8MP vs 10MP, an informal test

Discussion in 'Digital Photography' started by wayne, Feb 27, 2006.

  1. wayne

    wayne Guest

    Hi all,

    I've just placed on DIMi the results of an informal test of upsampling
    an 8MP Canon 350D image to the same resolution as the 10MP (roughly)
    Nikon D200. The article is here:
    <http://www.dimagemaker.com/article.php?articleID=460>

    Comments very welcome on whether this is meaningful, a load of rubbish
    or whatever :)

    BTW a reminder to get your first entries into the DIMi panorama
    competition for February.
    <http://www.dimagemaker.com/comps/realviz1stq2006/panorama.php>

    Cheers,

    Wayne

    Wayne J. Cosshall
    Publisher, The Digital ImageMaker, http://www.dimagemaker.com/
    Assistant Director, International Digital Art Award
    Personal art site http://www.artinyourface.com/
     
    wayne, Feb 27, 2006
    #1
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  2. wayne

    Alfred Molon Guest

    The D200 image is cleaner, while the upsampled 350D image contains a lot
    of artefacts (even the not upsampled 350D image contains many
    artefacts). Not sure if this is a JPEG compression problem or some 350D
    problem though.
     
    Alfred Molon, Feb 27, 2006
    #2
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  3. There are some serious JPEG artifacts on all those images. That
    removes all meaning from an already mostly useless comparison.
     
    =?iso-8859-1?Q?M=E5ns_Rullg=E5rd?=, Feb 27, 2006
    #3
  4. SNIP
    Noise reduction?

    Bart
     
    Bart van der Wolf, Feb 27, 2006
    #4
  5. wayne

    Alfred Molon Guest

    It's not noise, more something like a mix of aliasing, compression
    artifacts, oversharpening.
     
    Alfred Molon, Feb 27, 2006
    #5
  6. You'll be very hard pressed indeed to realize any significant
    improvement with a 10/8 increase in the total number of pixels. The
    increase in the number of pixels in either direction is only a very
    modest square root of (10/8) =1.118 . So, in an area where the maximum
    number of either horizontal or vertical lines was limited to say 100,
    then this would increase to only about 112 ...
     
    Stephen G. Giannoni, Feb 28, 2006
    #6
  7. wayne

    Alfred Molon Guest

    On the other hand the print area is 25% bigger - significant enough.
     
    Alfred Molon, Feb 28, 2006
    #7
  8. wayne

    wayne Guest

    Hi all,

    I'm going to redo the test. I'm sourcing two identical lenses in the
    respective mounts and will redo the whole thing. I will also put tiff
    crops up on the site so for those who wish to compare the actual pixels
    with no jpeg compression to put on the web page, they can do so.

    Thanks for all the observations.

    Cheers,

    Wayne

    Wayne J. Cosshall
    Publisher, The Digital ImageMaker, http://www.dimagemaker.com/
    Assistant Director, International Digital Art Award
    Writer and educator in graphic design, photography, digital technology
    Personal art site http://www.artinyourface.com/
     
    wayne, Feb 28, 2006
    #8
  9. wayne

    Don Stauffer Guest

    The old AF bar chart resolution charts had the patterns varying by about
    11%. This was done because it was believed the minimum perceived change
    in resolution was about this value. So a 12% increase in resolution
    should be right about at that minimum perceivable change- you probably
    wouldn't see it.
     
    Don Stauffer, Feb 28, 2006
    #9
  10. wayne

    AZ Nomad Guest

    Unless you're ptintout is one pixel tall, it won't seem like 25% bigger.
    More like 12% bigger.
     
    AZ Nomad, Feb 28, 2006
    #10
  11. wayne

    Alfred Molon Guest

    Did you read what I wrote ? The print area will be 25% bigger.
     
    Alfred Molon, Feb 28, 2006
    #11
  12. wayne

    AZ Nomad Guest

     
    AZ Nomad, Feb 28, 2006
    #12
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