Digital camera help

Discussion in 'Photos & Videos' started by Gary Pfeil, Oct 24, 2004.

  1. Gary Pfeil

    Gary Pfeil Active Member

    I wonder if anyone can help me find out how to get my camera, an Olympus C700, to take better photos of brick walls? It would seem that the rows of brick confuse the cameras brain and create curved lines thru the photo. They are less obvious the larger the photo is. When I download the images from the camera to my computer and I see all the shots as thumbnails, they tend to look awful. Opening one up it looks better, but not as it ought to. And when I reduce its size to post here at the Gauge, it starts looking bad again. When there is no brick in the photo, I don't seem to have the problem. I must have done something to some setting, I do not have a manual other than some quick instructions and there is nothing there that seems to relate to this problem. I have some photos in the Qiunn Ball Bearing thread in scratchbuilding, they were the best I could manage, but not great. Here are what I'm typically getting.

    Attached Files:

  2. Gary Pfeil

    Gary Pfeil Active Member

    The above, at 66KB, is about the largest I can post here. Here is what the same photo looks like at 320x200:

    Attached Files:

  3. jkristia

    jkristia Member

    I think know what it is, but I can't remember exactly what it is called, I think it's interference. I even searched to see if I could find the explanation in there somewhere, but wasn't able to (maybe it's too early, it's only 6.10am Sunday :) )
    It's the same phenomenon as when you see a person on TV wearing a pinstriped shirt or tie, a black / whit pinstriped shirt will sometime show multiple colors and the colors will be rolling with lines of different colors changing directions etc. That happens when the one color 'field' is less than 2 pixels, and that's why it's less obvious in a larger picture, and becomes more pronounced on a resized picture. On top of that, JPG compression somehow calculates the pixels based on neighboring pixels, which again will increase the 'interference'

    I think both JPG (in best quality) or RAW should both be able to take a picture without any 'interference', but I'm not sure how you can resize it without getting in to this problem.

    I might be wrong on this, bit I think that is what is happening.

  4. Fred_M

    Fred_M Guest

    Interlacing. I'm not sure that's what the problem is though. It's not just the bricks, it also appears in the Xs and angles on the fire escape. Is that a full frame shot or did you crop the image? It looks almost like a digital zoom problem. Fred
  5. N Gauger

    N Gauger 1:20.3 Train Addict

    That's a great explaination Jesper.. it is because of the amount of pixels in the camera "Capture Board" :( It doesn't go away until you get above 6 Mpix :( still too expensive for me :( Try changing to tiff if you can (if your camera supports it) & it may help - but tiff images are huge files :(

    I take car show pics & it's really irritating - almost every straight line on a car gets that "sawtooth" pattern :(
  6. jkristia

    jkristia Member

    Thanks Dash10, Interlacing is what is is calledI think the problem on the fire escape is a combination of low resolution and jpg compression
  7. spitfire

    spitfire Active Member

    It's a moiré!

    The problem is called a moiré (pronounced moray - like the eel!). As Jesper says, this is the same phenomenon you see on TV with a regular pattern such as pinstripes. Also you folks who are far enough north to have snow fences will have seen it when you drive by 2 sets of fences one in front of the other.

    It is produced when 2 transparent grids overlay each other and the look of it depends on the angle of the grids to each other. In your case Gary the grid of the bricks, and the grid of the pixels are what's producing the moiré pattern.

    The only solution is to change the resolution of your shots - thus altering one of the grids in the equation. Strange as it may seem, a lower resolution might actually help.

    Here's a link to one of many sites decribing the moiré effect.


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