Megapixels versus Lens optics

So are you planning to buy a new digital camera for Christmas? Like most electronics there are a ton of things to consider. One thing that often misguide consumers is the message “The most megapixels win”. Older Digital single lens reflex cameras (DSLR) can take on modern compact digital cameras any time. The true limit of the camera is the optics of the lens.

A lens that is made from low quality glass (or plastic!) will simply take less good pictures than a camera with a great lens. High quality lenses can take sharper pictures up close and far away.

Still, megapixels are not at all irrelevant. They determine how large images your cameras image sensor can save. Image sensors can also be in different sizes but let’s not touch that now. A 8 megapixel camera can take photos up to 3456 time 2304 pixels. That’s more than enough to print your photo on a 24 times 15 inch poster!

Megapixel count is still broadcasted as a competitor edge for mobile phone cameras and cheap compact cameras. The truth is that these cameras have small portable optics that work fine for your party photos or your vacation photos. Your images will print fine in smaller formats and will look good on web pages, but not on high quality printing products.

There are of course many more aspects that will put a DSLR above the smaller cameras, like aperture, shutter, ISO sensitivity and more. Those will not be covered here. The main lesson learned is: Don’t let the megapixels fool you! :)

Have a nice day.

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aodesign 10 years ago

my Sony A900 has far more detail (24mp) when compared to my A200 (10,1MP) with the same 2,8 lens... so mp, DOES matter.


smyles 10 years ago

A 6MP + good glass owns 20MP + cheap glass any day.

Why? The lens is the eye. In the "olden days", film got better, but if a lens was poor, images did not.

I nearly jumped from a Canon 10D to a 30D (6 to 8MP), but got a 24-105L instead (up from a 28-135IS). Quality is phenomenal (pretty good before, but holy moly). I've done 24x36 from 6MP, and blow up small areas, too. Razor sharp isn't always everything.

I have a 40D now (10MP), 100-400L and 50 1.4, and I'm still ecstatic about IQ. Even with 15 or 20MP, these lenses will still shine.

So, if you're thinking DSLR, budget for good glass first, even if it means last year's body to lower $. Save upgrade 'til pixels go up >50%. Any less, you won't see a difference. In fact, you may be disappointed; more pixels highlight lens limits and flaws.

My $0.03 (always give a bit more than expected).

Cheers to all.

(Perpetually under construction, please excuse the mess!)


aodesign 10 years ago

well, if you plan on cropping, the mp amount is quiet important


CLOSED USER 10 years ago

(user closed)

Björn Fant

Björn Fant 10 years ago

darrask: yes, the size of the image sensor is important. If it is more important than the lens is up for discussion from case to case I would say.


darrask 10 years ago

What determines image quality even more than lens quality is the surface available for each pixel, and hence how much light it gathers.
This is what makes the difference between SLR and compact cameras which share the same pixel count.
Lens quality can be quite nice on compacts, with wider apertures and longer zooms, and increasingly wider at the short end.

greg benic

greg benic 10 years ago

perhaps we should start a film revolution and forget megapixels altogether! :-)