Noise at night

Discussion in 'Digital Photography' started by superted666, Aug 3, 2006.

  1. superted666 Guest

    superted666

    Joined:
    Oct 17, 2005
    #1
    Hello again,

    Right ive been taking my first real night shots a short while ago on my a100.
    Attatched are some images i have made however i keep hitting one problem, NOISE.

    its fine during the day but shooting these scenes (it was way darker than the picture portrays. i get severe noise and the image doesnt look as detailed as i had hoped.

    Any tips on shooting at early night? static mostly.

    Images are big!

    http://www.fun-t.com/ft/images/DSC02112.jpg
    http://www.fun-t.com/ft/images/DSC02111.jpg

    Exif

    File Name
    DSC02112.ARW
    File Path
    Learning the Tricks
    Dimensions
    3872 x 2592
    Exposure
    1/2 sec at f/3.5
    Focal Length
    18 mm
    Brightness Value
    2
    Exposure Bias
    0EV
    ISO Speed Rating
    ISO 400
    Flash
    Did not fire
    Exposure Program
    Normal
    Metering Mode
    Pattern
    Date Time
    03/08/2006 21:32:58
    Make
    SONY
    Model
    DSLR-A100
    Software
    DSLR-A100 v1.00


    File Name
    DSC02111.ARW
    File Path
    Learning the Tricks
    Dimensions
    3872 x 2592
    Exposure
    1/2 sec at f/3.5
    Focal Length
    18 mm
    Brightness Value
    2
    Exposure Bias
    0EV
    ISO Speed Rating
    ISO 400
    Flash
    Did not fire
    Exposure Program
    Normal
    Metering Mode
    Pattern
    Date Time
    03/08/2006 21:32:54
    Make
    SONY
    Model
    DSLR-A100
    Software
    DSLR-A100 v1.00
     
  2. ChrisA macrumors G4

    Joined:
    Jan 5, 2006
    Location:
    Redondo Beach, California
    #2
    Looks like you have found out there is more to a camera than just the number of pixels.

    There are several sources of noise.

    (1) Thermal noise. The Nikon D50 has a feature where it will take an exposure with the shutter closed and substract that from the shuteer open picture. This removes much of the noise from long exposures. If the A100 lacks this you can do it in post processing. Just take an exposure of the same exact lenght but with the lens cap on and maybe a dark cover over the camera that is 100 light tight.

    2) the lens may have been "wide open". Only the very best (and expensive) lensesare really sharp when wide open. I suspect you might be using an inexpensive "kit lens" that lacks sharpness at f/3.5. Try stopping down to about f/8. The image shows signs (blur and color fringing) of not quite the best optics. stoping down hould fix this.

    3) Try some sective sharpening and blurring. In photoshop, gimp or whatever you use select the areas with details and apply a "sparpen" filter and select the areas with blank same tone aeras and apply a blurto them. The blur will kill the noise. You can use a very strong filter if the area is truely blank. and noise does not show so much in areas of detail bt of course the softness does.
     
  3. superted666 thread starter Guest

    superted666

    Joined:
    Oct 17, 2005
    #3
    thanks for the info!

    yea i knew not to be too focused on pixels when buying a new camera, i have two kit lenses this one was taken with the 17-80 fully open as you said, i might try a bit more experimentation with it then, i can shoot fine in daylight but this is first time at night properly!
     
  4. beavo451 macrumors 6502

    Joined:
    Jun 22, 2006
    #4
    Were you handholding? If so, that is a problem. Alot blur will be from camera shake from trying to handhold a 1/2 second exposure. Try for at least 1/focal length shutter speed if you are going to hand hold.

    The noise itself isn't too bad. The photo is just not sharp. Probably a combination of a higher ISO, camera shake, and soft lens.
     
  5. superted666 thread starter Guest

    superted666

    Joined:
    Oct 17, 2005
    #5
    yea i was hand holding but resting against a window frame (too lazy to leave my apartment ;)

    My lenses do appear to be soft, i might try out some of the zeiss lenses once there out but these are fine for starting!
     
  6. beavo451 macrumors 6502

    Joined:
    Jun 22, 2006
    #6
    The handholding is the main problem. Even with you resting against a support, the exposure time was still long enough to pick up vibrations from your hands.

    Your lens also shows some flare.

    What are your in camera settings regarding contrast, saturation, white balance, and sharpening?
     
  7. ChrisA macrumors G4

    Joined:
    Jan 5, 2006
    Location:
    Redondo Beach, California
    #7
    Way didn't you say so. A 1/2 second exposure requires a good camera support. A tripod or even a sand bag is required. Also try using the self timmer or a remote control so that your hand dose not shake the camera when you press the release. Even a zip lock bag filled with beans works if yo use the self timmer trick

    That said the softness does not look like camera shake. It just looks like a soft lens with some chromatic aberation and flair tossed in.

    Shooting out of a window at night adss another source of softness: Heat. I asume the apartment was heated. Thehot and cold air mixes when the window is open. This would have a pronouced effect if you wee using a telephoto lens but with your wide angle shot maybe not.
     
  8. andiwm2003 macrumors 601

    andiwm2003

    Joined:
    Mar 29, 2004
    Location:
    Boston, MA
    #8
    i also have the a100. you're lucky that the image stabilisation works so good. otherwise you would only have blurry pics.


    if you like to do night shot's buy a used minolta 50mm f1.7 lens from ebay. they are about $80. a fixed lens is always superior in color/sharpness to a zoom lens (in a reasonable price range). and at f1.7 or 2 you cut the exposure by a factor of 4. that means you can shoot at iso 200 or 100 with a lot less noise!

    have fun with your new toy. i will!:)

    from my window:

    50mm
    f2.2
    4sec exposure
    iso 200
     

    Attached Files:

  9. jared_kipe macrumors 68030

    jared_kipe

    Joined:
    Dec 8, 2003
    Location:
    Seattle
    #9
    iso400? That may be your problem. Try for something lower, preferably as low as it gets.
     
  10. beavo451 macrumors 6502

    Joined:
    Jun 22, 2006
    #10
    :confused: Your image seems to lack sharpness as well.

    I really don't think the problem is ISO 400 (unless Sony really blew it). Here are 2 test shots at ISO 800 and they both are sharp without losing detail:

    The photos are an overview picture and a 100% crop The watch is blurry because it is outside the DOF.
     

    Attached Files:

  11. andiwm2003 macrumors 601

    andiwm2003

    Joined:
    Mar 29, 2004
    Location:
    Boston, MA
    #11


    i think you're expecting too much from a night shot. my pics are a bit sharper in original size. also the lenses are usually a lot sharper at f/11 and up as on f/2. the only way to increase sharpness more is a $1500 lens and post processing.
    btw. in the settings of your sony you can increase the sharpness (left dial; set it to DEC and increase the sharpness with the lowest slider on the display).

    the reason why many point and shoot cameras seem to give very sharp images is because they electronically boost sharpness. dslr's are usually more conservative and leave the post processing to you.

    also when you zoom in like that it's like 30 inch wide picture. with the 10 MP of the sony that's a resolution of 126 dpi.

    if you really want that ultra sharp detailed picture you will have to invest in really expensive lenses. i'm looking right now into a wide angle and later into a macro zoom. but as life is i'm limited to ~$600 per lens. and the really good lenses are twice as expensive. but fortunately i'm not a good enough photographer for that equipment anyway.;)


    now that is sharp:

    http://www.flickr.com/photo_zoom.gne?id=184992740&size=o

    it's from a thread in macrumors. http://forums.macrumors.com/showthread.php?t=204316&page=47

    maybe macgfxdesigner can tell us how he did it.
     
  12. beavo451 macrumors 6502

    Joined:
    Jun 22, 2006
    #12
    That is not necessarily true. My Nikon 18-70DX (used in the above photos) approaches the sharpness of many higher dollar lenses when stopped down past f/5.6 to f/11.

    The $100 50mm f/1.8 is sharper than my 70-200 VR.

    There is no secret to taking sharp photos. Proper techinque is the key to getting good results, whether you hand hold or use a tripod. Sharpness wouldn't decrease just beacuse it is at night or the use of a long shutter speed. What little decrease in sharpness that might occur would result from long exposure noise. I don't know if Sony has in camera noise reduction, but that would eliminate much of the noise.

    The photos that I posted where to show that noise doesn't decrease sharpness dramatically (plus they are from a D2H which some regard as a very noisy camera).

    I only have the thumbnail version with me right now, but this came from a D50 and was a long exposure at night as well. Noise reduction was not used for this photo.

    D50 + 70-200 VR on a tripod. Weighed down with my camera bag to minimize vibrations. Self-timer set. IIRC, a 15 second exposure at ISO 200. I doubt the result would be much different with a Sony A100 or if I had used the 18-70 lens.

    [​IMG]
     
  13. Abstract macrumors Penryn

    Abstract

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    Dec 27, 2002
    Location:
    Location Location Location
    #13
    Firstly, there is no noise problem in that photo. Like others have said, it's due to your 1/2 second shooting handheld. If it wasn't for the in-body image stabalization, I think you'd end up with a lot of blurry photos. It doesn't matter how still you think your hands are. You're not going to end up with sharp images handheld.

    Get a tripod. It's great to take photos at f/8, but at night this isn't possible if you're handholding and were working at f3.5. At f8, you'd be handholding for longer than 1 second.

    Oh, turning up the ISO would let you cut your shutter speed. You'd get noisier images, but I never understood the people who stressed out so much about it anyway.

    Where is this feature? Do I need to turn this feature on?
     
  14. sjl macrumors 6502

    sjl

    Joined:
    Sep 15, 2004
    Location:
    Melbourne, Australia
    #14
    Quite. Look at it this way: in low light conditions, you can get the shot with the noise, or miss out on the shot completely. Which would you prefer? :p
     
  15. Abstract macrumors Penryn

    Abstract

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    Dec 27, 2002
    Location:
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    #15
    Exactly. If I sat on ISO 400 all night, I'd miss a lot of good shots that would end up blurry on ISO 400 and sharper at ISO 1600. What would I rather have......a slightly out of focus shot with less noise, or a perfectly sharp photo that's slightly noisy? I'd rather have a sharp photo. The noise issue isn't as big as it seems when you look at your screen.

    And aren't these digital SLRs producing less noise than film anyway? It's not like photographers look back at the film SLR days (ie: 5 years ago) and disregard any low light photo taken before 2000. We still see them for what they are. Composition, timing, luck, and sharpness.
     
  16. beavo451 macrumors 6502

    Joined:
    Jun 22, 2006
    #16
    I don't remember what setting it is, but it is called "Long Exposure NR". Consult your D50 manual to see where it exactly is in the menus.
     
  17. andiwm2003 macrumors 601

    andiwm2003

    Joined:
    Mar 29, 2004
    Location:
    Boston, MA
    #17
    at exposures of 1 sec or longer the Sony does a noise reduction processing step that lasts exactly as long as the exposure. they don't say it explicitely in the manual but i suspect this is exactly what the Nikon does. it simply takes another pic with the shutter closed.
     
  18. andiwm2003 macrumors 601

    andiwm2003

    Joined:
    Mar 29, 2004
    Location:
    Boston, MA
    #18
    if you where using the nikon 70-200 vr: well that's a $1500 lens.

    anyway i like your picture a lot.

    when you get the chance could you give some more info? where is it, the exif data, how far away from the city where you, weather/humidity and so on. a full res download would be too much to ask for i guess?

    sorry i know it's a lot but what i like about this pic are the great colors. white is really white!

    i want to take a similar shot of boston but with the current haze and humidity it's not gonna work. but on cold dry winter nights it should give some great pics.
     
  19. Abstract macrumors Penryn

    Abstract

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    #19
    Is that what he's talking about, though? I thought this was just one of those camera features (ie: ones you'd find in a small point and shoot) that masks the noisiness of the photo by making it less sharp, so I turned it off. :confused:
     
  20. beavo451 macrumors 6502

    Joined:
    Jun 22, 2006
    #20
    Yes. For long exposures, it takes a second exposure with the shutter closed and calculates the noise out.

    I'm out of town right now and don't have access to the original skyline photo. I'll post more info about it when I get back to my desktop in a few days.

    I remember it was slightly hazy and some contrast adjustments got rid of that. I was about a mile to mile and a half away on top of a parking garage.
     
  21. Abstract macrumors Penryn

    Abstract

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    #21
    Just tried it. Too bad it doesn't work for exposures less than 1 second. I'd like it to work at shutter times of 1/8th seconds and whenever it's set at ISO 1600.

    Well if it takes a photo with the shutter closed and subtracts the noise in that image from the original, I don't really see how it would work seeing as how noise is random. Subtracting random noise of the image with the shutter closed, from the original image would run the risk of not having any positive effect, or even making the photo more noisy. But I guess there's some other physical process happening that we don't know about, although I do study physics.
     
  22. andiwm2003 macrumors 601

    andiwm2003

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    Boston, MA
    #22
    i only know that even cooled cameras for microscopes do the same. maybe individual pixels have specific noise levels/types that you can substract. by that you don't eliminate random noise but at least imperfections of the chip.
     
  23. beavo451 macrumors 6502

    Joined:
    Jun 22, 2006
    #23
    I don't know the actual process behind it besides the fact that it takes two images and compares them.

    Correct White Balance ;)
     
  24. Abstract macrumors Penryn

    Abstract

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    #24
    I didn't even say that. :p
     
  25. andiwm2003 macrumors 601

    andiwm2003

    Joined:
    Mar 29, 2004
    Location:
    Boston, MA
    #25
    well, thats of course one part. but basically all colors are very vivid. that's why i asked for the weather conditions, distance and so on. i still suspect that good glass is a large part of it.
     

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