turning off pixels = less noise in low light?

Discussion in 'Open Discussion' started by Holymoly, Apr 5, 2013.

  1. Holymoly

    Holymoly Mu-43 Regular

    Dare I mention the word K-K-Ken again? (Anyone see A Fish Called Wanda?) I am contemplating another camera because I hate how my EPL2 turns that lovely gold morning/evening light into red. (Does anyone else have this problem by the way?)

    Anyway in the context of the Nikon D3200 K-Ken was talking about how he shoots high megapixel cameras on the 6MP setting. Having seen what my American g/f's 2005 model, 6MP Olympus SP500UZ (with P and S sized sensor) is capable of I wonder why I am too scared to follow suit.

    It did get me wondering however if turning off a few strategically placed pixels might up the light sensitivity of it's neighbours. I am not quite sure why I think that.. something about not mowing the lawn in the weekends and giving your neighbours a break from noise?

    I would be most grateful for your thoughts on the subject.
  2. speedandstyle

    speedandstyle Mu-43 Hall of Famer

    I don't have any problem with my E-PL2 turning golden hour shots red. What picture mode are you using?
  3. dwig

    dwig Mu-43 Top Veteran

    Jun 26, 2010
    Key West FL

    That's not how it works.

    When you set the camera to a lower pixel size all of the photosites still function. What happens is that the initially image data is downsampled prior to saving. This downsampling effectively averages the noise, a totally random thing, causing the result to display less noise.

    This same noise reduction can be done by blending multiple full resolution images, either matching exposures the way astrophotographers frequently do or bracketed exposures as is done for true HDR images.
  4. Holymoly

    Holymoly Mu-43 Regular

    Picture Mode?

    S and S that is indeed good news that you don't have the problem.. I really don't want another Nikon. When you say mode do you mean light balance? Auto, sunshine both have the same effect. I have attached one of my red photos.. couldn't see anything in the metadata which jumped out at me but.

    Attached Files:

  5. Holymoly

    Holymoly Mu-43 Regular

    Downsampling The Reason for Lower Noise

    When you set the camera to a lower pixel size all of the photosites still function. What happens is that the initially image data is downsampled prior to saving. This downsampling effectively averages the noise, a totally random thing, causing the result to display less noise.

    This same noise reduction can be done by blending multiple full resolution images, either matching exposures the way astrophotographers frequently do or bracketed exposures as is done for true HDR images.[/QUOTE]

    Brilliant.. thank you. If you would be so kind as to tell me something else I don't know.. HDR images being composites of bracketed exposures. I have never come across this idea before. (Wiki won't let me in either). Are these a part of daily life that I should know about or is it just for those other people?

    I suspect the latter as I only shoot JPEGs and avoid photo editing like the plague. This is partly why I bought the Olympus.. my American girlfriend's SP500UZ used to read my mind. My Nikon D60 was more like my ex-wife.. it would read my mind all right and then go completely it's own way. :rolleyes:
  6. speedandstyle

    speedandstyle Mu-43 Hall of Famer

    Not white balance, the picture mode. I guess I need to go a step further and ask which camera mode you are using{the dial on top}. I personally shoot in program, aperture priority, shutter priority or full manual modes only{M-S-A-P}. The other modes on the dial are iAuto, ART filters and Scene.

    If you are using auto or scene mode it may have the white balance and or picture mode set in a way that renders your color too red. The picture modes I am talking about are listed on page 40 of the manual. The icon on the LCD looks like a funky wand with a number next to it. The modes are iEnhance, Vivid, Natural, Muted and Portrait. You can also set it to Monotone{B&W}, Custom and the Art filters. I normally use the #3 Natural mode.

    Looking at your picture, it doesn't seem that much off if it was shot during golden hour. Although they call it golden it can often be reddish. I took the image and put it into Lightroom, it only needed a slight adjustment to the WB to balance out the red. You can custom set the WB on your camera. The last option in the WB selection is "CWB". Set it to that and then push the info button then use the wheel to set the WB to any Kelvin number you like. Lower numbers will be bluer and higher numbers will be redder.
  7. dwig

    dwig Mu-43 Top Veteran

    Jun 26, 2010
    Key West FL
    Check out: High-dynamic-range imaging - Wikipedia, the free encyclopedia

    and HDR photography software & plugin for Lightroom, Aperture & Photoshop - Tone Mapping, Exposure Fusion & High Dynamic Range Imaging for photography

    and Google: "hdr high dynamic range"

    Also, for image stacking, rather than HDR, check out: Understanding Image Stacking for Astrophotography

    HDR (aka High Dynamic Range Imaging or HDRI) is not too difficult but good work requires a tripod and either manual exposure control or aperture priority.
    I have, on a few occasions, managed to get good result hand held using a camera that will auto-bracket and that has a decently high frame rate (e.g. my Pany G-1 with Class 10 cards).

    It is also possible to shoot a single RAW image and use a set of varying conversions to generate a set of "bracketed" images from which an HDR image can be generated. Working this way, though, does not reduce high-ISO noise since all images come from the same source and have matching noise patterns.
  8. Holymoly

    Holymoly Mu-43 Regular


    Thank you DWIG. I will bookmark this and slowly work through it.
  9. Holymoly

    Holymoly Mu-43 Regular

    Camera Mode

    speedandstyle thanks for the clarification. Buying the E-PL2 was somewhat of an attempt to return to my Mamiya RZ 67 days.. Aperture, ASA, shutter speed, focus.. 1.. 2.. 3 clunk. Accordingly I keep it very simple (stupid) and shoot only aperture priority making exposure adjustments with the add or subtract control. Accordingly I set the white balance with the little icons.

    I have never used CWB.. thanks for the heads up on that. My concern however is that gold light is being so misrepresented by my camera when you say yours is OK. I have attached one from another series of pics taken in brilliant early morning gold light but it just looks red and a bit sad. Is there any chance you repost the one you tarted up with Lightroom?

    In turn I might post another taken by my girlfriend's little Oly and the gold is absolutely true to the scene. To think you can pick them up for $70 on ebay :)

    Attached Files:

  10. speedandstyle

    speedandstyle Mu-43 Hall of Famer

    I edited your pictures correcting the white balance away from red. The picture of the couple on the beach was corrected -16 in temperature and -16 in tint. The picture of the bike was corrected a little bit more at -24 each.



    Here is a picture I took at golden hour. This has been enhanced a little bit in Lightroom but the light is golden not red.


    It is possible that your camera is not giving a true WB reading. Of coarse no camera's auto WB is perfect which is why pros set it manually. I also highly recommend Lightroom or some other software so you can make corrections/enhancements. BTW both of my PENs have trouble with the WB under incandescent light, it is always too yellow.
  11. ghetto

    ghetto Mu-43 Regular

    hrmmm doesn't it depend on what the scene was though?

    as an example in the photo of the couple, I can see one is less red than the other, but on the other hand sometimes near sunset the whole sky does go red-ish along with just about everything the diminishing sunlight hits.
  12. Holymoly

    Holymoly Mu-43 Regular

    Red V Gold

    What an interesting pic speedandstyle. Was it taken in Roswell New Mexico? I would describe the colour to the right of the photo more as yellow than gold.

    Thanks for the colour corrected shots. The colour however is not actually accurate. I can't remember from my world travels what morning/evening light looks like elsewhere but here in NZ it has a definite gold hue as per the attached. (Taken on my Nikon but cropped to 4/3rds for the sake of politeness). Would it be possible to recreate this effect on the other 2 samples.

    I think I have just found someone suffering in the same way I am. They have been advised to use the custom white balance setting. https://www.mu-43.com/f35/custom-white-balance-do-you-use-19774/ Now that I might be able to do without deviating too far from my keep it simple stupid formula. Can anyone else vouch for it?

    Attached Files:

  13. speedandstyle

    speedandstyle Mu-43 Hall of Famer

    The picture I posted was taken at Coronado Springs resort, Disney World in Florida. It was enhanced a little bit in lightroom and is actually a composite of two EV bracketed shots. One exposed for the sky and one for the building.
  14. Mogul

    Mogul Mu-43 Regular

    Nov 9, 2012
    If you can set color balance by Kelvin temperature, set your camera to 4300° (Sunrise/Sunset) for those pictures. That will "cool off" your colors.
  15. speedandstyle

    speedandstyle Mu-43 Hall of Famer

    Here is the picture of the couple corrected towards yellow. I lowered the saturation of the red a tiny bit and boosted the yellow and orange up a small amount. I also shifted the WB toward the yellow a slight bit as well. Is this what you were wanting? [​IMG]
  16. Holymoly

    Holymoly Mu-43 Regular


    Thanks for this speedandstyle also for the (info on your Coronado photo). Yes you are now heading in the right direction. I would still describe the hue more as yellow rather than gold. I am speaking subjectively here but the gold "cloaking" the American girl photographer sitting atop Mokotahi hill is just somehow heavier than the red or yellow/orange and accordingly speaks to my emotions.. in truth in a Bubba Watson kind of way. (Having said that I had the thought to check the CMYK values.. the colour I am wanting is nowhere near gold.. it is orange. http://www.december.com/html/spec/colorcmyk.html)

    I am getting the impression that this result is achievable in lightroom. Something about telling the truth, the whole truth and nothing but the truth means that I really would like the camera to do the work for me. Thanks to Mogul at least I now have a colour temperature to work with and I have just discovered how to use the CWB function. I have also asked Olympus USA for their thoughts.. mine came from Cameta.
  17. Holymoly

    Holymoly Mu-43 Regular

    Cooling Off

    Cheers Mogul. Are you saying that 4300°K should give me "accurate" colours? You talk of cooling down but at that time of evening the colours are very warm. My problem is that all the wavelengths below green manifest as warm ie red, orange and yellow, but at present they are not playing well together but being over-run by red.
  18. GaryAyala

    GaryAyala Mu-43 Legend

    Jan 2, 2011
    That was very nice of you speedandstyle.
  19. speedandstyle

    speedandstyle Mu-43 Hall of Famer

    For the best results I think you will need to edit in Lightroom or some other software. Find a WB setting that comes as close as you can get and then fine tune it in Lightroom.
  20. Holymoly

    Holymoly Mu-43 Regular


    Yes indeed Gary. Very many thanks for going above and beyond for this slow learner speedandstyle. I really really hate editing colours and so I am most grateful that you were able to take away the pain by spoon-feeding me through a couple of scenarios. Hopefully my CWB revelation (I used it when I first started out but thought modern cameras had done away with it) is going to make most of my problems with red hues go away.

    Also I understand that the E-PL2 saves WB settings as custom presets. Inshallah I will be able to educate my "student" on the one "equation" it keeps getting wrong.