Go Back   Steve's Digicams Forums > Digicam Help > General Discussion

Reply
 
Thread Tools Search this Thread
Old Mar 14, 2007, 7:09 PM   #1
Junior Member
 
Join Date: Mar 2007
Posts: 6
Default

I think I'm disappointed in my recent purchase.

When the 5MP pics are viewed with ACDSee, etc. at 100%, this muddy noise is quite evident. For the past five years I've used a 2MP Canon Powershot A40 that would not show such "noise" at 100%. I expect pictures to be crystal clear at 100%, and then jaggies should appear at higher zooms. But I certainly did not expect to see this noise that reminds me of a crappy compression algorithm or something.

Is this a bum camera, or am I missing something?

I cropped the attached image so as to fit the file size requirement. It is an accurate reflection of the rest of the photo.

This was a factory refurb....still has a warranty on it....should I return it?
Attached Images
 
4Blades is offline   Reply With Quote
Sponsored Links
Old Mar 14, 2007, 7:24 PM   #2
Administrator
 
Join Date: Jun 2003
Location: Savannah, GA (USA)
Posts: 22,378
Default

What happens if you don't underexpose it and shoot in daylight?

It's pretty hard to tell from that one. What did the rest of the photo look like?

I see a brighter area just outside of the crop at the top, and this crop appears to be very underexposed.

My guess is that something bright in the image confused the metering system and underexposed most of it to protect those highlights, since a *much* longer exposure using a tripod would have normally been required for a photo taken at 8:00PM at night at ISO 80 and f/3.7 (not a fast 1/125 second).

In addition, you had Exposure Compensation set to -1 EV (underxposing it yet another stop over where the metering would have set it to by default).

Noise is going to be worse in underexposed areas of an image (especially if you brighten it later with software, since that's like using a much higher ISO speed to begin with).


JimC is offline   Reply With Quote
Old Mar 14, 2007, 8:24 PM   #3
Junior Member
 
Join Date: Mar 2007
Posts: 6
Default

JimC,
Thanks for the answer.

It does seem to take better pictures in bright light. I guess I'll have to pay better attention to the exposure settings.

One other problem I noticed just now while playing around with it is that frequently, the flash does not illuminate the captured picture...like the timing is off or something. I mean, it definitely flashes, but the picture clearly does not reflect that flash was used.....operator error, or crappy refurb camera?
4Blades is offline   Reply With Quote
Old Mar 14, 2007, 9:57 PM   #4
Administrator
 
Join Date: Jun 2003
Location: Savannah, GA (USA)
Posts: 22,378
Default

If you're also using a -EV setting with exposure compensation for the underexposed flash photos, it could be impacting flash exposure as well (with some models, telling the camera to underexpose by using a -EV setting with Exposure Compensation will impact flash photos, too). Your model also appears to have a separate flash exposure compensation setting (so, you may want to make sure you're not telling it to underexpose in either place).

But, chances are, you're just trying to shoot outside of the rated flash range. Your model has a maximum rated flash range of 13.78 feet at your wide angle zoom setting (least apparent magnification). This range drops off as you zoom in more (since your lens loses light as you zoom into longer focal lengths). So, your max flash range is down to around 8.5 Feet on the long end of the zoom range.

Chances are, you're just zooming in too much for the flash to handle it at the distance you're shooting from (exceeding it's maximum rated range).

These are Auto ISO Flash distance ratings. So, if you set your manually set your ISO speed to a lower value, you won't get that much flash range (instead of 8.5 feet max using Auto ISO when zoomed in, it will be less if you set your ISO speed to something like ISO 80). So, don't zoom in any more than you need to when using a Flash, since the lens loses a lot of light as more optical zoom is used (and that reduces your flash range). You may want to leave the ISO set to Auto to get the rated range (even if you get a tad more noise that way).


JimC is offline   Reply With Quote
Old Mar 15, 2007, 6:15 AM   #5
Junior Member
 
Join Date: Mar 2007
Posts: 6
Default

There is definitely something wrong with the camera.
I had pretty much convinced myself that the flash timing was off. But what you said about ISO settings made me think that the Auto ISO was messing up.
SO I forced it to 400, forced the flash to on, and took about 10 pictures in a row of the same thing which was about 4 feet away, using no zoom.

Only 1 time did the flash illuminate the photo, although it fired every time.
Here are two shots taken right in a row:

Shot where flash worked:

Attached Images
 
4Blades is offline   Reply With Quote
Old Mar 15, 2007, 6:16 AM   #6
Junior Member
 
Join Date: Mar 2007
Posts: 6
Default

Shot where flash (or something) failed:

Attached Images
 
4Blades is offline   Reply With Quote
Old Mar 15, 2007, 7:39 AM   #7
Administrator
 
Join Date: Jun 2003
Location: Savannah, GA (USA)
Posts: 22,378
Default

Yep... That's underexposed. :-)

Make sure you're not holding the camera in such a way that you're reflecting the flash back towards the camera (it's been known to happen). Even if it's not being blocked, you could be reflecting some of the light back towards the lens/sensor causing underexposure (because the camera is seeing too much reflected light). I've got a little pocket camera that I have to hold carefully. Otherwise, my finger will fall in front of a tiny hole in the front it uses as a flash sensor and cause exposure issues. lol

Your model probably uses a pre-flash to judge exposure. Basically, this type of system fires a very short pre-flash. Then, it measures how much reflected light it got from it in order to determine how long the main flash needs to be. So, if you have something reflecting back too much light for the pre-flash, it can cause an underexposed image.

A lot of white in the scene can cause it, too (as can anything shiny acting as a mirror). But, that subject looks neutral enough (shouldn't be causing that degree of underexposure)

Are you sure you waited on the flash ready light before shooting. Most models will wait until the flash is fully charged before firing. But, I don't know if your Panasonic fits into this category or not.

How about focus lock? Are you half pressing the shutter button and waiting for a good lock (steady light) before pressing the shutter button the rest of the way down? In addition to the reflected light returned by the pre-flash, most models also factor focus point and distance into the exposure calculations. So, if you don't have a focus lock, it can cause exposure errors.

JimC is offline   Reply With Quote
Old Mar 15, 2007, 8:33 AM   #8
Junior Member
 
Join Date: Mar 2007
Posts: 6
Default

I'm pretty sure I eliminated all that you've mentioned.
-not blocking anything, focus locked, flash fully charged, no direct light reflections, etc.

I've taken so many successive pictures at this point that I can tell when the flash goes off if it is going to illuminate the picture. When it's successful, there is more of a delay in the flash, and it seems to be a "louder" flash (sounds bigger). Every once in a while I get no flash at all! And all these variances take place without me moving the camera at all. I've tried numerous scenes in numerous conditions, and I can never get the flash to act consistently.

I'm gonna call tech support or whomever, and see what they say about getting it fixed.

Thanks for the help, you've been quite informative!
4Blades is offline   Reply With Quote
Old Mar 15, 2007, 9:47 AM   #9
Junior Member
 
Join Date: Mar 2007
Posts: 6
Default

Just got off the phone with Panasonic Tech Support. They were very friendly, helpful, and spoke English fluently!!

They agreed that there is a problem with the camera so I'm sending it in.
4Blades is offline   Reply With Quote
 
Reply


Thread Tools Search this Thread
Search this Thread:

Advanced Search

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off



All times are GMT -5. The time now is 1:18 AM.