You mean all 15 set got problems?Originally posted by kylelam77
AP still has lots! I tried my hands on almost all of them....... ^) went to replace my oly 2040 which had a dead pixel. Peter was nice enuff to let me try all the 15 oly 2040 there and test one by one. But as of sat morning there are at least 15 there. dun think they would be sold so quickly kuah. since this product already discontinued......
If u do a 16s lens cap test on the C-2040z.....all sure have problem with hot pixels one lah!!!!Originally posted by kylelam77
no lah, but most of them got some kind of green pixels in them. DUn know are they hot pixels or something. Some had red pixels so i guess those were dead pixels. I tried to pick a better one....
Oh! U mean u got those stuck pixels on the LCD is it???Originally posted by kylelam77
No, i didnt do any long exposures with all those cameras i tried out. When i opened the box and slot in the batteries, i saw the green pixels liao. Naturally i became worried. I wasnt gonna take those cameras. So i tried and tried until i saw a camera which didnt have any of those green pixels.
Originally posted by kylelam77
There was once i did a long exposure. then 2 green pixels came up. can't remember how long but i did enabled the slow fash thingy in the menu. After that my pics got 2 green pixels. After i let it cool about 20 mins later, i checked again. they were gone. So are those considered hot pixels?
Well......the hot pixels will get brighter and more obvious the longer the exposure time.Originally posted by kylelam77
Thanks for the elaborate answer Jayan! So is it true that once u get hot pixels say due to a long exposure the shots u take after that no matter whether are long or short exposure shots would also bear the same pixels?
wah Jayan, can stick this in the Olympus FAQOriginally posted by Jayan
Ok here's a highly simplified version of what's going on....
U see, the CCD (Charged Coupling Device) is basically a chip with millions of photo-sensitive cells on it.
When exposures to light....the individual cells charges up and sense the brightness and color of a particular spot, and together the millions of cells form the pix.
But some cells charges up more easily and brightly than the rest, this forms exceptionally bright pixels on the pix...that's, hot pixels...these gets brighter the longer the exposure time.
There r also cells that charges up regardless of exposure time, these're the dead pixels...
U'll notice that the green ones hot pixels r always more prominent cos our eyes r more sensitive to the green wavelength.
Heat due to prolonged usage can cause some cells to produce hot pixels as well, but these goes away when the CCD is sufficially cooled (temp vs perm hot pixels).
To do a test for hot/dead pixels, cover ur lens with ur lens cap and use a standard setting (use manual control to do this) for ur aperture, focus, ISO and WB. Only the shutter speed varies.
Then do a shot at 1/800, 1/600, 1/400, 1/200, 1/100, 1/50, 1/25, 1/12, 1/6, 1/4, 1/3, 1/2, 1, 2, 3, 4, 6, 8, 10, 12, 16 seconds.
(Note: These r here to illustrate how to conduct the test only, the options on ur DC may varies.)
Remember, after a few shots shut down the DC to allow the CCD to cool. For the multi-second shots, I suggest doing this after every shot.
Do the test in TIFF or SHQ JPEG, at max resolution.
Since the lens cap is on, logically u'll see only completely black in the pix. But here is where u chk for hot pixels. Go thru the various black frame pix, starting from the shortest exposure and go to the one where the hot pixels start to show.
The hot pixels shoudn't appear on the pix at anything lower than x (depends on ur tolerance level) seconds.
For me it's abt 4 seconds....for u, u decide.