How many pixels in a megapixel?

M

mrbrycel

Well-known member
I never understood how the term megapixel was used. I always see it on digital still cameras, but I never know what the actual ___x___ pixel resolution of say a 10 megapixel camera's photo is.

Also, are there digital still cameras yet that have passed 35mm film in quality? Or will that never happen? Because can't film be scanned to whatever resolution you want?
 
According to Kodak, as far as strictly resolution goes, 35mm movie film is about equivalent to 12 megapixels. That would put 35mm still film at around 24 megapixels. Film is constantly being improved, as is digital.

A "megapixel" means a million pixels on the chip, but it doesn't imply the ratio. So a 10-megapixel chip, in a square configuration, would be about 3300 x 3300. If it's in a 3:2 ratio, it might be something like 3600 x 2700.
 
Cubit is the length from the tip of the middle finger to the point of the elbow on a hebrew male, this is the type of sensor the new Scarlett cameras will have, something like 6 cubitpixel chips.
 
I read an article on the web about a gigapixel still camera the government uses. It's probably the one that can read a license plate from outerspace.
 
There's an interesting rough rule of thumb for still images that are printed...

An image looks sharp if the the number of pixels per inch is 250 or higher.


Assuming you had a 4" by 6" print:
4" x 250 = 1,000 and 6" x 250 = 1,500: Thus 1,000 x 1,500 = 1,500,000 or 1.5 MP (Mega pixels)
So a 2MP camera will produce very nice 4" x 6" prints...


Assume 5" by 7" print:
5" x 250 = 1250 and 7" x 250 = 1,750: Thus, 1250 x 1750 = 2,187,500 or 2.2 MP
A 2MP camera falls just a bit short, but a 3MP camera will work nicely.


Assume 8" x 10" print:
8" x 250 = 2,000 and 10" x 250 = 2,500: Thus, 2,000 x 2,500 = 5,000,000 or 5 MP
A 4MP camera falls a bit short, but a 5MP camera works very nicely.


Assume 11" x 14" print:
11" x 250 = 2,750 and 14" x 250 = 3,500: Thus, 2,750 x 3,500 = 9,625,000 or 9.6MP
A 9 MP camera might be a bit short of the mark, but is likely to be close enough.


One big issue is that as we move to the larger print sizes, the lenses of the low cost cameras might not fully resolve all the pixels. That is the image sensor has all the pixels, BUT the lens can NOT show all the detail.

If you must shoot big prints, go for the larger image sensors and better lenses; go for the Digital SLRs.


Bob Diaz
 
Drew Ott said:
So... about how many megapixels is this camera equivalent to?

http://www.polaroid.com/studio/20x24/
Click to expand...

Imagine a camera that stands 5-feet (150 cm) high and weighs 235 pounds (106 kg). Big, bulky and beautiful! At least that's what people say about it, especially after seeing the gorgeous, superbly detailed, color and black-and-white 20x24-inch (50x60 cm) prints it produces.
Click to expand...


Let's see, 6,000 h x 4,000 v = 24,000,000 or 24 MP

Given that 35mm film is 36mm x 24 mm

6,000 / 36mm = 167 pixels per mm
4,000 / 24mm = 167 pixels per mm

50 cm = 500mm
60 cm = 600mm

600mm x 167 pixels per mm = 100,200 pixels
500mm x 167 pixels per mm = 83,500 pixels

100,200 x 83,500 = 8,366,700,000 pixels or 8.4 GP


Bob Diaz
 
Barry_Green said:
According to Kodak, as far as strictly resolution goes, 35mm movie film is about equivalent to 12 megapixels. That would put 35mm still film at around 24 megapixels. Film is constantly being improved, as is digital.

A "megapixel" means a million pixels on the chip, but it doesn't imply the ratio. So a 10-megapixel chip, in a square configuration, would be about 3300 x 3300. If it's in a 3:2 ratio, it might be something like 3600 x 2700.
Click to expand...

Barry, forgive me being extremely clueless, but a 35mm movie frame is actually smaller than a 35mm still frame? I didn't even know that. A 35mm still frame is 35mm wide right? What are the dimensions of a 35mm movie frame?
 
Yes, a 35mm movie frame is half the size of a 35mm still frame. The film is the same (35mm from edge to edge) but in movies the film runs vertically, so the frame is as wide as the sprocket holes (max. of about 24mm x 18mm). In still photography the film runs horizontally, so the space between the sprocket holes is used for the height, so you get a frame of 36mm x 24mm. Twice the size of the 18x24mm of movie film.
 
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