initial review: 2/5/07
Wording fixes: 2/7/07
Minor updates: 3/14/07
Added D40x: 4/20/07
Minor fixes: 7/7/07

  Nikon D40 and D40x Review

Can a 6mp camera compete in a 10mp+ world? And is a 10mp version of the same camera really better?

  Add a comment or send Thom feedback on this article.


In what some saw as a surprise move late in 2006, Nikon announced and shipped another 6mp camera, the D40. Ostensibly, this camera replaced the D50 in the Nikon lineup and became the new entry camera for the Nikon DSLR lineup. The question on everyone's mind was whether or not a 6mp camera has any place in the new 10mp and higher world we seemed to have joined.

I'll answer that question right up front: yes, it does. Why? Well, that's what the rest of the review is here for...

The D40 with the Nikkor 18-55mm kit lens mounted. The D40x looks no different (other than an X after its name).

At US$599 with a lens, the D40 was an attractive option to many shopping for a camera during the 2006 Christmas season. That price will go lower, so if you're on the lookout for a good entry camera, or perhaps a carry-everywhere backup, pay close attention, as this review packs a few surprises. (Just as a reminder, really low prices listed on the Internet aren't always a good thing: they can be indicators of gray market imports, which NikonUSA won't warranty or repair. Moreover, a lot of advertised prices are come-ons. If you're unsure, check out a retailer on or a similar site.)

Along with the D40 we received an update of the "kit" lens, the 18-55mm f/3.5-5.6G AF-S ED DX, now with a II after its name. The primary change in the lens is the use of a new autofocus motor that provides faster and more precise autofocus over the predecessor. In terms of optical performance, I see no changes from its predecessor.

At PMA 2007 in early March we got another surprise: the D40x. The differences between the two models are minimal, but functional: a 10mp sensor instead of the 6mp one; a new mechanical shutter (which changes the flash sync capability), and a slightly faster continuous frame rate (3 fps instead of 2.5) are the only changes. Thus, I'll deal with both cameras in this review. Specifically, I'll speak to the D40 most of the time, and only point out places where the D40x is different. Most of those differences will pop up when I get to the image quality discussion.

Highly Recommended


Yes, the ratings are the same for both the D40 and D40x. While you get a bit more "performance" from the D40x due to the extra pixels and slightly faster frame rate, it's not enough to make me give an additional star, especially given the loss of flash sync speed. Likewise, the increase in price for the D40x, while slightly more than justified by the changes, doesn't warrant losing a full star for the D40x, either. The D40 value rating would be higher, though, if you could get the D40 without the kit lens. Put another way, body only at a lower price I'd give the D40 full marks. It's likely that at some point in the D40's lifespan that'll happen.


The Basics

The D40 is a refresh (and slight miniaturization) of the D50 body design with a major twist in the UI. Specifically, the body size, shape, and build are like a D50 that has successfully undergone a Weight Watchers program. Overall, the camera lost about 3 ounces and at least a quarter of a inch in every dimension (for you non-Americans, that's 70g and at least 7mm in every dimension). The primary notable differences from the D50 are the lack of a top LCD, a slightly brighter and larger viewfinder, a bigger color LCD on the back, and the OK button in the middle of the Autofocus direction pad. All of those things come into play when choosing between a D40 and a D50, by the way, so don't dismiss any small detail as unimportant.

Here are the D40 (left), D50 (middle), and D80 (right) side by side for comparison:

The D80 is only slightly bigger than the D50, but the D40 is significantly smaller than both of the others.

The sensor in the D40 is the same 6mp CCD made by Sony that was used in the D50 (and D70s). The 6mp effective megapixels mean 3008 x 2000 pixel images, enough to produce straight-from-camera prints up to a little larger than 8x11" without resizing. The base ISO of the CCD is 200, with third-stop increments up through ISO 1600. You can also boost ISO one more stop, up to an effective ISO 3200.

The sensor in the D40x is the same 10mp CCD made by Sony that was used in the D80. The 10mp means that you get 3872 x2592 pixel images, enough to produce straight-from camera prints up to almost 11x14" without resizing. The base ISO of the CCD is 100, otherwise the ISO capabilities of the two cameras are the same.

As with the other Nikon bodies that use this sensor, flash sync on the D40 is arbitrarily limited to 1/500 (with non-TTL sources you can shoot flash at any shutter speed). Shutter speeds above 1/90 on the D40 are done electronically by the sensor, not by the shutter opening time. This allows for use of a less complex, lower-cost shutter, but it introduces the propensity for blooming when you include a very bright light source like the sun in the frame. D40x users will be slightly disappointed to learn that the all-mechanical shutter necessary for that camera's sensor means flash sync is limited to 1/200. Unfortunately, TTL FP is not supported on the D40x.

Nikon has once again integrated a number of things into the D40 to address the potential for decreasing noise production versus the previous consumer cameras. For example, data is kept in 12-bit space right up until the final compression to an 8-bit JPEG. Second, the internal digitization engine has a noise reduction component in it. That, plus the fact that Nikon has a long, deep experience with this sensor and knows how to optimize the image data from it means that the D40 promises to be quite good in handling noise. When we get to the results section of the review, we'll talk more about whether or not Nikon was successful, but I'll preview the answer here: yes, they were.

The D40 is a relatively poor IR or UV camera. Each successive Nikon round of DSLRs seem to have more and more IR and UV filtering, though the D40 seems to be about the same as the D50/D70 in this respect. If you want to shoot images outside the visible spectrum, you're either going to have to hold onto those old D1's and D100's, or have your D40 modified to remove that filtration. (As an aside: the D40 and D40x are a bit unusual in that disassembly to remove the IR filter will require unsoldering and resoldering some leads. This makes conversions much more complex and time consuming.) Curiously, Nikon seems to have taken a step backward on the antialiasing filter. The D40 seems to use a less aggressive one, more akin to the D70's filter than the D50's. That means that acuity is quite high right up to the Nyquist frequency, but moire can be triggered by fine detail. I suspect that Nikon wanted to make the D40 images perceived as being as sharp and detailed as possible given that it's a 6mp camera competing in a mostly 8 and 10mp world. The D40x is more like the slightly relaxed acuity you find in the D80, and thus less likely to produce moire. Note that the change in filtering doesn't mean that the D40 has more resolution than the D50 (I don't think it does--it certainly doesn't test significantly different), but all the internal changes (12-bit processing, improved imaging ASIC, relaxed AA filter) appears to give a slight perception of more sharpness in JPEG images than I find from my D50 using the same lens and settings. The D40x seems to be very close to the D80 in acuity, though as you bump up the ISO value with noise reduction turned on, the D40x seems to lose a bit of detail that the D80 doesn't (but that detail comes at the expense of slightly more noise on the D80).

The D40 feature set is a cut-down feature set, as one would expect from the entry-level camera in a lineup. You can find the full comparison of current Nikon DSLRs here if you want the full list. But here's a short version of the important features:

D40: US$599 body and lens
D40x: US$799 body
US$800 body and lens at intro US$899 body only at intro
Shutter Speeds
30 to 1/4000 30 to 1/4000 30 to 1/8000
Flash Sync

D40: 1/500

1/500 1/500
Matrix Meter
420 pixel CCD 420 pixel CCD 1005 pixel CCD
i-TTL i-TTL i-TTL, commander mode
CAM 530, only AF-S lenses CAM 900, Adds AF-A CAM 900, standard Nikon AF
SD or SDHC card SD card CF card
USB 2.0 (High Speed) USB 2.0 (High Speed) USB 1.1 (USB 2.0 Full Speed)

D40: 200-1600 1EV steps + HI1
D40x: 100-1600 1EV steps + HI1

200-1600 1EV steps 200-1600 0.3EV steps
Frame Rate
D40: 2.5 fps
D40x: 3 fps
2.5 fps 3 fps
Color LCD
2.5", 230,000 pixels 2", 130,000 pixels 2", 130,000 pixels
Pentamirror, 95%, 0.8x magnification, 18mm eyepoint, -1.6 to +.5 diopters Pentamirror, 95%, 0.75x magnification, 18mm eyepoint, -1.6 to +.5 diopters Pentamirror, 95%, 0.75x magnification, 18mm eyepoint, -1.6 to +.5 diopters
No DOF Preview, No Top LCD, No Mirror Prerelease, No LCD cover, No Front Command dial, No vertical grip, has FUNC button, no bracketing No DOF Preview, No Top LCD Backlight, No Mirror Prerelease, No LCD cover, No Front Command dial, No vertical grip No Mirror Prerelease, No vertical grip
IR wireless only IR wireless only IR wireless, MC-DC1 wired
EN-EL9 EN-EL3 (originally; now comes with EN-EL3a) EN-EL3a
5 x 3.7 x 2.5" 5.2 x 4 x 3" 5.5 x 4.4 x 3.1"
1 lb (471g) 1 lb 3 oz (540g) 1 lb 5 oz (600g)

Substantive functional changes between the three consecutive entry-level models are for the most part minor, though the price has dropped with each successive generation.

The big changes, though, are the lack of support for lenses that don't have built-in focusing motors (ones with such motors include only Nikon's AF-S line and Sigma's HSM line at the present time), and the loss of the top informational LCD. I'll have more to say about each in the Handling section. Some may miss both of these, but I suggest you keep a more open mind.

One aspect of lenses that doesn't get mentioned much with the D40 is an intriguing one: you can mount any Nikkor on it. That's right, any, as in pre-AI lenses can be put on this camera and used without damaging it. Of course you'll be metering and focusing manually, but it did suddenly make a handful of lenses in my mom's gear closet that date back to the mid-1960's suddenly usable again.

The D40 adds intelligent battery life tracking ala the D80/D200, though it's done with a new battery, the EN-EL9, and doesn't give you specific information. The AC adapter is new (EP-5) and plugs into the battery compartment instead of the side of the camera. We get a FUNC button. The Scene exposure modes have changed a bit, with the addition of a new Flash Off mode.

There is no anti shake (VR in Nikon's language) or sensor cleaning function in the D40. The primary competitor at the low end, the Pentax K100D, has anti shake built-in. For a camera aimed at the amateur photographer, this is a bit of a feature lapse, I think. That's especially true since the least expensive lenses you'd use with the D40 don't come in VR versions (18-55mm, 55-200mm, for example).

Overall, the D40 is a very compact camera with a limited set of features, offered at a rock-bottom price. Still, features aren't the only thing you evaluate a potential camera purchase on (otherwise this review would be almost done, wouldn't it?). To me, the bigger issues are handling (ergonomics) and performance (image quality). So don't count the D40 out against the competitors just yet...


Reminder: the D40 and D40x are alike and I only mention the D40x where there are differences

I've written a lot about the handling of Nikon DSLRs in my other reviews, but the D40 is the first one in a long time that requires a closer look at the user interface aspects of the camera. That's because quite a bit has changed from, say, the D50. Fortunately, mostly for the better.

While the D40 is a very small camera (not much bigger than my largest Coolpix), I don't find any compromise in hand positions or grip. Indeed, I spend most of an afternoon wandering around a small preserve area without a camera strap--simply holding the camera in my right hand as I moved around taking pictures. The grip is the right size, and correctly positioned. The controls fall into the right positions. Indeed, it seems Nikon has made an effort to make the controls less likely to be accidentally engaged. The Autofocus direction pad, for instance, is not the miniature Gameboy one of the D50, for example, but a slightly bigger one that is easier to find and control with your thumb. Though the D40 is a far smaller camera than even the D50, Nikon has once again gotten the "grip" right. The same one-handed hold still feels comfortable and secure, and reaching the key buttons while holding the camera is natural for most people (if you have really large hands, the camera is small enough that you may feel constrained). For such an extraordinarily small camera, it doesn't feel small, at least other than the lowered weight. One caveat: if you use a really wide barreled lens on the D40, the edge of the barrel can extend so far that there isn't much room for your fingers to get between it and the grip. Given that there aren't really any AF-S lenses that fit that definition, it's not a big worry, but the "fat" Sigma 30mm f/1.4 HSM, which works nicely on this camera, leaves barely enough room for my fingers to fit.

Nikon's button-and-dial interface remains largely intact throughout, but it is now supplemented by a new way of controlling things (I'll get to that in a moment). The AE-L and Exposure Compensation buttons are where we expect them. The one primary exception is that the FUNC button has moved to the side of the camera below the flash release/options button, and doubles as self timer button. Of course, the fact that the D40 has a FUNC button ought to raise a few eyebrows (too bad Nikon didn't opt to allow one of those functions to be depth of field).

That missing top LCD and what Nikon did to compensate for it is the big story in handling. And it's a multi-part, complex story, at that. As you might suspect, the color LCD on the rear of the camera is now used to provide the information that is missing. You can bring up the "simulated top LCD" any time by pressing the new Info button just behind the shutter release (or the Zoom In button, which has additional functions; I told you it was complex). You also have the (needless) choice of Classic, Graphic, or Wallpaper styles. In Classic, the display mimics the old Nikon top LCD styles almost perfectly. In Graphic many of the items are made smaller so that a graphical representation of the size of the aperture being used can be displayed. Wallpaper uses the same small info items but places a picture on your card as the background.

Okay, so let's cut to the chase on those options: use Classic. If you're absolutely new to DSLRs and don't understand that bigger aperture numbers mean smaller openings, use Graphic for a day, then switch to Classic (if you don't get the connection after a day of use, you're not going to get the connection). Curiously, while the aperture opening display helps you visualize what is happening, the shutter speed display in Graphic doesn't. Longer shutter speeds result in shorter bars, and vice versa! Say what? Just another reason I say to get out of Graphic mode. And avoid Wallpaper (hint to Nikon: Wallpaper would have been interesting if you could put something useful into the background, like a DOF chart, but this personalization thing is hokey at best, and possibly confusing at worst because the picture can and does obscure the information). [One clever reader suggested the following: put a line of text that says "Property of MYNAME, email" on an otherwise plain background on your computer screen and photograph this so that the text is positioned so as not to obscure any of the other information. Good idea.]

Okay, with that out of the way, there's still more to say about the color-LCD-as-top-LCD change: there's a hugely useful aspect of it that lives on the very right side of the display. Press that Zoom In button again when the display is visible and you're taken to the right area, where you can directly set Image Quality, Image Size, White Balance, ISO, Frame Advance, Focus mode, AF Area mode, and Metering Method. (And curiously, the rest of the display reverts to Classic style even if you were in Graphic or Wallpaper! Shows you just how much Nikon thinks of those options.) Simply use the keys on the Direction pad to navigate to an item, then press the OK button and Direction pad to set the option you want.

Better still, the options are given sample pictures to indicate the things that you might use them for. For example, in AF Area mode we get images of two children playing (Closest Subject Priority), a motorcycle in motion (Dynamic Area), and a close-up macro shot (Single Area). For newcomers to the Nikon system, these photo "hints" are potentially useful, though I find more than a few of them slightly ambiguous (how are children playing and a motorcycle moving different? They both imply movement, after all [hint: a motorcycle moves faster than most children]). For the most part they work better as reminders once you learn what they're trying to tell you than they do clear tips on how to set the camera for a given situation. Still, a nice touch that is potentially useful for new-to-Nikon users that won't know what the difference between tech terms like Dynamic Area and Single Area are.

But wait, there's more. Order today and... Oops, wrong script. But, yes, there is more, and this time the news isn't quite so good: there's a bit of a delay to the updating of the color LCD info panel. The delay isn't usually objectionable, but it can be a nuisance if you're in a hurry. I've managed to overshoot an aperture or shutter speed setting I've wanted because of it. The delay also seems to be a bit variable in speed, and may have something to do with camera settings.

Unlike the D200 and D2 series, Custom Settings are a single scrolling list of 18 options (Reset is the 18th) instead of being "batched" by function. Moreover, the default of the camera is "only display the first few"--you have to use the Setup menu to display the full set of options. I continue to dislike this "feature" of having a simplified menu system, though I do like Nikon's other tweak: MyMenu. MyMenu allows you to define which menu options appear. Thus, for all those set-once-and-forget options, you can banish them from the menu system after setting them and not have to scroll through them time and time again. Unfortunately, on the D40 the only two menus you might want to use MyMenu on are the CSM and Setup menus, which you don't visit very often, anyway. MyMenu works better on a camera with more menu options than the D40.

Another newish-to-Nikon menu option is the Retouch menu (it appeared first on the D80), which replaces the D200's Recent Settings menu (Nikon giveth, Nikon taketh...). Retouch allows you to do quite a few editing types of things: D-lighting, Red-eye correction, Trim, Monochrome conversion, Filter effects, Small picture, and Image overlay. Most of these are things I wouldn't want to do in camera, as the color LCD just isn't good enough to evaluate D-lighting and Image overlay effects, for example. Trim is nice, as it allows you to do after-the-fact crops. Filter effects/Color balance is probably the most interesting, as it gives you a two-dimensional CIE color space to shift as you see fit (it also gives you access to an RGB histogram, which is otherwise missing from the normal options). This is much more flexible than Hue adjustments. In all cases, the Retouch options create new versions of your photo (your original remains intact).

While we're talking about images, let's talk about image review. With the D80 Nikon changed the way magnifying an image works, and the D40 uses this new method. We now have Zoom In and Zoom Out buttons, essentially. This simplification works quite nicely. Press Zoom In and you zoom in. Press Zoom Out and you zoom out, and once you're at Fit Screen view you then move to four thumbnails and then nine thumbnails with subsequent presses (zoom in gets you back to single image view). Much simpler to explain and understand, though not quite as fast as the old system. I think it's a perfectly appropriate design change for the intended audience of this camera. The Image Review On option is flexible (unlike the D80): you can change the value for the "timers" (unfortunately, we're now given vague Short, Normal, and Long options instead of exact seconds; the good news is that there's one other option, Custom, which allows you to set all the timers individually in seconds).

The new viewfinder is somewhat better than the D50/D70 viewfinders. It seems bigger and brighter, though the stats show that the changes are modest in nature compared to the D80/D200 viewfinder change. No grid lines or extra overlay icons can be made to appear, though. I can easily see both the framing area and the information underneath with my glasses on.

Now here's something you might not notice at first but I appreciate greatly: the camera strap mounts are recessed into the body (instead of sticking out) and are exactly opposite one another so that the camera absolute hangs straight off the strap. This may not seem like a big thing at all, but quite frankly, it shows me that someone actually is looking at the small issues that can impair handling.

Nits are few. I still don't like the Secure Digital door mechanism Nikon introduced with the D50 and has used on the D40 and D80 since. In extreme handling it has a tendency to pop open on me. The button overload is a bit much (particularly the Zoom In, Help, Info, Reset button ;~). The color LCD info display is very bright--it would have been nicer to have brightness options for when it displays data instead of Classic, Graphic, Wallpaper. The FUNC button is nice but needs more options. Some people will miss bracketing.

Overall, there's a lot to like about how Nikon created a smaller, simplified camera from the stock of previous models. Once you learn the nuances of using the rear LCD as the top LCD (and figure out that you can set 99% of what you need to set from this display), you'll find it "very Nikon." Within a few hours I was as comfortable with the D40 as I am with other Nikon bodies, and other than occasionally being too fast for the display updates, found nothing that I felt hindered my use of the camera. As I said earlier, despite being small and light, it still "feels right."


top | home

Cleaning the Sensor I've posted an article on how to clean sensors.

Looking for Mr. Goodlens Nikon shooters have been long looking for that perfect low-light combination and not quite finding it. The D40 may fix that, at least when coupled with the Sigma 30mm f/1.4 HSM lens. Since the lens is HSM, it'll focus on the D40. Since the lens is 30mm, it's about the "normal" focal length for the smaller sensor size. Since the lens is f/1.4 and the camera does great at ISO 1600, you have to be in pretty dark situations not to be able to shoot without flash. About the only drawback is that the lens is relatively heavy, making the combo about two pounds.

Just the right size: D40 w/ Sigma 30




Battery Life
Battery performance is quite good in my limited testing so far. That's surprising since the battery isn't a barn-burner in terms of amperage (1000 mAh) and the rear LCD is almost always on while you're shooting. Nikon's CIPA numbers are 470 to 2200 shots using different setting parameters and flash usage. For most people, I'd guess that a single full battery charge will get them through a day of shooting. Having one extra battery with you is probably enough for 99.9% of the D40 audience to never experience a power shortage. FWIW, keep the plastic cover on the battery when it isn't in the camera--the battery terminals are exposed, and you don't want to risk having them short out against something metal.

Surprisingly, there's not a lot to talk about in differences in battery life between the two models. On some shoots the D40 does a little better (usually when I'm shooting rapidly), on some the D40x does a little better. The one place where I can see a clear difference is in NEF shooting, where the D40x does slightly worse than the D40, probably due to the increased file sizes leading to increased write times.

(In passing, I'll mention that the AC adapter for the D40 is unusual: it's like a battery with a cord coming out of it; that cord goes to the actual AC/DC converter that plugs into the wall socket. The cord threads through a rubber gasket at the bottom of the battery chamber. This whole design actually works better than the ones used on the more expensive cameras, where there's a tendency to accidentally pull the power cord from the camera. Moreover, having the cord come out the bottom right of the camera is better than having a cable plugging in right where your left hand is trying to hold the camera.)

Writing to Card
The Secure Digital write performance is generally very good to excellent. Indeed, the same cards in my D40 perform much faster than they do in my D50--performance seems on par with the D80, so I think Nikon has moved on from the slower D50 write mechanism permanently. Even with some generic cards I was getting near 5MBs per second performance, which is pretty decent, if not quite state of the art. Like the D80, the D40 will shoot at a slightly reduced frame rate for most JPEG sizes until the card is filled up or you reach 100 images, whichever comes first.

Autofocus System
Autofocus performance is adequate. The number in the part name (CAM530 versus the old CAM900 in previous Nikon consumer DSLRs) indicates the number of overall points that are sampled for focus information, so it should be obvious that the D40 should be worse than a D70 (CAM900) or a D80/D200 (CAM1000). This is a little deceptive, though. Assuming you're using the central AF sensor only, there's no real performance difference between the D40 and the D50/D70, and only a small one with between the D40 and the D200 (mostly due to things other than the AF sensor itself). With only three AF sensors, the D40 actually gets a slight benefit in Closest Subject Priority over the D50, as not only is there less data to analyze, but it's less likely that an "unlit" sensor is going to cause the AF system to slow down.

For those shooting Single Area AF, the technical side of things means that the D40 isn't going to perform much differently than a D50 or D70s, actually. The D40 has two things that will affect performance for shooters who use other AF settings, though: (1) the AF-S only lens requirement means you'll never encounter the dreaded "screw-drive hunt"; and (2) the missing AF sensors mean you're going to be more tempted to revert to focus-and-recompose. That's especially evident when you shoot vertically--you don't have any sensors on the sides! In horizontal compositions I consistently found that I missed that bottom AF sensor (but not the top). In vertical compositions, the lack of the two extra focus sensors is more problematic, and you are forced to focus and recompose more often. Frankly, it's not a big deal, as you simply will start using this camera differently to compensate for its missing AF sophistication. Those of you who already are in the focus-and-recompose group won't have any trouble with the D40.

As one would expect from what is essentially a fourth generation of an imaging system (D100 -> D70 -> D50/D70s -> D40), Color integrity is very good, even with the slightly distorted sRGB color spaces that Nikon uses (Ia and IIIa). Indeed, I don't really see any significant differences from the D50 in this respect. Here's the gist:

  • Saturation is a little higher than correct at default settings, as it has been on most Nikon DSLRs since the D100 (and most DSLRs in general). Saturation stays high at ISO 1600, meaning that you don't get duller colors just because you use a higher ISO value (you can and do lose some shadow detail due to loss of dynamic range, though; see the noise section later in this review). Note that you can "goose up" the saturation by overriding the image quality settings, but personally I find such exaggerated results a bit too comic book like and not very photographic.
  • Color accuracy for the default sRGB Color Space is about the same as previous Nikons that use the same sensor: nearly perfect in most greens, browns, and some of the blues, a bit exaggerated in the deep blues and some of the yellow/red colors. Most people will find that pleasing (warmer skin tones, deeper sky colors). AdobeRGB Color Space is closer to correct, and requires very little correction in a converter to get fairly "neutral" coloration.
  • Auto White Balance tends to be a slight bit low in sunlit scenes, a bit high in indoor and mixed lighting scenes. As with most Nikon DSLRs, the top two-thirds of dynamic range tends to be relatively flat in whatever the camera sets (i.e. whites have the same white balance as mid-range grays), but the accuracy slips a bit as you get into the darkest tones. This is such a "standard" on all Nikon DSLRs these days I have to wonder if Nikon is trying to compensate slightly for cooler (reflected) light tones in shadows. Overall, the impact is again pleasing, if not 100% accurate. But I wouldn't recommend Auto White Balance in incandescent or fluorescent lighting: use Preset or one of the specific white balance settings.

One thing that Nikon seems to have no trouble doing is making a Nikon look like a Nikon. Yes, that's easy when you use the same sensor in four different generations of cameras, but it applies across sensor technologies, as well. In terms of color rendering, the D40, D80, D200, and D2xs all render colors so closely that it seems clear that Nikon has a specific color target in mind and is sticking to it. Only the D2hs varies much from this "Nikon DSLR look" in my experience.

Let's again start with amp noise. On a 10-minute exposure, amp noise is a bit excessive, much like it was on the D80. On the 6mp D40 you'll see it in two places along the top edge (top left corner and immediately to the right of that); on the 10mp D40 you'll see it in three places along the top edge (top left corner, immediately to the right, and a third spot in the upper right corner):

d40x amp noise

The built-in camera noise reduction is capable of dampening that considerably, to the point of where it isn't visible:

Not a great performance, but not a horrible performance. It is worrisome to me, however, that recent Nikon bodies seem to exhibit a strong degree of amp noise at that top edge. Moreover, the D40x showed a considerable amount of hot pixels in the 10-minute exposure without noise reduction turned on. There are plenty of competitor bodies out there that do better, so this is an engineering problem that Nikon simply hasn't directed much energy on. They need to.

For general noise I have far better news to report. The D40 produces decent noise results under pretty severe conditions (including my usual mixed lighting with low intensity torture test). Here's what the worst of the bunch of my tests looked like (ISO 200 on the left, ISO 1600 on the right):

For those of you who want an interpretation of what those charts show: in very low, spectrum challenged light, both ISO 200 and 1600 produced very usable images. Several things were noted: (1) the red channel differences at the lower ISO value are due to there not being a lot of red energy in the test lighting and the fact that Nikon's noise reduction obviously doesn't kick in at ISO 200; it very obviously does at ISO 1600, as the red channel has been "tamed" and more closely conforms with the other channels; (2) at the higher ISO levels the "usable" dynamic range decreases slightly due to the increased noise in the darker portions of the image, but this is normal and the D40 seems to be considerably better than the D70 in this regard and perhaps slightly better than the D50; (3) while noise is higher at ISO 1600 than 200, it is still well controlled and I don't see the sharply rising tendencies I've seen in some previous cameras (I've seen noise values considerably higher than 2 at ISO 1600 for many earlier cameras).

Amazingly, the D40x does a bit better than the D80 in the noise department, apparently due to slightly more aggressive noise reduction, as the level of detail is slightly lower at ISO 1600 on the D40x than it is on the D80. But again, ISO 100 to 1600 produced very usable images.

As I indicated in earlier reviews, I'm getting more leery of "number oriented" assessments of image quality properties like noise. That's because I have seen too many examples where an actual image from a camera with a "higher noise number" actually looks better than the supposedly superior camera. Put another way: raw noise numbers don't tell you a lot, which is why I've stopped publishing large tables of them. Since a lot of newcomers are probably reading this due to the low-end appeal of the D40, I need to elaborate.

The way we measure noise is by looking at large patches of the same color and looking at (adjacent) pixel value differences. In theory, the pixels all ought to be the same value, since adjacent pixels are reproductions from the same patch of color under the same lighting. Even on the best camera there is some minor pixel-to-pixel variation, though it may not always be visible to the naked eye, as the difference can be very small. The variations, however, can be in many forms. First, they can simply be overall intensity variations ("luminance noise"). Second, they can be color variations (look at the difference between the red, blue, and green samples in the lefthand chart, above--those are color variations, which we call "color noise"). Third, noise can have a "size." Two adjacent pixels may be the same but the third is different; or three adjacent ones are the same but the fourth is different. In JPEG files, such noise sizing can be variable and is usually due to camera's de-mosaic (image rendering) routine and JPEG encoding crudity, and further to any interaction between those. Fourth, noise can have a pattern. Indeed, digital cameras have pixels aligned in rows and columns while film had overlapping and random grain patterns. If there's an electronics frequency-related issue to the noise production (e.g. jitter in the analog-to-digital conversion circuitry), patterns easily appear in noise samples of digital cameras. Fifth, noise can and does interact with detail production, and noise reduction techniques can produce anything from watercolor-type effects (vagueness) on detail to what I simply call "mush." I could go on, but you get the idea: noise is a variety of deviations from the desired data.

And some of those deviations are more visible and disturbing to our eyes than others. Take luminance and color noise, for example. Color noise is easily seen while luminance noise generally isn't (unless it has a pattern ;~). Indeed, color noise is a dead giveaway for "digital" images, as there is really no corresponding problem in analog (film) recording. Bad color noise is disturbing visually because a block of color suddenly has impurities of prime colors (red, green, blue) in it. (The color noise in the D40 ISO 200 example I showed above is low enough in amplitude to be not-visible; the lack of color noise in the ISO 1600 example is refreshing, as it means that colors stay true as the noise increases.)

I've just alluded to two of the five types of noise the D40 could have. So how does it do on all five? Excellent, Excellent, Very Good, Excellent, and Excellent, actually. Ditto for the D40x. At high sharpening settings and low JPEG qualities, the noise size issue starts to just inch into visibility, but otherwise I'd say the D40 is visually non-disturbing in its noise tendencies. So let's put that assertion to the visual test. I've been using the gym I play basketball in as my test lab for low-light, high-ISO, weird light color images in reviews for awhile now, so I'll step out of the game for a moment and take a few shots for us to look at.

The first shot is actual pixels best case exposure at ISO 1600 from a D40, the second actual pixels worst case exposure at ISO HI 1 (3200), also from the D40. Both images taken from the sideline with a Sigma 50-150mm f/2.8 lens. ISO 1600 isn't quite good enough to stop motion at f/2.8 in this dim gym, as it only provides 1/250 best case (one of the reasons why the ball is slightly soft--the motion hasn't been completely stopped). Note how clean the ISO 1600 shot is, though. Instead of noise, you actually see some of the texture in the black seams. At ISO HI 1 we see blotchy color noise, which starts to wipe out any of the ball texture. Bottom line: ISO 1600 good, ISO HI 1 only slightly better than the other Nikon bodies. (BTW, the difference in mid-tone exposure is only about a third of a stop--this is one of the reasons why 3200 isn't labeled ISO 3200; the noise build up robs color saturation and takes everything down in tonality. Note that the highlights on the rim and ball remain slightly blown and the white wall and net are still relatively white. It's the dark noise build-up in the colored areas that is making everything look darker than it should. In short, the tonal ramp gets compromised at HI 1 in ways it isn't at the numbered ISO values.)

By way of illustration, here's the D40x at ISO 3200 (same lens, exposure, same ball, etc., but taken on a different day):

D40x iso3200

You should note that the D40x shot at ISO 3200 still has a fair amount of noise in it, but the color saturation is higher (look at the rim), the color noise is handled better, the blacks in the ball are really black instead of a mottled dark gray, and this is despite an increased pixel density. I didn't do a basketball shot with the D80 review, but the D40x does better than the D80 did at ISO 3200.

Let me put all this another way: most users can use ISO 200 to 1600 (and therefore the Auto ISO function) with relative impunity (100 to 1600 on the D40x). The two things that would restrict you are: (1) the slightly reduced dynamic range at ISO 1600 means that you really don't want to use high ISO values for things like high contrast scenes, like outdoor scenics in bright light; and (2) you probably want to avoid high sharpening and contrast settings at high ISO values if you're going to print large. Personally, the D40 is the only Nikon DSLR I leave on Auto ISO. I'll take it off that setting on occasion, but most of the time I just shoot with it on.

I guess the lack of AF sensors is a good thing. As you may know from my D80 review, that camera had perhaps an over reliance upon the area underneath the active AF sensor in its matrix metering. The D40 doesn't seem to have that problem near as much, though I do find it often meters a bit "hotter" than the D200 or D2 series, and this tendency still tends to follow what's under the current AF sensor. Indeed, I don't find the D40's matrix metering much different than the D50. That's easy enough to compensate for, since the matrix meter seems slightly more consistent on the D40 and D50 than the D80. And you always have the center weighted and spot metering to fall back on, a full array of metering options that you don't always find on entry-level cameras.

The step test (multiple wedges of neutral patches from black to white) at default settings showed the slight mid-range hump that appears to be standard now with Nikon bodies (early Nikon DSLRs were very flat from black to white). If there's a weakness in the D40 exposure, it's at the highlight (white) end of exposure, where the curve falls off rapidly enough that very bright detail suffers slightly. If that really is a problem for you, back the exposure off 0.3EV (through exposure compensation); the D40's noise handling is plenty good enough so that you don't have to worry about a small amount of underexposure generating more visible noise.

Short answer: I see no measurable difference between the D40 and its predecessor, the D50. As I've already noted, I do believe there is a bit more acuity to the D40's images than I found on the D50, and this doesn't seem to be simply a matter of tweaking the image settings, since moire is more easily produced on the D40 than it was on the D50. (Yes, I know I'm overdue in writing an article that explains the difference between resolution, detail, sharpness, acuity, and the other terms that we use to describe the integrity of the image quality versus the original scene. But in case you haven't already figured it out, you can have sharp images of low resolution and unsharp images of high resolution.)

And I see no meaningful difference between the D40x and the D80 (there's a slight loss at high ISO values on the D40x, though better noise handling).

Just to remind everyone, at the highest level of DPI you need to set most inkjet printers, the D40's 6mp will produce 7x10.5" without doing any resizing (the D40x gets you to 9x13.5"). And I'll repeat a variation on one of my more famous quotes: "If you can't produce 10x15" prints to your liking from the D40 (or D40x), it isn't the camera." By that I mean that those 6 megapixels pack more than enough information to get excellent prints at 10x15" that show no pixelation, no stair stepping, no per-pixel artifacts at any viewing distance you'd find comfortable (even held at arm's length). So now fess up, how often are you going to print bigger than that? Even if you do, you still might be able to coax enough quality out of the D40 to go bigger. My rule of thumb is that you can get to about 2x the normal print size if you make optimal image quality decisions all the way down the chain from initial exposure to final post processing. For a D40 that would be 14x20", for the D40x that would be 18x26"; both are bigger than the desktop inkjet printers can create.

Still, many of you don't trust my observations and want examples. Here's a shot handheld with the D40 and the kit lens (left is full image downsized, right is actual pixels view [hint: find the pine trees in lower left of full image; you're looking at the rightmost pine tree, the roof of a house, and a distant oak tree in the actual pixels view]).

Enough resolution for you? I hope so. You're almost seeing the shingle pattern on the house that's 400 yards away, and all those oaks on the right are over 200 yards away yet we're still seeing distinct branches that are very small in diameter. On the right you're looking at what would be a 1" wide area of a print, and this was taken handheld, at near the widest aperture (about half stop down), with the least expensive lens you're likely to stick on the D40. I see just a bit of camera motion in the example, so detail could be even better than it is here. And, yes, it was a gray, overcast day. (The D40x would do only slightly better on this--I'm trying to show you a worst case here, and the worst case isn't bad at all.)

Final Comments
The D40 is likely to be Nikon's only 6mp and entry-level DSLR for awhile. As such, it goes up against the Pentax K100 series, used bodies, high-end compact digicams, and a host of other products. And I think it'll hold its own.

First, the image quality is excellent. Nikon has proven once again that they know how to suck every last little bit of quality out of the 6mp sensors they've been using for more than four years. And amazingly, the included kit lens doesn't let the sensor down. For those that aren't trying to shoot wall murals and are satisfied with the size prints you'd get off, say, a really good desktop inkjet, there's nothing to complain about in image quality until you get to ISO 3200, and even then some will find it usable at smaller print sizes.

But the impressive thing about the D40 is that it is arguably the best-designed small camera to date. Handwise, it's perfect. The viewfinder is good, if not up to the D200 level. The controls are sensible and what we Nikon users expect. And the moving of the top LCD to the color LCD, while still with some slightly rough edges, turns out to be a lot more useful than you'd expect. As I note in the handling section, you can do 99% of the settings you're likely to make while shooting without dropping into the actual menus. Nikon almost hit a home run with that, and frankly, why their top end Coolpix cameras don't borrow the best aspects of this design I don't know. Color, noise, and resolution are quite good, and you have enough control over the first two items to get excellent image quality.

The D40x retains all the things that are likeable about the D40 and gives you a 10mp sensor that produces images that are arguably slightly better than the D80 can produce (at least for JPEG files). You pay for that extra resolution two ways: extra dollars up front and reduced flash flexibility due to the all-mechanical shutter. I don't expect to use my D80 much any more with the D40x being smaller and lighter. But someone with older AF lenses or who needs one of the D80's additional features might choose differently.

Personally, I'm trying to figure out how to pull a Galen with my newly acquired D40x I like it so much. By that I mean use the D40x as the camera I carry with me on my runs. Unlike what Galen did, I don't use a full on chest pouch to hold my camera while running, so I need to figure out the best way to carry it without it flopping around. Fortunately, I bought mom a new sewing machine for Christmas, so I can burn a few credits with her while experimenting on a new strap system that'll hold the camera against my body the way I want it to. (Another possible solution is the Dewitt Jones Chest Strap made by LowePro.)


  • Kit lens blues. The 18-55mm is a more than decent lens, but I'd like to have the option to buy a body only in the US (it's available as body only in Japan, and you have the option with the D40x). The D40 would have been killer with an 18-70 VR or 18-135mm VR, by the way. The current purchasing option is a bit limiting.
  • Nother new battery. Did we really need another new battery just because the camera is a smaller size?
  • Not for the late-to-the-party film converts. If you've got mostly AI, AI-S, and older AF lenses and are just now getting round to going digital, the D40 (or D40x) isn't the camera you want, as you'll be resorting to manual focus.


  • Small and beautiful. Makes you wonder why Four Thirds designs (e.g. Olympus) were necessary. And for a consumer camera, the frame rate, mirror return, shutter lag, and autofocus are fast enough to feel snappy.
  • Most of what you need. While it would have been nice to have a DOF Preview button, everything else you're likely to want is there, including spot metering.
  • Excellent Image Quality. State of the 6mp art. State of the 10mp art. Enough said. | Nikon | Gadgets | Writing | imho | Travel | Privacy statement | 2007 Thom Hogan. All rights reserved.