HMC150-how is the autofocus?

Jeffyr

Jeffyr

Active member
I currently have a Canon 5DMkII and am looking to upgrade my dedicated video camera. In the past I have used the Sony V1 and Z1, and more recently the Canon A1 (none of them owned by me). I will be shooting moving subjects at times and wanted to ask the focus and tracking capabilities of the HMC150. The 3 reasons I have for needing the dedicated video camera are 1. better audio handling and XLR and 2. autofocus and tracking while shooting, and 3. better ergonomics. Since the autofocus is 1 of the main reasons I wanted some opinions. Anybody using the HMC150 to shoot HS football or other sports where people are moving quickly and the camera may be subject to wandering or racking focus?


Thanks.
 
The autofocus is NOT very good in this camera.. and I wouldn't recommend using it at all. It will float a lot and be a bit too arbitrary for good quality results. For the most part you should plan on using manual focus as you'll end up with much better results..
 
That is disappointing to hear. I may actually be better off going back to the V1 then. I need to stay in the $3500 range and I can get one for $2700 and have room for some accessories. The HMC150 is so popular that I thought I would have read more about wandering focus.
 
The reason that you probably don't hear more about the auto-focus is that the manual focus on the camera is very good, and many folks (myself included) don't like auto-focus in principle anyways.
 
Lots of posts & discussions about the AF.

The 150 AF is about as good as any other 1/3" camera AF. I can only compare directly to the Canon XH-A1, and they are about the same.
 
It is awful, but ...

It is awful, but ...

Sadly, the autofocus on the HMC150 is awful. It wanders even with a stationary subject. (The Canon XH-A1 is much better in that specific regard because it uses a separate optical system just for focus.) But before you walk away from the other benefits of the HMC150, spend a little time thinking about depth-of-field and just how precise you have to be with manual focus even in high action sports.

One of the standard complaints about 1/3" CCD cameras is that you do not get the tight depth-of-field that 35mm cinematographers love. The compensating benefit is that you do not need to have a full-time focus-puller when the subject moves. For many applications, the depth-of-field is more than enough to cover the action. Depending on how you set up to capture your football game, what are the closest and the farthest distances that need to be in focus (without any opportunity for you to re-focus)? Now, consider the hyperfocal distance. Let's say you are using a lens setting of 10 mm (7.2 is roughly the "normal" focal length) at f/5.6. The hyperfocal distance is about 3 feet! If you zoom to 20mm, the hyperfocal distance is about 12 feet. Do you really have a focus problem that you cannot handle? You can set the HMC150 for continuous display of focus-distance, focal-length, and f-stop. As a practical matter, manual focus is sufficient for most (but admittedly not all) applications. My experience (with skateboarding) is that you can handle large near-far movement without much trouble.
 
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On my HDC-SD1 autofocus is really bad, the subject has to be in the middle of the frame and take at least half of the frame for the autofocus system to focus properly. More often than not I can see focused background and unfocused subject RIGHT IN THE MIDDLE OF THE FRAME when I use autofocus. The SD1 has no focus wheel, so all I can do is zoom in, lock and zoom out, but this does not work with the subject moves. So what I do is I set higher aperture value and keep focus locked until the subject is sufficiently close to me (in scenes where subject, usually my son, runs towards me) then I switch to auto and track him while panning to get a closeup. This works quite well.

But in all seriousness, the HMC150 has no iAF that the Canons have, and its LCD/EVF are not as good as on the Z5/Z7 and the new NXCAM camera. Focus assist tools should help, but they have their limitations, like the frame magnification tool does not show what is on the edge of the frame, so rack focus between an object on the left and object on the right is not possible. I haven't tried peaking when I played with the HMC150, so I cannot comment on it, but now using the Sony V1 for about two weeks I can say that peaking is not panacea. It works best with high-contrast objects like a car grille or a fence or a window frame, the objects that have a clear shade and a hotspot. With other objects like humans, peaking is pretty useless. Also it is impossible to judge real picture because peaking is drawn on top of the image.

All in all, it seems that nothing beats a proper large hi-res screen. The Z5/Z7/NXCAM have 3.2-2.5 screens with 900,000 pixels and 1.1MPix EVFs, these should be really good. Compared to these, Panasonic's screen is pretty much standard def. Barry said that one can reliably focus using this screen and focus assist aids, I don't know.
 
rpcx, I don't know about hyperfocal distance... Also, I am not sure is there a difference between the farthest focusing distance setting and hyperfocal setting, my consumer-grade SD1 does not have infinity setting (consumer Canons and Sonys do), so maybe this is just an issue of my particular camera, but when I was shooting my son in the park, he was about 100 feet away, I zoomed in, with 1/4-inch chip camera at about F8, he was behind the rock. I focused on the rock because it was easier, he was behind it about a foot or so. The rock was in focus, my son was not.
 
canons AF is pretty snappy, even in 24p. IMO the HMC is adequate in 24p, not as bad as others here feel. In 60i its good- but the cam's other features make up for it and i wouldn't trade it for a A1 or even an H1. I have got to have clean low light footage, and the low noise of the HMC trumphs them
 
As an owner of multiple copies of both of these cameras since their introduction, I would have to strongly disagree with this.

If you search DVinfo you will see my comparison tests from back in 2008 where I tested and compared the AF and low light of both the XH-A1 & HMC-150.

The HMC-150 focus does not hunt on stationary objects except in very low light. The XH-A1 focus system does tend to hunt far more than the 150, which I demonstrated in several tests.

rpcx said:
Sadly, the autofocus on the HMC150 is awful. It wanders even with a stationary subject. (The Canon XH-A1 is much better in that specific regard because it uses a separate optical system just for focus.)...
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Cranky said:
rpcx, I don't know about hyperfocal distance...
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Sorry about that. I assumed that most people on this board would be familiar with the term. Actually, it is a pretty simple concept. For a given lens focal length and f-stop, the hyperfocal distance is the lens distance setting which maximizes the depth of field. It does that because the hyperfocal distance is the closest distance setting which still extends the depth-of-field out to infinity. So, for the example I gave, with the HMC-150 lens zoomed to 20mm and the aperture at f/5.6, setting the distance to 12 feet will keep in focus objects out to "infinity". In addition, the regular depth-of-field calculation indicates that objects as close as 6 feet also will be in focus. That is a pretty large depth of field especially since 20mm is into the telephoto range on the HMC-150.

Cranky said:
Also, I am not sure is there a difference between the farthest focusing distance setting and hyperfocal setting, my consumer-grade SD1 does not have infinity setting (consumer Canons and Sonys do), so maybe this is just an issue of my particular camera, but when I was shooting my son in the park, he was about 100 feet away, I zoomed in, with 1/4-inch chip camera at about F8, he was behind the rock. I focused on the rock because it was easier, he was behind it about a foot or so. The rock was in focus, my son was not.
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Sorry, that scenario I cannot explain. Something has to be wrong (or incomplete) in that description. Assuming that your SD1 lens was zoomed to maximum focal length (48mm, I think), aperture was set at f/8, and distance was set at 100 feet, then there is just no way a consumer grade lens with a consumer grade 1/4" sensor could reveal a significant difference in focus for an object at 102 feet. Something else has to be involved.
 
jeff9329 said:
As an owner of multiple copies of both of these cameras since their introduction, I would have to strongly disagree with this.

If you search DVinfo you will see my comparison tests from back in 2008 where I tested and compared the AF and low light of both the XH-A1 & HMC-150.

The HMC-150 focus does not hunt on stationary objects except in very low light. The XH-A1 focus system does tend to hunt far more than the 150, which I demonstrated in several tests.
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Clearly, our experiences are different. I have not seen your tests nor do I know whether tests with an HMC-150 back in 2008 yield the same results as recent production cameras. (At a minimum, the firmware is likely to be different.) Also, we may not be talking about exactly the same thing. You said the HMC-150 "does not hunt." I never suggested that it did, at least, within my understanding of that term. What I can demonstrate easily with my camera (and another that I also tested) is that the focus setting WANDERS on stationary (relatively contrasty) objects in bright sunlight. (I used boats in a marina for my informal tests.) In addition, I turned off auto focus and used the focus assist button for a sequence of readings on the same object. Often (but not always) the variation among the readings was substantial.

More important than the tests was my practical experience using the cameras. I took an XH-A1 and shot about a 100 clips of varying length over a period of several hours. There was a lot of subject and camera movement. About two weeks later, I returned to the same site and shot similar content under virtually identical conditions. I used auto focus with both cameras. The XH-A1 was faultless. (Now, I am not talking about image quality overall, just focus.) Several clips from the HMC-150 were ruined by bad focus. The practical reality for me was that I could trust the XH-A1 autofocus but not the HMC-150. It was just as simple as that. If HMC-150 autofocus works for you, then be happy. It does not work for me.
 
rpcx said:
Sorry about that. I assumed that most people on this board would be familiar with the term.
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Sorry about that. I AM familiar with the term. I just did not know whether focusing to infinity is the same as focusing to hyperfocal distance.
 
I heard all this talk about bad AF but I have not noticed it. Sure, it's not as fast as some, but in the cases where I have used it (steadycam) in lowish light at 1080 30p, it seemed fine except for the odd time when it confused itself as to which object should be in focus.

I mostly use MF though, for I bought a Panny for its manual features, not it's auto features. :)
 
rpcx said:
Clearly, our experiences are different. I have not seen your tests nor do I know whether tests with an HMC-150 back in 2008 yield the same results as recent production cameras. (At a minimum, the firmware is likely to be different.)
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So far I have had at least one HMC-150 with each of the different firmwares from 1.15 to 1.20. The most recent 150 was purchased in November 2009. They have been functionally identical (with minor WB variations), and I have never updated the firmware on the older cameras.



rpcx said:
Also, we may not be talking about exactly the same thing. You said the HMC-150 "does not hunt." I never suggested that it did, at least, within my understanding of that term. What I can demonstrate easily with my camera (and another that I also tested) is that the focus setting WANDERS on stationary (relatively contrasty) objects in bright sunlight. (I used boats in a marina for my informal tests.)
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I have never seen that happen, but given there are unlimited factors to affect a shoot, anything can happen. I would not consider that normal.


rpcx said:
In addition, I turned off auto focus and used the focus assist button for a sequence of readings on the same object. Often (but not always) the variation among the readings was substantial..)
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That is normal if you are talking about focus set to "number" and the focus number varies +/- 5. Thats the nature of electronic focus. If you are saying the image comes & goes from correct focus, something is wrong with that camera.

rpcx said:
More important than the tests was my practical experience using the cameras. I took an XH-A1 and shot about a 100 clips of varying length over a period of several hours. There was a lot of subject and camera movement. About two weeks later, I returned to the same site and shot similar content under virtually identical conditions. I used auto focus with both cameras. The XH-A1 was faultless. (Now, I am not talking about image quality overall, just focus.) Several clips from the HMC-150 were ruined by bad focus. The practical reality for me was that I could trust the XH-A1 autofocus but not the HMC-150. It was just as simple as that. If HMC-150 autofocus works for you, then be happy. It does not work for me.
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I shot with 3 XH-A1s from 2006 to 2008 when I switched to the HMC-150 after extensive on tripod side by side tests. I know there are situations where either camera can have problems, but after you shoot them side by side, I can assue you the Panasonic has better auto focus capabilities. And neither is bad, but the IAF on the Canon will inevitably ruin a shot with a fast focus hunt right in a critical scene, if you use it long enough.
 
i've never been able to rely entirely/exlusively on auto-focus on any camera.

what does work well for me, with ALL cameras, is to set focus to manual and use a combination of manual focus, quick auto-focus button and/or locking focus.

i've recently begun to use the HMC's handy switches for jumping to infinity focus and the quick, temporary auto-focus button for pulling focus or follow focus.

the lack of that instant infrared focus that is so snappy on a Canon has taught me better camera operating skills that once you get over the learning curve have made me a better shooter.

if you absolutely must have a camera that does the focusing for you, then you may want to buy a consumer cam with face-tracking auto-focus or wait a couple years until the feature matures and is introduced on a prosumer cam.
 
More than likely... people will have a bit of a tough transition to HD from an SD environment.. It was a bit of a learning curve for me 4 years ago... as focus is so much more critical... exposure is more critical.. and overall it's possible to get wonderful HD images, but it takes more dilligence. In DV you could be close enough with it all and you'd be fine... Close enough in HD and your image could be a nuclear white out, and an unusable focus... Being comfortable in how you shoot and getting the right hand positions facilitates all of this... I also think that a lot of this stuff is compounded by expectations for auto functions to be as reliable and repeatable as they were on the DV cams and that's just not true..

One thing I like is being able to turn the focus ring to iris.. simply because I shoot with a fisheye a lot and the slightest bump off the focus wheel and you are soft.. and it's almost impossible to tell off the monitor....
 
The HMC-150 has usable auto focus, but when you do it manually, everything is just sharper.

Especially with a moving subject or camera, if you do it manually, you will think the camera is shooting better images, and it is.

Again, the auto focus is not bad, manual is just better.
 
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