HPX250: Steve Cooperman's explains HPX250 macro mode

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digitalgecko

Well-known member
Saw this at another site. Thought it was interesting.



"This is not a defect. The lens can zoom all the way in (616mm) as close as 3 feet without a close up filter. In this position, the optics are in a macro focus mode. In this situation, the lens cannot hold focus for a few mm’s when zooming out. When the lens is zoomed all the way in (616mm) at 6 feet, the lens can hold focus when zooming out to full wide (28mm). In this position, the optics are not in a macro mode.

The point is, this is not a back focus problem. This is the unique ability of having a 22x wide lens on this great new camera.

Oh, and thanks for your positive comments on the camera. Our engineering team listened to many requests and implemented them on this model. And the 10-bit, full-resolution AVC-Intra 100 video quality and 22x wide zoom lens are amazing for a one-piece, sub $6,000 camera."

Thanks and have a nice day.


Steve Cooperman
Product Manager - P2 HD, POVCAM, Production Displays
 
It's hard to imagine a scenario where someone needs to be fully zomed in (at 22x) to a subject only three feet away.
 
Jim Simon said:
It's hard to imagine a scenario where someone needs to be fully zomed in (at 22x) to a subject only three feet away.
Click to expand...
True. When I tested it at 3 feet, it only lost focus for a second at the 55mm mark. Just backup three more feet and zoom out normally. Perfect from at least 6 feet away.
 
Please, take a look at this, guys.
Zooming out-in from 00:21 to 00:31.
It happens when focusing on longer distances too.


Actually, something very similar to this happens with our Hvx200 and Hpx171 too, less noticeably, probably because of their limited focal range.
Macro focusing is definitely not the only way to bump into a temporary loss of focus, fast or nonlinear manual zoomings by ring make it happen while servozooming is slow and costant enough to hide the problem.
 
Faust said:
Please, take a look at this, guys.
Zooming out-in from 00:21 to 00:31.
It happens when focusing on longer distances too.
Click to expand...

Were you on auto focus for that shot? I saw the same thing on one of the first videos posted where there was a zoom out from a speed boat in the distance. It looked to me like the auto focus decided to hunt, even though nothing in the frame was closer than infinity.
 
Hi Mike, the video I linked above is not mine, but I'll soon ask the author Phil Hover about the focus settings.
The fact is that I've noticed losses of focus while quickly manual zoooming on both the Hvx200 and the Hpx171, manual focus mode, no macro at all.
Moreover, I've had the chance to play a little with the new Hpx250 one month ago and I perfectly remember this odd behaviour occurred when I was zooming out from full tele (manual zoom ring), soon after having manually set proper focus.
But sadly, I've got no recording about that focus check.
 
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Anyone know if this loss of focus while zooming would be an issue during shorter zooms? For instance, does the camera lose focus if you're zooming in from a full shot to a close-up? I don't love zooming during a shot, but when doing doc work, sometimes it's a necessity. I'm seriously thinking about this camera, but I want to understand this focus/zoom issue a bit more first. Thanks!
 
The Hpx250 has a manual assist mode that uses auto focus to help you focus in manual mode. It's under the SW switch menu. Try turning it off. When I did, all of my focus issues went away.
 
Hi digitalgecko,

MF ASSIST function engages a small automatic correction only when you spin the focus ring and, yes, it helps you to quickly set a focus distance when you're hurry.
But when focusing is set, there will be no further automatic adjustments until next time you spin the focus ring.

The problem I was talking about occurs with an already adjusted focus distance, in manual mode, no matter if MF ASSIST is enabled/disabled.

*** NOTE: The author of the beach video above confirmed that his camera was in manual focus and that the issues come out only when spinning the zoom ring very fast.
Most probably, focus compensating system while zooming needs a certain amount of time to do its work and that's why power zooming doesn't allow very quick speeds.

I'm not sure if I've clearly explained the exact kind of issue I'm referring to, for this reason, yesterday I did a test with the Hvx200 and the Hpx171.

Focus loss Hpx171.zip

Focus loss Hvx200.zip
Focus loss Hvx200.z01

Unzip both Hvx200 archives, as they are two spanned parts of the same content.

Once unzipped you'll find two valid P2 structures with a single clip in each one.
I put several TEXT MEMO indexes for an easier location of the out-of-focus frames, NLE softwares should recognize indexes by showing proper markers on the source timelines.

- I've chosen a 1/500 sec. shutter speed to completely get rid of motion blur, the only blur visible in some frames is absolutely due to a temporary wrong focus distance;
- Manual zooming;
- Manual focus distance was set at 5 meters (around 16 feet);
- Manual iris (exposures are anything but accurate, sorry for that);
- Scene file: F1 on both camcorders;
- 1080i/25p;
- WB: 5.6K PRST.
 
risultato: un si pole fa lo zoom veloce con la 250. Saperlo e importante tante grazie per quello :-)
All cameras have their pros and cons. Its good to know which and how to avoid them.
 
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