The Focus Pulsing 'Feature' - Error or with every Camera?
 

Having read so much about the annoying focus pulsing in this board i wonder: is this a legit error which canon can repair or even send me a new cam (as some of you have stated in the forums) or do i have to deal with it?

It's so unbelievably bad, when i zoom in on a still object it cannot hold focus for even a second :(

thanks
-daniel

I'm guessing this is when using an auto-focus, correct? This is a problem with many auto-focus cameras. The camera is not a human and doesn't always know exactly what you wish to focus on. Sometimes, the camera will get confused between two objects in the frame - especially at long focal lengths.

The sure-fire way to avoid this is to simply focus manually. It may take a little while to get comfortable with, but it is a great skill to get to know and is worth it in the long run.

Manual is defintely the way to go. It's one of the great features of prosumer cameras... use it! :)

Auto is always jerky and could ruin a shot.

hm ok, it maybe just me but neither my fx1, my old cheap 299 bucks canon dv or my sony hdr-hc1e has such problems. i often film interviews with the talents moving forwards and backwards on their chairs while i'm doing the interviews - so there's no way to focus manually for me, neither it seems feasible to control every bit of focus movement on every shot.

i sat on my couch yesterday, connected the A1 to my TV and positioned it about 1,5-2 meters away from me and did a closeup as we have it in mos interviews. it constantly moved back and forth, sometimes even went completely out of focus. light was quite ok.

:(

so... send the A1 back and go for a second FX1 !?

Yes. If you have an FX1 already, I'm not sure why you would choose a different make and model as a second camera. It's to your advantage to stiick with one brand -- in your case, Sony -- in order to insure compatibility between cameras for batteries, accessories, and most importantly the look of the video.

In my opinion you should definitely switch to a second FX1 or a Z1.

my original plan was to sell the fx1 and go for a second A1 as it is superior in terms of runtime with batteries, nightshots and, most of all, has the xlr inputs which are manditory for me right now :(

i've uploaded a sample clip of my problem. hope this helps!

http://www.dreffects.de/tmp/fokusproblem01.wmv

I was blown away by how bad the autofocus was too when I first got my cam. My old 3ccd consumer DV cam is way better. But then I was told that AF and HD doesn't work that well together, so I'm under the impression that that's the main issue.
I haven't tried shooting in DV with my XHA1 yet though, but if the AF is just as bad there, I'd never ever buy anything Canon again. Manual focusing works fine though, and is one of the reasons I needed a better camera anyway. And AF works good for a lot of shots, just have to learn what kind of situations it can't handle at all, and stay away from those, at least that's what I do.

hm what kind of situations would be bad? i somehow consider the clip with me sitting on a chouch pretty common and not at all difficult. what will happen when we start shooting with a steadycam which relies on autofocus on events with bad lightning?

No idea! hehe that's the fun part I guess... Some shots, especially somewhat caotiv ones, where focus shifts dramatically when someone approches the camera etc, with suboptimal lighting, has caused too much problems for me to trust AF for that. Other than that: try and see i guess, that's what I do, and for most shots where I'm not shooting scenery etc, or I am in control and able to keep up with the focusing, I do manual. And that seems to work for me, Auto for the things it can handle and manual for the rest.

Sorry for not being able to be more specific here, I just got the camera a couple weeks ago, so I'm still trying to figure this out myself. :)

I just got my A1, and my first impressions so far was that it was not nearly as good as my GL2 I upgraded from. I was suprised as well, even during bright daylight that it had problems focusing on subjects. I don't mind too much, because I have been wanting to work on my Manual skills more anyways, and this really forces me to do so.. It is good practice especially since I am planning on getting a 35mm adapter here soon, probably brevis.

Luke

thanks for your help. could you advise me on the F setting (sorry don't know the english word for it, german one is 'blende' like F3.2 or something^^)? I know from digital fotography that a F4 Value is barley enough for a portrait photograph. so when shooting interviews it would be good to choose a F value that covers about 30cm in each direction from the focuspoint on so that the talent can move a bit without the manual focus i cannot change when doing the interview myself, loses focus.

thanks for any advice :)

using manual focus and selectively hitting the 'push AF' button has worked great for me. only wish the button was a bit bigger, like on the canon xl lenses.

i'd agree - but i have to be in front of the camera with no operator at hand :(

I shoot with an XL2 and a manual lens, and my 3x which I use the auto focus on occasion.

I looked at your clip and I can say I think the lighting is a problem as well as the focus area. The only SHARP line is the edge of your head and the wall behind you. The lighting on your features is very soft, and the camera is trying to focus between your lips, nose and the sharp lines of your sideburns.

Not what I would consider interview lighting at all, and a challenging frame for autofocus to follow.

If you are not operating the camera, then I would set the subject in place, manually focus on them, and then join them in the scene.

The hazards of wearing too many hats.

Hm ok, i have tons of interviews lit in similar way, especially on events like E3 or Games Convention which's 'sets' are located on the presentation area of the videogame publisher. There it's being lit to please the human eye. So primarily dark, with red lights etc. I know that sucks compared to a studio environment.

thanks for the explanation on what the focus is trying to do. i just wonder why he can't decide even if i hold absolutely still ;)

My second problem is: when i'm not doing the interviews alone, a steadycam operator is handling the camera (without a focus puller) - do you think the AF will handle the situation better (or less noticeably bad) if there's a constant movement?

hehe, yep^^