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E-pl3 long exposure and LOTS of hot/deadx pixels

Discussion in 'Olympus Cameras' started by a_hit_of_meth, Jan 18, 2012.

  1. a_hit_of_meth

    a_hit_of_meth Mu-43 Veteran

    243
    Jan 7, 2012
    Got my E-pl3 today, good shots during the afternoon but in the evening I was messing around in my room taking shots with low lighting and I realized a few white pixels appear in the enlargements on my pc. Some of them appear on the same spots on different photo's and some appear in random areas. Initially I thought it was due to the ISO setting but they appear on and off no matter what ISO i use.

    Anyway this eventually led me to taking long exposures in A mode, and I noticed for shots around 6-8 seconds were covered in what I think are dead or flipped or hot pixels. The difference with the longer exposures are the pixels are green and are scattered all over the place. It's been a long day and I've only just discovered this so I haven't had a lot of time to take too many shots or look it up.

    Here are some samples, I don't know how to upload the full size but they are still visible. They start showing up on exposures past 1 second and get worse towards 6-8 seconds (I haven't had a chance to go past 8 seconds) with small aperture settings. .

    P1180543 | Flickr - Photo Sharing!
     
  2. pxpaulx

    pxpaulx Mu-43 All-Pro

    Jan 19, 2010
    Midwest
    Paul
    That is truly strange, I've never seen odd pixels like that...no real pattern and seems based on length of exposure which would lead you to believe the pixels are hot, but don't look like typical hot pixels either. If that is a new camera I'd consider a replacement for sure, otherwise might be warranty work.
     
  3. Ned

    Ned Mu-43 Legend

    Jul 18, 2010
    Alberta, Canada
    It might also be worth trying the Pixel Mapping utility.
     
    • Like Like x 1
  4. nickthetasmaniac

    nickthetasmaniac Mu-43 All-Pro

    Jan 11, 2011
    I can't see the link because of the censorship thing you're got set, but do you have 'dark frame subtraction' (or whatever Oly calls it...) turned ON?

    This will take a second exposure with the shutter closed, and use it to map out dead pixels from the first exposure. It's very effective for long exposures and also works in raw.
     
    • Like Like x 1
  5. a_hit_of_meth

    a_hit_of_meth Mu-43 Veteran

    243
    Jan 7, 2012
    I've put up some larger ones on photobucket, hope they show up here.

    f10 3.2sec, 320iso
    P1180541.

    Weird thing is, after putting up my original post I couldn't get to sleep so I tried a few more similar shots and the problem with the red dots seemed to be gone, or at least become less obvious in all but one of the shots.


    Here's one 10sec f/11 200iso,
    P1180557.

    One other thing I noticed which might be related is that all my test images from the shop when I purchased and the images I took on the 45 minute bus ride home seem to be clear of dead pixels. However after I went out for a walk in the afternoon to take some pics, I found out of the 280 or so that I took the last 30-40 images had some dead pixels (the white ones).
    Most of them were in the same spots (about 8 or so) but there were one or two on their own in some photos appearing at seemingly random places.

    @ned I'll try using it for another day to see if the problem reoccurs before trying the pixel mapping as I want to rule out a defective sensor first.
     
  6. Ray Sachs

    Ray Sachs Super Moderator

    Apr 17, 2010
    Near Philadephila
    That's really weird. I had a single dead pixel on my EPL3, used the pixel mapping command on the menu, and haven't seen it since. First dead pixel I've ever had on a camera. But it was very obvious and was in the same spot on every shot, as you'd expect. What you're describing is very different behavior and doesn't sound consistent enough to be dead pixels. Can't say what it is, but I doubt pixel mapping will fix it if it's not repeating on every shot.

    -Ray
     
  7. a_hit_of_meth

    a_hit_of_meth Mu-43 Veteran

    243
    Jan 7, 2012
    I don't know if this is just noise but it's weird that they show up usually between 1.3 to 8 seconds.

    I also have dead pixels on mine, they show up in several shots, usually in sequence but on many other shots they are nowhere to be found. Sometimes I also get the odd white or red dead pixel in a different area. Not sure if those are actual dead pixels or not though...
     
  8. mr_botak

    mr_botak Mu-43 Veteran

    222
    Dec 4, 2011
    Reading, UK
    David
    A pixel stuck on my e-pm1 after about the first day - used the pixel re-mapper and it hasn't bothered me since. Yours is a very different kind of effect though - are you able to swap it out or simply return it?
     
  9. a_hit_of_meth

    a_hit_of_meth Mu-43 Veteran

    243
    Jan 7, 2012
    I went to the Service center today which happens to be right across the street from the store where I bought it and the technician, as most of you already have, did agree that it was unusual. Beyond that he couldn't explain much. The store did agree to change it but I thought I'd take a few more shots and think about it some more since there's no guarantee that the replacement unit won't have any problems either.

    From today's photo's i've reviewed, I notice a lot of hot/stuck pixels around the lower corners when I shoot normal scenes starting at around 400 iso. Also quite unusual as I don't expect to see any at all until at least 800 for shots under normal conditions

    Could this be a voltage issue or some problem causing my camera to run hotter than usual which is causing this?
     
  10. mr_botak

    mr_botak Mu-43 Veteran

    222
    Dec 4, 2011
    Reading, UK
    David
    I'd swap it out if the offer is there. it's unusual and unlikely to fix itself.
     
  11. a_hit_of_meth

    a_hit_of_meth Mu-43 Veteran

    243
    Jan 7, 2012
    I swapped it out today and I got pretty much similar results.

    I haven't tried the long exposures yet but from the 200 or so shots I took with the new camera, it seems the hot pixel thing is still present. I found a lot of my street shots with hot pixels. One picture, I counted a dozen hot pixels under normal conditions. Many other images contain similar results and it's annoying when you get a good pic and there are white spots in someone's hair or shirt.

    Anyway, since most shops here in Hong Kong only allow for an item to be replaced once, I'll probably take the replacement camera to the service center later in the week.

    BTw I've been meaning to ask this, how do I upload onto this site? I tried several times but the images never show up....
     
  12. dhazeghi

    dhazeghi Mu-43 Hall of Famer

    Aug 6, 2010
    San Jose, CA
    Dara
    If this is happening with shots at short exposure times at normal temperatures (under say half a second), you have a defective camera.

    But if it's mainly happening at 1+ second exposures, it probably means that Noise Reduction (Dark Frame Subtraction) is Off or on Auto. At Off, DFS is disabled. At Auto, it only kicks on past 4 second exposures. At On, I believe it kicks in at 1 second+ exposures. Longer exposures will cause the appearance of additional hot pixels (which will disappear for shorter exposures) and DFS is the standard way to deal with it.

    Setup -> Gears -> G -> Noise Reduct.

    DH
     
  13. a_hit_of_meth

    a_hit_of_meth Mu-43 Veteran

    243
    Jan 7, 2012
  14. jaap

    jaap New to Mu-43

    2
    Jan 23, 2012
    One very important factor is the temprature of the image pickup device(sensor).

    Here's a snippet from the manual:
    While you are making long exposure shots the sensor temperature rises. Since you noted that the noise issue seems to be intermittent I'm suspecting he sensor might have been hot in these pictures.

    Can you recall what you've been doing prior/during shooting these photos(that could warm up the sensor)? Do you live in a warm environment? Have you ever seen these warning symbols?
    LMQ06.
     
  15. dhazeghi

    dhazeghi Mu-43 Hall of Famer

    Aug 6, 2010
    San Jose, CA
    Dara
    Link doesn't work here.

    But if you're getting more than one or two hot pixels at 1/60s and the camera hasn't been on and doing something (like video) for an extended period of time, it's definitely defective.

    FWIW, if you are annoyed by an occasional hot pixel (1 or 2) and shoot RAW files, Adobe's Lightroom other ACR products automatically detect and mask them out (but this isn't the case being described above).

    DH
     
  16. a_hit_of_meth

    a_hit_of_meth Mu-43 Veteran

    243
    Jan 7, 2012
    @jaap - That's what I initially suspected, since the first example I posted was after I had the camera on for 45 minutes trying to navigate through the menu, but most of the other shots were taken with the cam on for only around 15-20 mins. I also have a few I took first thing yesterday morning with the hot pixels appearing.


    @Dhazeghi - One or two I can live with but when they appear under normal daytime shots even at relatively high (400-800) iso settings, appearing frequently in people's faces, hair, clothing etc.. it gets annoying and frustrating to deal with. I have heard of how RAW gets rid of them but I don't want to have to switch to that to cover up a defect (if that's what this is) in my sensor.

    Anyway, I don't know why the links don't work, I've put them up on another site so hopefully this time they will work.

    You'll probably have to download the full image to see what I'm talking about.


    P1180343.JPG

    Free File Sharing Made Simple - MediaFire
     
  17. a_hit_of_meth

    a_hit_of_meth Mu-43 Veteran

    243
    Jan 7, 2012
    Just wanted to add that even for iso settings between 400-800, isn't it unusual for there to be so many hot pixels at speeds below 1 second?

    Funny thing is, on my long exposure shots, 20, 30, 40 even 60 seconds, there are barely any hot pixels to be found.
     
  18. a_hit_of_meth

    a_hit_of_meth Mu-43 Veteran

    243
    Jan 7, 2012
    I've finally replaced it. I third e-pl3 in nine days seems to have done the trick. I still see the odd hot pixel here and there under "normal" shooting conditions but not to the extent of the first two camera's. Sometimes there are more than one, maybe two or three but duller and not as obvious to spot as before. I guess it's an acceptable level now, I can finally start enjoying my images instead of looking for hot pixels in every frame.