Focus

Couple things. I'm gonna go ahead and assume you're talking about general focus pulling, not just for filming skiing since you mentioned pulling specifically.

The first thing you want is a lens with hard stops and markings. A lot of digital photography lenses nowadays have internal motors and no hard stops (i.e. Sony 24-70 2.8 F4 OSS) and the scaling changes each time you touch the focus ring, Making it almost impossible to pull with any reliability. If you have a lens that stays consistent and true to its marks (i.e. Canon 24-105 F4L) you'll be able to get a great feel for how much you need to pull for specific distances with some practice. All cinema lenses are built this way as well.

The next thing once you get a feel for the scaling on your lens is to have tools to help get distance marks for your pulls, which will always be the most reliable way to keep sharps. When I'm on set I carry a Leica Disto laser measure that is great in a pinch and allows you to get marks very quickly. Bosch also makes less expensive ones that are just as accurate. Another way to use these is to measure the distance to different fixed objects in the room so that you can eyeball how far your subject is from those. Having multiple reference distances will help you with relative distance if you can't laser your subject.

Once you have your marks it's helpful to mark your lens so that you can quickly glance at the barrel and know where your focus needs to be so that you don't have to physically read the distance every time you look at the lens. A white grease pencil is great for this because it comes off with a quick wipe with your finger when you need new marks.

This all takes some practice and discipline but it really pays off when you can look at your subject and know generally how far they are from your camera for reliable focus, then you just measure to confirm if you want.

I have a feeling you're only filming skiing and not as advanced as forcillo thinks.
what gear are you using? camera, lens, stabilization/rig
depending on what you're shooting on there are strategies to keep focus or make it easier.

for example on an 8mm fisheye you can "set and forget" - put it at infinity focus and get away with it.
if you're shooting long lens on a jump, you can shoot perpendicular to the skier so that they just about stay the same distance from you. or if you shoot parallel to the skier, you really just need 2 focus points - one at the tip of jump and one in the landing. its pretty easy to pull focus at the speed the skier is moving and keep it sharp enough.

if you're shooting follow cams on a kit lens or something you might be best with autofocus

You right, I’m shooting on a canon 80D, dropped all my money on that so I’m using a 18-55 kit lense.

LukasSchroederI have a feeling you're only filming skiing and not as advanced as forcillo thinks.
what gear are you using? camera, lens, stabilization/rig
depending on what you're shooting on there are strategies to keep focus or make it easier.

for example on an 8mm fisheye you can "set and forget" - put it at infinity focus and get away with it.
if you're shooting long lens on a jump, you can shoot perpendicular to the skier so that they just about stay the same distance from you. or if you shoot parallel to the skier, you really just need 2 focus points - one at the tip of jump and one in the landing. its pretty easy to pull focus at the speed the skier is moving and keep it sharp enough.

if you're shooting follow cams on a kit lens or something you might be best with autofocus

Oliver2003You right, I’m shooting on a canon 80D, dropped all my money on that so I’m using a 18-55 kit lense.

any sort of cam caddie type handle or just straight hand held?
any interest with new lenses in the future?

Yea I have a 10$ grip that works like a charm, I’m interested in getting a 55-200+ lense and an opteka fisheye.

LukasSchroederany sort of cam caddie type handle or just straight hand held?
any interest with new lenses in the future?