How to choose an optimum resolution setting on your camera?
Think about the biggest photo or poster you have printed so far or you see yourself printing. Most of us never print beyond 4x6 inch prints or maybe 8x10 inch prints once in a while. If that is true, a 20MP photo or a 4MP photo when printed as a 4x6 inch print or 8x10 inch print would not bring you any more sharpness or clarity in the photos printed at Costco, Shutterfly, or photo labs in most stores like Walgreens, CVS, Target, Walmart etc.
Print Size in inches
Pixels required for printing/viewing
MegaPixels in image (Rounded to nearest full number))
1600x2000 (@200 dpi printing (most stores print at 150 dpi)
1380x2070 (from Costco.com website)
16x20 Poster print
1840x2300 (from Costco.com website)
Viewing a photo on a 1080p HDTV
Viewing photos on a 22” LED monitor
Viewing photos on a 30” LED monitor
So in short, a high resolution can sometimes be useful as a zoom lens.
Which Camera is better? A 20 MP or a 30 MP Camera?
When it comes to buying a camera, often times you have to choose between cameras that have different Mega Pixels capacity. Provided a camera has more than 10MP capacity, I would prefer to buy a camera with lower MP than the one that has higher MP assuming sensor size is same. For same sensor size, one camera model can have 30 million pixels stuffed on it and other camera model may have put up only 16 million pixels on it. Naturally the more MP you put on same sized sensor, each pixel gets smaller. The smaller a pixel becomes, it loses some sensitivity to light and hence the pictures are likely to get more noisy at higher ISO. As in my world, there is really no benefit in going more than 10-16MP, I would prefer the camera with 16MP compared to the one that has 30MP. to get bigger pixels, better capture of light and better sensitivity to light.