10 second timer release

I have taken several group photos using my 5N with the 10 second timer set to take 3 photos.  My experience to date has been without flash.  Without flash the camera takes the exposures so fast that it essentially the same as taking one picture.  Is there any way of increasing the interval between when the camera takes the 3 pictures???  I have looked through the manner an can not locate any way of doing this,

Thanks in advance for any advice.