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Photo Forum / Digital Photography / Digital Photo / February 20068MP vs 10MP, an informal test
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/ > Hi all, > [quoted text clipped - 5 lines] > Comments very welcome on whether this is meaningful, a load of rubbish > or whatever :) 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.  SignatureAlfred Molon ------------------------------ Olympus 50X0, 7070, 8080, E300, E330 and E500 forum at http://groups.yahoo.com/group/MyOlympus/ Olympus E500 resource - http://myolympus.org/E500/ >> Hi all, >> [quoted text clipped - 10 lines] > artefacts). Not sure if this is a JPEG compression problem or some 350D > problem though. There are some serious JPEG artifacts on all those images. That removes all meaning from an already mostly useless comparison. SignatureMåns Rullgård mru@inprovide.com SNIP > The D200 image is cleaner, [...] Noise reduction? Bart > SNIP > > The D200 image is cleaner, [...] > > Noise reduction? > > Bart It's not noise, more something like a mix of aliasing, compression artifacts, oversharpening. SignatureAlfred Molon ------------------------------ Olympus 50X0, 7070, 8080, E300, E330 and E500 forum at http://groups.yahoo.com/group/MyOlympus/ Olympus E500 resource - http://myolympus.org/E500/ 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 ... >Hi all, > [quoted text clipped - 18 lines] >Assistant Director, International Digital Art Award >Personal art site http://www.artinyourface.com/ > 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 ... On the other hand the print area is 25% bigger - significant enough. SignatureAlfred Molon ------------------------------ Olympus 50X0, 7070, 8080, E300, E330 and E500 forum at http://groups.yahoo.com/group/MyOlympus/ Olympus E500 resource - http://myolympus.org/E500/ 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@dimagemaker.com >> 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 ... >On the other hand the print area is 25% bigger - significant enough. Unless you're ptintout is one pixel tall, it won't seem like 25% bigger. More like 12% bigger. > >On the other hand the print area is 25% bigger - significant enough. > > Unless you're ptintout is one pixel tall, it won't seem like 25% bigger. > More like 12% bigger. Did you read what I wrote ? The print area will be 25% bigger. SignatureAlfred Molon ------------------------------ Olympus 50X0, 7070, 8080, E300, E330 and E500 forum at http://groups.yahoo.com/group/MyOlympus/ Olympus E500 resource - http://myolympus.org/E500/ >> >On the other hand the print area is 25% bigger - significant enough. >> >> Unless you're ptintout is one pixel tall, it won't seem like 25% bigger. >> More like 12% bigger. >Did you read what I wrote ? The print area will be 25% bigger. Yes, but it will only look 12% bigger. Unless, of course, you print it as a one pixel line. > 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 ... 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. |
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