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Old Jul 12, 2005, 11:11 AM   #1
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After reading about pre-focusing your pictures from Cybershot Nut, I've have been doing tests with my W1, with indoor light pictures.

And unknown to me, because I always pre-focus my shots, if you do not pre-focus them, a good proportion of pictures seem to come out Blurry, even when the camera says it has a focus lock. This seems to happen when the AF light is needed.

And this does not seem related to a slow shutter speed, as I though earlier.

I guess I'm writing this message to see if other people can confirm this odd behavior, and/or if we can nail down a consistant behavoir we could attribute as a BUG.

(or ISSUE for people which the word BUG has them running for the hills :evil: )

This could account as for why some people get bad results.


Don't get me wrong, I get great results from my W1, BUT I hate loose ends more!




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Old Jul 12, 2005, 7:43 PM   #2
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Pic-It wrote:
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And unknown to me, because I always pre-focus my shots, if you do not pre-focus them, a good proportion of pictures seem to come out Blurry, even when the camera says it has a focus lock. This seems to happen when the AF light is needed.
I don't own a W1, but this doesn't make sense to me...

How do you know if the camera has focus lock if you don't prefocus your shots?

You said "if you do not pre-focus them, a good proportion of pictures seem to come out Blurry, even when the camera says it has focus lock".

Unless I'm missing something, you won't know if you have focus lock unless you prefocus (half press of shutter button). How do you know it had focus lock? Is the camera recording Autofocus Lock in the EXIF? I haven't looked at the EXIF from this model to tell.

As for a camera's ability to take a photo without focus lock, I think that's a feature versus a bug. Some older model cameras would not take a photo without focus lock. This can result in missing shots in questionable lighting. I'd rather a camera take the photo without focus lock (versus not taking it at all).

My guess is that most focus problems occur because users are using multi-point (versus Center point) focusing. So, the camera may be picking a focus point other than your intended subject (and a half press of the shutter button should tell you where your focus point is).

But, focus problems are rarer than motion blur with compact digicams (thanks to pretty good Depth of Field from a small sensored camera).


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Old Jul 12, 2005, 9:24 PM   #3
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Hmmm, doesn't happen with my P150.I have noticed that if there is no contrast in the subject (like a black cat or a white shirt), and you don't wait for focus-lock confirmation (ie., just mash the shutter release), it'll give up trying to focus and take the shot so quickly that you think it must have focused (but no AF confirmation beep/green dot/green box). My Canon S70 was the same, (itstill let you take anunfocused shot)but it was alot slower so it was more obvious when it didn't achieve focus (which was much more often than my P150 indoors).

To get around the slow default flash shutter speed of 1/40, I just use manual mode. I keep manual set at 1/100 and F2.8, so that when I want to take a flash shot, I just rotate to M and take the shot. It's still properly exposed since the flash duration is much shorterthan any shutter speed the P150 is capable of. It'll sync all the way up to 1/1000, since the mechnical shutter is not used except when reading the CCD to avoid smear and for dark image subtraction NR on long exposures.

Maxx
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Old Jul 16, 2005, 9:35 AM   #4
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Ok, I'll try to re-phrase my last post...

I can take an average picture in indoor lighting, camera on a tripod, auto settings (or manual, doesn't seem to matter), the AF light goes on :

1 )If I pre-focus my shot, the picture will come out perfectly 100% of the time. And very few cameras in the W1's price range (Or above) can compete with these pictures!

2 ) If I just press the shutter & leave my finger on the shutter button waiting for the focus to be LOCKED, then the camera will take the picture. But now, I would say a good 25% of the pictures come out of focus. I cannot seem to find a reason, or a series of actions I do, to trouble shoot this problem.


Now, for myself this is not a problem, since I always pre-focus my shots as a reflex over the years of taking photographs.

However when I lend my W1 to friends who just use this camera as a point & shoot, they are starting to ask me why a lot of their pictures are blurry. I always assumed it was the 1/40th shutter speed (the most probable & easiest answer is usually the right one right?), but I have to correct myself after having done these tests. AND there are other cameras of other companies which use similar AUTO settings without this problem.

Can anybody confirm if they can duplicate this problem?
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Old Jul 18, 2005, 10:17 AM   #5
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I'm not quite sure what you mean by pre-focus, but I have had blurry pictures with my P100 (before I sold it), even outside when shutter speed was faster than 1/40. I loved the camera except for too many blurry shots.

Yeah, yeah, user error and all, I've heard it all, but it was not reliable. I, and many others have tried everything. However, given the otherwise outstanding performance, I am still considering buying a P200. Hence I am monitoring info about the P200 and W series (and maybe even the S90.)

Of course the algorithm that selects 1/40 for flash stuff in auto mode doesn't help matters. My wife doesn't want to know about using the M setting -- too often the flash gets accidentically shut off in M mode and then the faster shutter speed that I program in doesn't help for indoor stuff.

Anyway, by prefocus do you mean setting the camera to focus at a specific distance (hyperfocal focussing) , or half-pressing the shutter? I have never found the combination of events that led to a totally blurry photo.
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Old Jul 19, 2005, 6:02 AM   #6
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By pre-focusing, I mean Half press the shutter. Whenever I do this, I don't get any blurry shots what-so-ever.
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Old Jul 19, 2005, 8:15 AM   #7
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That's good to hear. I don't believe that was my experience. I might try the P200 againg and make sure I pre-focus. I guess it would be nice to have an option to set so that you can specify that the camera will NOT take a shot unless focus was achieved.




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