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72 or 96 dpi?

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  #1  
Old 12-10-2009, 04:10 AM
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jarulex jarulex is offline
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72 or 96 dpi?

Hi Folks!
using Rapid Weaver I'm working in my new site.
My problem is: better-I mean for image's better quality- to save pics in 72 or 96 dpi?
Besides, 1): someone could tell me how many dpi newest monitors display?
2): someone could tell me if RW manipulates my pics 'reducing' from 96 to 72 dpi anyway?
Thanks in advance.
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Old 12-10-2009, 11:16 PM
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TommyO TommyO is offline
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Re: 72 or 96 dpi?

Jarulex,
I provided an answer on your other thread..... here.

I hope it is helpful.

Regarding your second question here, I have no clue... never used Rapid Weaver.
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Old 12-10-2009, 11:43 PM
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MiningArt MiningArt is offline
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Re: 72 or 96 dpi?

This is the best explanation that I have read about computer image display. In short dpi has no meaning to the display hardware, it displays pixels. You can prove this to yourself, make an image 800x600 pixels at 10 dpi and another at 800x600 pixels at 100 dpi. They will both display the same.

http://www.scantips.com/no72dpib.html

"The 72 or 96 dpi numbers are NEVER used to show images on the monitor screen. There is no concept of inches or dpi in the video system. Those logical inch dpi numbers are only used as a crude approximation to size text fonts on the screen.
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Old 12-11-2009, 12:12 AM
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seattle-light seattle-light is offline
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Re: 72 or 96 dpi?

Dear jarulex...

If you scale a 96x96 pixel image to fit into a 72x72 pixel square, then the computer needs to interpolate all the pixels on the fly (and the resulting quality on-screen will suffer as it tries to make it work when the pixel matrix is all wrong). The higher resolution will not give you better quality on screen, but it will increase download times.

Better to put images in at their actual pixel resolution. Not every system has 72 pixels per inch. For example, the iPhone has a much finer pixel matrix at 163 pixels per inch. But for display purposes a pixel is a pixel no matter what its size.

Some people use much bigger images and have their images redrawn to the proper scale (often defined by the size of the browser window -- as in garibaldi's site). I believe this resizing is done on the server side (but I could be wrong about that), but in any case it's a much more intensive operation. And there's something going on in between the larger image on file and what is finally displayed.

As for screen sizes, they are all over the map. No standard size. iPhone 480x320 pixels to the 30-inch Apple Cinema Display at 2520x1600 pixels. Trying to optimize for everything can be a mess. Make sure that what you do will work well on a Dell laptop and not look too stupid on a 24-inch iMac.

Hope you are doing well. Take care. Alan.
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Old 12-11-2009, 01:09 AM
Quantum3 Quantum3 is offline
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Re: 72 or 96 dpi?

Oh wise Alan, Son of Kunti! What's the PPI of the 21" Cinema Apple Display of Power?

Mart

Btw, I'm doing some cool electronic music by now, realli nteresting.

Have a good life!

Mart
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Old 12-11-2009, 01:11 AM
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TommyO TommyO is offline
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Re: 72 or 96 dpi?

Quote:
Originally Posted by MiningArt View Post
You can prove this to yourself, make an image 800x600 pixels at 10 dpi and another at 800x600 pixels at 100 dpi. They will both display the same.
What MiningArt says is true. This relates to the fact that a pixel itself does not have a defined size. In fact, pixel size within an image can vary quite widely. This is the whole concept behind Photoshop's resize image command when you turn OFF the resample checkbox. In this case, it adjusts pixels per inch by merely resizing the pixels. Make them too large and they begin to look like bricks.

PS... LCD displays and digital images use PPI; inkjet and laser printers use DPI.
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Old 12-11-2009, 01:20 AM
Quantum3 Quantum3 is offline
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Re: 72 or 96 dpi?

Oh yea, you can put 1 px and the image will look always the same, but don't print it! lol!
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Old 12-11-2009, 03:10 AM
photoart36 photoart36 is offline
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Re: 72 or 96 dpi?

Hi I think that seattle-light has given you the best information that you will get its informed and correct. Best regards from Photoart36
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