Audio Visual · Digital Printing Group · Cameras

The MegaPixel Question

by
July 1, 2024
How many megapixel do you really need in a camera? Explore this question before you spend money on a new camera.

A lot of people believe more is better without thinking about what they really need or what the cost of a 45 megapixel (MP) or larger camera really costs. Yes, they will be more expensive to buy. The Canon R6 Mk II is currently $1,999 with rebates and the R5 is $2,899. Nikon Z6II and Z7II are$1,599 and $2,299 respectively. A Fuji GFX 100 S II $4,999 and a Hasselblad X2D100C is $8,199. All of these before getting a lens. This is not pocket change.But a lot of photographers feel they need the MEGAPIXELS!

Cost beyond the bodies people often overlook. SD memory cards are not that bad but most of the 45MP or greater can require the newer cards like CF Express or XQD, and they are often over a $100 (plus new card readers.) Then there are the computers. I had to upgrade my MAC to handle the larger files and even then, if I’m doing a panoramic, I’m into half a gig image or greater. We are talking around $7,000 in new computer and backup storage.

The cost can add up fast and do you really need files that large? Let’s talk about two groups who probably do. The first is your professional product commercial photographer. Clients always want larger files,and the art directors love to have wiggle room. For us it’s a cost of business and we figure it into our rates. The other group, which I have been doing a lot more of, is the landscape photographer. Our clientele love to pixel peek and I often kid they want to be able to count the leaves on that mountain 30 miles away. I know a few wildlife photographers who also insist on having 45MP plus camera. They often can’t get close enough to their subjects so they also like having the ability to crop in.

You need to ask yourself what the final output is going to be. Let’s be honest, most photos today are seen on our phones or maybe a laptop or desktop computer. We should print more (read “The Importance of Making Prints” blog) and share our photos in a more substantial way. So how many MP do you need to make a print?

Time to get geeky!

We have all been to the eye doctor and used an eye chart to test our eyes. These charts are developed using the eyes resolution power, or visual acuity. This measured is in arcminutes. Taking the arcminute with the distance of the viewer, we can determent how many MP we need. For 20/20 vision the height of the letters on an eye chart is about 5 arcminutes. Using some trigonometry, we get Acuity Constant = 3,438.

Using this constant, we can do some math and come up with this chart showing the dots per inch (DPI) needed to see a sharp image at different distances.

From this we see at about 1 foot we need an image printed at about 300dpi to have a sharp image. Most printers ask for this resolution when you submit your photos. Notice how quickly the DPI’s needed drops fast as the distance increases. At five feet you are looking at 57dpi. As your viewing distance increases you need less detail because the human eye can’t resolve anything finer. A billboard is often viewed at over a hundred feet and are often printed at 15DPI, yet they look good.

Now let’s bring this back to camera resolution and how large of a print you can make with your camera. I grafted two common resolutions,24MP and 45MP. I used the Canon R6II and R5 with 6000x 4000 and 8192 x 5464respectively.

At five feet, a common viewing distance, you can print a105in wide photo with a 24MP camera and a 143in wide with a 45MP camera and have sharp photos. This is without using any up sizing. For most of us, these are large prints, larger than we would ever make.

So how many megapixels do you really need. Not as many as you think. You are much better off putting the extra cash into a high-end lens that gives great resolution power like a Canon L series, Nikon “S”, Sony GMaster, or Sigma Art. Buy the camera body you can but invest in the glass! That said, to have a little breathing space to crop is not a bad idea, but unless you are making money with your camera, 24MP is plenty.

And just for fun, I did the math for a phone using specs for an iPhone 14 you need 2.96MP and the average 21in computer monitor a 9.44MPimage looks sharp.

For a real world example. If you have been to Schillers you have probable seen the photograph of the eagle we use to show a 30x40 Gallery Wrap print. That was taken with a 12MP camera. Take a look next time you are in and here it is with a detail shot so you can see how well you can still see the feathers. Sorry about the light glare.