The big news for digital photography hobbyists and enthusiasts looking at purchasing their first DSLR is that the Nikon D3100 is the company’s first entry-level DSLR with live view. Another first for the D3100 is that it’s the only SLR that combines continuous auto-focus mode (AF-F) and Subject-Tracking AF mode to maintain focus on a subject moving across the frame. Another upside of the camera’s live-view function is the availability of depth-of-field preview and mirror lock. Photographers new to DSLR capabilities will also like how contrast-detect auto-focus allows them to aim AF at a precise point at any position within the frame.
Focusing speed is certainly above average and faster than a number of its competitors; but many of the mirror-less cameras with interchangeable lenses, such as the Panasonic G series, focus even quicker. Nikon has given the D3100 a feature of its big brother, the D7000, and that is the mirror remains in the up position during live-view mode. This eliminates the need for the mirror to be in the down position to reset the shutter or determine the exposure. Live view will also act like a mirror-lock function, so there is less shaking when shooting hand held. Put the D3100 in live-view mode, wait for any shaking to cease and then release the shutter.
 | | Nikon D3100 & 18-55MM VR+ Nikon 55-200MM VR KIT + More |  |   | $546.95 |  | |  | | $459.00 | | |  | | $798.00 | | |
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Live View Limitations
As nice as it is to have live view in a DSLR at the Nikon D3100’s price point, some limitations were to be expected. For example, you don’t see a live histogram to help determine the best exposure, although the live-view image will become darker or brighter in PAS shooting modes, as you compensate for exposure. Switch to M, or manual, mode and the existing exposure you’ve set is not displayed. To complicate matters even more, you can only review your exposure by leaving the live-view display, which occurs when you press the “i” button, which takes you to the control panel.
 | | Nikon D7000 16.2 MP DX-format Digital SLR Camera | | $1,349.99 |  |
|  | | Nikon J1 w/10-30mm and 30-110mm VR Lenses- White - 10MP, 3", 1080P, New Nikon 1 Mount | | $696.95 | |
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 | | Nikon D90 DX-Format 12.3MP Digital SLR Camera Kit | | $1,632.48 | |
|  | | Nikon D300S 12.3MP SLR Camera | | $1,889.00 | |
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 | | Nikon D3200 w/18-55mm DX VR Lens- 24.2MP, 3" LCD, 1080P, ISO 100 to 6400- Black | | $696.95 | |
|  | | Nikon D3100 LENS KIT #25472 and 55-200 VR LENS #2166 | | $699.90 | |
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One of the reasons why it is difficult to use non-AF-S lenses with the Nikon D3100 is that the magnification of the display in live view only provides low-resolution sensor results. This is not very helpful in manual focus where high-resolution output would reveal more details. A flaw that has puzzled many D3000 photographers can also be found on the D3100. The good is that the camera will adjust to the recently set exposure or the one the meter reads. The bad is that it doesn’t reset the diaphragm in real-time if you decide to select a different aperture. Live view will retain the set aperture during and after an exposure. You can also compel it to make that readjustment by switching from live view and then returning to it.
This appears to be more of a software issue than a basic design error, since all Nikon D3 series of cameras adjust aperture in live view without interruption. The depth of field may not be what you expected, however; and part of manual focus operations requires that you start live view at an appropriate aperture (typically with the lens at its widest opening). Jump into live view at a small aperture setting and below-normal lighting conditions and you’re apt to see a dark and/or grainy view.
Despite these limitations, the live-view function of the D3100 will provide the entry-level DSLR buyer with all the essential operations to shoot still photos and video, although it works better for video. It’s not surprising that the Nikon D3100 lacks the sophisticated live-view performance of more costly cameras or those with continuous live-view functionality, as are standard on Sony’s NEX series or Olympus Pens. You simple can’t expect everything on a camera priced at approximately $650.
Part 4 of this PhotographyTalk.com article focuses on the video capabilities of the Nikon D3100. (Coming Soon)
