About ldisposable camera lens

[cul8r]

I've gathered the lenses from three major brands of diposable cameras. Non of them have made the dot size any smaller than it was without it. I have even got the glass lens sets, which are three lens sets from cheap 35mm cameras I found at the good will. No luck with them either. In fact some of the plastic lensers from the disposable cameras had to be held a good two feet from the laser so mounting would be stupid. Has anyone actually made this work and if so what brand of camera did it come from. That would make a possible difference from what I've tested.

 

[FireMyLaser]

eep... What exactly are you trying to achieve?

 

[nikokapo]

eep... What exactly are you trying to achieve?

I think he's trying to focus a laser with a plastic disposable camera lens.

 

[FireMyLaser]

I believe so too. But if that's the case there's really no problem if he's using a convex lens, that I'm sure he'll find in a camera.

 

[randomlugia]

Just buy an Ebay laser for $3 and take the collimating lens out. I have a few, and they can all focus the dot of any laser to a pinpoint.

 

[potatorage]

The lenses from disposable cameras are total crap, all disposable cameras are good for is the flash lamp and the cap inside

 

[Cyparagon]

But they DO focus. You must be doing something wrong.

 

[cul8r]

What I have already is a e-bay laser and the dot is ugly and big, it doesn't focus to anything smaller than a 1/4 of an inch at 3 feet. I've tried all shapes and sizes of lenses in front of it with no luck in making it smaller. The best thing I've seen is a combo of two lenses I have a concaved one right up against the module and a convexed magnifying type about a 10th of an inch from the concaved, seemed to tighten it somewhat. but not a pinpoint by no means.

 

[RA_pierce]

What I have already is a e-bay laser and the dot is ugly and big, it doesn't focus to anything smaller than a 1/4 of an inch at 3 feet. I've tried all shapes and sizes of lenses in front of it with no luck in making it smaller. The best thing I've seen is a combo of two lenses I have a concaved one right up against the module and a convexed magnifying type about a 10th of an inch from the concaved, seemed to tighten it somewhat. but not a pinpoint by no means.

Adding a single convex lens will not fix the beam divergence (which is what you are trying to do, from my understanding).
It will, however, focus the beam to a point at whatever the lens' focal point is. Disposable camera lenses typically focus the beam at about 1-3 inches.

A convex lens will focus the beam, but the beam will diverge again.

If you want to correct the divergence (make the size of the dot smaller over greater distances) you will need to adjust the collimating lens of the laser or use a beam expander (which basically does what you described above).
If you are able to remove the aperture cap of your laser, you may be able to adjust the lens for better beam divergence. Providing the type of laser you have as well as pictures will make it much easier for us to help you.