image sizes for powerpoint projector show?

I have a small presentation to create with powerpoint a 15 photo image slide type show.

I am a bit lost with what size and resolution the images should be? the. I have followed one guide which recommended a 100 pix/inch with dimensions at 1000x 750 pix the final size was 170 Kb JPEG.

When viewed in photoshop the image looks very pixelated compared to the original image.

The presentation is using a digital projector, so I guess that this size will result in a poor quality image?

Any tips please for resizing images for Powerpoint?

Thanks for any help

Guess there is 2 schools of thought really.
Am I creating slides to be printed (large) or just viewed on-screen?

Most projectors (& laptops for that matter) output 1024x768 resolution, so there is basically no point going above this.
i.e. Say you have a graphic that fills a quarter of the screen then there is no need to make it bigger than 512x384.

Your resolution (& hence quality) is going to be restricted by the weakest link ti the display chain.
ie: really bad webgraphic is going to look terrible on everything!
A great high spec laptop putting out 1400x1050 into an old projector at 800x600 will never look better than 800x600.

Having said that I tend to prefer to insert lightly better quality graphics and let PowerPoint crunch them down in Slideshow mode. This is something PP seems to do a good job at! If you produce graphics at 1024x768 then find yourself displaying on a 1400x1050 native projector then your presentation ain't going to look it's best.

Quick comment on DPI. My experience is this has little to do with the projected image. How can dpi mean anything to a projector which is displaying on some screen size it doesn't even know. DPI does relate to the default monitor DPI (usually around 96dpi with default page size). Only thing I find it useful for is when you first insert a picture - PP reads the DPI from the image and tries to scale it to suit. i.e. a high res image with high dpi (2000x2000@600dpi) can appear insert into PowerPoint the same size as a medium image (500x500@150dpi) if things are all in proportion. Get the idea.

Something I haven't tried but assume to be true is that increasing the "Page Size" would mean needing larger ratio for imagesize/dpi to insert the same size. This is really academic anyway when the slideshow is just being projected or multi-page handouts being produced.

So summary - the lowest resolution in your "display system" (laptop, switcher, projector) determines the maximum image resolution you'll require.

Sorry about the long winded answer.

K.