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-   -   Focus Problems with the Sony DSR PD-170. (https://www.dvinfo.net/forum/sony-vx2100-pd170-pdx10-companion/62910-focus-problems-sony-dsr-pd-170-a.html)

Michael Breez March 15th, 2006 09:30 AM

Focus Problems with the Sony DSR PD-170.
 
Greetings Folks. I haven't been able to find this specific thread yet...so here goes.

I am a new owner of the PD-170. I have been excited about the low light capabilities but I am finding that the picture is not really very good when viewed on a 16:9 or 4:3 monitor. I have shot in both focus modes....manual and auto focus. I do find that it shoots quite clearly up close but my distance or maybe zoomed about 1/2 in is not to my liking. For example when shooting someone....their face and hair might look ok but I notice that the teeth are blurry. I am fairly new to videography and have a lot to learn...but help!

Michael

Boyd Ostroff March 15th, 2006 02:42 PM

Are you shooting in 16:9 mode and viewing on a 16:9 TV? If so then the PD-170 just doesn't look all that great. It doesn't have high enough resolution CCD's to produce a quality 16:9 image unfortunately. This has been discussed extensively in the past.

Now if you're shooting in 4:3 mode and viewing on a decent monitor, then that should look nice however.

J. Stephen McDonald March 16th, 2006 06:10 AM

Quote:

Originally Posted by Michael Breez
Greetings Folks. I haven't been able to find this specific thread yet...so here goes.

I am a new owner of the PD-170. I have been excited about the low light capabilities but I am finding that the picture is not really very good when viewed on a 16:9 or 4:3 monitor. I have shot in both focus modes....manual and auto focus. I do find that it shoots quite clearly up close but my distance or maybe zoomed about 1/2 in is not to my liking. For example when shooting someone....their face and hair might look ok but I notice that the teeth are blurry. I am fairly new to videography and have a lot to learn...but help!

Michael

Have you adjusted the focus on the viewfinder, by turning the little lever on the bottom side?

When you are zoomed out, the depth of focus is greater and there's more leeway in how precise the focus is adjusted. When you go in tight, you have to focus very finely, especially in lower light levels. If you are zoomed in very tight on a person, it's possible that the depth of focus might be so shallow, that parts of the face could be out of focus. You could move in closer and not zoom the lens in so far, to correct this. Also, when a high shutter speed is set, this could reduce the depth of focus.

However, if there is anything wrong with the alignment of the lens on its mountings or the assembly of its parts, this could be the cause for the problem you reported. If you can't resolve the situation, you might consider that the lens has a fault and have it checked, although few local video repair places know much about working on lenses. Is this a factory-new camcorder or is it used? It's a problem for the dealer, if it's new. A blow that could have knocked the lens out of line, might not have left any evidence behind, other than the way it functions. I had similar symptoms once, with a camcorder that had one of its internal lens mountings broken. Does the image seem more out of focus near one edge, than the other side?

There are types of lens adjustments that can be made externally on some professional video lenses, but would have to have been set internally at the factory on this type. If it wasn't set just right during its assembly, this could cause what you're experiencing. If you know other people who are expert video shooters, have them give the camera a try and see what they think about the focus. Good luck.

Mike Rehmus March 16th, 2006 10:52 AM

Autofocus would cover up having the back-focus misadjusted so that is not likely the problem.

What you describe sounds like a lens aperature wide open at a fairly long focal length. That is a characteristic of all optics. If one element in the image is sharp, then the lens/camera combination is sharp and your problem is one of selecting where you want the focus to be or increasing the available light on the subject which will allow you to close down on the aperature and increase the depth of field.

As mentioned before, insure the viewfinder is adjusted correctly by looking only at the symbols imposed in the viewfinder by the camera. Adjust the focus for that and then you can use the viewfinder for critical focus.

If you are working in manual focus, you zoom in all the way on the subject, focus and then adjust the field of view to your liking. You cannot focus the camera with the lens set wide and then zoom in and expect it to be in focus.

Since you say you are new to photography, I think you need to go on the Internet or buy a book and read the section on focus, depth of field, etc.

Michael Breez March 17th, 2006 01:47 PM

Thanks for the input
 
Thanks to those who have responded. I've actually had quite good success with up close shots. What I have noticed most recently is that when in auto focus and zoomed out....partially or all the way...I'm not able to count on the camera focusing on what I want. A couple times it has focued on the background behind the subject. I've heard recently that this is not the camera to leave unmanned.

I'll definitely look into more information on depth of field and focusing.

Michael

Michael Breez March 17th, 2006 01:59 PM

Quote:

Originally Posted by Boyd Ostroff
Are you shooting in 16:9 mode and viewing on a 16:9 TV? If so then the PD-170 just doesn't look all that great. It doesn't have high enough resolution CCD's to produce a quality 16:9 image unfortunately. This has been discussed extensively in the past.

Now if you're shooting in 4:3 mode and viewing on a decent monitor, then that should look nice however.

I have tried a variety of things....shooting 16:9 and viewing 16:9 and 4:3. (Our TV can be set to either) and shooting 4:3 and viewing both. Each time I got the expected results.

Thanks

Michael Breez

Chris Barcellos March 17th, 2006 02:36 PM

Also, make sure your ND filters are switched off in low light. That will degrade image.

Mike Rehmus March 17th, 2006 05:49 PM

Michael,

You cannot depend on any camera in autofocus mode. The camera is always testing the image and looking for high-contrast features. Very frequently the background is of higher contrast than people.

No pro uses autofocus unless the action demands that but the chances are that the camera can pick the wrong object on which to focus. Gets worse in dim light.

Bob Hart March 17th, 2006 09:27 PM

In talking about internal optics being knocked out of centre, be mindful that the VX2000/PD150/VX2100/PD170 - PAL camera family and maybe the NTSC as well, has the lens centre axis slightly off-centre relative to the CCDs, so that the view is off-centre slightly to the right as seen through the viewfinder or TV screen. So if you see this, don't send the camera back to the repair shop.

Michael Breez March 21st, 2006 09:50 AM

Quote:

Originally Posted by Mike Rehmus
Michael,

You cannot depend on any camera in autofocus mode. The camera is always testing the image and looking for high-contrast features. Very frequently the background is of higher contrast than people.

No pro uses autofocus unless the action demands that but the chances are that the camera can pick the wrong object on which to focus. Gets worse in dim light.


I got this loud and clear! I've been using an auto focus camera for so many years it seemed the easiest way to get started. Since this discussion I've done my homework and am now having much better results. Thanks for the coaching and suggestions.

J. Stephen McDonald March 21st, 2006 04:29 PM

Quote:

Originally Posted by Mike Rehmus
No pro uses autofocus unless the action demands that but the chances are that the camera can pick the wrong object on which to focus. Gets worse in dim light.

This is mostly true, but when I do one-camera shoots of entire athletic events, getting every second of the action, I have to use a good autofocus to accomplish it. When a multi-camera crew works on an event, each camera operator has an assigned sector and covers it usually for short periods. In between, the re-focusing, zooming and framing of the shot can be done, to prepare for the next time the camera is "hot". News crews need only short clips. But at a game or an airshow, I couldn't hope to reach my goal of having usable footage of the whole thing, without autofocus. My original Canon A-1 Hi-8 was the best at this. It could grab and hold with autofocus on a small flying bird or distant plane and most of the time stay on it, even in lower light levels. My TR700 was almost as good at this and in recent years, my MegaPixel TRV730 Digital8 did a very acceptable job of autofocusing, at least when there were no intermediate objects to divert it. Although I appreciate most of the qualities of my VX2100, it isn't as good at autofocusing as these others and tends to go to smaller things in the foreground. It sometimes fails to find an autofocus on distant, flying birds. But, it is pretty dependable in a clear field of view, if the subject has enough size. Frankly, its fly-by-wire manual focus ring is not that great, when quick focusing is needed. That situation is where you go to the momentary autofocus button, to put you to where only fine-tuning is needed to be done manually.

Learning to use autofocus is a skill that comes only to those who practice with it a lot. You can eventually predict when your camera will autofocus well and when it will not and work around those situations. With the new HDV model, the Sony HC3, the limited type of controls will not allow it to be very effective with manual focus, on fast-moving and widely-ranging subjects. So, with camcorders like it, autofocusing abilities will have to be developed. If you know what sorts of light conditions or objects in front of or behind the subject will impact autofocusing, you can carefully set up shooting positions to avoid or minimize their effects. And, you have to recognize that in some circumstances, good autofocus shooting isn't possible. For that matter, there are times and places where you just can't get any good video, no matter what camera or focusing capabilities you have.

Paulo Teixeira March 23rd, 2006 09:03 PM

At least Sony is trying to solve most of the problems. I’m one of those people that have complained about the auto focusing of most Sony Camcorders and I thought the Successor of the PD150 will have solve the focusing problem by now. What I have noticed is that the manual focusing on the HC1 is a whole lot better than the PD150 and the auto focusing is a little bit better.

Personally I never noticed the focusing problem of the PD150 because I mostly used manual until I started videotaping myself for a project when I was in college. I used the Panasonic DV953 and a Sony PD150 and when my project was finally completed the DV953 was always sharp while the PD150 didn’t even attempt to fix the picture to much. You wouldn’t believe how pissed off I was. So far I never heard of any Z1u or FX1 user having problems with the focusing.

The best thing to do is to stay away from the auto-focusing as much as possible but the good news is that it forces people to practice using manual focusing.

This may not be the place to say it but unless you get a Z1u or an FX1 then you should be getting a Panasonic camera if the only thing you’re concerned about is having very good auto focusing because Panasonic camera does it very well.


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