Tips for Focusing

[Maik Müller]

The only "pure one truth" about pulling focus is do whatever it takes to get the shot.

That said, here's a few thoughts.

Thanks Phil! That was a very nice post, i guess you got all covered.

 

[Phil Holland]

Thanks Phil! That was a very nice post, i guess you got all covered.

Nah. There's more to it than that, but it's certainly a subject with a good deal of answers and opinions.

Always remember those truths though. Whatever it takes to get the shot and practice makes you better. Those are the only things I can really say for sure

 

[James McLellan]

Something I have found useful when shooting solo and very shallow is the idea not to pull focus. Instead rock toward or away from the subject.
It is very intuitive and for detail shots it can give a natural feel with the focus rolling up or down an object.

 

[paul schefz]

i use the grid loupe www.gridsuportes.com on my 5" touch and with focus enabled i can keep up with moving subjects...within reason....the magnify has not much use for me and edge is great but just too weird....i have been looking at the 9" touch but without a loupe to go on it, i doubt it will be any better then the 5"...the resolution is not that great....
i totally agree with the "rocking back and forth" especially when shooting really wide open....it makes the slight in and out look much smoother....

i have to say that i am jealous when i see how well face focus tracking works in consumer p&s....and not only on stills and small sensors....i had a sony DSLR (actually mirror less) and it was able to keep up with subjects moving around the frame in video mode...pretty amazing....no miracles of course, a dog running and cutting threw it off....but someone walking along a straight line, even at an angle (not straight into camera), no problem....

 

[Jacek Zakowicz]

We use 14 bit encoders.
Lenses are definitely a bottle neck here.
The steps on lenses vary from about 600-800 to about 6000. The L lenses have generally more steps.

When I say "bottle neck" it just means that the lenses always have less steps than the OptiTron.
On average the (L) lenses have 2000-3000 steps. That's way more than enough for smooth focus pulls with still lenses. And precision with the steps spread over a 320 degrees rotation.

 

[Oliver Skibbe]

The steps on lenses vary from about 600-800 to about 6000. The L lenses have generally more steps.

Some numbers from an old thread about the Birger EF mount:

LENS NAME: #STEPS
CANON LENS EF 50mm 1:1.4 USM: 660
CANON ZOOM LENS EF-S 10-22mm 1:3.5-4.5 USM: 1185
CANON LENS EF 14mm 1:2.8L USM: 1398
CANON ZOOM LENS 16-35mm 1:2.8L USM: 1566
CANON LENS EF 100mm 1:2 USM: 1687
CANON LENS EF 28mm 1:1.8 USM: 1800
CANON ZOOM LENS EF 28-105mm 1:3.5-4.5 USM: 1900
CANON LENS EF 200mm 1:2.8L USM: 2098
CANON ZOOM LENS EF 28-135mm 1:3.5-5.6 IS USM: 2276
CANON ZOOM LENS EF 70-200mm 1:2.8L IS USM: 2512
CANON LENS EF 35mm 1:1.4L USM: 2517
CANON LENS EF 24mm 1:1.4L USM: 2521
CANON MACRO LENS EF 100mm 1:2.8 USM: 2535
CANON MACRO LENS EF-S 60mm 1:2.8 USM: 3298
CANON LENS EF 200mm 1:1.8L USM: 3706
CANON LENS EF 85mm 1:1.2L USM: 4212

 

[AndreasOberg]

Why do you feel it is failing you? Why are you missing critical focus? Do you feel unable to see the focal point adequately, or can you see it enough to know that you are not hitting the mark? If you are unable to hit the mark without hunting, I would suggest that the problem is mechanical and not due to the assist.

Hi, I'm just pointing to objects that I know are in focus and the assist will claim that it's not in focus. My only point was that so far I haven't found a use for the assist turning green/orange/red to show if things are in focus.
Best,
Andreas

 

[AndreasOberg]

Fantastic reply Phil. I will digest what you wrote for a while. Thanks for taking the time, I really value it!
/Andreas

 

[Denis Buhot]

much expected thread...

much expected thread...

Hi guys.

I'm spending a lot of time practicing focusing. Do you guys have any tips for how to become better.
I have the RED 9" Touch Screen right now. I have both Canon lenses and a few Red Primes. It's much easier to focus with the Red Primes and CFF1 follow focus than Canon. My jobs so far are documentaries and commercials. Worst situation i had was hanging backwars from a snow mobile trying to focus on running sleid dogs.

A few thoughts
- should I use the CFF1 with Canon lenses. The main downside is that the setup is less portable and doesn't fit in my backpack. Now I can just take the canon setup into handheld quickly.
- I'm experimenting with using 2 fingers for focusing (70-200) and then 2 other fingers for pulling focus after a zoom. Am I'm doing it right?
- Should I get another screen for another focus puller. So far I have been operating it solo all the time so have no experience with using a focus puller. What screen mode would they use normally?
- Normally I use the F(ocus assist) mode. I never use the edge mode since you don't really see anything on it. What do you guys use?
- If I'm unsure what direction I should focus I begun by verifying by looking outside the screen to measure distance first. Few things are worse than pulling the wrong direction and then changing your mind.
- Can you use the focus modes that the Epic that pulls focus for you.
- Are there any tutorials, lessons etc for this? I guess the real answer is that I need to be taught by someone experienced.

Right now I'm taking time every day to sit and practice, back, forward, back forward etc, seems to help a lot. Anyway any thoughts would be welcome. What tricks do you use?
/Andreas

For documentary use, focussing with the epic is THE issue, to me. Wildlife shooting makes it even more crucial.


Here is what works for me. Very basic, I fear...

- use zooms rather than prime, provided their track focus all the way down (hard to find in dslr lenses today, since it's not free, and automatic focussing has made it unnecessary) Always focus at the maximum range, then zoom out at the desired focal lengtj.
- on a moving subject, focus by zooming out, rather than using the focus ring, just as tv cameramen do...
- focus with iris as much wide open as possible to retain a discernible image to focus on, then close to desired aperture
- when recording a long sequence with a moving subject, open iris from time to time to ensure you're still in focus, and do not rely on DOF. A subject steadily moving out of focus will still look in focus, if you don't give proper attention...
- almost never use focus assist !! totally confusing ! The only situation I have found it useful and not misleading is when focussing on to an isolated subject, with no close backgrouns.

Basic, as I said... Hope that helps

 

[James McLellan]

I have had mixed results with the edge detect feature. When shooting tight and WFO it is hard to tell when you are on the mark, only close. However if you are WFO and you have some distance from subject to lens it can be pretty accurate. The one time I am quite confident using it is shooting straight down hallways and such. When you have lines of distance that can help you track your subject it can be very good to use. If I have that scenario I almost always switch to edge detect mode.

 

[AndreasOberg]

- focus with iris as much wide open as possible to retain a discernible image to focus on, then close to desired aperture
- when recording a long sequence with a moving subject, open iris from time to time to ensure you're still in focus, and do not rely on DOF. A subject steadily moving out of focus will still look in focus, if you don't give proper attention...
- almost never use focus assist !! totally confusing ! The only situation I have found it useful and not misleading is when focussing on to an isolated subject, with no close backgrouns.

Basic, as I said... Hope that helps

That is a great tip, exactly what I was looking for. To use the maximum wide apperture and then increase it. Clever, I rememer using it back in the Canon days, but forgot about it. You mention that you do it when you follow a moving object longer. I guess you plan on cutting those sections out, right?

I've taken up the habbit to practice every day for 30-60 minutes just focusing on different objects around me. Also with the Canon 70-200 I practice on zooming and then focusing directly after. So I have 2 fingers on the zoom and then directly focus after with 2 other fingers. Works pretty well.

If we continue shooting more documentaries I think I will may get something like the Fujinon Cabrio so I woud get with 2 zooms the complete range from 18-300 without being too heavy. Pretty expensive lenses though so they are outside my price range for now. I never liked the hand held feeling much that I have been forced to film in documentaries. But in the future maybe by using a Movi setup one could actually do handheld with very smooth results.

I done several tests and it seems like it's impossible to actually focus 100% in 5k resolution by just looking at the screen with Focus mode one. I have tried to focus on details and from what I can see the focus is spot on, but if I go into magnify mode I can see that focus can actually be improved more. I really miss that the Epic doesn't have a magnified little window that one could see for the area in the middle.

/Andreas