abstracts wrote:Thanks Chris, that sounds exactly what I was after. Is there an accepted 'rule of thumb' as to how much you can upscale.
It will depend on the quality of your images. But other factors come into play with image size:
1) Viewing distance
If the viewer of the image is going to be standing inches away from the image, then of course the quality of the image has to be very good, else if the viewer is standing several meters away (think of those large billboards you see in the streets) the quality can be sacrificed by a certain amount.
2) Resolution and sharpness you need
Increasing image size means adding more pixels to the image, pixels which weren't there. Newer versions of PS and other image tools have better algorithms that handle image resizing. If you want to keep the same dpi/ppi and keep the image sharp then better not to do more than doubling the size. Or if the dpi/ppi is not important, change their values to increase or decrease width/height values. Still, you need to make a judgement call about what you are willing to compromise or sacrifice.
3) Purpose it will serve
Are you planning to put your images on Stock Image websites? They generally ask for large and high quality images?
Are you going to print your images: what paper size? and what paper type?
Upload to the web/view on a screen?