View Full Version : Zone Focussing in Sport: Best Practice for One Man Operation


Miggy Sanchez
March 26th, 2015, 06:26 PM
Hi there

What is the best practice/process for setting a manual focus for a large sporting area/zone?

For example, let's say I want to film a soccer game with one camera.

How should I set my manual focus to keep the whole field sharp while concentrating on pans/zooms?

All advice and information, as always, much appreciated.

Onwards,
Mig

Bruce Dempsey
March 27th, 2015, 05:20 AM
The alternative is auto focus
Whenever you point the camera at a different section of the field, the camera will adjust to the new focal range

Miggy Sanchez
March 27th, 2015, 05:33 AM
Hi Bruce

Thanks for the reply.

I am trying to extend my skill set and expand my knowledge by pushing myself out of my comfort zone :-)

Nice to know AF is there, but there will be a day when it isn't!!!

Bryan Cantwell
March 27th, 2015, 10:33 AM
What camera/lens are you using? Where will you be positioned in relation to the field?

How much zooming will you be doing, and how tight will you be framing those shots?

Shaun Roemich
March 27th, 2015, 12:26 PM
Sensor size, lens focal length and f-stop are the big factors here.

As someone who used to do swingseat/tight follow for AHL hockey on a Sony UVW100 (1/2" CCDs), I could focus on the blue line in the middle of the lateral ice surface and follow the action at f4 without needing to adjust focus until I pushed in to tighter than a waist-up/medium shot most of the time. Outdoors in bright sunlight you should have an easier time ASSUMING you aren't using a 600mm lens on a S35 sensor with 6 stops of ND dialled in.

Miggy Sanchez
March 27th, 2015, 05:11 PM
Hi guys,

The required details as follows:

Lens: 4.1-82.0 mm Sony G Lens

Sensors: 3CMOS (1/3 type)

F Stop: Being outside in the middle of the day usually, I would have thought this to be variable? Unsure here.

Zooming: Lots of zooms, hopefully well disguised when panning :-)

Framing: Want to get as wide as possible, especially when action is closest to the sideline I am on. Want to get close-ups (glory shots?) of goal scorers. In sum, I'd love to be able to get in as close as the zoom allows and out as wide as the zoom allows. Am I asking for the impossible here?

Camera position: Almost always, right on or very near to the centre of the field. That is, I usually have an even perspective of both sides of the field. Usually elevated. Elevation varies.

I have been advised to:

1. Zoom right in on a point just past the centre of the pitch.
2. Focus.
3. Zoom out.
4. Shoot/zoom/pan at will.

After intensively digging around on the topic, I am doubting that it is that easy. And as someone who has just got to know why/how/the science of things, well...I want to know exactly what it is I am doing!!!

Thanks for your help so far and look forward to your responses.

Jim Andrada
March 30th, 2015, 05:18 PM
Things are never as easy as they sound!

The idea of zone focusing is based on the concept of hyperfocal distance - for a given aperture and focal length there is point of focus X that will allow reasonably sharp imaging from half the distance from the lens to X, to infinity. As you zoom, in the closest edge of the hyperfocal range moves further away (but you're zooming because the subject IS further away, so this works) and as you zoom out, the closest edge moves toward you, which also works in your favor.

The key to having a usable hyperfocal distance is to be able to shoot at a small aperture and not wide open. And this all assumes a parfocal lens because if the focus shifts as a function of zoom, all bets are off.

Understanding Your Camera’s Hyperfocal Distance (http://www.cambridgeincolour.com/tutorials/hyperfocal-distance.htm)

This is a good nontechnical description - it's relative to a stills lens, but optics is optics and the principle applies to all lenses.

Another reference (but more math!) is Hyperfocal distance - Wikipedia, the free encyclopedia (http://en.wikipedia.org/wiki/Hyperfocal_distance)

Google around for "Hyperfocal Distance" and "Circle of Confusion" and you'll find a lot of info

If this didn't work, GoPro's wouldn't sell!

David Stoneburner
March 31st, 2015, 07:03 AM
Here is a couple of tips that I use.
1. try to make sure you can keep your iris to between 4-8, with 5.6 being the sweet spot. This gives you over all best depth of field. Use your ND filter when needed to accomplish that. Meaning you zoom in and everything from the point back is generally in focus.

2. Make sure that you have your camera information displayed on your LCD or viewfinder. Then when you know what your general iris is, you can easily get back to that starting point by dialing it in. Tweek from there.

3. Generally I focus on the far pitch line in the middle. That way if you push in for throw ins you have a better chance to be in focus.

4. Get ready to manually focus depending on how far you push in. You are just going to need to ride the focus.

5. Try setting the shutter speed to 100, this will take some of the motion blur out of your movements, but cut the amount of light coming into the camera. You have to experiment.

6. If you have a second camera, make sure to set up a safety wide shot. Better to have action on a lower spec camera than no action at all.

Cheers!

Steven Digges
April 1st, 2015, 11:29 AM
Is the Sony G lens a servo zoom or a manual still lens? If it is a servo manual focusing is tough. Either way, before the game starts you can pick your critical focus areas ie; goals, center line etc and remember the focus distance displayed in the viewfinder. Sometimes you can hit a focus distance by number faster than with eye. Especially on servo lenses.

If your shooting for anything more than some highlight clips a second or third camera is mandatory.

Also, when shooting sports anticipation is critical.

Want to be humbled? Try shooting hockey like Shaun did for broadcast. It is hands down the hardest sport I ever shot. Thank god I only had to do it a few times.

Steve

Shaun Roemich
April 1st, 2015, 12:57 PM
Want to be humbled? Try shooting hockey like Shaun did for broadcast. It is hands down the hardest sport I ever shot. Thank god I only had to do it a few times.



And I had it EASY! 1/2" sensors with an 18x zoom... my colleague Alf Carboni from Winnipeg is one of the best tight follow guys in the business and he routinely did "skates only" tight follow with 2/3" and 80+x zoom lenses.

HE was humbling to watch... and a humble guy as well. Multiple Olympic games in sports and figure skating in addition to "regular old" broadcast. I was a hack in comparison.

Shaun Roemich
April 1st, 2015, 12:59 PM
Another DVInfo regular Calvin Bellows does a LOT of live broadcast sports... granted, on studio cams with 2/3" sensors and box lenses but... perhaps he'll weigh in.

Bruce Dempsey
April 1st, 2015, 02:09 PM
I've shot something like 10,000 figureskating solos since 2004 and I would be totally insane at the moment if the extra burden of manual focus was needed. I keep the skater head to toe full frame all the time when possible and in the centre of the screen just trying to keep the rule of thirds in mind a bit.
First sports I shot were with the cameras the CBC bought for the 68 Mexico olympics and I used one the following year at the Coral in Calgary shooting Hockey for Calgary Cable South when I took Broadcasting at Mount Royal. I don't remember if focus was such a problem then and there was no autofocus of course.
Shot and Live Streamed the Atlantic Canada Figureskating Championships this past weekend in Nova Scotia and there were 201 skates to record. It is really hard work keeping them framed for their 3 or 4 minute skate and the thought of doing manual focus as well just depresses the hell out of me lol besides the cameras can do it better than I

Miggy Sanchez
April 5th, 2015, 01:00 AM
Thanks to all of you for your input. I have been trying to match up what has been written in this thread with the reality of some recent sports shoots. My brain is a sludgy processor, so I still have a murky understanding of zone focussing. But I am a keen student and I want to see the light!


...I could focus on the blue line in the middle of the lateral ice surface and follow the action at f4 without needing to adjust focus until I pushed in to tighter than a waist-up/medium shot most of the time.

Hi Shaun, why would you lose focus as you pushed in tighter?


If your shooting for anything more than some highlight clips a second or third camera is mandatory.


Hi Steve, in your school of thought, does it follow that in a strictly ONE MAN OPERATION, you would be employing AF? The gig I have is definitely a one man operation.


...for a given aperture and focal length there is point of focus X that will allow reasonably sharp imaging from half the distance from the lens to X, to infinity. As you zoom, in the closest edge of the hyperfocal range moves further away (but you're zooming because the subject IS further away, so this works) and as you zoom out, the closest edge moves toward you, which also works in your favor.


Hi Jim. I am going to try and apply your post to a recent situation. Any advice/observations/thoughts you, or anyone else can give, is much appreciated.

1. I zoomed in all the way just past the centre of the field, say 70 meters away.
2. I manually tweaked the focus to get the sharpest image possible by using my peaking function.
3. I then shot the game, panning and zooming at will.
4. Upon post-match viewing on a MASSIVE TV display, I found the images to be reasonably sharp in all parts of the ground. The closest play/action was about 25-30 meters away. Furthest action about 100 meters away.

I kept the iris on auto to concentrate on other aspects of my shooting. The weather was sunny and fine.

Now I suppose my main question: the process I employed worked. No complaint from the client. Why did it work?

Right now I am trying to work out if I understand the "hyperfocal distance" concept. Is it right to say that I had a depth of field that was set between 35-70 meters and beyond? And that when I zoomed back out, the bottom edge of that 35-70 meter depth of field moved with the zoom?

Again all input much appreciated!

Tim Polster
April 5th, 2015, 08:02 AM
Miggy,

Always great to learn your gear and use it manually. A lot of technical info has been given which is good. In all reality, filming with a 1/3" camera is pretty forgiving as the sensor is on the small side. You would probably benefit from reading about depth of field and experimenting with a depth of field calculator. Here is one I like - Online Depth of Field Calculator (http://dofmaster.com/dofjs.html)

You will find that your camera has a lot in focus a lot of the time. What Shaun meant about adjusting focus when "in tight" is that the wider you shoot, the deeper the depth of field is. As you zoom in the depth of field gets thinner, or more shallow.

For example, put your camera in a wide angle zoom position and rotate the focus wheel all the way to the extremes. You will not see any change in the detail. Then zoom all the way in and do the same. You will then see the focus point change. Experiment, experiment and experiment more to learn your equipment. Knowledge is power in your field. Sort of like setting up a tripod to shoot a landscape photo in the middle of the day, you really do not need the tripod to stop camera shake because there is so much light around...

Another thing to remember, your camera moves in an arc when shooting from a fixed location. What this means is that when you focus on say the exact center of the pitch, when you pan to the end of the field your focus point will be closer to the near edge of the field instead of being in the center. That is why people set the focus beyond the center so when they pan to the end they will be in the center.

Modern auto focus is so good that I would say for the sport you are filming, (mainly wide shots) do not sweat it and use auto focus. That way if a fight breaks out on the stands you will be ready for quick zoom! :) Now, about that auto exposure...

Hope this helps.

Steven Digges
April 5th, 2015, 12:05 PM
Hey Miggy,

Yes I would be in AF mode, as long as it worked. Every camera and lens is different and AF is not a perfect world but it has gotten better than the eye and hand in many cases. It is all about knowing "your gear".

I'll tell you a story of my own about it. My background in this industry started in sports photography as a still shooter. In 1992 I covered the Albertville Olympic Games for the United States Ski Team and AT&T. That meat I had to shoot Skiing and every other event I could possibly fit in. There was a time when a pro photographer shot Nikon or he was not a Pro. Today you can walk in any media center anywhere in the world at a major sporting event and all you see are "white lenses". Canon is now the industry standard. They began the takeover in the early nineties and they did it with AF technology that worked!

Focus was a sports shooters biggest nemesis. And in some sports you literally get one shot at doing your job and it happens in the blink of an eye. Take downhill skiing for example. Each competitor goes by you once at sixty miles an hour and bang, that's it. What you shot is what you got. If you missed focus you went back to your boss at the media center empty handed. And my would be waiting there to send my photos out all over the world. Missing focus really sucked to say the least. That is why sports guys were so quick to dump Nikon for Canon.

I shot the US Hockey vs. France game. I had a 600mm F4 Nikor lens on one F3 body and a 70-200mm F2.8 on the other. That's how we all do it, long on one and short on the other. By the end of the first period I never picked up the 600mm again. I was haunted for days after that by four words I could not get out of my head, 'WHERE IS THE PUCK?" I was not joking when I said hockey is the hardest sport I ever shot.

So, AF technology changed an industry and put Canon at the top of the heap. Yes I use it in video and stills when it works. That is most of the time if you know how to do it.

And when I came home from those games I began my own conversion to Canon and never looked back at Nikon. You can't earn a living standing next to a guy that is going to get his shot every time when your hit and miss.

Steve

Shaun Roemich
April 6th, 2015, 10:37 AM
Hi Shaun, why would you lose focus as you pushed in tighter?

Because longer focal length creates shallower depth of field and it is unlikely I would have been in focus on that EXACT focal distance.

Miggy Sanchez
April 9th, 2015, 05:20 AM
Always great to learn your gear and use it manually.

Knowledge is power in your field.

Hope this helps.


Guys, help it does so thanks. It’s so exciting to be able to tap into the varying perspectives you have to offer.



As you zoom in the depth of field gets thinner, or more shallow.



OK, this is coming in loud and clear.



Now, about that auto exposure...



Any tips here? Often the brightness of the pitch shifts quickly, especially during overcast days. I am starting to live stream these games so I have got a whole bunch of stuff going on there. I set my shutter to 1/50, ND filter to 1 or 2 depending on the glare, and let AE do its thing. Should I be getting more proactive with it, especially in relation to maintaining a greater depth of field?


Again, much appreciated.

Mark Koha
April 12th, 2015, 09:04 AM
I would just keep riding the manual focus. If you are a one man band and you are live streaming this then you shouldn't be making drastic zooms anyways. If someone scores then you can push in but you should be acting as a game camera most of the time. And when they do score, just be mindful of where you are in your zoom range. If people are moving away from you, turn left. If they are coming towards you turn right. Flip your peaking on and make it happen. Be an operator, not a lens pointer.

Shaun Roemich
April 12th, 2015, 08:51 PM
Much of what Mark says above is absolutely true but don't forget that Zone Focussing IS an integral part of BEING a camera operator at the level some of us are discussing here. A camera operator indeed does more than point/aim a camera - he/she should also know the mechanics and physics of what they are doing and developing skills and practices that maximize readiness for focus, framing et al.

I know that my focus isn't critical if I'm doing play by play (because my framing is looser and my depth of field is greater) but if I'm doing tight follow, I know that I'll have VERY shallow depth of field as I push in so I'm have the lens already in the ballpark (pardon the pun) before I need to start follow focusing.

Most of my experience in live sports has been in multicamera live switched environments but as a tight follow operator I also recognized my ISO angle would be used in replays so I needed to maximize usable footage throughout the game and not just when I was "on air".

Yes, on a broadcast lens and on most video camera lenses turning counterclockwise IS "further away" but be CLOSE before you need to touch up focus. As a Technical Director/Switcher the thing that frustrated me with camera ops just starting out is they wouldn't have "prepared" the lens for when the action was coming their way and would lose focus in a zoom.

It's a SKILL. Learn it by practicing but at the same time, walk in with a quiver of knowledge that helps you to "guess" right more of the time.

Mark Koha
April 13th, 2015, 06:21 PM
Shaun, as an EVS operator my pet peeve isn't focus so much as people whipping off of shots after something big happens to go get crowd shots. I'm sure you know what I'm talking about.

Shaun Roemich
April 13th, 2015, 06:58 PM
Mark obviously yells less than I do... My guys might do that once... Then they go deaf. <sly wink >

Tim Polster
April 13th, 2015, 08:37 PM
Any tips here? Often the brightness of the pitch shifts quickly, especially during overcast days. I am starting to live stream these games so I have got a whole bunch of stuff going on there. I set my shutter to 1/50, ND filter to 1 or 2 depending on the glare, and let AE do its thing. Should I be getting more proactive with it, especially in relation to maintaining a greater depth of field?


Again, much appreciated.

AE is only good when there is constant lighting or when you can not handle the camera. The problem with filming outdoors is the horizon. Sunny days are better as the light is relatively even. Overcast is tougher.

I prefer to run exposure manually if possible. I always film with a preview monitor. If outside I go off of the EVF as it is the only visual reference you can trust with so much ambient light.

To me, manual exposure is where the professional/non professional divide exists. By using manual exposure, YOU are deciding what the subject is and how it should be exposed. Using AE, the camera is just trying to not over expose anything in the frame which might not relate to your subject. There are times when it works, but I prefer to know it will work by setting exposure myself.

More to learn, but it will pay off in the end.