Megapixels Aren’t the Only Factor to Consider When Buying a Camera

megapixSome questions from our clients and our readers seem to come up more often than others. Many of those questions center around the importance of Mega-pixels. This question came across my desk this morning and since it’s often relevant to our readers, I am sharing my response with you.

 

 

 

“When customers order larger photographs from the lab…let’s say using the Kodak Metallic Print paper…is anyone able to tell me how many pixels their cameras usually use or how does one figure this out?…I am thinking about upgrading my Camera and would like the ability to offer larger prints without losing quality.  I know that some of the new cameras offer more pixals some offer 20 etc.  However, is that what I truly want to look at?”

The good news is that you are asking the good questions. The flip-side is that this is opening a door to a warehouse full of more questions.

Yes, megapixels are an important factor to the end result. It is only one factor however.  Megapixels are top of mind for everyone because the camera manufacturers need “features” they can market with.  They are looking for ways to set their product apart from the others, and this stat is one that is easily digestible to the consumer. We tend to like easy comparisons, and anything with a number fits that bill nicely. Unfortunately, the marketers rarely tell you the benefits of the various features and leave it up to you to infer them.

Here is a short list of what are often considered the primary stats to consider:

  • Chip Resolution (megapixels)
  • Raw file capabilities ( shooting in raw provides greater editing flexibility after the shoot)
  • Max ISO ( high ISO with low noise is generally considered favorable)
  • Dynamic Range ( The ability to capture shadow detail and highlights in the same shot)

There are other considerations that are often driven by an individuals needs.

  • Price
  • Video capable (frame rate and resolution are important factors for video quality)
  • Max burst rate ( more frames per second is important to action shooters who will shoot in bursts to try to get the perfect shot – think sports photography)
  • Auto bracketing ( Auto brackets help you get maximum dynamic range if the scene’s range is greater than the camera can capture in a single shot)
  • Auto HDR ( takes a bracket and automatically merges them for highlight and shadow detail)
  • zoom level if it’s fixed lens (The higher the X number the more zoom range from wide to telephoto)
  • auto focus speed ( important when you are shooting moving objects or if shot timing is critical)
  • max f/stop – again if it’s fixed lens ( f/2 lets in more light than f/3.5 and thus allows for faster shutter speeds)
  • included software ( some cameras come with specialized software – usually consumer grade software)
  • form factor ( How big, how heavy, what’s the shape and color, etc.  Will you carry it in a pocket or purse? Around your neck? etc)
  • tethered shooting ( remotely controlling your camera from a laptop, tablet or smartphone allows for instant downloads of the captured image to your device for enlarged viewing and fast editing)
  • position and accessibility of controls ( how fast can you get to often used controls such as shutter speed, aperture, white balance, and any settings that are important to you. Also are you likely to accidental bump something during casual use and handling)
  • bells and whistles ( fancy stuff like shooting in sepia or black and white, special effects, built-in timers for time-lapse, etc.)

Since your question was in regards to image quality in relation to enlargement, I’ll focus comments there.

There are several generally accepted aspects to image quality:

  • Pixel dimensions (megapixels = file resolution H x W)
  • Image resolution (actual sharpness – it’s a combined result of lens sharpness and pixel resolution)
  • Color fidelity ( color accuracy for every pixel – this affects how true-to-life the image is)
  • Noise level ( less noise is generally considered ideal – noise looks like film grain)
  • Compression artifacts ( these are generally considered detrimental as they destroy color fidelity and detail – to avoid these you will need a camera that shoots RAW or TIFF in addition to the usual JPEG)
  • Tonal range (contrast and detail without clipping to pure black or pure white – the ability to capture shadow detail and highlights at the same time)

All of the items are important to quality, but items in bold are specific to how big the image will reasonably print before the quality drops to unacceptable.   While pixel count is certainly important, equally, if not more important is lens quality. Pixels are not a representation of sharpness, but of resolution. While the two are inter-twined, sharpness is in my opinion a bigger factor.  We have printed many files that had low pixel count but were shot with really nice lenses. The results are better than a high pixel count file shot with inferior lenses.  A not so good 24MP file will not print as well as a good sharp high quality file from an 18MP file scaled up to 24MP  If your budget demands picking either good glass or high mega-pixels, I would suggest you go with the better glass – you’ll get a better return on your investment. Stats and specs can be misleading, so use them as general guide, not as gospel and remember, more is not always better. Especially if you are giving up something more important to get the “more”.

Noise level varies from model to model and is a result of the quality of the chip, the amount of light falling on the chip and the quality of the camera’s internal computer and it’s software.  It can also come from the software you use on your computer to process your RAW files. Part of the cost of a pro-level camera is to pay for the high-end and high-speed processors and CCD chips used in the body.

Most in-camera file compression is destructive and at varying degrees. In my opinion, JPEG is not the ideal file format if detail in the print is of paramount consideration. The compresson process throws away critical detail and is very damaging to the color fidelity. If you pay for a 24MP camera and shoot jpeg, you may only get 12-18MP worth of real detail and around 6MP of color fidelity.  You can learn more about RAW versus JPEG in a previous post here.
When choosing a new camera, make a thorough list that covers what kinds of shooting you do and what features and controls you use for that style. Use that list to determine your must haves as well as any features that would just be nice to have.  Here is an example such a list:

Portraits:

  • Top Shutter speed
  • Aperture priority
  • flash sync
  • white balance
  • interchangeable lenses
  • high ISO
  • Tripod mount
  • Vibration reduction for hand held shooting
  • Jpeg and raw in single capture

Landscapes:

  • Top Shutter speed
  • Aperture priority
  • flash sync
  • white balance
  • interchangeable lenses
  • Tripod mount
  • Bracketing
  • Tilt-able view screen for low angle shooting

Studio:

  • Top Shutter speed
  • Aperture priority
  • flash sync
  • white balance
  • interchangeable lenses
  • high ISO
  • Tripod mount
  • Vibration reduction for hand held shooting
  • Tethered shooting
  • Jpeg and raw in single capture

Nice-to-haves:

  • Large megapixels
  • Full-frame sensor
  • Uses my existing lenses
  • Large view screen
  • Lightweight
  • Accepts accessory grip with additional battery
Now distill this down to one list to remove the duplicates, refine the details then put them in order of priority for you:
  1. Interchangeable lenses
  2. Uses my existing lenses
  3. High megapixels
  4. Full-frame sensor
  5. Top shutter speed 1/5000 or better
  6. Aperture priority
  7. flash sync
  8. white balance
  9. Tripod mount
  10. high ISO
  11. Bracketing
  12. Large view screen
  13. Tilt-able view screen for low angle shooting
  14. Jpeg and raw in single capture
  15. Tethered shooting
  16. Lightweight
  17. Vibration reduction for hand held shooting
  18. Accepts accessory grip with additional battery
With list in hand, the internet or a good camera store should be your next destination for finding models that fit your needs. Nothing beats a well informed and experienced camera sales-person. If you have your list, they can often point you to a few selections in a matter of minutes. It might cost a small amount extra to buy in the store, but the time and frustrations you save instead of doing the search yourself can be worth it.
In the comments below, share what your priorities are and your methods for picking the ideal camera or other tools in your arsenal.  I’ll send the first five helpful responders a nice gift.