Nikon D3 and D700 can switch between DX (24×16mm) and FX (36×24mm) modes to accommodate different lens formats. If “Auto DX Crop” is enabled, the camera will automatically adjust the picture angle (field of view) to DX format when a DX lens is attached, and to FX format if a 35mm format lens is attached.
Obviously, the DX format can use only the pixels in the center of the FX frame on the FX DSLRs. For Nikon D3 and D700, it is 5MP. This is indeed a lot fewer pixels compared to a DX format DSLR such as Nikon D300, but you enjoy the superior picture quality throughout a wider ISO sensitivity range attributed to larger pixel size that yields a higher signal-to-noise ratio and wider dynamic range. Therefore users can actually take advantage of the DX mode when you only need or have the center area of the frame even with a FX format lens. Example of such situation is when your subject is too far away to fill the FX frame. Not only you have smaller file size to handle, but also you don’t need to crop every photo to remove unnecessary pixels. Read More…
According to DPReview, Tamron announced the SP AF70-200mm F/2.8 Di LD (IF) Macro at PMA 2008. It seems to be an interesting addition to the camp of Sigma 70-200mm f/2.8 EX DG Macro and Tokina AT-X 828 AF Pro 80-200mm f/2.8 as a low cost alternative to the expensive OEM counterparts. Although not mentioned in the DPReview coverage, the Nikon mount version will have a built-in auto focus motor so it works on all Nikon DSLR cameras including D40/D40X/D60, which do not have in-body AF motor. Quoting from the product overview from Tamron:
While overall dimensions are confined to the absolute minimum, the new SP AF70-200mm F/2.8 zoom lens is packed with features that allow stress-free photography: a versatile MFD of just 37.4″ over the entire zoom range; best-in-class maximum macro magnification ratio of 1:3.1 at f=200mm; and an advantageous internal focusing (IF) system. The new tele-zoom lens covers a desirable focal length range of 70mm medium telephoto to 200mm telephoto when mounted on full-size format SLR cameras and a focal length range from 109mm to 310mm* ultra telephoto when mounted on a DSLR camera with an APS-C sized imager.
Posted in
Digital SLR Cameras,
Lens on February 7th, 2008.
No Comments.
