Mega Pixels

Discussion in 'Digital Photography' started by Tumeg101, Aug 28, 2007.

  1. Tumeg101 macrumors 6502a

    Tumeg101

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    #1
    This is really really sad... but I have no idea what mega pixels are...
    Could someone maybe tell me the diff between 7.2MP and 10.2MP?? This is such a noobish question, sorry...
     
  2. Silverbird0000 macrumors 6502a

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    Fort Myers, FL
    #2
  3. Tumeg101 thread starter macrumors 6502a

    Tumeg101

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  4. Kamera RAWr macrumors 65816

    Kamera RAWr

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    I'm where I need to be
    #5
    More is better if you have the need to make large prints or do some cropping and still get good sized prints. For example: 11x14 and larger.
     
  5. Westside guy macrumors 601

    Westside guy

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    #6
    Everything I'm about to say applies to digital SLR cameras. If you're talking more megapixels on a compact point and shoot, then more is almost NEVER better - it is usually worse (read what I say below, and then multiply it by a factor of 10 or 100...)

    Actually "more" often is not better. Higher pixel count sensors are more prone to diffraction effects (blurring that's basically due to the laws of physics) at smaller aperture settings (F11, F13, F16...) because the individual photosites (pixels) are smaller. Also, higher pixel count sensors are more sensitive to small camera movements, such as sometimes occur when you're depressing your shutter.

    The idea that "more pixels means you can blow up the photo larger" is based on the idea that your photo is actually being captured to a level of detail surpassing the resolution of the sensor - and for a large number of people (I'm tempted to even say "most people"), that assumption is false.

    The one setting where a higher pixel count arguably has an advantage over a lower pixel count is when you're shooting portraits with a tripod (and preferably a remote shutter release) using a wide aperture (f/2, f/2.8, maybe f/4). Pro photographers with great technique and great glass also benefit from more pixels as well. I just don't personally believe (or see much evidence) that most dSLR owners demonstrate that they're really taking advantage of even 6 or 8 megapixels, let alone 10 or 12.
     
  6. GyroFX macrumors 6502

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    Los Angeles and NorCal
    #7
    more is always better...what are you talking about. It's the "American Way". Don't try to stop the goodness. :D

    LOL
     
  7. Westside guy macrumors 601

    Westside guy

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    #8
    But I live in the granola-eating, tree-hugging, Birkenstock-wearing Pacific Northwest - we like to be contrary up here, even when there's no justification for it. :D
     
  8. Tumeg101 thread starter macrumors 6502a

    Tumeg101

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    #9
    yeah, this sounds weird...
    I currently have a 7.2MP digi camera (sony cybershot), this camera has gotten me interested in photography and I am planning to buy a digi SLR camera, but because of the MP count I cant decide between the Nikon D40 (6.1mp) or the Nikon D40x(10.2mp)
     
  9. Heb1228 macrumors 68020

    Heb1228

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    Virginia Beach, VA
    #10
    And I thought this thread was about who had the biggest pixels.
     
  10. Westside guy macrumors 601

    Westside guy

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    #11
    You'll probably be happy with either, actually. If it were me, I'd probably get the D40x simply because the technology is newer - each generation of sensors gets a little bit better in terms of noise reduction and dynamic range.* But you should just know that, going in, you may have to focus a little more on good camera technique to get the absolute best pictures. **

    The one thing to note with both the D40 and the D40x is they don't have in-camera lens motors. This means that you'll need to buy AF-S lenses - pretty much any new Nikon lens - if you want to use auto-focus, since those have a little motor in the lens (note that the third-party lens makers like Sigma are now offering their own version of this. Sigma's is called HSM). It may not matter to you if you think you're likely to stick with one lens for a while anyway.

    * So, for example, the D40's or D50's 6MP sensor has better noise characteristics than my older D70's 6MP sensor.

    ** This is more for down the road when you start getting good, and wonder about things like "why is that tree in the far background a bit fuzzy?"

    *** Sorry for all the addenda! ;)
     
  11. ChrisA macrumors G4

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    Redondo Beach, California
    #12
    It is not always better. For every situation there is an optimal pixel count.

    "megapixel" is a pure marketing term. What you really care about is the number of pixels across the widest side of the frame. For example a 3000 x 2000 frame is 6MP but what matters is the "3000" part. These is no reason in the world for a photographer to care about the product of hight times width. He cares about pixels across.

    Here is how to find the optimal pixel count -- Working backwards from the final print first you determine the nimimum number of pixels you need. How big is the print on the widest edge? Let's say "ten inches". Then we apply a rule of thumb that say "it's best to print at 300 pixels per inch". So we se that for 10 inch prints we need 3000 pixels. If your camera shoots 3000 pixel images there is zero room to crop a 10" print. Going with a 4000 pixel camera or with a smaller print size would give some crop room. Note that a 4000 pixel camers works out to about 10.4MP

    Assuming the sensor is the same physical size, If the pixels are smaller than needed the camera is less sensitive to light and will have more noise in the image.

    Why more MPs? Because Long ago cameras did not have anything even close to the above "minimum number of pixels" and you could clearly see the result. Enlargements looked bad. So people learned they wanted more MPs and the marketing people pushed MP as an indicator of image quality. MP is one indicaor of quality but once you have your minimum number more does not matter.

    I don't like any of the D40 models. They lack an in-body focus motor. For me that's a deal breaker. Find a used D50 or D70. Some of Nikon's best prime lenses will not autofocus with the D40. Also you are locked out from many of the best deals on the used lens market too. If you add up the cost of a system with one body and three lenses you may be best off buying a body with a focus motor. But if you are hapy with just the kit lens and nothing else then the D40 is fine. But do plan ahead.

    I have the D50 it is 6MP and does fine for most of my work which is viewed on electronic media. I was at a show last week where I put images on a large screen using a projector. The projectors can not even show 1MP. My 1080p Sony LCD TV set can't even show 2MP and my 24" iMac is not much better. Only large paper prints call for large pixel counts. And then 10MP v. 6Mp is not much different. Compare pixels along the wide edge not total pixels.

    For large sized fine art prints film still wins. If I want a 3 foot wide print, digital ain't going to cut it. 4x5 sheet film is the way to go for that
     
  12. srf4real macrumors 68030

    srf4real

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    #13
    Having went from a 5mp Kodak to a 10mp Panasonic (both superzoom p+s)
    I can say that having 3650x2740 pixel sized images with the 10mp sensor is very nice for cropping smaller portions of the photo and still having excellent large images for print. Especially since I am new to photography and don't always get the composition right, or am using center spot focus and cropping for composition later. I now own a Panasonic L1 dslr with only 7.5mp sensor and it blows away the images from my 10mp Panasonic FZ-50, probably due to lens quality actually, with no noise until ISO 1600, so...

    I highly reccomend a high pixel count, but as has already been said bigger is not always better... it's how you use it.;)
     
  13. Foggy macrumors 6502a

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    Jul 4, 2006
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    London, UK
    #14
    I was in the same situation, and after reading ken rockwells site (and specifically the bit about what camera to buy: LINK) I went for the D40 and am putting the money saved towards an 18-200mm VR lense.
     
  14. BurtonCCC macrumors 65816

    BurtonCCC

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    Wheaton/Normal, IL
    #15
    Megapixels are largely confused with quality, as mentioned above. Take Canon's consumer SLR cameras, for example. The Rebel XT, which has an 8.0MP sensor has been reviewed on many different occasions to take crisper and more defined pictures than Canon's 10MP Rebel XTi. However, if a person wanted to make larger prints, 10MP would be preferred. I will let you know that I use a 8MP SLR and my 8X10 shots still look very nice, any smaller than 7MP is going to produce frustrating results when shots are blown up.
     
  15. notjustjay macrumors 603

    notjustjay

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    Sep 19, 2003
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    Canada, eh?
    #16
    Even then, it's in the eye of the beholder (and the quality of the printer). I've printed 8x10s from 2 megapixel cameras, ordered from the professional printing places, and they look pretty good. Probably not portrait studio quality, but certainly fine for the average person to put in a frame and hang on a wall.
     
  16. wmmk macrumors 68020

    wmmk

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    #17
    I can print pretty damn close to poster size prints at great quality with just a bit of Genuine Fractals from my Canon 1D, which has a mere 4 MP. How? Good lenses, large photosites, and a sturdy tripod tend to help.

    Good luck with your decision that the most important part of your kit is behind the viewfinder.
     

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