Screen resolution

Perhaps those who are more computer savvy than me (most I would suspect) could answer this question.

If i have my screen resolution set to 1024x768, and i place a picture on the desktop that is 3008x2008, what happens to the "excess" pixels. Does the screen "compress" the pixels or actually discard some pixels ?

Sorry if this is a silly question ?

If i am not mistaken you can Check an option in your display properties to allow it to fit the window other wise it crops it back to fit. I could be wrong but i cant access the display properties on my work computer to check.

Clarky

If I select "stretch" in the display properties window, the screen resizes the picture to show it in its entirety. In this case it is sowing a 3008x2008 pixel image in a 1024x768 pixel space.

No it's not.

It's showing a 1024x768 pixel image in a 1024x768 pixel space.

The original may have been 3008x2008, but what you're seeing isn't that.

This is why people claiming to be able to compare anything but the grossest of sharpness differences by looking at full frame images on a computer screen are sadly mistaken.

It's not the screen that does it. It's whatever software is converting the graphics file for screen display, and/or whatever the graphics card hardware does. But the excess pixels are discarded, and/or replaced with averages of the neighbouring ones.

No such thing as half a pixel.

So does that mean that the screen disregards some of the pixels in the original file, actually changes the displayed pixel width of the image ?

Well, depending on the software, I'd say eliminates, rather than disregards. It does it according to an algorithm, not randomly.

But
Absolutely.

This is a very good question and Chris has given a very good description of what happens when you resize for screen...but this also applies to your image editing program too.

For instance when applying sharpening to an image you should ALWAYS view the image a 100%, not less or not more, your sharpening may look horrendous when the image is displayed in a window half the size of your screen but when viewed at 100% it may very well be just the ticket.

Thanks Chris

logical reallly I suppose, but somehow I couldnt get my head around it. Happens a lot these days I am afraid.

Thanks for that McBrian - had never taken that on board before. Means I can probably sharpen more than I do when wanting to print!

Andy

Sharpening for print always looks too aggressive on screen.
In general you should view at 50% on screen and apply sharpening so you just see the halos appearing.
The 50% view size in Photoshop roughly approximates how it will print.

Have a look at the guides on www.thelightsrightstudio.com - the PDFs and lessons on "Putting a fine edge on your sharpening skills". I think it's covered in there.

Matt

Thanks for the link, Matt.
Followed the link through and went to copy a version to my PC, and then discovered I had already downloaded it sometime ago and forgotten about it.

Must read it now, and see how the techniques apply to using Pic Window Pro (the programme this weeks Amateur Photographer has reviewed)

Andy

Thanks for the link Matt, just when you think youv'e got it some other bit falls into your lap.

Been trying to find this thread so that I can say thanks to Matt for this little nugget. Used this when doing a small catalogue and the images came out so crisp and detailed - looked stunning. Also worked a treat on my calendar pics too.

Dan

Glad it helped Dan
Matt