HPX250: Focus changing on HPX250? Or is it me?

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digitalgecko

Well-known member
Has anyone noticed this. I've noticed sometimes on manual focus after you zoom in and focus and pull out, I would make a small adjustment and stop down the iris a bit. Then I would zoom back in to the same place and my focus would be soft. Shouldn't the focus remain the same no matter the f-stop?
 
Interesting.

I've noticed this anomaly.

I pull a correct, clean manual focus zoomed in to an object from about three feet. Then as I slowly pull back just a couple of inches, it goes blurry. Not soft but clearly out of focus. Pull back another inch or two and focus returns.

But if I move the cam back four or five inches, and do the same thing, it stays in focus.

I have no idea why.
 
I haven't noticed the issue throughout the zoom range, but I have heard of that. Mine seems related to F-Stop. I will have to look at that more carefully. One thing I am not a fan of is the auto iris button. On Broadcast cameras you have a button on the lens for checking iris momentarily in auto. As soon as your finger leaves the button it's back in manual mode. On the 250, you are toggling between auto and manual. So you have to hit the button twice to get it back into manual mode. I sometimes thought I was inadvertently leaving it in auto iris mode because I'm just used to hitting the button once. Have to retrain brain.
 
The camera is trying to focus on an object within the MOD, therefore Macro is automatically being engaged, disengaged. If wide open, or close to it, the transition is more apparent.
 
Could the problem be the manual assist switch under the SW menu? I switched it off and it seems to be keeping focus as I zoom in, set focus, zoom out, adjust iris down, zoom in and check focus. Does the manual focus assist make small adjustments in focus even in manual mode? The book doesn't go into alot of detail.
 
digitalgecko said:
I sometimes thought I was inadvertently leaving it in auto iris mode because I'm just used to hitting the button once. Have to retrain brain.
Click to expand...
If you see "STD" displayed above the iris readout in the LCD, that means it's in "STANDARD" auto-iris mode. The other options in auto-iris would be BLC for backlight compensation, or SPT for spotlight. If you see any of those words displayed over the iris, that means you're in auto-iris mode.

If there's nothing displayed over the iris readout, that means manual iris mode.

So auto-iris would look like this:

STD
5.6

and manual iris would be just
5.6
 
digitalgecko said:
Could the problem be the manual assist switch under the SW menu? I switched it off and it seems to be keeping focus as I zoom in, set focus, zoom out, adjust iris down, zoom in and check focus. Does the manual focus assist make small adjustments in focus even in manual mode? The book doesn't go into alot of detail.
Click to expand...
The HPX250 Book will be rolling off the presses in about two weeks, and answers a lot more questions like this.

The "MA" manual assist mode does two things - it changes the range of movement of the focus ring (about 300 degrees for cine-style when it's off, and about 150 degrees for video-style when it's on) and, it also engages a tiny little bit of autofocus. It's meant to trigger just a very limited little bit of autofocus at the very end of your focus move, to sharpen up the focus just that extra little bit (to compensate for the loss of range that you give up when you go to 150 degrees instead of 300 degrees). So yes it's possible that MA mode is using just enough autofocus to overcome that issue.
 
Barry_Green said:
The HPX250 Book will be rolling off the presses in about two weeks, and answers a lot more questions like this.

The "MA" manual assist mode does two things - it changes the range of movement of the focus ring (about 300 degrees for cine-style when it's off, and about 150 degrees for video-style when it's on) and, it also engages a tiny little bit of autofocus. It's meant to trigger just a very limited little bit of autofocus at the very end of your focus move, to sharpen up the focus just that extra little bit (to compensate for the loss of range that you give up when you go to 150 degrees instead of 300 degrees). So yes it's possible that MA mode is using just enough autofocus to overcome that issue.
Click to expand...

Thanks for the explanation of manual assist.. I'm going to try shooting today with it off. It just seemed wierd that you could zoom to a closeup of someone say 50ft away, focus the camera. Come out wide, iris down a bit. And then zoom back to the same place and the close up would be soft. We may be trying to program too many tricks into these new cameras. Camera guy needs to have confidence that when focus is set it. It will be sharp when he zoom backs in.

Can't wait to get your new book.
 
So glad I can learn about these traps BEFORE I get the cam :-) One thing I am wondering about in manual focus is this entry in the manual:
<Note> Use the mm/feet or mm/m display only as a general guideline since it is not entirely accurate.
Now I have always used the display setup like this and worked a LOT with this feature. I never ever use autofocus or any auto function! I was always relying very much on the accuracy of the numbers displayed and it worked fine on the 201. I focus and get a distance readout then manually adjust focus as things move. I am curious how un-accurate this is now oing to be...
 
The exact same warnings applied to the 200, the 150, the 170, the 100... If you're using it in general, it's going to be fine. If you're trying to tape-measure it to the inch, you may find it slightly off. But the marks are definitely good enough for most purposes.
 
We tried to use AF with the 250 1080/30pN 1/60 shutter (AVCINTRA100) at a basketball game tonight, and gave up quickly.

Our view is that the 250 AF is much slower, and continues to seek much more than anything we shot with our 170.

We regularly used the 170 successfully with AF shooting DVCProHD 720/24pN with the 170. Not possible with the 250.

Thoughts anyone?
 
I'm curious about the speed of the auto focus as well. While I tend to avoid AF in general, every once in a while it can be a life saver. Is it conceivable that there could be a firmware fix that could speed up the AF in the future?
 
We have the same approach to AF. Prefer manual, but at times a fast moving sports event necessitates AF.

Again, the 170 performed well in the same well lit arena even at 720/24pN. I very surprised that 1080/30pN with a 1/60 shutter wasn't workable with the 250

However, the images are startling good.
 
We have just received our 250 at work. I did some test shooting at a hockey game. I tried the AF and it seemed to be able to keep up with the action o.k.
Terry
P.S. Just joined the forum, this is going to be a great resource.
 
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Barry,

Did you experience any of the following problems with your 250 or could this post from another forum be an isolated incident? Thanks in advance.

It would be good to get your thoughts (and anyone else out there) on the following focus-related issues I have been encountering with the Panasonic HPX250 which I have now been using on an observational documentary for the past month.
This project involves a lot of actuality shooting where continually being able to adjust your focus quickly whilst recording is crucial. I've been a broadcast self-shooter for over 10 years working with the various Sony cameras (Z1, Z5, Z7) and more recently the Canon XF305. While I love the quality of the image with the HPX250 when I manage to achieve focus, it would be great to hear what you would advise with the following problems:

  1. It is hard to tell whether or not I am in focus.
    • The LCD picture is not good enough to indicate this (unlike the Canon XF305)
    • I can only seem to activate the EVF peaking on the viewfinder and not the LCD. I rarely use the viewfinder in actuality filming, I rely heavily on the LCD.
    • The expanded 'Focus Assist' button seems to only work when the camera is not recording. Not useful if you are filming actuality and would like to check/adjust focus whilst recording.
    • The focus bar does not solve these problems. It is meant to show how in focus the image is, however I am not confident it knows what I am actually focusing on (see below for the focus hunting issues).
  2. The focus tools seem a little 'buggy':
    • I will sometimes need to use the 'push auto' button - a function that is your friend in fast-paced filming to sharpen the focus quickly while recording. However, the 'push auto' on the Panasonic hunts a lot, so I will begin with a slightly soft shot, press down the 'push auto' to focus it, the shot will then go completely out of focus, then start hunting – bouncing into and out of focus and often settling out of focus. This hunting means I have abandoned using the push-auto button completely and at times I really miss it.
    • The MF Assist mode also seems to be a problem. I understand it is designed to fine tune manual ring focusing but I have found that it will often fine tune in the wrong direction and will hunt for quite a while. I have therefore turned it off.
So I am left with only one focus option: manual focusing with the LCD giving me little clue as to how I am doing (with no peaking and magnification during recording). I have been using the distance to subject on the FOCUS CONTROL DISPLAY but this is also guesswork and again with a fast moving scene is nigh on impossible to maintain. In addition sometimes the distances don't seem to be correct e.g. yesterday a wide landscape shot said it was on 'Infinity' but it looked very out of focus, I flicked the 'Infinity' switch and it came into focus. What's that about?
 
I am also seeing a LOT of focus issue-postings on other forums! I just bought mine and am picking it up tomorrow, lets hope its not back at the factory in a week! I am getting a bit worried now....:-(
 
White peaking is quite good with LCD, along with much better resolution than previous LCD's. Peaking is also very good with EVF. Focus in red would be nice, but on 1/3" cameras, often ends up being a sea of red vs. on a large sensor camera, where I find it to be more useful. I haven't seen the 305 LCD, but the 250 LCD is certainly as good
as the EX1, other than not having peaking in red.

We now know the 250 lens is not parfocal, depending upon computer focus tracking. This could be why auto focus zoom numbers are all over the map while zooming.
 
>The HPX250 Book will be rolling off the presses in about two weeks, and answers a lot more questions like this.
Bummer.... just noticed this as I'm ending a few days in New York to fly back to London.... TODAY.

Despite it now being December I can't find ANY information about the HPX250 book. Unless B&H have stock gonna have to wait until my next trip back to NY.

Any Further info etc on this book Barry?
 
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