How do I figure out how many mega pixels a photo is?
Apr 12, 2018 18:27:34 #
RichardTaylor wrote:
No.
PIXELS have no size! They are just numbers that define color and brightness values. You can scale them to any number of pixels per inch (PPI) then represent them with ink dots or dye spots at the printer’s output dots per inch (dpi).
Sensor sites DO have size, measured in microns.
Apr 12, 2018 18:41:15 #
Just Fred wrote:
I appreciate the answers to this, but doesn't pixel size have something to do with this?
No.
Apr 12, 2018 19:01:50 #
Ok, you have been explained the megapixel size and the megabyte size, and their meanings, but think the real question here is whether a 3456x1584 pixel photo is a "good size"? The answer is "good size for what?" If printing a 4"x6" photo, maybe/probably. If printing 8x10, a poster, use in high-end publication, etc. probably not. It would need to be twice those numbers. So, you need to define from your buyer what they consider "good size", or better yet "good quality"?
Apr 12, 2018 19:26:46 #
Stardust wrote:
Ok, you have been explained the megapixel size and... (show quote)
Uh, no.
An 8x10 at extinction resolution (the resolution beyond which more pixels don’t make any visible difference) requires 240 PPI coming from the camera’s original file. That’s 1920x2400.
At the digital lab where I ran the image adjustment and printing areas, our standard was 250 PPI for 8x10s. We printed millions of every size from sub-wallets to 11x14s, from lightly cropped 8.2MP (or larger) originals.
Many editors and graphic designers do ask for more, i.e.; 300 PPI, just to be sure they can crop and/or enlarge an image. But unless they need to crop or enlarge, they don’t need 300 PPI.
Apr 12, 2018 20:41:46 #
tita1948 wrote:
Yes it dies. I have been ask to sell a picture but it has to be a good size. I'm guessing at least 5 or 7 mega pixel. When I looked at my Meta data it said 2.85 mg. But according to the example that I was given it equate to 5.47.
The 2.85 megabit file should be large enough. If not they will let you know.
Apr 12, 2018 22:02:08 #
Apr 13, 2018 06:58:51 #
CHG_CANON wrote:
Now that you know the megapixel count, how does this information help? There's probably another reason / question that prompted this query about the dimensions 1584x3456. Can we help with the 'other' question?
It helps because he had a question. Perhaps you should submit to him questions that you think he should ask.
Apr 13, 2018 08:16:27 #
Here's my mathematics lesson for today:
The pixel size is the number of pixels in the image. Think of it as a rectangle, where the length & width are 3456 and 1584 pixels. The area of that rectangle is 3456 x 1584 or 5,474,304 pixels. Mega means millions. To convert the total pixels (5,474,304) to mega pixels (millions of pixels) divide the total by 1,000,000. Consequently, an image with dimensions of 3456 by 1584 is 5.474304 or about 5.5 mega pixels. "Capish"?
Mark
The pixel size is the number of pixels in the image. Think of it as a rectangle, where the length & width are 3456 and 1584 pixels. The area of that rectangle is 3456 x 1584 or 5,474,304 pixels. Mega means millions. To convert the total pixels (5,474,304) to mega pixels (millions of pixels) divide the total by 1,000,000. Consequently, an image with dimensions of 3456 by 1584 is 5.474304 or about 5.5 mega pixels. "Capish"?
Mark
tita1948 wrote:
I hate to bother you but if you have the time please answer. I have a picture that in my meta data it says 1584x3456. How do I transform this into mega pixels?
Thank you.
Thank you.
Apr 13, 2018 08:31:58 #
One thousand bytes (a kilobyte) is 1024 bytes not 1000. So the width(in pixels) times the height(in pixels) divided by 1024.
Apr 13, 2018 08:56:02 #
tita1948 wrote:
I hate to bother you but if you have the time please answer. I have a picture that in my meta data it says 1584x3456. How do I transform this into mega pixels?
Thank you.
Thank you.
Lightroom Library module metadata right panel shows the pixel dimensions and at the top the megapixel total. You can also export the image and get info from your Finder (mac) and PC equivalent.
Apr 13, 2018 09:14:59 #
If you have Photoshop or any good image editing program, you can open the photo and look for image size and it will tell you the size in pixels or inches and megabytes (and probably a bunch of other measurements).
Apr 13, 2018 09:20:50 #
TheDman
Loc: USA
CPR wrote:
One thousand bytes (a kilobyte) is 1024 bytes not 1000. So the width(in pixels) times the height(in pixels) divided by 1024.
You're confusing bytes and pixels.
Apr 13, 2018 09:44:21 #
TheDman wrote:
You're confusing bytes and pixels.
Does the amount of light and dark areas in the capture effect the number megapixels or the megabytes? Or both? Or neither?
Apr 13, 2018 10:12:09 #
gvarner
Loc: Central Oregon Coast
tita1948 wrote:
Yes it dies. I have been ask to sell a picture but it has to be a good size. I'm guessing at least 5 or 7 mega pixel. When I looked at my Meta data it said 2.85 mg. But according to the example that I was given it equate to 5.47.
Be careful, you're confusing abbreviations. Megapixels is MP, megabytes is MB. A photo file dimension, length X height, is measured in pixels, it's file size or volume is measured in bytes. A reference to "good size" for a potential sale is for its file size in megabytes. Your metadata gives you both pixel dimensions and file size. Beyond this, the discussion gets very very technical. Hope this helps.
Apr 13, 2018 10:24:56 #
Just Fred wrote:
I appreciate the answers to this, but doesn't pixel size have something to do with this?
My understanding is that not all pixels are created equal. The larger - or deeper - the pixel, the more data. So you may have a 5 MP image and be able to print a 4x6 nicely. Or you may have a 5 mp image and be able to print a 16x20. I think (but am not sure) that the depth of the pixels will show when translated to megabyte size.
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