Why is the autofocus so terrible on HVX? Is a fix possible through firmware upgrade?

C

conrad787

Member
I've had my HVX200A for a year and can't ignore the fact that the autofocus is VERY inaccurate, especially when zooming. I find myself using the ND filter just so the lens will close down more and give me deeper DOF. Otherwise, things fall out of focus.

Why is the autofocus sensor so bad? I've had better success with AF in cheap DV cameras. Is there any possibility of this being fixed in the future w a firmware update?

Conrad
 
Cheap DV cameras inherently have a larger DOF due to the smaller sensor size (1/4 or 1/6" many times). The larger DOF makes autofocus "hunting" less problematic as does shooting in 60i which most cheap cameras do. Shooting in 24p reduces the sampling to 24 times a second as opposed to 60. The general consensus is to not use auto focus. Practice manually focus on the fly and pretty soon you'll be great at it.
 
Auto focus suffers at 24p and telephoto.At wide it's not so much a problem, seeing that the wide angle makes more of the image appear acceptably sharp. Telephoto will magnify focus errors.
 
Keep in mind that the "consensus" of not using autofocus isn't because of the HVX200, but in general, across the board. Autofocus is a consumer feature, not a pro one.
 
Ahh thanks for the clarification on that point David - for the record I've run into the same problem on every 1/3" camera i've used. Definitely not limited to just the HVX.
 
Story of my life. Autofocus sucks on an hvx. Try using it for a fast run n' gun reality show. It's a great camera for shorts and movies where actors have marks or you have time to set up a shot but if you don't focus is random. I'll shoot 60i where it is better but it is nowhere near as good as the sony or cannon camera's. When I'm shooting wide I always use infinity focus, have too. I have made so many post here about finding ways to improve it.
 
ChipG, agreed.

I understand is a consumer feature, and not a pro feature, but...... some days I shoot as a professional, and other days, like today, I wanted to shoot some footage of my two german shepard puppies running around. I don't want to have to manually focus if it's not needed.

It sounds like the only solution is to increase the sampling rate of the autofocus sensor by shooting in 60 frames instead of 24.
 
It's well known and documented that the autofocus performance at 24P is nowhere near as good as it is at 60p/60i. The system needs frequent updates in order to perform well, and the slower sampling rate doesn't provide it with what it needs.

In the original DVX100, they actually *disabled* autofocus when in 24p mode. People screamed, so they enabled it but they wouldn't call it "autofocus", they instead called it "focus assist" because the performance just isn't fast enough to qualify as autofocus. All 24p camcorders work the same way. If you want good autofocus, use 60p or 60i.
 
I shoot in 60i & 60p, it's not good, trust me. It's better than 24p but for action stuff it sucks. People think they can focus on the crappy lcd monitor (it's very bad) in fast n gun' action scenarios. It's luck if you get the shot in AF. I'd recommend shooting the dogs with the lens wide and infinity focus. HVX is a pretty sweet camera for the most part, learn the weak points so you can use it to it's best.
 
conrad787 said:
ChipG, agreed.

I understand is a consumer feature, and not a pro feature, but...... some days I shoot as a professional, and other days, like today, I wanted to shoot some footage of my two german shepard puppies running around. I don't want to have to manually focus if it's not needed.

It sounds like the only solution is to increase the sampling rate of the autofocus sensor by shooting in 60 frames instead of 24.
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I'll tell you this right now, if your a PRO and can manually focus on an hvx with fast action run n' gun / dog's running around (not wide in infinity)on the stock lcd screen you are the only one who can do it.
 
Sony Z7 (& others) and most new canon camera's are way better in 24p than the hvx / hpx in 60i or 60p.

It's still a great camera but people tell me how to guess what's going to happen in a reality show (ha!) then tell me how to focus on them with the stock lcd screen shooting in 1080 then they tell me to buy a big monitor, get a focus puller etc... It never ends... I think Panny needs to make a better focusing camera. Disco Channel hates the hvx's after 700+ hours of thier 800 hours of footage of Iditarod was out of focus. Original Productions almost beheaded me when I sent them hvx footage...

Sorry guy's, this is something that I have to say. HVX rocks for a movie camera!
 
I'm a documentary filmmaker, have been for a long, long, long time, and have never used auto-focus - ever! Even if it is fast enough, and accurate enough, it doesn't necessarily focus where I want it to - and if something passes in front of the subject like a car, well, you know...

Although I use the HVX infrequently (it's my B camera), I have shot with it enough to know it's weaknesses and it's strengths... The viewfinder isn't great, but the focus assist does help a lot, although sometimes that's impractical when shooting fast (I personally deplore the term "run and gun", by the way).

There are manual focus solutions for this problem. The easiest and cheapest is to get used to referring to the focus scale at the bottom of the viewfinder and estimate distance... you can get pretty good at it with practice.

Another is to use one of the external follow focus devices (I use the FOXY - stupid name but good product - Bogen makes one too). This gives you a large knob which you can mount anywhere, like mini-rods or handgrip. The focus and iris are locked in electronically, so you can actually mark a permanent focus scale on the unit (taking measurements with a tape measure) and refer to it visually to estimate distances.

True, you may never get good enough to differentiate between 6 foot 4 inches and 5 foot 7 inches, but you can certainly recognize the difference between 3 feet and 7 feet, or 14 feet and 50 feet - and that's usually good enough for a 1/3" camera.
 
Auto focus is convenient in a pinch situation, or when it is not practical to use manual.
However, even the best autofocus cameras will still seek, sometimes even while on a static shot. The HVX auto focus could and should be quicker, but this camera was designed to be primarily a "film like" camera.

I don't know many film cameras that can auto focus. Think of it as a bonus! (sarcasm)- it needs to be improved.
 
David Jimerson said:
Keep in mind that the "consensus" of not using autofocus isn't because of the HVX200, but in general, across the board. Autofocus is a consumer feature, not a pro one.
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...then it's just perfect that the manual focussing on the HVX is so extremely professional... NOT!

Focussing manually is a pain even when you're shooting from a tripod. As soon as I'm shooting handheld, documentary/eng, then I just can't use it.
I'm perfectly able to do that with a real lens, otherwise I'd think I just wasn't pro enough. The HVX forces me to use autofocus in most handheld situations.
 
Barry_Green said:
It's well known and documented that the autofocus performance at 24P is nowhere near as good as it is at 60p/60i. The system needs frequent updates in order to perform well, and the slower sampling rate doesn't provide it with what it needs.

In the original DVX100, they actually *disabled* autofocus when in 24p mode. People screamed, so they enabled it but they wouldn't call it "autofocus", they instead called it "focus assist" because the performance just isn't fast enough to qualify as autofocus. All 24p camcorders work the same way. If you want good autofocus, use 60p or 60i.
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Wow that's something worth knowing, because anyone new to the cam would think it's a bad performer, when I've seen with my own eyes how truly great that little camera is.
 
As far as I know the only camera that does well in AF in 24p mode is the Canon A1/G1 in their 24f mode. This is because the autofocus IR sensor is located on the side of the lens and is independent of the frame rate. Of course that also means you have to be careful about blocking the sensor if you are using a mattebox and want to use AF.
 
I manual focus on the HVX when running-and-gunning and my footage is always sharp, probably because I have never ever used autofocus (ever) in the 30-odd years of using cameras, and simply have a lot of practice. Even with the forever-spinning focus ring, once you're in focus your hand will automatically know which way to move the ring and how much to keep a moving subject in focus.

As for using the tiny LCD screen for judging sharpness: When you're hunting for focus, the median between two out-of-focus points (using the focus ring to judge) is always going to be in focus. It doesn't take a lot of hunting to tell you these points, so is almost imperceptible on screen and takes literally a fraction of a second to find focus.
 
dantewaters said:
Wow that's something worth knowing, because anyone new to the cam would think it's a bad performer, when I've seen with my own eyes how truly great that little camera is.
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Hey Dante,

No one is saying the hvx/hpx is a bad camera. Best camera on the market for movies & docs where you can pre plan and set up your shots.

It is weak for FAST stuff but overall I still give it a 9 out of 10. I love it, great camera, didn't know this until after I made a big investment and wish someone whou had of givin me a heads up. Not trying to bash it just maybe improve it for my situation.
 
pmark23 said:
I manual focus on the HVX when running-and-gunning and my footage is always sharp, probably because I have never ever used autofocus (ever) in the 30-odd years of using cameras, and simply have a lot of practice. Even with the forever-spinning focus ring, once you're in focus your hand will automatically know which way to move the ring and how much to keep a moving subject in focus.

As for using the tiny LCD screen for judging sharpness: When you're hunting for focus, the median between two out-of-focus points (using the focus ring to judge) is always going to be in focus. It doesn't take a lot of hunting to tell you these points, so is almost imperceptible on screen and takes literally a fraction of a second to find focus.
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Heh? What kind of fast stuff do you shoot and you are hired, if 25% of your footage is in focus for my project I'll pay you double. If not you work for free, fair? We shoot in 1080.
 
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