Please do this quick focus check on your HVX200A

T

TwinCitiesShooter

Active member
I've gone through hell on a focus repair issue with Panasonic on my HVX200A. They've changed lenses twice, changed CAMERAS twice, and though they had it fixed the last time, the focus ring had dirt/sand in it. So now they exchanged the camera again - and the focus is off again. It's absolutely driving me nuts! Can a few people please do a simple test to see if this is a common issue? Simply point your HVX at a flat surface (a wall with artwork is best) that's about 10 feet away, zoom all the way in, and set the focus to Auto. See what comes up for a focus distance. Now zoom out to the 10mm mark. Do you still get the same number for focus or is there a difference? I'm getting a difference of about 4 ft. when I'm 10 ft. from the wall (i.e. when zoomed out the focus reads 6 ft., and is indeed sharper at that setting). Please let me know what you find. Thanks!
 
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Come on now, guys, don't you want to know if your camera holds focus through the zoom range? My friend just checked his HPX170 and found that it was off as well. Report what you find on your camera.
 
Interesting, can't think of why that would be. But my AF is set to off in Auto SW and the focus distance is still different depending on how much I'm zoomed in or out.
 
I dont have my cam in front of me, but I can try this tonight. It should stay the same. When focusing manually you zoom in to focus then zoom out and everything stays in focus.
 
When zooming, many cameras seem to go slightly out of focus - that's the issue. I just tested it on my Canon 5D MII as well - zoomed out, auto-focused on a picture on the wall. Zoomed in, and it's now a bit out of focus. Saw the same thing with the AF100 and 14-140 lens - in focus when zoomed out is not necessary totally in focus when zoomed in, and vice versa. Same with my HVX200A and my friend's HPX170. The DEGREE of focus shift varies from tolerable to seriously out of focus. And that's what I'm trying to collect data on from other people: when you zoom in on something ten feet away and set accurate focus (whether manually or auto), then zoom out, you may very well have to adjust your focus a foot or two (or four) to achieve optimal focus. As proof, press Push Auto and you'll probably see the focus shift. Having sent my camera to Panasonic over and over for focus adjustments, I'm becoming more convinced that this is just the way it is with sub-$5000 cameras.

But I am very open to hearing from other people on this, from newbs to senior guys like Barry ("Paging Mr. Green..."), to learn what their experiences are with their cameras.
 
My HPX-170 does not exhibit serious out of focus as you describe. The number changes slightly every once in awhile. Shoot something well lit and your focus should not change. It also depends on what you are shooting. The majority of the subjects I shot, the focus never changed. Auto or manual. This was in a controlled environment.

Keep in mind, auto is just that. That camera will adjust automatically. Different light passes through the lens at different distances. That will effect your focus. You also need to set your iris to manual to keep constant focus.
 
The camera should definitely hold focus if you achieve critical focus at telephoto and then zoom out.
 
Thanks for the replies. Barry, glad the DVXUser paging system is working. ;-) I agree with you guys that the camera SHOULD hold focus whether zoomed in or out. Believe me, I've been shooting with the HVX200 and HVX200A for a living for five years, and that's how I've always shot. However, I've now personally tested my camera (HVX200A), an HPX170, and a HVX200, and my friend tested his HPX170 and ALL cameras showed a shift in focus. Again, I understand what SHOULD happen, but please actually take out your camera and do the 30 second test and you may well see what I'm talking about. With all cameras tested, I zoomed in on flat subjects (e.g. a wall with artwork) and used auto or push auto to set focus. If the wall was 10' away, focus was sharp at 10'. Zoomed out to 10mm and hit push auto again, and now the number changed - in almost every case it went down (that's important to note, because I could maybe understand if the number went up - e.g. perhaps the AF was locking in on a higher portion of the wall - but there is no reason the focus distance should go down). On the cameras that I would say are functioning normally, the focus distance shifted generally about one foot. If I stepped back to 12', the focus difference between zoomed in and zoomed out was about 1.5'. On a 1/3" CCD camera at 10mm and 10', one foot of focus is inconsequential, that's easily within the DOF, and I think that's why no one ever notices this issue - because for them, it's not an issue. However, it does show that the camera does not hold focus throughout the zoom range. And the problem arises in cases like mine, where the shift is exacerbated. It's not 1 foot, it's 4 feet. So I zoom in and set focus to 10', but when I zoom out it's now a bit soft. Can't see it on the LCD, but you can see it full res.

When I've filmed the tests at 1080 and watched them full res, the camera was absolutely right to shift focus - the lens' auto-focus always found the sharpest focus. But when I'm 10' from a subject, the sharpest focus should not be at 9' and most certainly it should not be at 6'. Please report what you find with your cameras, I'm really curious to see if others find a focus shift at different zoom settings.

Steve, interesting that you found this too sometimes. I always have the iris in manual, so that's not the cause.

By the way, Panasonic tried to fix the issue with a computer alignment. It does not solve the problem, and they don't know what else to do.
 
Out of curiosity, have you zoomed to full telephoto in manual focus and then zoomed out to wide (or something between tele and wide) and checked focus on a Siemens chart? If your viewfinder peaking is up, you should be able to discern focus on the chart.
 
The reason I ask is related to back-focus, which the user obviously can't adjust on the HVX200. If you zoom in on a chart, focus up manually and then zoom out to wide, you should have perfect focus. If not, your camera needs to be sent in for back-focus adjustment. The AF is going to hunt around even if you're flat-fielded to a surface like a wall. I'm just trying to get a control experiment where the camera's logic circuits aren't doing the work for you.
 
When it first happened, I immediately thought back-focus, and communicated that to Panasonic, but they've been unable to fix the issue (whether it actually is back-focus or not). The AF locks on fine, but whether I focus manually using a monitor or use AF, either way I get the same measurement results.

I was hoping people would take out their cameras and try the test themselves - zoom in, push auto, zoom out to 10mm and push-auto again, see if you get the same number - but it doesn't look like anyone is doing it.
 
Can't do it on my HVX, it's on a job, but I just did it with my HMC150. Zoom all the way in, focus (3.20 feet), zoom all the way out -- it still looks great. Put it on autofocus, and it autofocused at 12 feet. But it was still in perfect focus. 1/3" chips, at 3.9 mm, the DOF is so deep it made no difference. I popped on the magnified focus assist and verified -- it didn't go noticeably out of focus until I manually focused to like 200 feet or something. Anywhere in the range from 2 feet to 100 feet, it was in sharp focus.

So even though the auto number was off on the wide, it was still focused sharply.
 
Thanks for doing the tests. Richter, glad to hear yours didn't change. Barry, even on my camera I don't think the effect I'm talking about will be noticeable all the way zoomed out, it's more an issue when zoomed out to 10mm or 20mm, where DOF is still a factor. As an example, I just shot this test. In the first screengrab (cropped and resized down to save space here) the camera is 10ft from the chart and is focused at 10ft., all the way zoomed in - perfectly in focus.
10mm_1.jpg
In the second screengrab (also cropped but NOT resized down), the camera and chart have not moved, still 10ft apart, and the focus is still set to 10ft, but I've zoomed out to 20mm.
20mm_1.jpg
This is not horrible, but definitely is not sharp focus. A push-auto test, verified by manually focusing with a monitor, shows the ideal focus setting is 8.85ft. So I adjust focus to 8.85ft. and get this screengrab (cropped):
20mm_3.jpg
And so on. Once I zoom out to 10mm, I have to adjust focus to 6.89ft. If I leave the focus at 10ft, the image will be soft. So I'm going back to Panasonic because this just isn't cutting it.
 
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