Pinhole Slide Projector

Hi! I have no idea whether this is the right place to post this topic, but it does say 'burning questions' and that's what this is, so here goes. :-) I've had this idea for a kind of pinhole lense slide projector. The (very basic) diagram is pretty self explanatory, and I was wondering if anyone's tried/heard of anything like this, and whether it could work? Do you think a 100 LED torch would be bright enough? Also, if I'm right in thinking that LEDs don't get hot, there shouldn't be a risk of overheating/fire should there? Thanks! Looking forward to hearing what you think! :-)

Picture of Pinhole Slide Projector
sort by: active | newest | oldest
lemonie8 years ago
The problem with this is the amount of light you'll get through a pin-hole. In the reverse fashion bright sunlight (very bright as compared to a torch) will give a reasonable if dim small image. Think about how much light you'll get coming out of this? L
MissPennyFarthing (author)  lemonie8 years ago
Good point. Do you think that if I used a magnifying lense instead of a pinhole, that it might increase the brightness of the image?
Yes, with a glass lens you've got much more light coming out of the device, and for a projection system light is what you need. Note that most projectors have very bright (and usually expensive) bulbs.
Have a look at these:

MissPennyFarthing (author)  lemonie8 years ago
Well I was planning on using a 900+ lumen tactical torch. Ideally I'd like to keep it portable; so preferably without needing an external power supply for a traditional projector bulb.

I also found this YouTube video, where he seems to be using a straightforward halogen bulb.
It seems to give quite a good picture, judging from around the 7.30 mark. :-)
I looked at the first 30 sec, probably a good guide. So best wishes for it, hope you get it done. L
MissPennyFarthing (author)  lemonie8 years ago
Thanks! :-) If it works I'll post an 'ible about it.