Bigger box pinhole camera - better image with smaller hole and longer box

After school finished yesterday I looked at the partial eclipse using the cardboard roll pinhole camera

and using the cuboid box camera (see picture below)

...the images were small...how could I make the image larger?

Mr Parkin also took a picture using a digital camera with a coloured filter...but the image was unclear and too bright to see...see below

I thought for a few seconds and realised that if I made the box longer and kept the hole very small it would let the beams of light from the sun be further apart when they hit the screen...this would make the image bigger!

Below is a photo taken using the larger camera.  I enlarged it using photo software (picasa) but it looks a lot clearer.

You can see the grainy texture of the tracing paper, which I used as a screen.

This is the original photo of the screen before using picasa:

Did you manage to take any good pictures from your pinhole cameras?