Very strange pic question!!??
Discussion
Below are 2 images. The first is saved as a jpg 702x750 pixels and 250kb saved and worked in PS CS
The 2nd is the same picture, opened in PS6 and then resaved as a different name from within PS6. It is also 702x750 and 250kb.
[pic]http://i11.photobucket.com/albums/a169/Mr_Noble/DevilCat.jpg[/pic]
[pic]http://i11.photobucket.com/albums/a169/Mr_Noble/Cat.jpg[/pic]
Now, why the f*** (excuse me but I have just spent over an hour trying to work this out) would one image be 6cm wide on this screen and the other 15cm wide????
They are both exactally the same, hosted next to each other etc etc. Only difference is that I tried saving the 2nd through my old PS6 programme rather than my new PS CS one!!
Please someone explain, I feel soooo stooopid!
Greg
The 2nd is the same picture, opened in PS6 and then resaved as a different name from within PS6. It is also 702x750 and 250kb.
[pic]http://i11.photobucket.com/albums/a169/Mr_Noble/DevilCat.jpg[/pic]
[pic]http://i11.photobucket.com/albums/a169/Mr_Noble/Cat.jpg[/pic]
Now, why the f*** (excuse me but I have just spent over an hour trying to work this out) would one image be 6cm wide on this screen and the other 15cm wide????
They are both exactally the same, hosted next to each other etc etc. Only difference is that I tried saving the 2nd through my old PS6 programme rather than my new PS CS one!!
Please someone explain, I feel soooo stooopid!
Greg
I think the dpi settings are the same. I always change it to 750 pixels wide (landscape) or high (portrait) and then save as a tiff or jpg.
Can't think why a PS CS image would be resized to 6cm wide and a PS6 image becomes about 15 cm wide once uploaded to photobucket.
Very odd, but I am sure someone on here will tell me the answer.
Nothing to do with constrain proportions is it?
Greg
Can't think why a PS CS image would be resized to 6cm wide and a PS6 image becomes about 15 cm wide once uploaded to photobucket.
Very odd, but I am sure someone on here will tell me the answer.
Nothing to do with constrain proportions is it?
Greg
Same sizes as Simpo Two here.....
My guess is that it is what Photobucket has managed to do to it.
If you notice, when you upload to Photobucket it lets you know it will resize >250Kb files. In my experience it will (though I don't know why) resize to something smaller. My guess is it is to do with the JPEG compression and therefore the file size. As Photobucket doesn't change teh JPEG compression, presumably it decimates the pixel numbers???
Does that make any sense to anyone?
My guess is that it is what Photobucket has managed to do to it.
If you notice, when you upload to Photobucket it lets you know it will resize >250Kb files. In my experience it will (though I don't know why) resize to something smaller. My guess is it is to do with the JPEG compression and therefore the file size. As Photobucket doesn't change teh JPEG compression, presumably it decimates the pixel numbers???
Does that make any sense to anyone?
If they're around the 250K mark, and you've saved them on photobucket, then one might have gone over some magic limit and been automatically resized. The online galleries are 'helpfull' (read: bl**dy minded and unpredictable) like this. To keep their bandwidth down, they may automatically edit your pictures to reduce file and image size.
Pixels and DPI should not be confused. Pixels define the amount of information (square blocks of colour) that make up the image. The more pixels, the larger the file.
Computer screens are typically between 1024 and 1992 pixels wide, and 768 to 1024 pixels high. For most people, an image 800x700 will take up the majority of their screen at 'full size'. Anything above 2000 pixels is too big for the vast majority of computer monitors. The most common monitor size is still barely above 1024 x 768 - which in camera terms is less than a megapixel.
DPI defines the number of dots per inch - it does nothing to the image, but is the expected number of pixels per inch that the image is displayed/printed at. So if you have an image 750 pixels wide, and print it at 250 DPI, it will be 3" wide (750/250). Monitors typically are around 75 DPI - so the same image will display as 10" across. On paper, the human eye works best with 300DPI upwards - we can see higher resolutions, but block colour at 300DPI will look smooth to most people. When you set the DPI in Photoshop, it uses the information it has about your monitor and tries to display the image at 'real' size - so if you set your image as 300DPI, and you have a 75DPI monitor it will actually scale it down to 25% to show it accurately. The theory is that when you print it, the same calculation will be made and it will end up the same size on the paper as it is on screen (if your screen and printer are both properly calibrated). Setting DPI doesn't change the number of pixels, it just tells programs that care how many pixels should be fit into each inch of display/paper.
The point is that DPI only controls print and display sizes and ONLY if you view the image in a paint program that has been correctly set up. Setting DPI does not control how large an image is when someone views it on the web, or in a slideshow program. Web browsers display images at whatever is the native resolution of the screen that the browser shows on. One pixel of image = one pixel of display. That means that typically images are shown at or a little above 75DPI (the most common screen pitch), and a 750 pixel image will take 10" of screen.
When saving as JPG you can decide the amount of compression, which also affects file size. However, JPG compression damages your images - the higher compression, the more damage you will see. JPG is cleverly designed to cause the least noticable damage, and at normal compression rates you'll not really notice the difference. Saving as Raw doesn't compress the image, so no damage is done. Pro photographers care about raw for two reasons: (1) Raw allows different bit depths, which become important when you need to recover photos with high dynamic range, or when you want to print (as professional printers show a much higher range of colours than a computer monitor). (2) Each time you re-save a JPG image, more damage is done on top of the damage that was previously saved. If you therefore edit your images extensively, saving and reloading them, the quality will steadily decline. Again, this doesn't really matter when the images are shown on screen (unless the compression is set really high), but matters a lot for print images.
Pixels and DPI should not be confused. Pixels define the amount of information (square blocks of colour) that make up the image. The more pixels, the larger the file.
Computer screens are typically between 1024 and 1992 pixels wide, and 768 to 1024 pixels high. For most people, an image 800x700 will take up the majority of their screen at 'full size'. Anything above 2000 pixels is too big for the vast majority of computer monitors. The most common monitor size is still barely above 1024 x 768 - which in camera terms is less than a megapixel.
DPI defines the number of dots per inch - it does nothing to the image, but is the expected number of pixels per inch that the image is displayed/printed at. So if you have an image 750 pixels wide, and print it at 250 DPI, it will be 3" wide (750/250). Monitors typically are around 75 DPI - so the same image will display as 10" across. On paper, the human eye works best with 300DPI upwards - we can see higher resolutions, but block colour at 300DPI will look smooth to most people. When you set the DPI in Photoshop, it uses the information it has about your monitor and tries to display the image at 'real' size - so if you set your image as 300DPI, and you have a 75DPI monitor it will actually scale it down to 25% to show it accurately. The theory is that when you print it, the same calculation will be made and it will end up the same size on the paper as it is on screen (if your screen and printer are both properly calibrated). Setting DPI doesn't change the number of pixels, it just tells programs that care how many pixels should be fit into each inch of display/paper.
The point is that DPI only controls print and display sizes and ONLY if you view the image in a paint program that has been correctly set up. Setting DPI does not control how large an image is when someone views it on the web, or in a slideshow program. Web browsers display images at whatever is the native resolution of the screen that the browser shows on. One pixel of image = one pixel of display. That means that typically images are shown at or a little above 75DPI (the most common screen pitch), and a 750 pixel image will take 10" of screen.
When saving as JPG you can decide the amount of compression, which also affects file size. However, JPG compression damages your images - the higher compression, the more damage you will see. JPG is cleverly designed to cause the least noticable damage, and at normal compression rates you'll not really notice the difference. Saving as Raw doesn't compress the image, so no damage is done. Pro photographers care about raw for two reasons: (1) Raw allows different bit depths, which become important when you need to recover photos with high dynamic range, or when you want to print (as professional printers show a much higher range of colours than a computer monitor). (2) Each time you re-save a JPG image, more damage is done on top of the damage that was previously saved. If you therefore edit your images extensively, saving and reloading them, the quality will steadily decline. Again, this doesn't really matter when the images are shown on screen (unless the compression is set really high), but matters a lot for print images.
Mr Noble said:
John,
When posted, they are both exactally the same. As the chap above says, when you save them to your desktop, they are both the same size.
I am still very confused.
Greg
I saved them to desktop, and they came out big and small, I blame the gremlins...... bring back 35 mm I say..
Thank you very much for the in-depth lesson Tuna, very helpful and very well written for a layman like me!
I do just about understand all this, its not a problem to do with photobucket or resizing issues.
The problem is that simply, I currently run Photoshop CS and Photoshop 6.
If I open an image, make it 750 pixels wide save it and post in photobucket..........PS6 makes it look big on PH and PS CS makes it look small.
No other changes, the difference is solely dependant on which programe I happen to be using!
Thats the odd bit!
Help!
Greg
I do just about understand all this, its not a problem to do with photobucket or resizing issues.
The problem is that simply, I currently run Photoshop CS and Photoshop 6.
If I open an image, make it 750 pixels wide save it and post in photobucket..........PS6 makes it look big on PH and PS CS makes it look small.
No other changes, the difference is solely dependant on which programe I happen to be using!
Thats the odd bit!
Help!
Greg
Mr Noble said:
If I open an image, make it 750 pixels wide save it and post in photobucket..........PS6 makes it look big on PH and PS CS makes it look small.
No other changes, the difference is solely dependant on which programe I happen to be using!
Er - you've lost me here. Are you saying that PS6 defaults to a different "size" than CS? Just change each to "actual pixels" surely???
or are you saving as a JPEG at different compressions with each program? Then the one at higher quality is being re-sized to make it sub 250k by bucket?Tried it saving them both as tiffs and it was exactally the same.
It is as odd as it sounds and I am not a numptie (i hope).
PS CS seems to do something odd that PS6 doesn't. I am sure I always set the save size to 12 or max and have tested it with everything the same.
I did wonder if it could be something to do with the constraint proportions or something. Only thing I have not tested.
Making me go
It is as odd as it sounds and I am not a numptie (i hope).
PS CS seems to do something odd that PS6 doesn't. I am sure I always set the save size to 12 or max and have tested it with everything the same.
I did wonder if it could be something to do with the constraint proportions or something. Only thing I have not tested.
Making me go
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