Summary: Oddly, though, both Nikons lack standard exposure bracketing, where the camera takes three shots instead of one -- one normal, one at a slightly higher exposure and one slightly lower -- just in case the normal exposure wasn't quite right. The Canon EOS Rebel T3 has this feature. Even so, PhotographyBlog.com calls the D3100 "a surprisingly well-featured and complete package for an entry-level digital SLR camera.
Pros: Great image quality for the price, Compact and lightweight, Easy for beginners to use
Cons: Lower resolution than newer Nikon D3200, Slower burst rate than D3200, Movie mode is limited, no external mic jack
Excerpt: The Nikon D3100 is one of the hottest digital SLRs on the market right now. The great price (under $600 with a lens), plenty of features, excellent image quality and access to Nikon’s excellent lenses make it a no-brainer for first time digital SLR buyers or even serious photographers on a budget.
Summary: The D3100 is a refinement of the D3000 which now sits at the low-end of Nikon's entry-level DSLRs. The notable changes are a 14 megapixels sensor and 1080p video capability with autofocus. It is a relatively compact DSLR with the most basic feature set. The D3100 is directly aimed at new DLSR owners. Among entry-level DSLRs, the Nikon D3100 is one of the most basic but also one of the most consistent in terms of performance.
Pros: Very low image noise, Excellent white-balance, Conservative metering, Accurate autofocus system, Short shutter-lag, Good shot-to-shoot speed, Excellent time-to-first-shot, Generally good ergonomics, Full HD video with autofocus, Good build quality, Easily usable with gloves on
Cons: Slow autofocus, Uneven color response, Slight image softness, LCD glare when settings are changed, Live-View not exposure-priority, Microphone records camera noise, Impossible to setup video framing, Limited interface control, No exposure bracketing, Odd Auto ISO behavior, Exposure steps always 1/3 EV, Lens mount lacks mechanical-coupling
Summary: Like earlier entry-level Nikon DSLRs, some older lenses that lack built-in motors won’t work with the camera. The unit feels plasticky in hand, and you should be careful in wet weather, as it’s not well-sealed. Video settings are limited, but this camera is a good foray into the DSLR world.
Pros: Lightweight and compact; low cost; good low-light performance.
Cons: Body balance feels awkward; limited manual (but built-in guide is useful)
Summary: Considering that you can get the D3100 for $250 less than Canon's Rebel T2i, the D3100 stacks up well against that top dog of the entry level. Sure, it trails the Canon a bit in resolution and focusing speed, especially in dim light. But the D3100 has even more accurate colors than the Canon and basically matches it in noise performance.
Excerpt: Quote from review: "Ho-hum-another new DSLR that shoots HD video. That was our reaction at the announcement of this new Nikon geared for first-timers to interchangeable lens ranks. And yet there's something unique about this camera we'll share with you in a click or two.
Excerpt: In the last several years, Nikon has been updating their 10MP, entry-level DSLR on an annual basis. In the past, the D40X, D60, and D3000 all share a version of the 10MP CCD sensor that was also used on the D200 and D80, but there have been some significant improvements such as the AF system.
Excerpt: Apparently, when Nikon decided to add video capture functionality to its D3000 follow-up, they weren't just kidding around. Not only have they made it the first Nikon DSLR to capture full 1080p (1920 x 1080) footage, but they also made it the "world's first" DSLR with full-time auto focus in Live View and D-Movie modes. It can even capture the 24p stuff that cinema-types crave.