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Old Dec 14, 2005, 12:44 PM   #1
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I purchased an Olympus Evolt E-500 / Dual Lens Kit about 2 weeks ago while on vacation in Sedona Arizona. I used the new

camera for the entire trip using both lenses. When I got home I transfered my images to my pc. I decided to look at some of the

images I shot in photoshop and while zooming in to see the detail of the image I noticed a red and a blue square near the

center of the screen. I looked through the other images from the trip and there were the same 2 squares in the same place in

every shot. These are very tiny (pixel level) and are for the most part not visible unless you zoom in or know to look for them,

but are clearly visible without any zooming in other shots, especially darker shots.

So I called Olympus and the cs rep told me that this could be one of three things.

1. A scratch on the lense.

2. Dust in the camera.

3. Or pixels that are stuck on or off.

He told me that it probably wasn't either of the lenses since it happened on images from both lenses.

And he really didn't think it was dust because of the dust reduction function.

Which leaves the dead pixels. He told me that there are always going to be dead pixels on a new camera and that it's almost

impossible to have all 8 million pixels working. He then said for example if you have a camera with 2 dead pixels and return it

you may get one that has 5 in its place. So he told me that I could use the pixel mapping option which will check all of the pixels

and find the bad ones and have the camera ignore them buy guessing at what information should be there.

So can anyone tell me what is acceptable for a new camera like the E-500? I called the camera shop where I bought the

camera and talked to the salesman that I dealt with and told him what the cs rep said. He told me that he had never heard of

having to accept some non-working pixels and that he would expexct them all to work, but suggested that I find out if the pixel

remapping fixes the pixels by getting the stuck ones unstuck (either on or off), or if it is just going to ignore those pixels because

if its the latter then he would replace the camera for me. Now a new camera sounds great to me but if it has a chance of having

the same issue then it might not be worth it. I live in Pittsbugh and bought the camera in Arizona so unneeded shipping back

and forth will save me some time and effort but I will certainly return it if this problem is unacceptable.

One last question. Does anyone know if the pixel remapping process gives you the option to just "CHECK" the pixels without

fixing them or does it automatically fix them once it finds them?

Any help would be greatly appreciated

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mezark is offline   Reply With Quote
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Old Dec 14, 2005, 7:44 PM   #2
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A few dead/hot pixels in a new 8mP camera is by no means unusual (probably closer to the rule than the exception). I would run the pixel-mapping function and check it again. If the problem is still there, then send the camera.

In fact, be glad that Olympus includes the pixel-mapping as an in-camera freebie. Most other manufacturers require that you send the camera in for pixel mapping, so you have to pay for the same service.

Olympus began including free pixel-mapping at least as early as 2001; see this article.

For more information, just google for "pixel mapping"--there's lots out there.

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Old Dec 15, 2005, 10:15 AM   #3
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They are 2 stuck pixels, but check with a dark and short (to differentiate from hot pixels) exposure for more. Pixel mapping does not "unstuck" but interpolates for the missing value. I don't know a way to "undo" pixel mapping, reseting to the factory default settings does not reveals the ones mapped (also in the manual p. 120). And not even "hard reset", using the service hidden menu. I read that in some (older ?) Olympuses the raw is not processed, it is possible to see the (eliminated in jpeg/tiff) defects. Once you mapped, here you go, no camera change anymore, no more proof of dead/stuck pixels, they may be a thousand. I wonder if is a way to find the location of all the dead/stuck pixels, even of those eliminated by the manufacturer. That will be interesting

Is true that you may get in place of your camera one with more stuck pixels or one with no apparent stuck pixels that have been mapped (Olympus said once that cameras are verified for stuck pixels twice before leaving the factory). 2 is a very low number, but I think a sensor that keeps coming after the in factory testing will havemore than average defects after a year. If you have the opportunity to change the camera, do not map and change it. Pixel mapping should preferable not be used for brand new cameras, but for older ones.
What is Oly thinking ? If they have in camera pixel mapping, they can use cheaper second grade CCD's in their cameras or careless CCD handling ?? I'm angry with my ten (twelve, updated today) stuck pixels, that's it...
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Old Jan 3, 2006, 7:53 PM   #4
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Hi, could you please help me, i want to access the service hidden menu of my Olympus C-720UZ camera, do you know the keys combination? My camera focus is not working ok and i wanted to check if there is any kind of focus calibration on the menu.

style="BACKGROUND-COLOR: #000000"Thanks!
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Old Jan 3, 2006, 11:41 PM   #5
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Sorry, Mav, but this is the wrong thread for that question.

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Old Jan 3, 2006, 11:48 PM   #6
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I have no way to prove it. But, I suspect that most new cameras have some stuck pixels.

You just don't see them because they're already mapped out at the factory.

I can remember a new Sony DSC-F828 owner complaing about them on another forum. They exchanged cameras three or four times trying to find a better one (and never succeeded). ;-)

ISO speed, camera temperature and exposure length all come into play.

Pixels that may not be hot at lower temperatures, shorter shudder speeds and lower ISO speeds, may be hot at other camera settings and conditions.

You see complaints about bad pixels from all of the manufacturers from time to time anymore.Part of it is probably that sensors are becoming very dense.

But, virtually all cameras have an internal table that tracks bad pixels and maps around them.Even with older models, I can remember users sendingback cameras for "CCD Repair", and figuring out that the same CCD was still in the camera when they got it back.

They determined this by looking at hot pixels on longer exposures, and shooting with the repaired camera later. The hot pixels were in the same places (even though "stuck" pixels visible on normal exposures were no longer visible).

I suspect that virtually all CCDs in digicams have a number of bad pixels. We just don't see them because the factory maps them out ahead of time (with the camera interpolating values from adjacent pixels to replace the ones that are bad). But, sometimes they can develop bad pixels later. So, some if it may be QC, and some of it may be bad luck. ;-)

When you think about it, the pixels you see are all interpolated from surrrounding pixels anyway. That's how a digital camera works (with the exception of the Foveon sensors). You've got a color filter array, with each photosite only sensitive to one color (with the sensors actually being color blind -- the filters simply block out all colors except for one for each photosite). Then, the image processing algorithms combine the values from multiple photosites into individual pixels when processing the images.

That's why a 3MP Foveon sensor can produce as much detail as a 6MP or higher Bayer Type Sensor.

Are you really going to see an impact from a couple of bad pixels out of millions, when the values are being interpolated from surrounding pixels to replace them after the factory maps them out? I don't think so.

A lot of newer models map them out automatically, too. Olympus started this trend

Now, you're seeing the same type ofpixel remapping functions built intoa number of modelsfrom Konica-Minolta (once per month automatically in some models) and Olympus (via a menu choice).

Canon has beena little slow "jumping on the bandwagon", but I think they'll probably put this feature into future models at some point, too.

Older Nikon and Olympus models also have a bad pixel table (but no user available menu choice to update it).

But, a Russian Programmer figured out how to get it to and has a downloadable utility that seems to work on some of these models (some Nikon and Olympus models apparently shared a common chipset and interface language). I've seen users of various Nikon and Olympus models report that it works on them -- including models like theOlympus 2100UZ, 3030z and Nikon 990:


Bottom Line: If you exchange your camera for one that doesn't have any stuck pixels showing, that doesn't mean that it doesn't have any bad pixels. They're probably already mapped out at the factory. The menu choice to remap them is good for bad pixels that occur later (and they can occur at any time). ;-)

IOW, I wouldn't worry about it, unless the remap function can't find them (they may not be bright enough for remapping yet, depending on the thresholds Olympus set in the camera for this function).

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Old Jan 4, 2006, 7:53 AM   #7
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My E-1 that I've now owned for 3 months had one stuck pixel out of the box. Did the pixel mapping and forgot about it- do it, it's a great feature that Olympus should be commended for including. Between that and the sensor wave filter, Olympus DSLR'sare about as worry-free as it gets today.
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Old Jan 4, 2006, 11:37 AM   #8
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Sorry, i just thought that viggen could share that info and that it might be the same on my Camera, sorry once again!
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