Large photos

[ianmunt]

If I enlarge a digital image too much it pixelates,how is this avoided in digital projectors,they seem able to produce very large images without exhibiting this problem

[wildwood]

If you scan a photo at the maximum resolution your scanner can muster you'll find the image will be enlarged without pixelating. The quality however depends very much on just how sharp the original photo was.
Now imagine industrial quality image scanners, they are able to make a person'e head 8ft tall without too much degradation.

[ianmunt]

That would suggest a straight digital photo,even taken with a high megapixel rating would still be unable to compare with a conventional film image appropriately scanned,yet I have seen digital camera produced images projected at great magnification without significant detail loss.I can only assume it is some clever upsizing software.If so what is it ?

[pug100]

Hi,
A digital projector works by shining a light through an lcd screen which is only a couple of inches wide. The determining factors on projected image size is the quality of the glass lens at the front of the projector and the intesity of the lamp. As long as the initial image is good then these are the main constraints

http://en.wikipedia.org/wiki/Digital_projector

[ianmunt]

That gives some answers,but it must mean the pixel count of the LCD image is very high,otherwise as with conventional film,magnification will reveal grain or in the case of a digital image pixels.If the original digital shot has been taken with a 7 megapixel camera,then surely without upscaling the LCD image cannot have a higher figure.When a comparable level of enlargement is used to print such an image it would be almost unviewable,yet projected it is still detailed.Thats the discrepancy I'm trying to resolve.

[wildwood]

I know that photo editing software employs "fuzzy logic" technology with focusing and sharpening images. Perhaps a digital camera uses that too to smooth out the pixelisation.

[wildwood]

That should read digital projector odcourse.

[ianmunt]

Thanks to all for some clarification