102 Technical Notes/Optional AccessoriesOther AccessoriesApproved Memory CardsThe following SD memory cards have been tested and approved for use in the D40. Allcards of the designated make and capacity can be used, regardless of speed.Operation is not guaranteed with other makes of card. Contact the manufacturer for detailson the above cards.Viewfindereyepieceaccessories• Diopter adjustment viewfinder lenses: Lenses are available with diopters of –5, –4, –3, –2, 0,+0.5, +1, +2, and +3m –1. Use diopter adjustment lenses only if the desired focus can notbe achieved with the built-in diopter adjustment control (–1.7 to +0.5m–1 ). Test diopteradjustment lenses before purchase to ensure that the desired focus can be achieved.• DG-2 magnifier: Magnify the scene displayed in the center of the viewfinder for close-upphotography, copying, telephoto lenses, and other tasks that require added precision.Eyepiece adapter required (available separately).• Eyepiece adapter: Attach the DG-2 magnifier to the D40.• DR-6 right-angle viewing attachment: The DR-6 attaches at a right angle to the viewfindereyepiece, allowing the image in the viewfinder to be viewed from above when the cam-era is in portrait orientation.Filters• Nikon filters can be divided into three types: screw-in, slip-in, and rear-interchange. UseNikon filters; other filters may interfere with autofocus or electronic range finding.• The D40 can not be used with linear polarizing filters. Use the C-PL circular polarizing fil-ter instead.• The NC and L37C filters are recommended for protecting the lens.• When using an R60 filter, set exposure compensation to +1.• Moiré may occur if a filter is used when the subject is framed against a bright light orwhen a bright light source is in the frame.• Center-weighted metering is recommended with filters with exposure factors (filter fac-tors) over 1× (Y48, O56, R60, X0, X1, C-PL, ND4S, ND8S, A2, A12, B2, B8, B12).Memory Cards• Format memory cards in the camera before first use.• Turn the power off before inserting or removing memory cards. Do not remove memory cards fromthe camera, turn the camera off, or remove or disconnect the power source during formatting orwhile data are being recorded, deleted, or copied to a computer. Failure to observe these precau-tions could result in loss of data or in damage to the camera or card.• Do not touch the card terminals with your fingers or metal objects.• Do not apply force to the card casing. Failure to observe this precaution could damage the card.• Do not bend, drop, or subject to strong physical shocks.• Do not expose to heat, water, high levels of humidity, or direct sunlight.SanDisk 64MB, 128MB, 256MB, 512MB, 1GB, 2GB *, 4GB *†Toshiba 64MB, 128MB, 256MB, 512MB, 1GB, 2GB *Panasonic 64MB, 128MB, 256MB, 512MB, 1GB, 2GB *, 4GB *†Lexar 128MB, 256MB, 512MB, 1GB, 2GB ** If card will be used with card reader or other device, check that devicesupports 2GB and 4GB cards.† SDHC compliant. If card will be used with card reader orother device, check that device supports SDHC.