Long veils convey a romantic mood via all that added gossamer sheer.  . . . . .Women who  go traditional sporting the full regalia of a classic bride typically love those long, flowing veils. So what you ask is considered a long veil? Let's start at the ‘finger tip’ length and work all the way down to the twenty-five foot cathedral.veil.

Long Veil Lengths
Fingertip-Most popular length; can be worn by nearly every figure type with most silhouettes.
           Waltz-Falls anywhere between knee and ankle.
          Chapel-Considered formal. Extends about a two feet beyond the hemline.
          Cathedral-Most formal. Extends three feet or more beyond the hem.
          Double Tier-Two layers, typically the shorter one a blusher but not always.  
Long Veil Styles
Pouf-Pictured directly below, width of veil is gathered at the crown and can be attached to a headpiece. Generally made out of tulle or English netting.
Dropped-Second picture below. This veil is actually dropped onto the head in a single layer of tulle or lace; often bordered with lace or ribbon. The Mantilla is a type of dropped veil.
Waltz Length
Cathedral Length

All veils and gowns by Amy-Jo Tatum Bride
Top  photo by S1 Studio.  White Chantilly lace mantilla
                                3rd photos by Stellar Q Danielo: Ivory tulle cathedral length veil
                        Last four photos by Piximage: Ivory fingertip veil//White two layered waltz veil outlined in ribbon// ivory  Chantilly lace mantilla//Single layer cathedral legnth veil dappled in Chantilly lace appliques