Duplication of photos when transferring to laptop

[Greyhoundman]

Can someone explain please why when we transfer photos onto laptop they duplicate, I can't find a subject anywhere in the manual- I'm sure it must be there somewhere.
Thanks

[Skirball]

I'm not sure what you mean.  Transferring from Camera to Laptop?  Using specific program?  Duplicate as in there are two copies on the laptop, or one on the camera and one on the laptop?

[Greyhoundman]

Two on laptop. I use USB to transfer photos from camera onto laptop via iphoto

[Skirball]

I can't speak to iPhoto, never used it.

Are the files identical, or is one perhaps a RAW and the other a JPG?  If they really are just copies of each other there must be some setting in iPhoto that is doing it, because it's not normal to duplicate files upon transfer.  There might be some option that allows for making backup files and it just happens to put the backup files in the same folder.

Just something to consider:  if you're using SD cards and your laptop has a card reader, I recommend using the card reader over USB connection.  I find it much easier to manage.  So much so that I'd even recommend using a card reader for CF.