View Full Version : HVX-200 back focus issues?


George Odell
September 14th, 2009, 11:03 AM
Looking for some feedback on this one.

I'm wondering how many others out there are aware of this funky back focus issue with the HVX-200 camera? The rental house I got it from (Talamas in Mass) says it's a non-issue.... the way it is with that camera. "All our 200's are like that".

Panasonic's P2 rep also says "there is no back focus problem" on that model.


Here's the test:

Under low to moderate room lighting so the iris is wide open... not outdoors...

Focus up on the subject. Use Focus Assist for critical focus. Then zoom back to compose the shot. Recheck with FA and the picture is out of focus. Readjust with the focus ring. Zoom back in and it's way out, again.

Do you get the same results or will your camera hold critical (with Focus assist) focus throughout the full zoom range... the way it's supposed to?

Dan Brockett
September 14th, 2009, 11:22 AM
This is B.S., not all 200s have back focus issues. The only way for a fixed lens camera to have a back focus issue is if the camera has been dropped or jarred and a lens element has come loose or become tweaked.

How are you judging focus? Only using the LCD and focus enhancement? You really need to hook it up to a decent sized HD monitor, the LCD on the 200 is not very good so you really have to have a lot of hours under your belt with the camera to accurately judge focus using just the LCD IMHO. The 170 has the same monitor but they tweaked it to display a lot more peaking so it is easier to judge focus with it than the 200.

Hook it up to a 17" or larger HD monitor. Then run your focus test and if it still loses focus from zoomed in to wide angle, the camera is broken and needs to have the lens element replaced. I have used a local repair shop who is a Panasonic approved whiz at HVX200 repairs and he told me that you cannot do anything to "repair" the HVX200 lens, Panasonic made it that way. With almost any problems with the lens, the entire lens assembly must be replaced, it is pretty expensive, he told me about $1,200.00 inc. labor. But as far as doing traditional lens repair like you would on a detachable lens, you can't do it on an HVX. Seeing as HVX's are rapidly approaching beoing worth only about $2,000.00 used, a $1,200.00 repair doesn't make financial sense, it would make more sense to just buy a new camera for the rental house.

If I rented a camera and it was defective, I would demand my rental fee back. This, "all 200s have back focus issues" is a crock. When a rental house sends out defective gear, it is their responsibility to make good on the rental, either by replacing the camera during the shoot or offering to refund the rental fee. I would find a new rental source personally, the economy and production are in tatters and their a lot of hungry rental companies out there who will want to earn your business.

Dan

George Odell
September 14th, 2009, 11:59 AM
Hey Dan:

We had a Panasonic 17" HD monitor on the set, a green screen shoot, and it was soft when zoomed out.

BTW: The Focus Assist, which is just a digital zoom with a fancy name, does work well enough on the LCD screen to show you are in or out of focus.

Yes, after much haggling and even some name calling on their part (you would not believe what happened) they have agreed to refund the camera rental but they refuse to own up to their camera being at fault. Panasonic is no help, either, so that's why I'm taking this one "to the street".

What I'd like to have happen is for some owner/operators out there to try the test, above, and post their results. There may be cameras with this same issue and the owners are not even aware of it.

Dan Brockett
September 14th, 2009, 04:27 PM
Good to hear that you had a monitor on set. It does sound like the definition of a back focus issue to me. I know that my 200 never did that and my 170 doesn't either. The method you describe is how 90% of HD users focus their cameras, zoom in all of the way, sharp focus, then re-frame for medium or wide.

If all of their 200s are like that, they they have all been dropped or abused. Trust me, I have shot with dozens of different HVX200s (I was TD on a couple of network pilots where we shot 4-5 HVX200s at once), plus I owned my own, plus the production company I worked for bought four of them on my recommendation and I shot with all of their 200s, this is not normal or acceptable. I have probably shot with more HVX200s than 95% of the people out there and I would call what you went through as a defective piece of gear.

Dan

Noah Kadner
September 14th, 2009, 11:31 PM
Yeah that's a crappy rental house that doesn't keep their cameras maintained...

Noah

George Odell
September 15th, 2009, 07:01 AM
The method you describe is how 90% of HD users focus their cameras, zoom in all of the way, sharp focus, then re-frame for medium or wide.Dan

90%? What other way is there to obtain proper focus with a video camera?

What's interesting is that, sans that Focus Assist, it would be very difficult for a shooter to know he/she is not in focus throughout the entire zoom range on that camera. The LCD monitor on the 200 offers very little definition and when you start to back off on the zoom it gets worse. It's for framing and nothing more.

Even with a standard circle wedge focus chart framed up it was hard to see the loss UNTIL you checked it with Focus Assist. Then it was very clear you were out.

I'd still like to have someone who has that camera now do this test and report back.

Daniel Epstein
September 18th, 2009, 09:06 PM
Of course if you adjust the focus when the lens is at the wide end its chances of being focused at the tight end are slim. If the focus on a zoom lens is not holding then back focus is not correct. It is true that many lenses with Autofocus mechanisms don't always have the best back focus. Also low light situations will be more likely to show back focus issues more dramatically than brighter scenes

TingSern Wong
September 18th, 2009, 10:13 PM
I owned a HVX-202 previously and now a HPX-172. Never had any issue with focusing. I always set it up on MANUAL focus, ZOOM in the max, focus, then zoom out. Never seen the image loose focus this way. The auto focusing is lousy - I don't even know where the camera is focusing - hence, Manual.

Tom Chartrand
September 22nd, 2009, 08:43 AM
I own a 200 and have not had any issues. A colleague of mine had a 200 as well and the backfocus was out, but we determined it was due to being mishandled. He sent it to Panasonic for repair which they expedited and it's been fine since.

No doubt you know how to focus and it's likely that the camera was mistreated and never looked at for backfocus issues after being the rental pool for a while.

Talamas in Boston has been good for me, just an issue that is often overlooked.


Tom

Tom Wheeler
November 25th, 2009, 06:48 AM
I have had my 200 for 2 years and just in the last shoot I noticed what appeared as a back focus issue. If I zoomed in on something and the distance in the view finder reported it was at 97 ft and I pulled back the distance would now change during the pull resulting in a very soft image. It did not matter if I used auto or manual focus, same result. I also noticed that there was no infinite focus as well.

I took my camera to Roscor for service and in two days and $270 they fixed the problem. There were cold solder joints in two of the ribbon cables that went around the lens. The service tech notice if he touch or moved them, servo motors went nuts. He re-soldered the cables and connections and the problem went away. This also fixed a problem I had with getting any audio at all if I shot at 720 30PN, all of the other recording resolutions, no problem with audio.

Tom Wheeler

Denny Lajeunesse
November 29th, 2009, 04:28 AM
Tom, could you clarify what your audio problem was? I buddy of mine is having a similar issue with his HVX200.

Tom Wheeler
September 3rd, 2010, 06:59 AM
Sorry for the very late reply, but the issue was NO audio at all in the native 720 mode. The ribbon cable resolder fixed that issue as well.

But here is an update, just checked my camera for a big shoot next week and the "back focus" issue has returned. If I tap the camera handle the focus comes back and if I tap it again the focus goes out. I'm taking it back to Roscor this afternoon.

I'm surprized not more have had this issue because when I took the camera for repair the last time Roscor stated that Panasonic is aware of this problem with the 200's.

Tom

George Odell
September 14th, 2010, 01:48 PM
I spoke with the head tech engineer who handled the HVX200 for Panasonic and he flatly denied there was any problem. He even laughed at me for suggesting there were any back focus issues with the camera.

"Don't you think if there was a back focus problem with all the thousands of cameras we have sold that other people would be calling us" was his sarcastic reply to me.

TingSern Wong
September 21st, 2010, 08:37 AM
Maybe if you rent your camera from the rental house, you could get this problem. Locally in Singapore, very few people rents - and I never heard of back focus problems.

George Odell
September 22nd, 2010, 12:03 PM
So what was the point of your reply? It has already been confirmed in this posting by several others that the back focus problem DOES exist.

Denying it ain't gonna make it go away.

Sarah Goss
May 11th, 2011, 12:04 AM
I know it's been awhile on this one, but here's confirmation of another person having the same issue with a Panasonic HVX-200. There are three of these cameras in my shop, and the person I replaced and whose camera I took over said she always shot on auto-focus, but didn't say why. I found out soon enough when I went out to shoot some footage of a ceremony and switched it to manual. Zoomed in for critical focus on the speaker, zoomed out for a long shot including the crowd, and everything was soft. I tested it on a back focus chart when I got back to the office. And, yeah. Way off. However, the other two HVX-200s in the shop are perfectly fine. According to Panasonic, the camera needs to be shipped back to them for calibration, and of course, the warranty's expired. Go figure.

George Odell
May 11th, 2011, 10:36 AM
Hey Sarah...

Well the fact they are at least willing to admit it needs to be "re-calibrated" is a good sign I suppose. Any camera can have a shift in back focus if it takes a hit or even just from extreme temperature exposure in the case of these light weight cameras like the HVX-200.

I think my anger was with the rental house wanting to make the issue go away and not admit there was something wrong. All I was asking was that they simply address it and move on. In the end they did give me a full credit for the rental and offer a freebie for the next time. Since then I've found a source closer to home and have had no issues with his two 200's.

In the good old tube camera days Sony came out with something called the DXC-M3A camera with mixed field diode gun tubes. Magnetic focus and electrostatic deflection for the beam. This was a bid deal because up until then cameras used magnetic coils for both focus and deflection and they would interact with each other making critical beam focus impossible.

I got one of the first cameras and found right off the bat there was an issue. It was called the butterfly effect. In the blacks you could see this butterfly shaped pattern caused by the fields mixing with each other. Sony knew it was there but would not admit it. I told the dealer to take the camera back and return my money. At first they balked saying there was nothing wrong with the camera. They said the head of Sony's regional sales wanted to come to my office to "discuss" the issue. I showed him a 3/4" tape that I made clearly documenting the problem. He looked at it and said nothing. Now, I cannot prove he took it, but the next day I went to show that same tape to a shooter friend and I could not find it anywhere.

Go figure!