The noise levels at comparable spatial scales are equal even prior to resampling, as one can see from the noise spectra.
-
It's not a perfect example, there are focus and exposure differences, but for noise it's reasonable to use the Imaging-Resource raw files. I did that with the 40D and 50D at ISO 1600. Here they are at native resolution, converted by DPP with default settings for each camera, except for turning off NR:
Emil,
Thanks for saving me the time and trouble of doing such comparisons myself. I went to some trouble comparing 40D and 50D resolution, photographing a banknote, but was quite sure that 50D noise would be no worse than 40D noise, when comparing equal size images, so I did not bother to shoot any high-ISO images for comparison. I generally only make tests when I have reason to doubt what is claimed.
Out of curiosity, I upsampled the 40D image to the 50D size, using PS bicubic, then sharpened the interpolated image with Focus Magic using a blur width of 1 pixel and an amount of 50%.
At 200% magnification on the monitor, the text on the beer bottle is clearer in the 50D image, despite the fact that the 40D shot appears to have been taken from a slightly closer distance to the scene (or the focal length was slightly greater). The slightly greater resolution of the 50D is consistent with my own tests, but the magnitude of the resolution difference is a bit disappointing and highlights the fact that improvements in lens design and manufacture are not keeping pace with improvements in sensor technology.
[attachment=10589:40D_upsa...50D_size.jpg]
What we need now is a similar comparison between the D3 and D3X.
-
Back to the topic of initial impressions regarding the D3x image quality, Lloyd Chambers has been shooting with one and while his observations are on his paid-access site, he does post some general impressions on his blog: http://www.diglloyd.com/diglloyd/blog.html (http://www.diglloyd.com/diglloyd/blog.html) For those who haven't checked out Lloyd's site, there's a lot of information to be found there regarding Zeiss lenses.
-
Emil,
Thanks for saving me the time and trouble of doing such comparisons myself. I went to some trouble comparing 40D and 50D resolution, photographing a banknote, but was quite sure that 50D noise would be no worse than 40D noise, when comparing equal size images, so I did not bother to shoot any high-ISO images for comparison. I generally only make tests when I have reason to doubt what is claimed.
Out of curiosity, I upsampled the 40D image to the 50D size, using PS bicubic, then sharpened the interpolated image with Focus Magic using a blur width of 1 pixel and an amount of 50%.
At 200% magnification on the monitor, the text on the beer bottle is clearer in the 50D image, despite the fact that the 40D shot appears to have been taken from a slightly closer distance to the scene (or the focal length was slightly greater). The slightly greater resolution of the 50D is consistent with my own tests, but the magnitude of the resolution difference is a bit disappointing and highlights the fact that improvements in lens design and manufacture are not keeping pace with improvements in sensor technology.
[attachment=10589:40D_upsa...50D_size.jpg]
What we need now is a similar comparison between the D3 and D3X.
Hi Ray.
I think the image on the left is significantly more detailed than the one on the right. I'm assuming the one on the left is the 50D? A pretty good increase of resolution in my book.
-
Hi Ray.
I think the image on the left is significantly more detailed than the one on the right. I'm assuming the one on the left is the 50D? A pretty good increase of resolution in my book.
Yes, the one of the left is labelled 50D at the top. At 200% the difference is clear. If I were comparing lenses in the store before buying and I got this degree of difference, I would definitely buy the lens that produced the image on the left.
The problem is, if you were to make a print of the full image in order to view such differences from the same distance you view your monitor, the print would need to be about 6ftx9ft.
Nevertheless, if one is shooting wildlife using one's longest telephoto lens and the result needs extensive cropping, then the 50D will have a clear advantage over the 40D.
-
Yes, the one of the left is labelled 50D at the top. At 200% the difference is clear. If I were comparing lenses in the store before buying and I got this degree of difference, I would definitely buy the lens that produced the image on the left.
The problem is, if you were to make a print of the full image in order to view such differences from the same distance you view your monitor, the print would need to be about 6ftx9ft.
Nevertheless, if one is shooting wildlife using one's longest telephoto lens and the result needs extensive cropping, then the 50D will have a clear advantage over the 40D.
Ray, thanks for all your contributions here. If MBroad has had the fewest posts in the last four years (1) you have got to have the most (6003) in the last six years, as of this writing
There probably isn't anyone on here who tries to offer more input than you, and I have to say, it was actually your repeated posts and comparisons of the 50D and the 40D that helped me finally "pull the trigger" and get the 50D today, and what you have articulated above is exactly the difference I was looking for. There may be 100 other people on here who have made similar comparisons, but only you seem to take the time to post them.
I have been vascillating and procrastinating on the 40D, 50D, and Nikon D300 for quite awhile, but after being turned off by the way the Nikon D300 feels in my hands compared to the 50D, your contributions on the difference between the 40D and 50D have cinched it.
I am not sure what this has to do with the D3x, LOL, but I just thought I would add my $0.02 here on your post above.
Happy (soon to be) New Year,
Jack
.
-
I have been vascillating and procrastinating on the 40D, 50D, and Nikon D300 for quite awhile, but after being turned off by the way the Nikon D300 feels in my hands compared to the 50D, your contributions on the difference between the 40D and 50D have cinched it.
I am not sure what this has to do with the D3x, LOL, but I just thought I would add my $0.02 here on your post above.
Happy (soon to be) New Year,
Jack
Glad to be of help, Jack. I try to post the sort of comparisons of equipment which I would like to see myself when undecided about the relative merits of different models and brands of cameras and lenses.
I would have no hesitation in recommending the 50D over the 40D.
What has this got to do with the D3X? I consider the comparisons that have been made between the 40D and 50D, by myself and by Emil and others, as being the sort of comparisons that need to be made between the D3X and D3, so we can get an idea of just how much image quality improvement the D3X has to offer for the high price. Fine words by themselves won't convince me of anything.
A happy new year to you too, and a prosperous one so you can afford to buy a good telephoto lens for that 50D .
-
Getting back to the D3x, I just printed 24x36 from mine yesterday. The conditions were far from optimal (although the image was carefully taken - tripod, ISO 100, 14-bit NEF) - the printer was not mine (used a Z3100 at my photo dealer), I don't have my big computer with me to postprocess on, and the paper was not my favorite Hahnemuhle, but rather whatever Calumet had in their HP. Even so, it produced an amazingly sharp image at 24x36 inches - a 25x enlargement! It is certainly capable of printing that big on a routine basis, and my next printer will certainly be a 24 inch model to accommodate that. I would say that I am slightly more comfortable printing 24x36 from the D3x than 16x24 from the 1Ds mkII (which means that the D3x is getting quite a bit more detail per pixel, because it has only 1.5x the pixels, but the print area is just over twice as large). That detail difference could be in the AA/Low Pass filter, which is probably weaker and possibly a new design in the D3x. The D3x also has significantly higher DR (I'd say quite a bit more than 1 stop, but I haven't seen any real numbers yet), and is visually noiseless even in the deepest shadows at base ISO (the 1Ds mkII is low-noise, but NOT noiseless in the shadows, even at base ISO). Overall, a performance I have NOT seen from any DSLR before, and the images on screen look like the one sample I was able to print was not a fluke - it really is that good (the files really do look medium-format - I would say the subjective film equivalent is significantly over 6x9, but not yet 4x5 - some of the MFDBs DO reach 4x5 quality).
-Dan
-
I notice that Imaging Resource has images of both the D3 and D3X on their Comparator. Playing around with such images it's easy to see that the D3X has about the same noise as the D3 at ISO 6400, when the D3X is downsampled to the D3 size.
In fact, the D3X noise appears to be slightly greater in the IR images I used for comparison, but the D3X image is also slightly sharper than the D3 image when downsampled.
Panopeeper should pay attention to this. Downsampling a D3X image to 12mp using bicubic sharper, results in an image that is noticeably sharper and more detailed than the D3 image, at ISO 6400. Downsampling using standard bicubic still produces a slightly sharper result than the D3 image.
This additional sharpness would allow one to reduce noise in the D3X image whilst still retaining at least equal resolution to the D3, at ISO 6400.
The first image below compares the downsampled D3X image using bicubic sharper. The second shows what I would describe as slightly greater noise in the black cup which has been lightened considerably in 'Levels'. In the second image I used standard bicubic for downsampling.
[attachment=10654:D3X_down...mparison.jpg] [attachment=10655:D3X_down...ISO_6400.jpg]
Of course, it goes without saying, when the full resolution of the D3X is required for a large print, an upsampled D3 image just can't compete. The resolution difference is greater than that between the 40D and 50D, as one would expect. A doubling of pixel count always produces a worthwhile increase in resolution.
-
I notice that Imaging Resource has images of both the D3 and D3X on their Comparator. Playing around with such images it's easy to see that the D3X has about the same noise as the D3 at ISO 6400, when the D3X is downsampled to the D3 size.
For what it is worth both Thom Hogan and Iliah Borg claim after having compared the D3 and D3x side to side that overall, they will keep using their D3 beyond a certain ISO because they like the overall result better (that must include noise, detail, DR, colors,...):
- Iliah says that the threashold is around ISO 800,
- Thom has not given a definite number yet
Cheers,
Bernard
-
I notice that Imaging Resource has images of both the D3 and D3X on their Comparator. Playing around with such images it's easy to see that the D3X has about the same noise as the D3 at ISO 6400, when the D3X is downsampled to the D3 size.
I find it a worthless excercise to play the downsampling game with JPEG images (pre-sharpened and lossy).
Panopeeper should pay attention to this. Downsampling a D3X image to 12mp using bicubic sharper, results in an image that is noticeably sharper and more detailed than the D3 image, at ISO 6400. Downsampling using standard bicubic still produces a slightly sharper result than the D3 image
If Panopeeper downsizes an image with bicubic sharper, then the noise does not get "improved"; can YOU do that better? See Emil's condemnation regarding bicubic sharper.
This additional sharpness would allow one to reduce noise in the D3X image whilst still retaining at least equal resolution to the D3, at ISO 6400
BS
Forget the above:
Happy New Year
-
For what it is worth both Thom Hogan and Iliah Borg claim after having compared the D3 and D3x side to side that overall, they will keep using their D3 beyond a certain ISO because they like the overall result better (that must include noise, detail, DR, colors,...):
- Iliah says that the threashold is around ISO 800,
- Thom has not given a definite number yet
It is not disputable, that the D3's noise is lower at ALL ISO's. Therefor it is the question of personal preference, and even more of the specific setting (lighting, subject, requirement) if the higher pixel count or the lower noise is important.
For example if I am shooting for a pano and it does not cause much headache in that setting, I may pick a longer lens, shoot more frames with the D3 and have the same resolution as with the D3X in less frames, while having enjoyed a higher dynamic range. In other situations the D3X could be the better choice.
IMO these cameras should not be compared as competitors.
Bernard,. you too: Happy New Year (here, at the Pacific coast, it is still several hours away).
-
For what it is worth both Thom Hogan and Iliah Borg claim after having compared the D3 and D3x side to side that overall, they will keep using their D3 beyond a certain ISO because they like the overall result better (that must include noise, detail, DR, colors,...):
- Iliah says that the threashold is around ISO 800,
- Thom has not given a definite number yet
Cheers,
Bernard
Then they should show us their results, describe their comparison methodology and tell us precisely what it is about the D3 images they prefer. I can draw conclusions only from what I see when the medium is visual.
-
I find it a worthless excercise to play the downsampling game with JPEG images (pre-sharpened and lossy).
If Panopeeper downsizes an image with bicubic sharper, then the noise does not get "improved"; can YOU do that better? See Emil's condemnation regarding bicubic sharper.
BS
Forget the above:
Happy New Year
Maybe. However, if your point is valid it raises at least three questions. Why are Imaging Resource producing worthless images for comparison? Why should the lossy jpeg compression favour the D3X? Where are the RAW images from these cameras, of identical scenes, that could provide a more accurate impression of noise and resolution?
Happy New year to you too .
-
Why are Imaging Resource producing worthless images for comparison?
I did not say they are worthless for comparison. I said downsizing of JPEGs and comparing the result is worthless. If you want to downsize the D3X images, then pls in lossless form, without output sharpening.
Where are the RAW images from these cameras, of identical scenes, that could provide a more accurate impression of noise and resolution?
On the Thumbnail page. However, the D3X images can be converted only with Nikon Capture at the moment. Michael got a "pre-production copy" (a beta version) of ACR for his test.
I can measure the noise with Rawnalyze, but that is a single aspect of the comparison.
-
Bernard,. you too: Happy New Year (here, at the Pacific coast, it is still several hours away).
Happy new year to you as well, all the best for 2009!
Cheers,
Bernard
-
Then they should show us their results, describe their comparison methodology and tell us precisely what it is about the D3 images they prefer. I can draw conclusions only from what I see when the medium is visual.
You could also get both bodies. Thinking of yourself as a high end consultant, you should be able to make 1500 US$ per day easily, considering the time you are spending at LL, you should be able to buy a D3 and a D3x within 2 weeks.
Cheers,
Bernard
-
On the Thumbnail page. However, the D3X images can be converted only with Nikon Capture at the moment. Michael got a "pre-production copy" (a beta version) of ACR for his test.
Raw Developper 1.8.2 does also support the D3x if you are on OSX.
Cheers,
Bernard
-
I did not say they are worthless for comparison. I said downsizing of JPEGs and comparing the result is worthless. If you want to downsize the D3X images, then pls in lossless form, without output sharpening.
But you already know, Gabor, that I would never be so foolish as to compare different size images when addressing specific issues such as noise and resolution. Different size images are simply different images, different with respect to size, and therefore they require a different viewing distance for comparison purposes, which is very awkward.
Whether the source image is jpeg, tif or raw, whether it's been pre-sharpened or not, the image sizes have to be equalised for meaningful comparison from the perspective of the photographer who is concerned with a print or display output.
The question still remains, why does the processing that Imaging Resource has applied to images in their 'Comparator', favour the D3X over the D3 when the D3X image is downsized?
On the Thumbnail page. However, the D3X images can be converted only with Nikon Capture at the moment. Michael got a "pre-production copy" (a beta version) of ACR for his test.
It will be interesting to see how significantly the result changes when the same procedure is applied to unsharpened RAW conversions.
-
You could also get both bodies. Thinking of yourself as a high end consultant, you should be able to make 1500 US$ per day easily, considering the time you are spending at LL, you should be able to buy a D3 and a D3x within 2 weeks.
Cheers,
Bernard
Yeah! Sure! Happy New Year to you too, Bernard .
-
ok it is kind of crazy how many people keep looking at noise levels only.
I'm using the 5D MKII right now and the noise control is great of course but I'm more interested in a few things:
Tonal range
Quality of noise (does it distract or degrade the rendering of the objects in the photograph)
Sharpness of the overall image
I've seen a lot of cameras that have great noise control but which also manage to turn the picture into some sort of softer mush instead of maintaining the integrity of the tones.
That said I noticed my 5DmkII does soften up abit beyond 400ISO and I'm interested in seeing if the D3x has better image quality in that aspect ( I don't care if there's noise or not)
-
That said I noticed my 5DmkII does soften up abit beyond 400ISO and I'm interested in seeing if the D3x has better image quality in that aspect ( I don't care if there's noise or not)
Michael's review of the big three, A900, 5D2 and D3X demonstrates there's no significant difference between the 5D2 and D3X up to ISO 6400. As I understand, it's the noise and in-camera processes to reduce it that have the effect of softening the image. I would also prefer to use ISO 3200 instead of ISO 1600 if doing so means I can use either a faster shutter speed or a sharper aperture. A sharp but noisy image is often preferrable to an image which is less noisy but also less sharp.
I always remember my first impressions of the tremendous sense of value I considered my 20D was, when I upgraded from the D60. With the D60 I tried to avoid using ISO 400 and would very rarely go above that. However, using the Canon 100-400 IS with the D60, there were many occasions when I needed to either stop up to full aperture or use ISO 800 at F8 to get a sufficiently fast shutter speed for a sharp hand-held shot at 400mm. Neither option produced good results, technically. However, the 20D could produce images at ISO 1600 that are on a par with D60 images at ISO 400. It was like my lens had been upgraded from a soft maximum aperture of F5.6 to a sharp maximum aperture of F4. Such lenses are very expensive. Consider the Canon 400 F4 DO IS, and I'm not at all sure just how sharp that lens is at F4. Is it as sharp at F4 as the 100-400 at F8?
-
But you already know, Gabor, that I would never be so foolish as to compare different size images when addressing specific issues such as noise and resolution
1. I don't see any foolishnes in comparing the noise characteristics of images of different sizes; I am not an downsizing maniac.
2. I see foolishnes in downsizing presharpened JPEG images (probably after noise reduction) for comparison.
The question still remains, why does the processing that Imaging Resource has applied to images in their 'Comparator', favour the D3X over the D3 when the D3X image is downsized?
Does it? I don't know about that.
-
I am not an downsizing maniac.
Nor am I. I generally upsample more frequently than I downsample when making prints, but recently I've been doing a lot of downsampling in order to display jpeg images on my plasma TV. I would say that it is very rare that I would display any image at its native resolution, whether on monitor or print, although in practice I frequently hand the resampling job to Qimage.
I see foolishnes in downsizing presharpened JPEG images (probably after noise reduction) for comparison.
Well, that's where you and I differ. It might be regrettable that the only images available for comparison are in jpeg format with an unknown processing and sharpening already applied. However, to refuse to equalise the size of both images on the grounds that they are jpegs, makes no sense at all to me.
You should either discard the images on the grounds they are not suitable at all for comparison (in which case it raises the question as to what IR is doing in providing images on their Comparator which are not suitable for comparison) or you do the best you can, despite the fact that the source images may not be ideal.
Does it? I don't know about that.
Yes. The downsampled D3X image is clearly sharper and more detailed than the D3 image, whether standard bicubic is used or bicubic sharper. The situation might change with different processing of the RAW images, but I suspect the bottom line will be the same, ie. the D3 has no IQ advantage over the D3X in respect of resolution or noise when comparing equal size images.