Home
>
Photography
>
Why 1.5 Megapixels is Enough

Why 1.5 Megapixels is Enough

Dots Per Inch is a useful measure of relative resolution. But if you don't know the image size in inches or some other measure of size, then the amount of dots per inch doesn't mean much. That's why DPI is used in conjunction with scanner Specifications, because you know that the size is going to be 3.8 by 1.7 inches!

Different resolutions are used for different purposes. 72 or 75 DPI for screen viewing; 250 for digital photography and 300 dpi for printing. See how this is a nice comparison, yes, you can get away with 50 less pixels per inch in your photographs than would be required for A4 printing, this is because of the physical size of the photo!

Dots Per Inch specifies how much information is resolved in a picture, whereas the number of megapixels is usually used to describe the total output size (in pixels) of an image.

Example: I want to reproduce the standard photograph size. This would be 6 by 4 inches. Digital photography requires a minimum of only about 250dpi, So: 6 * 250 = 1500 and 4 * 250 = 1000, so you need an image sized about 1500 * 1000 pixels (about 1.5 megapixels). Thus you can get a perfectly good standard print from a 1.5 megapixel camera!

If you take a photo twice, one at 5 and the other at 1.5 megapixels, than ask your self which one looks "better"? They will both look reasonable because your computer generates colours such that the image looks better than it really is; if you were to print both as a 6 by 4 image, they will look identical, because your printer can't generate more than 300 dpi so the "better" image is effectively reduced in quality anyway. This example demonstrates how it is possible to literally waste memory, ie for everyday use the additional memory required for the other 4 megapixcels gives you no real benefit!

This is quite good because a 36 Megabyte media card can store 50 to 65 images at 1.3 megapixcels but only 8 to 10 at 5 megapixcels, so unless you are planning on getting your images printed larger than 6 by 4 there's no real advantage to the full 5 megapixcels.

Now we have established that a 1.5 megapixel camera will produce a 6 by 4 inch standard photograph, that is, it will generate a resolution such that each pixel is simply reproduced "as is", we come to the more interesting issue of enlargement.

If you wanted to print your 6 by 4 inch image as a 10 by 8 photo (which would normally need the full 5 megapixels), there would not be a sufficient number of pixels for the additional surface area, so we now need to scale up the existing pixels by "resampling" the existing pixels, a process which estimates how the "missing" pixels should appear, and fills them with the appropriate "colour". A 25% resample

I am the website administrator of the Wandle industrial museum (http://www.wandle.org). Established in 1983 by local people to ensure that the history of the valley was no longer neglected but enhanced awareness its heritage for the use and benefits of the community.

Hanover Park shuttle to O'Hare .. Lockport Chicago limo O’Hare

In The News:

Tech expert Kurt “CyberGuy" Knutsson urges you to use Apple’s App Privacy Report to see what your apps are really up to.

Tech expert Kurt “CyberGuy" Knutsson talks about how to smoothly transfer your data from an old laptop to a new one using cloud storage or external drives.

Kurt the CyberGuy offers tips to safeguard your personal information as scammers become more sophisticated with scam texts and other methods.

WeRide's unmanned electric delivery van, the Robovan W5, has 194 cubic feet of cargo space and can carry payloads up to about 2,205 pounds

Kurt the CyberGuy recommends deleting 16 browser extensions immediately in response to a report saying more than 3.2 million web users were affected by a security breach.

Stay up to date on the latest AI technology advancements and learn about the challenges and opportunities AI presents now and for the future.

A robotics firm in China claims a robot has performed the world's first humanoid robot front flip, which is significantly more difficult than a backflip.

A digital ID may be even more secure than a physical ID. Storing your driver's license in your Apple Wallet is an ideal solution for commuters.

A cybersecurity firm has shed some light on just how common tax scams have become. Kurt the CyberGuy offers his advice for how to protect your refund.

Lifesize Plans offers immersive walk-throughs that allow customers the opportunity to tour a home's design before construction actually begins.

Stay up to date on the latest AI technology advancements and learn about the challenges and opportunities AI presents now and for the future.

A man invested $4 million in bitcoin and lost it all with a single click when he was targeted by a vishing scam, which uses phone calls to trick people.

Expandable's Touchdown is a designer trailer that promises a luxury off-grid living experience and unfolds into a home in about 15 minutes.

Major employee screening company data breach affects 3.3 million people. Tech expert Kurt “CyberGuy" Knutsson explains what happened and gives five ways to protect your data.

Kurt “CyberGuy" Knutsson reveals mind-blowing tech that gives you sunlight on demand.

New malware "FrigidStealer" targets Mac computers. Tech expert Kurt “CyberGuy" Knutsson offers four ways to stay safe from infostealer malware.

Kurt “CyberGuy" Knutsson talks about how lab-grown muscles power a biohybrid hand for scalable prosthetics and research.

Reports of task scams have significantly risen in the past four years, according to the Federal Trade Commission. Kurt the CyberGuy offers some red flags.

iPhones have a hidden folder that eats up storage without you knowing it. Kurt the CyberGuy offers some tricks to free up storage on your device.

A recent ransomeware attack targeted Zacks, an American investment firm, and a cybercriminal claimed to have stolen records for millions of customers.

Stay up to date on the latest AI technology advancements and learn about the challenges and opportunities AI presents now and for the future.

Researchers unveiled a new soft prosthetic hand that combines the natural coordination patterns of our fingers with the decoding of motoneuron activity in the spinal column.

Accidentally deleting a text message on your iPhone or iPad is not a problem if you still need the message. Apple has a built-in way to recover it.

Just two months into 2025 there have been numerous Mac malware threats targeting Apple laptops, ranging from infostealers to malicious software.

A self-driving electric bus powered by artificial intelligence has an electric powertrain for zero-emission operation and an automated drive system.

Why 1.5 Megapixels is Enough

Photography