For the most part is racquet face is more flat (sih) at contact than after contact as part of the follow thru, which is what that frame shows. Check out any of the slomo vids of him. This is good and the thumbnail even shows the typical racquet angle.
My two cents, one line at a time. lol.
First, "what does Fed do?"...or other very good players. The angle at and through the instant of contacy is 5º to 8º. It depends how high the ball is at contact, the extent to which you are swinging low to high, and how good you are at swift use of ISR just into contact. The numbers aren't mine, but come from a tennis physics reference.
ISR comes from the rotation of the upper arm bone in the shoulder socket. The muscles that control it are fast twitch and powerful.
ISR (it's easier to see with the straight-arm guys, Fed and Rafa, but others too) does three things, and you don't want them to happen until the instant before contact. It:
1. causes the racquet to tilt forward, closing. You want to train it so that the timing of your ISR application happens so that you're only getting 3º to 6º tilt. (The rest really is just follow through. Once you get it (as in serving pronation...) you'll be able to make the ISR rotation constantly increasing the angle just the right amount at contact. Underdo it at first, so that you don't become frustrated by netting the ball.
2. It causes the racquet to accelerate forward, adding racquet head velocity.
3. It forces the racquet face upward fast so that, timed correctly, you get more topspin.
These three parts work together, and must be trained that way: Especially, the ISR tilt and upward motion in the plane of the stringbed must complement each other. The forward tilt only works to your advantage if you're also getting the upward slide motion. This sounds complicated, but it isn't so difficult in practice. You are currently coming at the ball with a perpindicular RF. Fine. If you did get ESR into the forward launch...which lags in time by millseconds the beginning of UB rotation...you'll have room in the shoulder set-up to provide good ISR into contact.
You can see all these things if you do the things in slo mo in your living room. If your shadow swing imagines contact with the ball well out front, and you keep your wrist loose (help it stay back in your shadow swing), you can, at the end, do fast ISR from the shoulder. You will see the three components, forward motion, upward slide motion, racquet face tilt motion. Since the rest of your swing is pretty decent, you can focus on the ISR into contact. It is a major element, not a minor one. It happens to fast to see without super-slo mo, available in great variety on various sights like tennisplayerDOTcom.
Picky little comments:
You should watch the timing of Fed or Nadal, the synchronization of the off-arm swing and pull-in as it times with the shoulder rotation (not with the racquet's first forward motion, which comes milliseconds later. The off-arm pull in is about helping the UB initiate rotation. The UB has all the power needed to launch the racquet, once it gets going. The UB should very briefly stop in most in-position forhands just as it roughly faces the net...letting it's last power run out into the hitting arm, hand, racquet, racquet head. The stop is extremely brief, then UB is let go, muscles relaxing, racquet closing continuing. You can see this UB stop in any good Fed super slo mo shot from in front.
Hope these comments were clear. I don't have time to edit them.
