In September, 2010, Nikon introduced the D7000, which was the beginning of a new class of DX-format (with a 16×24mm, APS-C sensor) DSLRs with a body whose size and controls that are similar to those on the D80 and D90 but with more advanced features such as better auto focus, metering with pre-AF AI/AI-S type lenses, semi alloy frame, and weather sealing similar to the higher-end D300, D700, and D800.
The D7000 was an instant hit and was flying off store shelves in the first few months of availability. After two and half years, Nikon has updated it to the new D7100, still with a similar camera body style as the D7000 but increased to 24MP with Nikon’s top-of-the-line AF system.
This review is based on my experience with two different D7100 cameras. In last March, 2013, Nikon USA loaned me a D7100 kit with the 18-105mm DX AF-S lens. I used that for over a month and about 5000 captures, and then I bought my own D7100, body only. For a couple of weeks, I had two of them at the same time. As usual, both samples are free of any problems.
For the purpose of still-image capture, the two big improvements on the D7100 are the incorporation of the Multi-CAM 3500 AF module with 51 AF points, 15 of them cross type and the new 24MP sensor.
Among Nikon DX-format DSLRs, previously only the D300 and D300S use this AF system, which is also shared by the FX-format D3, D4, D700, and D800-family DSLRs. However, Nikon manages to improve the AF speed and accuracy on the new generation DSLRs introduced since the beginning of 2012, namely the D800 and D7100 (and presumably also the D4, which I have not tested).
The three current Nikon DX-format DSLRs, namely the D3200, D5200, and D7100 all feature a 24MP sensor. However, the one on the D3200 is unique with a slightly different pixel count and different video capabilities. The ones on the D5200 and D7100 have similar specifications. Earlier, some people took apart a D5200 and they found a Toshiba sensor inside. The older D7000 uses a 16MP sensor, which does a fine job as well.
The controls on the D7100 are largely identical to those on the D7000. Similar to all Nikon DSLRs introduced since the beginning of 2012, the dedicated video recording button is now on the top side of the camera, indicated by a red dot in the center. On the back, the column of the buttons on the left side now has 5 buttons instead of 4. The new “i” info button displays the current settings on the LCD. The positions for the + and – buttons to enlarge and reduce the image under review are reversed from the D7000. The LCD on the back is a slightly larger at 3.2", similar to other modern DSLRs.
One of the minor flaws on the D300-D700-generation DSLR is that Nikon somehow removed the dedicated auto bracketing button (BKT), which is available on the earlier D200. The BKT button returns in the D7000 but it is limited to 3 frames, i.e. 1 over-exposed and 1 under. Nikon further improves that so that the D7100 can bracket up to 5 frames, 2 over and 2 under. The exposure increment can be 1/3, 2/3, 1, 2 or 3 frames (with the limitation that you cannot bracket among 5 frames at 3-stop increments as that would have covered a whopping 13-stop range).
The D7100 features Nikon’s top-of-the-line Multi-CAM 3500 auto focus module that has 51 AF point in total, including 15 cross-type AF points in the center three columns of five each. It is the same AF module that debut with the D3 and D300 back in 2007 but has been improved with even more-responsive AF and can work with maximum f8 lenses in some of its AF points. Previously, I found this AF module works even better on the D800, introduced a year ago in February 2012, compared to those on earlier DSLRs from 2007 to 2009, including the D3 family, D700 and D300. This improvement carries onto the D7100, which can drive really long lenses such as the 500mm/f4 AF-S and 600mm/f4 AF-S with ease.
Personally, I have some reservations with the Multi-CAM 3500 on FX-format bodies as the cross-type AF points are too concentrated in the center of the frame. On DX, however, the coverage is quite good as it is with the D300. In particular, in the 1.3x crop mode on the D7100, the 51 AF points cover almost the entire image area except for the extreme corners.
Avocet in Flight
I have captured plenty of bird images with the D7100 with 400mm (in the 200-400mm/f4 AF-S), 500mm, and 600mm super telephoto lenses, especially hummingbirds whose erratic flight pattern is very demanding on AF system. The D7100 handles it very well. For birds in flight, typically I use continuous AF (AF-C) with either 9 or 21 AF points. However, hummingbirds tend to appear along blooming flowers where they feed on the nectar. Initially I was using 9 AF points and frequently the D7100 would focus on the flower; since depth of field with those long lenses is extremely shallow even at f5.6, the hummingbirds tend to be out of focus. Subsequently I switched to just one AF point still with AF-C, and it works out much better for me. For the more usual birds in flight in the sky without other near-by distracting subjects, I would use 9 or 21 AF points, and the D7100, along with the D800, handles those AF challenges very well. For capturing larger subjects such as people playing sports, I would involve more AF points such as 21 or even 51.
The D7100 features a 24MP sensor, which (along with the D3200 and D5200) has the highest pixel count among DX-format Nikon DSLRs. For comparison, under the DX crop mode, the 36MP D800 yields approximately a 15MP image, just below the 16MP D7000. Therefore, the D7100 is very demanding on lenses, in certain ways even more so than the D800, although FX requires a much larger image circle and needs to cover far more edge areas.
Previously, I was surprised by the D7000 two and half years ago. While you might feel that its 16MP is not that different from 12MP from the D300/D300S, it turns out that the D7000 is far more demanding on lenses than its 12MP predecessors. For example, I have a first-generation 500mm/f4 AF-S (introduced in 1996) that I have been using since 1998, and I used to set it wide open at f4 on a regular basis. I was surprised to find out that on the D7000, I needed to stop it down to f5.6 to get really sharp results.
Essentially, the same applies to the D7100. Long lenses such as the 500mm/f4 and 600mm/f4 noticeably improve at f5.6 from wide open. DX wide-angle-zooms such as the 12-24mm/f4 DX AF-S are rather poor away from the center of the frame on their wide end (but the long end is still excellent, so is the center of the lens), and consumer kit lenses such as the 18-105mm DX have rather poor edge performance through-out their zoom range. If you would like to get the most out of those 24MP DX sensors, you need to use top-quality optics, stopped down a bit.
For Nikon DSLRs, my rule of thumb is that you can get fairly good results up to one stop below the maximum rates ISO. For example, the D7100 has a scale from ISO 100 to 6400, plus Hi 1 (12800) and Hi 2 (25600), and I am happy enough with ISO 3200 from the D7100. Its top ISO 6400 is marginal and I would only use the Hi range because it is better than nothing.
Compared to the D7000, I would say the D7100 has about the same noise level at ISO 3200 and 6400. However, since the D7100 has 24MP vs. 16 from the D7000, the D7100 can resolve more details than its predecessor at those high ISOs. As long as you lens is up to it, the difference is quite obvious.
As FX-format DSLRs become more affordable in these days, we have accustomed to their excellent low-light performance. In comparison, while the D7100 has the best high-ISO results I have seen among Nikon DX-format DSLRs, it is still over a stop behind the D800E. I.e., I prefer ISO 6400 results from the D800E over ISO 3200 from the D7100 under the same indoor lighting.
Similar to the D800E that I also have, the D7100 has no anti-alias filter in front of its sensor. When the D800E was introduced, there was some concern about moiré issues as Nikon pointed it out themselves. It turns out to be a rare problem with the D800E. In fact, I deliberately tried to cause the problem by capturing a lot of patterns in fabrics and feather, and I hardly had any moiré problems. The same is true for the D7100. I have a few sample images from the D7100 where you can find some minor moiré on bird feather and some building patterns, but it is rare to find them and when you do, they typically only affect a small area inside the frame so that it is hardly a concern.
Depending on the settings, the D7100 has a RAW buffer that can hold 6 to 9 frames, which is rather shallow. In particular, if you photograph sports and action at 6 fps, you can fill up that buffer in just over a second. However, when Nikon announced the D3 in 2007, it came with a RAW buffer of approximately 16 frames, depending on setting. (A year later in 2008, Nikon offered a $500 memory upgrade option, essentially doubling that buffer. Later on, a similar memory enhancement became standard on the subsequent D3S and D4.) Given that the D3 is 12MP while the D7100 is 24MP, the D7100 actually has about the same amount of buffer memory as the D3 (in terms of number of bytes in memory chips), but with twice as many pixels and therefore much large image files, the D7100’s image buffer is shallow.
The D7100’s RAW buffer:
It turns out that 14-bit vs. 12-bit capture makes only a small difference in terms of image file size, but lossy compressed RAW (Nikon just refers to that as plain “compressed RAW”) really cuts file size down compared to lossless compressed. Therefore, if you capture a lot of action, I would definitely use (lossy) compressed RAW and perhaps also 12-bit capture. Lossy RAW compression removes some detail from the highlight area and the difference is usually not visible by human.
If you prefer to capture RAW + JPEG, keep in mind that the memory buffer needs to keep both files briefly after each capture, thus further reducing buffer depth. Therefore, if you must capture both at a high frame rate, I would try capturing RAW + JPEG basic instead of JPEG fine to reduce overall image file sizes. If you capture JPEG only, even JPEG fine files are small enough so that the buffer is not a concern.
The D7100 is UHS-1 104 (Ultra High Speed) compatible so that theoretically it can write at 104 MB/sec into memory cards. Again, if you capture a lot of action at 6, 7 fps, I would use fast SD cards such as SanDisk’s Exreme Pro, which are (theoretically) 95 MB/sec. And if you use two SD cards in the backup mode on the D7100 so that it writes the same RAW file onto both cards, you need two fast cards as the slower card would dominate the write speed in that setting.
I use two Extreme Pro cards in my D7100, which can write about 3 compressed RAW files per second on those cards. Therefore, even though the memory buffer is full, whenever there is a pause in action, the D7100 can write everything in a couple of seconds and I have a completely empty buffer for 8 fresh frames again. While the D7100 is not nearly as fast as a dedicated sports camera like the $6000 D4, with the right settings and memory cards, it still does a fine job as a sports DSLR at a fraction of the cost.
This feature was last available on the Nikon D2X and D2Xs, although it was called the 2x crop mode back then. It crops 18.8×12.5mm area from the center of the DX (24×16mm, APS-C) sensor to form a 4800×3200-pixel image. That crop factor is 1.3x from DX, which is 1.5x from FX; that was why it was called the 1.3×1.5=1.95x or 2x, from FX.
In the 1.3x crop mode, if you capture 12-bit lossy compressed RAW files, each image file is about 14MB. As long as you use UHS-1-compatible SD memory cards such as SanDisk’s Extreme Pro, which is 95MB/sec, the D7100 can write to the memory card almost as fast as it can capture them at 7 fps. In other words, in the 1.3x crop mode, you can potentially capture 40, 50 images at the D7100’s maximum 7 fps before the camera slows down.
Back in 2005 to 2007, the D2X was my primary DSLR, and I used its 2x high-speed crop mode once in a while. However, I found the frame inside the D2X’s viewfinder insufficient for reminding the photographer that the camera is in the crop mode. A few times I was too concentrating on the action and accidentally placed part of the subject outside of the crop area. When Nikon introduced the D2XS, one enhancement Nikon introduced was to gray out the area outside of the 2x crop. That gray-out option continues to be available as a Custom Setting on all Nikon FX-format DSLRs, all of which have the DX crop mode.
To my surprise, on the D7100, once again there is only a frame inside the viewfinder that shows the 1.3x crop area, along with a 1.3x symbol. Unfortunately, on the D7100, there is no way to set it such that the area outside of the crop is clearly gray out. In other words, you need to be careful during composition. In particular, if you use the 1.3x crop mode to capture action, you need to constantly keep that in mind.
Similar to its predecessors the D7000 and D300S, the D7100 has the virtual horizon feature, but it is the earlier, one dimensional virtual horizon, not the newer, two dimension variety on the D800 and D600.
Similar to the D7000 and D600, the D7100 has a partial alloy frame with the same type of weather sealing as the D300. My D7000 has been on multiple trips to South America without any problems. In fact, recently, I once accidentally dropped my D7000 (not D7100) from an open backpack on my back onto a parking lot. The battery compartment popped open and the battery fell out. It broke the latch that holds the battery in. Otherwise, my D7000 continues to work perfectly and I don’t bother to fix that little damage. I expect the D7100 to be just as strong as the D7000, although it is probably not quite as well built as the D300 and D800.
The form factor for the D7100 is very similar to those for the D7000, although the dimensions are slightly different such that the D7100 requires a different battery pack and quick-release plates. Size-wide, the D7100 is similar to the D80, D90, and D7000 before it. Unlike the D300, D700, and D800, there is no dedicated AF-ON button, although that functionality can be programmed into the AE-L/AF-L button.
While the D7100 looks very similar to the earlier D7000, the dimensions are slightly different so that it takes a new MB-D15 grip, which is in turn slightly different from the MB-D11 for the D7000. The FX-format D600, while having very similar controls as the D7100, is larger because it is FX so that it uses yet another MB-D14 grip. It is a bit annoying that Nikon makes all of these slightly different vertical grips for similar camera bodies. Their current approach is quite different from what it was a few years ago when the MB-D10 matched the D300, D300S (both DX), and D700 (FX).
The MB-D15 can accept an EL-EN15 battery, in addition to the one inside the camera, or it can take 6 AA batteries. However, it would not speed up the D7100’s frame rate. The MB-D15 features an additional shutter release, main and sub-command dials, and AE/AF lock button for the vertical orientation.
Similar to the D7000, the D7100 captures excellent full HD video, 1920×1080 at 24, 25, 50 and 60 fps., but 50 and 60 fps are only available in the 1.3x crop mode. The D7100 has a built-in stereo microphone. However, for outdoor video, it still tends to record a lot of ambient wind noise. For best sound quality, it is best to use an external microphone.
Similar to the D7000, the D7100 provides excellent video quality. However, I still prefer the controls on a dedicated video camcorder than those on a DSLR for video capture.
Based on my discussion with Nikon USA during the introduction of the D7100, they have made it very clear that Nikon expects both D300/D300S users and D7000 users to upgrade to the D7100 (if they need to upgrade to a newer DX-format DSLR). They have also made it very clear that the D7100 is now Nikon’s top-of-the-line, flagship DX model. Given how strong the specifications are for the D7100, such as including Nikon’s top-of-the-line AF module the Multi-CAM 3500 and having the same weather sealing as the D300, it is my opinion that Nikon has no intention to continue the D200-D300/D300S line of DX-format DSLRs. The D300S was officially discontinued towards the end of 2011, as new safety regulation in Japan prevents the sale of any EN-EL3e-battery-based products, including the Nikon D300S, D700, and MB-D10 grip, within Japan after November 21, 2011, as those batteries have exposed contacts; by now, that was over a year and half back. If Nikon had intentions to upgrade the D300S, they would have done so a long time ago, before they were forced to stop selling the D300S in Japan. Instead, lower-end FX DSLRs such as the D600 and Canon 6D are now occupying the $2000 price point. And since the specifications for the D7100 are so strong, there is not much room for a higher-end DX-format DSLR in the D200/D300’s $1700 to $1800 price range.
The 18-105mm DX is a very popular consumer-grade kit lens for Nikon DX-format DSLRs. It features a plastic lens mount and a mostly plastic construction; therefore it is very light. This lens covers a convenient zoom range and is designed for casual photography. Optically, it is sharp in the center but edge and corner performance is rather weak throughout its zoom range. There is noticeable chromatic aberration and sharpness degradation away from the center of the frame. It is also quite slow at f5.6 in its long end. If you are getting the D7100 for more casual photography outdoors and with a flash indoors, the 18-105mm kit lens may suit you quite well at a very affordable price. If you are demanding about image quality or a bit ruff on your cameras, Nikon (and other brands) has a very long list of lenses with better optical performance and stronger construction than those consumer lenses so that you can get the most out of those 24MP from the D7100.
The D7100 has excellent AF and state-of-the-art memory write speed to perform as a sports/action DSLR, but its memory buffer is on the shallow side due to the fact that it is 24MP so that one needs to use lossy compressed RAW to reduce image file sizes and capture more selectively at the right moments so as not to fill up the memory buffer unnecessarily. Similar to its predecessor the D7000, the D7100 has a number of advanced features including a 100% viewfinder, dual memory cards (both SD), and weather sealing.
Besides various Nikon DX DSLRs, I own two FX bodies, the D700 and D800E. For any wide-angle or portrait photography, I by far prefer FX as there is a large selection of excellent wide-angle lenses and portrait lenses to choose from, and the D7100 can easily expose weaknesses even on higher-end DX wide-angle lenses such as the 12-24mm/f4 AF-S at 12mm. I use DX mainly for wildlife photography in conjunction with various long lenses, and the D7100 performs very well with super telephotos such as the 200-400mm/f4, 500mm/f4, and 600mm/f4. Its excellent AF is a major plus. However, if you need to capture a lot of consecutive frame in “machine gun” style capturing certain sports, birds in flight, etc., the D7100’s shallow memory buffer can become a major issue unless you only capture JPEG, although its very fast write speed onto modern SD cards such as SanDisk’s Extreme Pro alleviates that problem. To that end, a dedicated sports DSLR such as the D4 would perform much better, but the $6000 D4 is 5 times as expensive and does not have the pixel density the D7100 has.
Balloon Guy under Fisheye Lens
All in all, it is an excellent DX-format DSLR that is well built and responsive. It also works very well as a general-purpose, prosumer camera for the more serious amateurs. At $1200, like its predecessor the D7000 but now with more advanced features, it is a bargain.
You can find additional images showing different angles of the D7100, some together with the D7000, and plenty of images captured with the D7100 and various lenses in my D7100 folder.