Way OT: Powerful laser pointer?

JackW wrote on 8/23/2010, 11:52 AM
Anyone have experience with a bright laser pointer? I frequently have to tape live PowerPoint presentations in which a nurse or physician is pointing to areas of he screen. Most use a red 5mW laser pointer. Often the PP slides have dark colored backgrounds and the red dot hardly shows up or doesn't show up at all.

During the last shoot the speaker abandoned the pointer and walked back and forth in front of the projection to point to various body parts, resulting in a great deal of extra post work with levels and color correction. A real pain for me and definitely no cost effective!

I'm hoping to solve this problem by supplying a laser pointer for these shoots. Can anyone recommend a good pointer? I've been looking on line at 10mW and 20mW green pointers but don't know from experience which to select and whether green is better than red.



nedski wrote on 8/23/2010, 1:48 PM
I've been recording the monthly lectures at a local observatory for the past two+ years. I've slowly been improving my techniques.

Most presenters simply point to items on the slides with their hands, some use red Laser pointers. One time a green Laser pointer was used, I think it might have been ~ 10mw. It is normally used outdoors to point out stars to the people who visit.

Check out this video at 9:32. The green Laser spot is VERY visible. It was actually uncomfortably bright, the beaded projection screen bounced back a lot of the light.


More details:
It's a small room ~ 15' x 20'
I fix the exposure, focus & white balance on projection screen.

Here are some of the my latest improvements.
Better lighting, made light on presenter as bright as light from projector on screen using two 3W LED spotlights ~ 8' from speaker (will add a third light above presenter to light hair and shoulders).
Three camcorders, the center is a Sony HDR-SR7, a Kodak Zi8 and a Kodak Zx3 on the sides.


A. Grandt wrote on 8/23/2010, 1:56 PM
I only have a green 5mW pointer, and some people have complained that it's uncomfortable for them when it's used on a white/silver screen.

Btw, is that the Sony ECM-HW2 wireless microphone you are using?
farss wrote on 8/23/2010, 2:01 PM
Green semiconductor lasers are pretty dangerous. For same power they can do more damage to eyes than the red ones. The red light does damage but the burnt part can heal. The wavelength of the green ones damages cells in a way that stops them from healing.

nedski wrote on 8/23/2010, 2:15 PM
You are correct sir, it's a Sony ECM-HW2 Bluetooth microphone. It's sensitive, quiet and reliable and relatively inexpensive.

I had been using an inexpensive (~$130) FM wireless microphone Audio-Technica Pro 88W/R, sometimes it worked perfectly and other times it picked up all sorts of noise, even in the same room.

The Sony was only about $180 at the time. Professional UHF wireless mic sets start at around $400 and go up to thousands!

The only downside is that it's only usable on Sony camcorders with their proprietary Active Interface Shoe.

Edit: I covered the bright blue LED on the microphone with a few layers of duct tape!
JackW wrote on 8/23/2010, 4:03 PM
Sounds like a 10mW red pointer might be a better way to go. Interesting to hear from Bob how potentially dangerous the green laser can be and from others how bright it is.

On to Google!

Thanks for the input.

Serena wrote on 8/23/2010, 10:15 PM
Surprising that no one has mentioned legislation pertinent to lasers. A 5mW laser is capable of damaging eyesight although it is generally considered that the eye's blink reflex will prevent the length of exposure necessary (several seconds). Generally lasers used in pointers are limited to 1mW, although this varies from country to country and even state to state. In Australia any laser of greater than 1mW is classified as a weapon (with associated restrictions). In UK and Europe pointers are limited to 1mW max, restricted under OH&S. In the USA laser pointers must be <5mW, with various interesting consequences for misuse.
farss wrote on 8/24/2010, 1:26 AM
Alarmingly enough the most powerful handheld green laser is 1,000mW. Available from Wicked Lasers and yes, it runs on batteries and yes it can cause very major damage to eyesight.

There seems to be a difference between the new "green" lasers and the older ones and the risks involved with them seem pretty significant as acknowledged by the manufacturers:


Whether or not that has anything to do with the common green laser pointers or not I don't know for certain but I would not entirely rely on the power output as an indication of the risks involved.


RZ wrote on 8/24/2010, 6:20 AM
What is the main purpose of recording these lectures. If it is to make them available to others who are not physically present in the lecture hall of to have lecture archive, I think one suggestion would be to have the lecturer play the Powerpoint show on a computer and do audio and screen recording with a screen capture (Camatsia). This video can then be edited and made available. I personally did one project like that (although I am not a pro by any means). But my results were impressive.

This also gets to the "meat" of the lecture. The mouse pointer/cursor will also eliminate the need for the lase pointer. My .02 cents
Byron K wrote on 8/24/2010, 10:39 AM
Posted by: JackW, Date: 8/23/2010 8:52:55 AM
Anyone have experience with a bright laser pointer?
Posted by: A. Grandt, Date: 8/23/2010 10:56:58 AM
I only have a green 5mW pointer, and some people have complained that it's uncomfortable for them when it's used on a white/silver screen.
I use a green laser pointer and as Grandt mentioned, it can be annoyingly bright especially on silver screens.

What I've done is place a piece of electrical or masking tape over the front of the laser pointer and poke a very small pin hole (I'm talking .25mm or even less) this creates a much smaller less intense and IMHO cooler looking pin point which is a lot easier on the eyes. Enlarge the size of the hole as necessary.
nedski wrote on 8/24/2010, 1:37 PM

I tried the method you suggested and while it certainly made reading the slides easier, what was lost is the interaction of the presenter.

There are several different people who typically do the lectures and each one has their own style. Some are very interactive with the screen and the audience. They also use a variety of software, not just MS PowerPoint, so getting them to do screen capturing might prove to be too much of a burden for them. They already complain about the lights being too bright!

Thanks, I take your .02 cents and put them in my piggy bank. ;-)
Serena wrote on 8/24/2010, 9:20 PM
Noting farss's comment about 1watt green lasers, perhaps I should clarify that while a 5mW laser requires some seconds to do permanent damage, a 1w laser will do it instantly. Just catching bounce from a wall would likely be sufficient. So don't mess with the eyes; certainly not other people's. Take from the various legislations that no laser of greater power than 1 mW should be used in a general environment. And, as farss said, be wary of the stated power output (especially of unfamiliar manufacture). I'd also be wary of using an aperture to restrict the output of a laser; coherent light is a little different to a torch.