How we show our manners is dictated according to the who, what, when, where, & why we are doing something. In bowing this is the timing, spacing, and the depth of the bow.
We also have Ritsu-Rei, standing bows, and Za-Rei, sitting bows.
The 5 basic depths for bows are:
Also today we have incorporated a more small 1/2 bow called 'yu' which only bends about 10 cm from our straight up position.
1. Shiken-Rei, or what in our school we call the fnger tip bow, uses a touch of the fingers to the floor to re-inforce our ikasu (or enlivening) to allow for a stable bow. Shiken-Rei is not very deep, just bending from the tanden (core/center) and allowing the fingers to touch the floor (when in seiza 'correct sitting' on our heels) [note when we ikasu the buttocks may come off the heels slightly, but when we bow we should be sure not to increase this distancing of the buttocks from the heels]. From Sankyo [squating] or kiza [kneeling] the fingers need not necessarily touch the floor, it can be symbolic the angle of the body should be roughly the same as when doing shiken-rei from seiza.
2. Sesshu-rei, or what we call hand-bending bow. This is for us the standard bow of about 45 degree bend of the body. The hand bending part comes from the fact that from shiken-rei as we bend foward more the wrist bends to place the palm on the floor and slides forward parallel to our knees.
3. Takushu-Rei, is to open something that is closed. Until this point the hands have been along side the body, but with Takushyu-Rei the hands begin to move out in front of us, this happens naturally as we bow deeper to have our forehead (with a straight back and our buttocks down) to about 24 cm from the floor. Esoterically we speak of this bow representing a true offering of ourselves, and so we consider it the first of the deep bows.
4. Sosshu-Rei, is both hands or a pair of hand that move ever closer together as our bow deepens to about 15 cm from the floor, and is certainly a fukai-rei or deep bow.
5. Gosshu-Rei, is when our hands match or come together. Generally with index fingers touching and forming a /\ shape under our nose. Our forehead is about 10cm away from the floor. This is considered Sarani Fukai Rei or a more deep bow, and is the deepest of the standard 5 bows.