Camera lens or megapixel value: which defines the quality and clarity of the picture?
I have a 5MP camera in my phone. The pictures shows good clarity both in the phone screen and my computer screen. But one of my friends has a different camera with the same 5MP in his phone (brand is different and a new one). But the photos taken with that camera are not as good quality when viewed in computer screen. We didn't use digital zoom (since we heard digital zoom reduce the quality).
Why is one 5MP camera so much better than the other? I think not only the megapixel values but also camera lens needs to be considered while buying a camera... right?
This isn't quite a duplicate of Do megapixels matter with modern sensor technology? but learning that should help you understand _this_ better.
Also worth considering, are you viewing the photos zoomed out to for example fill the screen, or are you viewing them at 100% crop? Hardly anybody views photos at 100% on a computer screen, unless perhaps they are into truly detailed digital retouching work.
You're right. Picture quality is as complex as, say, how well a food item tastes. Megapixels only tell you the number of pixels the picture is made up of, and more is certainly not always better. More pixels on a small sensor means more noise. Megapixels are often used by marketing just because people want simple truths, like 18 MP must be better than 10. However, that's like comparing two cups of coffee based on the quantity in the cup - and saying the one with more in the cup must be better. But, how does it actually taste?
So, like the coffee, what those pixels contain is the critical part. Of course, it needs to be said, what is meant by quality is also subjective. Instagram filters for example often simulate old camera defects, like vignetting, noise and color shift, still they often come across as great looking photos, right?
Underexposed photo with dark corners, i e vignetting. Originally a lens imperfection, it's often used creatively because it helps frame the picture.
Anyhow, subjectivity out of the way. Main factors for pure image quality are:
- Sensor quality (low noise, high dynamic range, and so on - all of which get better with a large sensor)
- Lens quality (sharpness, lack of chromatic abberation, quality of bokeh etc)
- Camera firmware, i e ability to use RAW format, or create JPEG files with good quality.
Also, it's important to understand that lighting plays a HUGE role in how the photo turns out, so if your friend shoots indoors and you outdoors for example, yours are likely going to look infinitely more high quality. Cameras wanna bathe in light! Here's a guy even doing a fashion shoot with his 3 Megapixel iPhone 3GS, and it looks absolutely stunning thanks to high quality lighting, and the camera being just good enough to capture it. https://fstoppers.com/editorial/iphone-fashion-shoot-lee-morris-6173
There's definitely a lower threshold for being able to capture that, and I'd say an old Nokia phone from the late-mid 2000's would still show pretty low quality even in great lighting, it's just really a bad camera.
To put this into perspective, 2MP = 2 Mega Pixel = 2 million pixels = 1920*1080 = Full HD. I'm not a photographer (nor do I know a thing about photography), but as a programmer I know Full HD is more then enough to create a sharp image with lots of detail (might be different for a photo, but still 5MP should be the highest you will ever need for non-billboard photos).
@Kevin Well, you're partly right. Most images we're used to seeing on the web though, are scaled down from 3-24 MP photos. A photo viewed 100% zoom level doesn't look that great generally, but scaled down they do, so you "need" a higher MP count. And for print there's the 300DPI thing, which puts much higher demand on resolution. There are many reasons for having a higher MP count than 5, but I guess that's a whole other discussion.
@Jan'Saffi'Stekelgunsson "all of which get better with a large sensor" but sensors don't (always) get larger with higher megapixel count.
@Calimo - Yes, you are correct. And it's been discussed to death. Eg. here: http://photo.stackexchange.com/q/14773/15918
More pixels also allow you to shoot wide and then crop later, which is very valuable as you don't always have the luxury of perfectly framing your shot before opening the shutter.