What size to post photos on the internet?

[donnaj]

Hello, I am not sure if I am in the right forum or not for asking this question. Sorry, I am new here.
I am wondering if someone can tell me what resolution is a good size for posting a photo, say, on facebook, so it isn't big enough for someone to right click and print a nice photo from it? Thank you very much.

 

[KmH]

Define 'a nice photo'.

If the photo is 600 pixels on the long side, they can get a print 6 inches wide at 100 pixels-per-inch (PPI), or a 12" wide photo at 50 PPI, or an 8" wide photo at 75 PPI.

This photo is 600 pixels by 400 pixels:

 

[Derrel]

Define 'a nice photo'.

If the photo is 600 pixels on the long side, they can get a print 6 inches wide at 100 pixels-per-inch (PPI), or a 12" wide photo at 50 PPI, or an 8" wide photo at 75 PPI.

This photo is 600 pixels by 400 pixels:

THAT IS A BEAUTIFUL old-fashioned grocery store Keith!@!

 

[Bossy]

The highest most (if not all) computer screens can reproduce is 72ppi. So there's no point in going higher than that. You can go lower, but your image quality can suffer, and regardless people will print it if they like it, even if its so pixelated it looks like the original mario.

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[The_Traveler]

The highest most (if not all) computer screens can reproduce is 72dpi.

Perhaps in 1982

 

[Bossy]

The highest most (if not all) computer screens can reproduce is 72dpi.

Perhaps in 1982

Did you get that from Google or did you actually have something productive to add to the conversation?
If I'm wrong, prove I'm wrong. I don't mind, I'm here to learn. I learned that from my professor in college, so if he's wrong I'm sure he'd want to know.

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[The_Traveler]

Just correcting a misstatement.

for the OP

Most screens used today are at least xga which displays 1024 x 768 pixels regardless of their physical size.

For display most forums have either a fixed maximum size or, as this one does, allows you to display pictures at your desired size.
Most people resize their posts to about 1000 wide x 700 high as that fits in the majority of display screens.
Since printing decent prints requires about 2 or 3 times the resolution of a typical screen, putting up prints this size makes them reasonably safe from being stolen and printed altho people can still redisplay them on a computer screen.

 

[Bossy]

Just correcting a misstatement.

for the OP

Most screens used today are at least xga which displays 1024 x 768 pixels regardless of their physical size.

For display most forums have either a fixed maximum size or, as this one does, allows you to display pictures at your desired size.
Most people resize their posts to about 1000 wide x 700 high as that fits in the majority of display screens.
Since printing decent prints requires about 2 or 3 times the resolution of a typical screen, putting up prints this size makes them reasonably safe from being stolen and printed altho people can still redisplay them on a computer screen.

Ok. But you can have an image at 1000x700 at 72ppi as well as 1000X700 at 300ppi. So what PPI are you saying to post at.

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[KmH]

Define 'a nice photo'.

If the photo is 600 pixels on the long side, they can get a print 6 inches wide at 100 pixels-per-inch (PPI), or a 12" wide photo at 50 PPI, or an 8" wide photo at 75 PPI.

This photo is 600 pixels by 400 pixels:

THAT IS A BEAUTIFUL old-fashioned grocery store Keith!@!

Actually, it's an old-fashioned blacksmith shop - State Historical Society of Iowa

 

[KmH]

The highest most (if not all) computer screens can reproduce is 72ppi. So there's no point in going higher than that. You can go lower, but your image quality can suffer, and regardless people will print it if they like it, even if its so pixelated it looks like the original mario.

PPI is meaningless for electronic display, so it can be set to any value and the image size will not change, unless it's automatically resized by a web sites software. Like I mentioned in my post, once copied the thief could change the PPI to any value.

I have a 22"(diagonal) main computer display. It is configured to display 1600x1200 pixels. The display has a horizontal dimension of 18.625".
1600 pixels divided by 18.625 inched = 86 PPI....Not 72 PPI.

I can change how many pixels my display shows, within limits, thus changing the PPI resolution to some other value.

In short, the only way to determine the resolution of a display is to measure the width or height of the display and divide by the pixel dimensions the display is set to.

 

[Bossy]

The highest most (if not all) computer screens can reproduce is 72ppi. So there's no point in going higher than that. You can go lower, but your image quality can suffer, and regardless people will print it if they like it, even if its so pixelated it looks like the original mario.

PPI is meaningless for electronic display, so it can be set to any value and the image size will not change, unless it's automatically resized by a web sites software. Like I mentioned in my post, once copied the thief could change the PPI to any value.

I have a 22"(diagonal) main computer display. It is configured to display 1600x1200 pixels. The display has a horizontal dimension of 18.625".
1600 pixels divided by 18.625 inched = 86 PPI....Not 72 PPI.

I can change how many pixels my display shows, within limits, thus changing the PPI resolution to some other value.

In short, the only way to determine the resolution of a display is to measure the width or height of the display and divide by the pixel dimensions the display is set to.

But if you change the ppi from say, 72 to 300, wouldn't that be upsizing and you'll have a not so great image? Or is a basic free program capable of reducing pixel size without loss?

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[The_Traveler]

But if you change the ppi from say, 72 to 300, wouldn't that be upsizing and you'll have a not so great image? Or is a basic free program capable of reducing pixel size without loss?

Don't think about PPI unless you are printing, then it is important to have 250-300 PPI to have a nicely resolved print.
PPI doesn't mean anything in web display.
Only think in terms of number of pixels on a side.

 

[Derrel]

Define 'a nice photo'.

If the photo is 600 pixels on the long side, they can get a print 6 inches wide at 100 pixels-per-inch (PPI), or a 12" wide photo at 50 PPI, or an 8" wide photo at 75 PPI.

This photo is 600 pixels by 400 pixels:

THAT IS A BEAUTIFUL old-fashioned grocery store Keith!@!

Actually, it's an old-fashioned blacksmith shop - State Historical Society of Iowa

I think you missed the joke there...

 

[Bossy]

I missed the joke too :/

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[Bossy]

But if you change the ppi from say, 72 to 300, wouldn't that be upsizing and you'll have a not so great image? Or is a basic free program capable of reducing pixel size without loss?

Don't think about PPI unless you are printing, then it is important to have 250-300 PPI to have a nicely resolved print.
PPI doesn't men anything in web display.
Only think in terms of number of pixels on a side.

What am I looking at when I see pics on the internet that are pixelly? Does that not have to do with re/ppi?

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