Field Tests: The Nikon D4 - The Best Gets Better?
I. Introduction
Post Date: April 9, 2012
My Executive Summary:
Even after only shooting with the D4 for 10 days, I can offer up a limited executive summary (and this summary WILL change at least once in the coming months). For this wildlife photographer the D4 offers a large, but not revolutionary, step forward in image capture capabilities. In day-to-day field use the biggest improvement - and the one that will contribute most to me capturing images that were missed before - is in autofocus performance. Ergonomic changes rank a close second, particularly the effective mirroring of key controls in horizontal and vertical camera orientation. While noise differences at high ISO settings are virtually unchanged from the D3s, improvement to overall image quality at high ISO's (while hard to define) leave me more comfortable at shooting at ISO's above about ISO 3200. The increase in resolution to 16.2 MP is welcomed and will make a difference to me at times. Overall? For this wildlife photographer, the best camera for day-to-day use in the field just got a lot better...
Back to the Introduction...
As always, the release of Nikon's newest flagship was eagerly anticipated. Since its predecessor (the D3s) was introduced in 2009 many serious photographers have considered it to be the overall top DSLR on the market. While the D3s was generally accepted as the "King of ISO Performance", it was its overall mix of outstanding features that distinguished it - things like great build quality, fast frame rate, excellent autofocus system, and more. About the only substantitive complaint you ever heard about the D3s was that at 12.1 MP perhaps it was a tad low in resolution. As the introduction of the D4 approached, I (and probably thousands of others) had one major question in my mind: how much can a D3s really be improved on?
Those that simply look at the specs of a camera and then judge it would probably conclude that the D4 represents only a small, incremental upgrade. After all, if you exclude video (I always exclude video!), no single feature really jumps out as "revolutionary". I have to admit that's how I felt about the D4 - until it was in my hands and I began shooting it and pushing some boundaries with it. I don't want to get too far ahead of myself yet, but as I write this introduction only 10 days (and about 1000 frames) after getting my D4 I am already prepared to confidently say this - the best has got better. And for me (and my shooting style) - it has got a lot better!
Once again, this field test is not intended as a regurgitation of the specs of the camera - it's simply intended to convey how it works for me in the field. Producing spec spews bores me, and others do it better anyway - go here on dpreview's website for a real nice summary of the features of the D4. A more "interpretive" (and I think more readable) overview of the D4 may be found found here on Rob Galbraith's website (thanks once more Rob). I'll simply say that the D4 is Nikon's flagship DSLR targeted at serious photographers who like to photograph action in any form - sports, wildlife, etc. I would describe its most significant upgrades to be increased resolution (from 12.1 MP to 16.2 MP), improved autofocus, improved metering, and a signficantly improved functional "user experience", which includes not only ergonomic changes but also tweaks to viewfinder displays. Things like how the camera operates in vertical orientation, how you change ALL the autofocus settings with one button, etc.
PLEASE READ: Qualifiers, Caveats, and Context:
I test my gear quite extensively in an effort to discover how it will perform for ME (using my own shooting style) in a field situation. I'm not paid to test equipment, nor do I receive my gear for free. I test them under field conditions only (no lab work) and use the same techniques I'm likely to use when I'm shooting the particular item in the field. While I do some of my testing very methodically, much of it is pure "field shooting". I do not shoot images of targets under rigidly controlled lab conditions - I shoot images of landscapes, wildlife (or "proxies", such as my Portuguese Water Dogs) in the field. It's not critical to me to produce results that are generalizable or that are rigorous enough to be published in a peer-reviewed journal - I care about how I can use the gear in the field and how to get the results I need to sell images! While some "lab tests" have a real-world correlate that translates into a limitation in the field, I find an increasing number of tests quite esoteric and the "differences" between two products is real only in a statistical sense (and has no real correlate in producing a quality image, which is definitely not a pure science). There are a few tests I rely on - for instance, I normally find dxomark.com's published values for "Low-Light ISO" performance are almost always close to what I consider "acceptable image quality" (in terms of noise), and thus they usually have a real-world correlate for me.
This field test is intended as a living, evolving document. It will be produced and modified over time as I learn more and more about the D4. There will be a minimum of two chapters in this story. Chapter 1 includes my early impressions of the camera - the good, the bad, and possibly the ugly (if it exists).
Chapter 2 will be a more detailed treatment of some of the improved things that make the D4 shine, including performance of the new autofocus system, my thoughts (and tests) on its ISO performance, and some comments on its image quality.
Chapter 3? Don't know if there will be a chapter 3 and, if there is, what I'll include in it. Remember I said this was going to be a living, evolving document!
It is important for readers of this document to realize that it is intentionally written from the perspective of a nature/wildlife photographer who spends a lot of his time shooting wildlife in dark places, like the Great Bear Rainforest. And, like the majority of nature photographers, I shoot raw images only - so you will not find detailed discussions of JPEG-only features, such as Active D-Lighting or in-camera HDR functions. I personally feel that the majority of issues facing wildlife photographers are similar to those facing sports photographers - and certainly both put a premium on autofocus and ISO performance. So many sports shooters will likely find this field report useful. How useful will this be to other genres of photographers? That's up to them to decide.
Finally, some may think this field test omits half of the camera's new functionality - everything that deals with video. Yep, I don't hide that fact - I'm a still photographer. And, I think most people buying a D4 are more concerned with its still photography capabilities than its video features. From the little information I've picked up about video, I expect if someone is primarily concerned about shooting video, they're more likely to buy a D800 anyway. And, given I know next-to-nothing about video (and probably never will) I am totally unqualified to talk about it. So, you'll have to go elsewhere to read about that. C'est la vie.
II. Chapter 1: The Nikon D4 - Early Impressions.
Post Date: April 9, 2012.
I'm testing and writing about my first impressions of the D4 while simultaneously testing and writing about the D800. And, I still own a D3s. So...there will be lots of "comparative" comments in this section AND in chapter 2. Based on email I'm receiving about the D800 and D4 I have the impression that there's a lot of shooters out there that are debating one or the other. Hopefully all my "comparative" comments will help them come to the purchasing decision that's best for them.
1. Build Quality: There's not much to say here - this is Nikon's flagship and they have ALWAYS understood how to build their pro cameras - robust and durable. The D4 is no exception to this long-standing tradition - overall superb build quality. While it's nice that the D4 is slightly lighter than the D3s (60 gm on my scales), in use I don't notice the difference (they're both heavy cameras) and 60 gm is pretty insignficant when you have 5 kg lenses attached to the front of the camera. One niggling "irritant" - which I doubt has any functional signficance: if you tap on the door that covers the memory cards, the D4 produces a very slight "rattling" sound - almost like the latch is not fully "locked". The D3s doesn't do this. I have to admit I did NOT notice this myself and I'm not sure I would have if someone hadn't pointed it out to me (thanks are extended to Henk F. from The Netherlands). I consider this a "niggly" irritating thing at worst, but it's a tad surprising on a camera pushing $6k CAD.
2. The "New" Autofocus System: Nikon has changed BOTH how you control/change the settings on the AF system and the "guts" of it. Here's a bit on both sides of the equation:
• The New AF Controls: You now control all aspects of AF function using a single button on the left side of the lens mount (in combination with the commmand and sub-command dials). Which means you can modify your settings while looking through the viewfinder. How does it work in practice? Because this feature is shared with the D800 and I had a week to get used to using it on that camera before my D4 arrived, I found it very easy to use (it only took me a few tries with the D800 to become accustomed to it). And, I can say I love it. I virtually never use Single servo mode, but various continuous modes (Single Area, 9-point Dynamic Area, 21-point Dynamic Area, etc,) are super-fast to access. When I'm shooting wildlife I am ALWAYS jumping between these modes, so for me being able to do it while looking through the viewfinder is a godsend.
• The New AF "Guts": Most of the hoopla surrounding the internal workings of the AF system has focused on (pardon the pun) on its improved lower light performance, increased number of cross-type sensors, and full functioning at maximum apertures of f8 (so now you can use teleconverters with compatible f4 and f5.6 lenses). To date I haven't been in the situation to test these aspects of the new AF system. But, when I was talking with Nikon a month or so ago, they stressed to me that the system also would acquire initial focus AND focus-track moving subjects better. I will gush on about this more in chapter 2 (and provide sample images), but right now I will say it DOES appear to acquire intial focus better (tho' I really have no way of measuring this) and it DEFINITELY tracks subjects markedly better than the D3s did (and it was no slouch in this regard).
There's one other little addition to the AF control system that merits discussion that I really like (and that I think many may overlook). Custom function a10 is called "Store Points by Orientation". If you have it turned on, this D4-only feature remembers the last position you left the focus bracket at in both horizontal and vertical orientations. Working on a composition where the subject is off-centre and you have re-positioned the AF bracket? Can't decide on horizontal vs. vertical? Each time you change the camera's orientation the focus bracket instantly returns to the spot you left it when you were last in that orientation. As one who shoots a lot of vertical shots (and often changes the camera's orientation between horizontal and vertical) I REALLY like this function.
3. ISO Performance? Like with autofocus performance, this issue is so critical to potential buyers of this camera that I will deal with it in great detail in chapter 2 below. For now, I'll say this - if you look at JUST visible noise, my own testing has shown the D3s and D4 to be in virtual dead heat. But...there's more to ISO performance than just visible noise (dynamic range, colour depth, and tonal range ALL decrease with increasing ISO and all affect overall image quality). I give the overall edge in image quality at high ISO's to the D4. See the details in chapter 2 for more detail...
4. Ergonomic Improvements. There have been a lot of tweaks to the ergonomics of the D4. Things like losing the AE-L/AF-L button on the back of the camera, moving the AF modes from the back of the camera to the front left side of the camera, etc. But to me the biggest improvement in the ergonomics of the D4 - by a long shot - is the almost perfect "mirroring" of the primary controls (the shutter release, command and sub-command dials, AF-bracket "toggler", and AF-ON button) of the camera when held horizontally or vertically. Yep, it took me a few days to "retrain" my thumb to go to the new "sub-selector" toggle to move the focus bracket around the viewfinder (instead of going to the multi-selector button) when I held the camera horizontally, but once I had that nailed and turned the camera vertically...presto...my fingers and thumbs were in the right position to get to the right controls. So - when held vertically OR horizontally, my index finger finds the shutter release and moving my thumb by the same amount (as when held horizontally) I find the command dial, AF bracket toggler, or AF-ON button (which I have programmed to AF-Lock) exactly where they "should" be (relative to their position when the camera is held horizontally). Love it. Definitely one of those "why didn't they think of this before?" things - but glad they did now...
5. Improved Auto ISO Function: OK, I admit it - since the "old new" Auto ISO function was introduced on the D3, I've liked it. And, now (on this camera and the D800) it's a lot better. In the "old new" Auto ISO system you "told" the camera what the longest shutter speed it could employ before bumping the ISO. The "new new" system still offers this. But, it also offers an "Auto Shutter Speed" option where the camera examines the focal length in use (including on zoom lenses) and picks the slowest shutter speed that the average person could hand-hold (using that old 1/lens focal length = shutter speed formula). But what if you're a human tripod (or using VR) and can hand-hold slower shutter speeds? Or if you're kinda shaky? Well, there's a 4 stop over-ride to the auto - up to 2 stops faster than 1/focal length or 2 stops slower than 1/focal length. What does this mean in the field? It means that when you change lenses - or zoom your lens - you don't have to give your Auto ISO settings a second thought. Very slick. Very cool. And one other little thing that can contribute to a higher percentage of sharp "keeper" shots. Well done Nikon!
6. New Exposure Metering System. This is another feature that is shared with the D800. In the D3s (and D700) Nikon used light input from a total of 2016 pixels to calculate exposure, while on the D4 and D800 it now uses 91,000 pixels. "So what goes that mean to me?" you astutely ask. What I've noticed with both cameras (slightly more so with the D800), is that the camera's metering "suggestion" (using matrix metering) is more accurate - which often means it over-exposes (blows out) small highlights in a scene less often. With my D3s I commonly left my camera "hard set" to a -0.3 exposure compensation (to avoid blowing out highlights). I'm no longer doing this. It should be pointed out that this tendency to preserve highlights better may also be wholly or partly due to the D4 reportedly having about an additional stop of dynamic range than the D3s (13.1 Evs vs. 12 Evs according to dxomark.com). As with the D800, my best guess that this tendency to perserve highlights is a function of both the new metering system and the increased dynamic range of the camera. The important thing in day-to-day shooting though, is simply the more reliable metering.
7. Live View (Still Photography Mode): Finally, and as I mentioned in my D800 field test, Nikon has figured out how to do Live View! Besides multiple new focus modes (Normal-area AF, Wide-area AF, Subject-tracking AF, Face-priority AF), we now have live histograms, dynamically updated aperture (depth of field) effects, dynamic white balance adjustments, and several display options, including a virtual horizon, grid view, different data views, etc. Simply put, Live View is now dramatically improved, and, for some types of photography, a major asset. In still photography I suspect the two main uses for Live View are when shooting landscapes and close-ups (macro shots) - I can't imagine relying on it for most wildlife shooting. Thus, I will likely rely on it more when using my D800 than when using my D4. Two little quirks with the Live View system on the D4...
• No Easy Exposure Compensation: When using the preview feature of Live View to judge exposure (visually or using the histogram), the system doesn't notice "soft" exposure compensations (those made using "Easy Exposure Compensation" via rotating the master command dial alone). For Live View to pick up exposure changes you must make "hard" exposure compensations, i.e., by pushing the exposure compensation button and then rotating the master command dial. Not a big deal - while I use the Easy Exposure Compensation all the time with my wildlife shooting, I don't use it much for my landscape shooting or macro shooting (and I doubt many others would either). This quirk is shared with the D800.
• Menu Changes Shuts Down Live View: I noticed this quirk when shooting side-by-side test shots with the D4 and D800. On the D4 (only), if you're in Live View mode and decide you want to make a setting change that involves menus, the moment you hit the Menu button, Live View shuts down. In contrast, Live View remains active on the D800 regardless of how many times you go into and out of the menus. I'm not sure why this difference exists or if it was intended. When performing test shots it was annoying (and "stretched out" the image capture process), but day-to-day I probably won't notice it much. But I tend to think that whenever you can make functions on two cameras in your lineup perform identically, it's a good thing...
8. Virtual Horizon - Sowewhat Improved? In my D800 Field Test I described the modifications of the Virtual Horizon as "Much Improved", and that was primarily directed at how it worked when looking through the viewfinder (compared to when using Live View). I'm not as thrilled about the new way Virtual Horizon works on the D4. On the D800 turning Virtual Horizon on produces tilt and rotation displays that are superimposed on the image in the viewfinder (on the bottom and on the right side). These indicators don't intefere at all with the other "tool displays" (like focus brackets, exposure indicator, etc.) in the viewfinder. However, on the D4 the Virtual Horizon hijacks the focus brackets (for side-to-side rotation) and the exposure meter (for front-to-back tilt). Yes, they do automatically turn off when you use one of those functions (e.g., toggle the focus brackets), but...why approach the problem this way? At least the way I use a camera I far prefer the execution of this feature on the D800. Perhaps there is some technical reason why they couldn't do it the same way on the D4 and D800 (i.e., the way it's done on the D800), but if this is a case of non-communication between product development groups (the D4 silo doesn't talk to the D800 silo?) it's pretty bad. Bottom line is that I'll rarely use the viewfinder mode of Virtual Horizon on the D4, while I'm already using it all the time on my D800. In Live View Mode both implementations of Virtual Horizon seem to function the same way and I do find the feature useful there (tho' I doubt I will use Live View mode much on my D4, owing to what I will be primarily using the camera for...meaning wildlife photography).
9. Burst Depth. If you're a raw shooter, you can shoot a minimum of 52 frames at 10 fps. JPEG shooters can shoot 130 or more shots in a 10 fps burst (JPEG Fine). I don't think most photographers were too limited by the 35 or so raw file burst depth of the D3s, but when you're shooting action sequences with the D4 the burst depth almost seems limitless.
10. Fully Independent Flash/Ambient Exposure Control. With the D4 (and not the D800) exposure compensation on the flash and ambient light are totally independent (so "dialing down" the exposure on the camera dials it down for ambient only, not the flash). I am likely to use these feature almost exclusively when photographing small birds (which I like to do in side- or back-lighting situations and use flash fill). At this point I haven't tried the feature and can't comment on how well it works. But I like the concept.
11. New EN-EL18 Battery. This new battery was imposed on NIkon by environmental regulations, not by choice. While slightly lower-powered than the battery of the D3s (EN-EL4a), it is supposed to hold up better when shooting bursts. So far all I've noticed about the battery is it's a different colour (gray vs. black). I have no quantititative analysis of number of shots per charge, but subjectively I have not noticed the battery under-performing at all. And, I doubt many wildlife shooters will notice any difference between the batteries when in the field. Sports shooters might (given their need to shoot thousands of shots during a single sporting event).
12. The New Sony XQD Card. I was one of the fortunate ones who received a complimentary 16 GB XQD card (and card reader) with my D4 (I've heard this was an introductory "special" - presumably because if they hadn't included the card and reader no one could have obtained them - they don't appear to available at the time of this writing - April 9, 2012). I won't comment on the optics of the D4 reportedly going up in price (in at least some countries) and NOT including the XQD card and reader in future shipments. Anyway - back to the card itself...I haven't noticed anything in the field - seems to store images just fine. BUT, I definitely notice the faster image transfer rate to the computer (when using the XQD reader) - and that's real nice. I have NO issues with having an XQD slot on the camera - but definitely wish there were TWO XQD slots there...
13. Video? Same comments as on the D800 - video? This camera has video? Oh...that's what that big section in the middle of the manual was about! Sorry - haven't tried it. Would be surprised if I ever did. You'll have to go elsewhere to get someone else's first impressions about video.
14. On the Negative Side: Non-matching Memory Card Slots: The decision by Nikon to offer non-matched dual card slots on the D4 (one CompactFlash and one XQD) continues to baffle me. And frustrate me. The only rationale I've been directly heard (from Nikon) about this mixed-card slot strategy is "legacy support", but at the professional level (especially given the ever-dropping price of memory cards) you'd think performance and convenience in the field would trump "legacy support". It becomes a particularly large pain in the butt if one is going in the field with a D800 and D4 - be prepared to carry 3 types of cards and associated readers. And, when you're in the heat of the action (sparring grizzlies??) and have to change cards, you better remember to grab the RIGHT card type and put it in the RIGHT slot. What a pain. Smells like a "committee decision" to me - and definitely isn't one a confident market-leading company (like Apple..or Nikon?) would (or should) ever make. Sorry, but I have to be blunt - I think this is plain dumb.
15. On the Negative Side: Inconsistencies Between Cameras: This is not a complaint about the D4 per se, but rather in what I consider frustrating inconsistencies in certain features BETWEEN concurrent camera models. I don't expect between-generation consistency (othewise the cameras could never change!), but when two models come out virtually simultaneously, why features unrelated to ergonomics (dictated by camera size) or function (landscape shooting of the D800 vs. action shooting of the D4) both baffle and frustrate me (and I suspect anyone else who plans on shooting these two cameras in the field). Some examples:
• Live View Differences Between the D4 and D800: Discussed above.
• Virtual Horizon (Viewfinder Mode) Differences Between the D4 and D800: Discussed above.
• Inexplicable, Frustrating Button Customization Differences Between the D4 and D800: As one who will be shooting the D4 and D800 side-by-side in the field (and used to shoot the D3s and D700 together, which had the same problem), this one drives me up the wall. Like almost everyone, I like to have my camera's buttons (at least those shared between cameras) set up the same way. Saves unnecessary "what does this button do again on this camera?" thought. One example: For reasons that aren't important here, I like to have my Function button programmed so that when I push it and rotate the main command dial it cycles through the 4 shooting banks (which I have set up for different shooting situations). The D800 has shooting banks too, and like the D4, four of them. And it has a Function button. But check the programming options for the Function button on the two cameras: There are 6 options on the D4 and 5 on the D800. The 5 on the D800 are all on the D4. The sixth one on the D4 - "Shooting menu bank" - is absent. And, you won't find it as an option on ANY of the programmable buttons. Why?? Argh!!! And...why does it make sense at all to give each programmable button a different array of custom functions to choose from? Why not "open it right up" and have all custom functions programmable on all the buttons and let the USER DECIDE how they want to set up the camera?
My sole point here is that, wherever physically and economically possible, Nikon should ensure the functions and/or options on their cameras are consistent between models. I don't believe make customization options consistent will tip the lower-priced camera up to a higher price point.
My one sentence summary of my first impressions of the Nikon D4? Just this: For me, the best HAS got better - WAY better (but there's still room for improvement!).
III. Chapter 2: More Detail About Selected "Improved" Features...
Post Date: April 9, 2012.
For many photographers the critical features of an action camera are autofocus performance, ISO performance, and overall image quality. So, with no further ado...
1. Autofocus Performance: I make no bones about my excitement about what I've found with the autofocus (AF) system of the D4 - the "tweaks" to the AF system make a BIG difference in the field and I love them. And, action shooters of any genre should be ecstatic about these results. Note that the D800 shares the identical new AF system (called the "Advanced Multi-CAM 3500FX autofocus sensor module with TTL phase detection") - I was very impressed with its accuracy on the D800, but at 10 fps on the D4 its ability to track a subject is MUCH more impressive!
The shots below were taken using my favourite subjects for putting a new camera's AF system through its paces - my Portuguese Water Dogs (yes, I pay them for this work - in treats). I'm not trying to bore you with shots of my dogs, but I have past comparative data on the performance of how the D3s handled these types of action sequences. And it's a heckuva test for an AF system and - for a wildlife OR sports shooter - it's a convenient "proxy" for what you would shoot when working. Note that I intentionally shot these images under bright sunlight (mostly side-lit) to test other aspects of the camera (metering accuracy, raw file "malleability" - how much I can push the files around with creating noise in the shadows, etc.), but those "stories" will come later.
As always - best to view these images at 100% magnification (and sorry for the large size - you will have to scroll some on most monitors):
A. D4 paired with the 400mm f2.8 VR:
• Jose the Portie Performing for the D4 - Download 1200 pixel version WITH ALL TECH NOTES
• Poncho the Portie Performing for the D4 - Download 1200 pixel version WITH ALL TECH NOTES
B. D4 paired with the 600mm f4 VR:
• Poncho Testing the D4 AF System - Download 1200 pixel version WITH ALL TECH NOTES
What about shorter focal length professional lenses? Every one I have tested is as good as the results shown above.
To those who haven't shot with a D3s, there are two very significant improvements over the D4 shown in these images (or image sequences I yanked them out of):
A. The Proportion of In-focus shots: Capturing sharp shots in a sequence like this with a pro DSLR using pro lenses isn't at all surprising. But what blew me away was that in all the test sequences that these shots came out of almost every single shot was as sharp as the ones shown above! The results for the 400mm f2.8 VR were incredibly impressive - in the case of the first shot (the mostly black dog) the full sequence consisted of 25 shots at 10 fps; in the second case (the gray-white dog) the sequence was 32 shots in length (again at 10 fps). I ended up shooting 5 sequences of shots with the D4 and 400mm f2.8 combo, for a total of 120 images. How many were out of focus? One. Which means 119 (or 99.2%) were in focus. I'm still shaking my head. The results with the D4 and 600mm lens were almost as impressive - again 5 series of shot taken, this time for a total of 140 shots. Ten were out of focus - which means 130 (or 92.8%) were in-focus!
In comparison, when I performed these tests with my D3s about 80% of the shots were in sharp focus when the D3s was paired with the 400mm f2.8 VR. And with the 600mm f4 VR you'd get about 70-75% of the shots in sharp focus. I can hardly wait to start shooting bird-in-flight shots!
B. Much Better "Predictive" AF Tracking: To capture shots like this (when a subject is moving directly at you) the camera must predict where the subject will be at the exact moment of exposure. If it's out at all in its calculation the camera will focus slightly in front of, or slightly behind, the leading edge of the subject. In this case, those "crinkles" in the nose tell the story - the D4 is predicting the focal point almost perfectly (at 10 fps). In contrast, the D3s did a good job, but often the focus point was just behind the leading edge of the subject (and thus those nose crinkles were often soft, even in shots that I considered "in-focus").
I pride myself on my objectivity, but I'm literally blown away by the improvements in the AF system. For a pro shooter, the difference between 70-80% and 90-99.x% of their shots in-focus can mean the difference between getting that winning (and profitable) shot and missing it. But - on the somewhat negative side - this new AF system takes away one's excuses - it's darned hard to blame the camera if you miss the focus on a shot! ;-)
One non-focus related issue I feel compelled to mention. I used Auto ISO with the minimum shutter speed set to 1/4000 of a second and the aperture set to f5.6 (aperture priority automatic). Which meant my ISO was free to jump around during the sequences - and it did jump around between about ISO 640 and 2000. This was most noticeable when I was shooting images of Jose (the mostly black dog with white chest and socks). As expected, when this mostly dark dog filled more and more of the frame the light meter perceived the scene as darker and bumped the ISO as it "thought" it needed to. Which meant that in the shots where the dog was very close some of the white portions were over-exposed to the point where they were close to non-retrievably blown out (and would have been if I was shooting JPEGs). Those understanding this problem will be thinking "ahhh...be careful with auto-exposure settings on sequences of shots of high contrast subjects when they are changing in relative size in the viewfinder." Those lost by what I'm talking about will be thinking "HUH?". ;-)
2. ISO Performance: The relationship between ISO, resolution, and intended image use is complex. A full-frame, full-resolution image that shows extreme noise when viewed at 100% can look almost "pristine" clean when that same full-frame image is reduced in resolution down to "web-size". Producing a single metric for ISO performance destroys the variation in visible noise between image samples examined at different resolutions, and the information that you really need to choose your ISO settings when shooting in the field is contained in that variation. So...here ya go - some real world ISO comparison between Nikon's top 3 ISO performers - the D3s, the D4, and the D800.
TEST 1: Noise - A Head-to-head-to-head High ISO Performance Test - The Nikon D3s, D4, and D800: Here's some composite images that show head-to-head-to-head ISO comparisons between the D3s, D4, and D800 shot at ISO 1600, ISO 3200, ISO 6400, and ISO 12,800. The images were captured in the field under heavy overcast skies (just like when you WOULD need to use high ISO's). And, I intentionally chose a scene with in-focus, partially out-of-focus, and completely out-of-focus elements (that's what MOST images wildlife - or sports - shooters have, and the visible noise DOES differ between regions that differ in sharpness of focus). The comparison includes images that show extreme examples of how images are used - including taking the full-framed image and reducing it in resolution all the way down to web-size AND using every single pixel of the image (such as you would do if you REALLY wanted to crop your image). Realistically, most image uses would fall between these two extremes - but by showing these extreme examples you should get a feel for how you can use each cameras images at various ISO's. It's best to view these images at 100% magnification - sorry for the huge size but it was necessary. Anyone trying to view these graphics on an iPhone will be hooped! ;-)
• ISO 1600 Comparison WITH ALL TECH NOTES (JPEG file: 1.1 MB)
• ISO 3200 Comparison WITH ALL TECH NOTES (JPEG file: 1.2 MB)
• ISO 6400 Comparison WITH ALL TECH NOTES (JPEG file: 1.3 MB)
• ISO 12800 Comparison WITH ALL TECH NOTES (JPEG file: 1.5 MB)
The obvious take home lessons?
A. Resolution reduction masks visible noise! You want to shoot images primarily for electronic displays (such as web images)? You could use each of these cameras at almost any ISO setting! You want to produce 8"x10" at 300 dpi prints (that require about 8.4 MP)? You won't have too much noise "masking" on the 12.4 MP D3s, a little more on the 16.2 MP D4, and a lot on the 36.2 MP D800 (simply because you'll reduce the resolution more on the D4 and a lot more on the D800). But with all the cameras you'll have to watch the ISO. You want to use full resolution crops? You have to be REALLY careful of the ISO, especially on the D800.
B. D3s and D4 VERY close in ISO performance, D800 lags. When it comes to visible noise, if you look at images at 100% resolution the D4 and D3s are really, really close. And, the D800 lags by a stop or slightly more. But, given the D800's resolution, this is really, really good performance!
TEST 2: Overall High ISO Image Quality Comparisons? ISO performance is about more than just visible noise. The effects of cranking up the ISO on your final image are also VERY dependent on the scene type. Besides image noise, dynamic range, tonal range, colour sensitivity - and even some "derivatives" of these measures such as contrast - vary with ISO (they ALL decline with increasing ISO). If one is shooting a low-contrast scene with pastel colours (think of a foggy scene) the dynamic range of almost any ISO might be sufficient to capture the scene. But in other high contrast shots (think, for instance of photographing a white Spirit Bear in a dark forest) you might need ALL (or most of) the dynamic range your camera can provide to effectively capture the shot.
While producing this next series of shots I varied ISO from 200 to 6400 using both D800 and D4 cameras (sorry, I was hiking and couldn't bring ALL my gear with me and the D3s was left at home). All camera settings and ALL post-processing was identical on all the captures (except, of course, ISO). All images are full-frame (uncropped). The noise characteristics of virtually all the shots are "masked" when they are reduced to 1200 pixels, but are apparent on the hi-res samples. With this scene the D4 seemed to hold contrast much better throughout the range of ISO's tested and was about 1 to 1.3 stops less "noisy" than the D800 (as judged when viewing the full resolution files at 100%).
• D4 at 200 ISO:Annotated 1200 pixel version (JPEG; 818 KB)
• D4 at 200 ISO:Full res version (JPEG; 5.8 MB)
• D4 at 6400 ISO:Annotated 1200 pixel version (JPEG; 836 KB)
• D4 at 6400 ISO:Full res version (JPEG; 8.9 MB)
• D800 at 6400 ISO:Annotated 1200 pixel version (JPEG; 894 KB)
• D800 at 6400 ISO:Full res version (JPEG; 17.9 MB)
"TEST" 3: And Some Subjectivity: And a few final comments on some subjective observations I've made when comparing high ISO shots taken with the D4 and those taken with the D3s...
A. Dynamic Range, Tonal Range, Colour Sensitivity: Well, perhaps some folks can see these things in any given image, but I struggle with making meaningful comparisons between similar images in these parameters. The only published data on these parameters (that of dxomark.com) indicate that the D4 and D3s are almost identical in these 3 parameters. So...does that mean the ISO performance of the D4 and D3s are the same? I don't think so...
B. Image "Quality": Ok, I'm admittedly walking into Persig's terrain here (Zen and the Art of Motorcycle Maintenance), but when I compare D4 and D3s images shot at high ISO's (about ISO 3600 and above), I'm seeing "nicer", less harsh, and more "realistic" images being spit out by the D4. I think I'm seeing a combination of slightly better detail (especially in the shaded areas), a nicer gradation between tones and colours, and just a tad better contrast. My gut tells me to set my "Maximum ISO" on my Auto ISO function about one stop higher than on my D3s (and I reiterate - this is NOT because of noise, just better image "quality" at high ISO's). With my D3s I went to ISO 6400 with reluctance and only when absolutely necessary - with my D4 that Maximum ISO will now be set at 12,800 (and I'll tread that high only when I have to, but I won't be sweating ISO 6400!). A few more images to view to demonstrate what I mean...
• Don't Bite that Tongue! Nikon D4 @ ISO 3600: Annotated 1200 pixel version (JPEG; 451 KB)
• Red Squirrel & the Nikon D4 @ ISO 9000 - Download 1200 pixel version WITH ALL TECH NOTES
3. The D4's Overall Image Quality: Sorry...this section - and its supporeting sample images - can't be completed until I've shot more shots and under a greater variety of lighting and overall conditions...