How to make my SD stop making doubles?

I have a Nikon D3100 and my SD card is copying doubles in which when I upload them onto iPhoto there's a double of each. But when I view them on my camera there's just one of each. Is there a setting I pushed on my camera that made it do this? Or what should I do? Please and thank you!

Try to format your sd maybe it has a virus or problem i don't know but try it.

Check the size of each of the pictures. If one of the doubles is larger than the other (so speaking in terms of MegaBytes) your camera is in JPEG+RAW mode (which is the mode I shoot in and typically recommend). The larger of the photos is in NEF or Raw format and the smaller of the two is in JPEG. I like this mode because I'll always have the RAW available for editing later when I want to develop for display or sale (you should ALWAYS, ALWAYS shoot in either RAW or RAW+JPEG), but on the other hand I also have an JPEG that I can show to friends and potential clients and don't really need to spend time editing.

Just go through your folders (mine are sorted by date of shoot) and create a folder entitled NEF or RAW in each, select all the RAW pictures (I think they are generally the second of the doubles, just make sure) by holding CTRL while clicking on each of them (CTRL lets you select multiple files as long as you are holding it while selecting) and move them into the RAW folder. You can have the JPEGs to admire or throw on the interwebs, the RAW to edit at a later date.

Hope this helps.
Regards<
Rocky

This could be the camera is set to record both a jpg and a raw file. Check the file extensions to see if this is true. If so, look in the user's manual for this setting and change it so the camera records in only one format.

If the camera is only recording one image, check your imaging software settings to see if it is making a jpg from a raw automatically. Change the setting. Usually the settings can be found under "File". Also called preferences in some applications and programs.

Formatting the card will only erase the pictures. Don't do this until you are sure you've downloaded them as you want them. Only format the card in the camera, never on the computer.

You have your camera set to save RAW AND JPEG at the same time so it. Saving 2 files for each image. Your camera knows to show you only one but IPhoto CORRECTLY shows you both.

If you want to stop taking two pictures at once then simply go into your camera menuu and select either RAW OR Fine JPEG. Not both.