Photography Tip: MegaPixel Primer in 5 Minutes

These days cameras come with MegaPixels as high as 20 to 30 MP but like other cameras, you can use them in a wide range of image resolution. In my opinion, setting camera to a proper resolution value is a very important setting. Let us quickly look at the costs and benefits of using too high resolution setting.

Like many things in modern life, we believe in 'bigger the better'. So many of us, without putting many thoughts into it, use the camera in the highest resolution it offers. However we need to have a reason for choosing a 20MP resolution for a photo that you are never going to print. Most computer monitors CAN'T display more than 4 Mega-Pixels. Your smart 1080p HD-TV can show only 2 Mega-Pixels. 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. Here is the resolution typically required for various prints or for viewing.

Print Size in inches Pixels required for printing/viewing MegaPixels in image (Rounded to nearest full number))
4x6 800x1200 1MP
8x10 1600x2000 (@200 dpi printing (most stores print at 150 dpi) 3MP
12x18 1380x2070 (from website) 3MP
16x20 Poster print 1840x2300 (from website) 4MP
Viewing a photo on a 1080p HDTV 1920x1080 pixels 2MP
Viewing photos on a 22" LED monitor 1920x1080 pixels 2MP
Viewing photos on a 30" LED monitor 2560x1600 pixels 4MP


For many situations, like photos in some party, if you know that you are not going to print any photo in a size bigger than 8x10 inch, you can save space on your memory card, on your computer, or conserve bandwidth while emailing photos or uploading them on Facebook by setting MP to 6 to 8MP instead of using camera's maximum resolution of 16 or 20 MP. Costs of taking unnecessarily large resolution photos:

  1. o obvious gain in sharpness or clarity in printed photos: Too much resolution does not make your 4x6 inch or 8x10 inch prints any sharper or more colorful. Most printers can't print more than specific DPIs. Evenif a printer can print very high DPIs, human eye will not be able to distinguish any difference. (Read about Retina Display in iPads or MacBook Pro. That is the maximum DPIs that make an image look smooth and continuous to our eyes. iPads has 264 pixels per inch and MacBook Pro has 227. This also depends on from how far you are looking at the picture/screen. A 18x24 poster viewed from 3 feet away doesn't benefit from as many DPIs as a 4x6 inch photo viewed from a feet away)
  2. No gain when viewing photos on a monitor or an HDTV: When you look at the photos on the computer screen, or on your HDTV, maximum resolution is normally 1280x720 pixels which is around 1MP. For higher resolution computer monitors, it can be no more than 3MP. So a 20MP photo would NOT appear better than a 6 MP photo on computer or on your HDTV.
  3. Can save more photos on your Memory cards, on your computer Hard Disk or on you back up drives: By keeping size to 6MP instead of 18MP, you can store 3 times more photos on your memory card.
  4. Save time while transferring, uploading photos: Downloading photos from the camera, or uploading them to Facebook, can also save you time and bandwidth with 6MP photos compared to 18MP photos. Facebook, at the time of this writing, does not display an image in more than 2MP resolution.
  5. Use the camera's power for something more useful: In many situations, it is advisable to take multiple shots consecutively to capture the right moment. As an example, when your child is playing soccer and you want to capture the perfect moment. In most cameras, if you select a lower resolution, you can take more photos in a second- frames per second (FPS). As an example, with a 16MP setting, your camera can take say 4 photos in a second but with 6MP setting, your camera can take up to 8 photos in a second. This gives you better odds in capturing the right moment.

  6. Potential Benefits of Higher Resolution photos:

    1. Using High Resolution when you can't zoom in: If you don't have a zoom lens, a higher resolution photo can come handy. If you want to take a photo of something specific but you can't zoom in, set your camera to the maximum resolution it supports and then crop out the unnecessary things from the photo. This way what you wanted in the photo is still in high resolution. So in short, a high resolution can sometimes be useful as a zoom lens.
    2. Avoid regrets: If you took a photo that came out too good and you simply loved it. Say you want to make a life size portrait of your kid's photo. In such situation, sometimes it is too later if you took photo in only 6MP mode. You would regret why you didn't take photo in highest resolution your camera offered! So it is a choice to make. You can take a rational approach or try to cover all possibilities and decide to take each photo in 20MP. Would you take 10000 20MP photos to avoid one photo down the road that really would have benefitted from 20MP!

    In my opinion, if you are probably not going to print photos in print size bigger than 12x18, but want to keep options open, take photos in 10MP mode. Or depending on situation, keep changing resolution setting on your camera. When taking photos for selling items on eBay or Craigslist, I set my camera to 2MP mode. Taking photos of kids at my son's birthday party or during his soccer game, I would set camera to 6MP. For family photos and photos of friends, I set it to 10MP. When I come across beautiful landscapes or am taking portraits, I set camera to the maximum resolution it offers.