Taking Photos

Any advice on how to take good (even great will do ;) ) photos of lasers?
In most of the pics that are posted the haze/fog is really well defined and lasers pin sharp.
I have a Sony 7.2Mpixel camera with all the usual features.

Jim

:!:
It seems I have "burnt" several pixels out of both my DV and Digi cameras by placing them in the path of the beams. Not sure if i did something "wrong" but you can see in some of my pictures and both of the latest videos I posted a few "dead" spots that were'nt there a month or so ago. :?

When I take pictures I make sure I'm not it the path of the beam so it can't get directly into the lense of the camera. If it did the picture would be unusable anyhow.
What I want to take is a couple of tunnel or fan pictures.

Jim

Here are some examples of my crappy pics from last night.

http://www.prismdisco.co.uk/galvos/DSC01797.JPG
http://www.prismdisco.co.uk/galvos/DSC01798.JPG
http://www.prismdisco.co.uk/galvos/DSC01799.JPG

HELLLPPPPPPPPPPPPPPPPP

Jim

I made a couple of cool tunnel pic yesterday. i was tryin to emulate what andy_con was doin. I think I overdid the colors though... :oops: I'll toss a couple up here in a few. I'm about to synch a mp3 to video for a popelscan show I taped. :D Actually to get a tunnel shot you kinda need to get the camera "into" the tunnel, hence passing through a beam. I'm not sure if the damage to my camera happened that way or from a static beam. :?

here are some of my photos, i use a nikon 8mp SLR camera.

and tips???? take your time and keep the camera stedy

http://i80.photobucket.com/albums/j1...k/DSCN3220.jpg

http://i80.photobucket.com/albums/j1...r/DSCN3106.jpg

http://i80.photobucket.com/albums/j1...r/DSCN3101.jpg

and my best photo

http://i80.photobucket.com/albums/j1...s/DSCN2875.jpg

Taking pictures of laser beams is tricky. Allthat already mentioned the danger of frying pixels on the CCD inside your camera... But beyond that there are a few things you can do to improve the look of your shots.

First, USE A TRIPOD. Seriously, this is probably the most important step. When you snap a picture of a laser in operation, the total amount of light entering the lens of the camera is going to be very low, thus you'll need a long exposure time. So if you're looking to avoid the blurry, smeared out look, you need to have the camera perfectly still. I don't care how rock steady you think your hand is - a tripod will be better.

Second, you want to position the camera so you are looking close to head-on at the beam. If you are 90 degrees off to one side, there will be a lot less light reflected towards the camera. But if you are just to the side of head-on, more light will reach the camera. Also, for the same position of the camera, shots that have the beam traveling towards the camera will appear brighter than shots where the beam is traveling away from the camera. So you always want to be out in front of the projector, not behind it.

Third, you'll obviously need some fog in the air, but be careful not to make it too thick. If you have too much fog it will block the light from the beam(s) in the background. This can be tricky, so start with a little fog and shoot some pictures, then add more fog and repeat. Save the pics that turn out well and chuck the rest. After doing this a few times you'll get a feel for how much fog is needed.

Fourth, don't be afraid to put your camera in manual mode and increase the exposure time. If there are other lights on in the room, even very dim ones, the camera may end up under-exposing the shot. So experiment with keeping the shutter open longer and see if the beams don't start to look brighter in the finished shot. (I've got some lame-looking pictures of a 1 watt DPSS green laser running at a show... The beam looks like it's from a modified laser pointer, it's so dim! But there were lots of intelligent lighting fixtures running at the same time, so the camera underexposed the shots.)

Finally, when trying to get great shots of the "time tunnel" effect, get the camera positioned in the center of the circle (or square, or whatever shape you are using for the tunnel) and shoot a few pics first just to make sure you like where the camera is. Then, activate your fogger and start snapping pictures as the FRESH fog moves through the beam path. You'll be able to capture the random paisley-like patterns in amazing detail. You don't need a lot of fog, but you do need that fresh blast... (When the fog first starts to mix with the air, the density changes pretty radically within the expanding fog cloud. That density variation creates the cool patterns you see.)

Adam

I find my Canon Powershot A70 (and even my older a40 that got stolen) does a nice job of taking AWESOME laser photos in "auto mode"....

I find Daves camera, the model escapes me, sucks dog balls at taking laser shots.

Buy a canon ;)

Quote:

---

Actually to get a tunnel shot you kinda need to get the camera "into" the tunnel, hence passing through a beam.

---

You can always keep the lens covered when getting into the tunnel :wink: . Also, depending on the laser's power, that kind of abuse won't result in dead pixels. For that, you'll need a rather powerful laser, I think. As the laser is scanning, the power is somewhat reduced on any given point. Don't get me wrong though, I'm not saying that doing that is safe, always cover your lenses before it can get into the beam, just in case :wink:

A standing beam is the most dangerous for the pixels, as the entire energy is being focused onto it/them.

All things considered, my camera also has several dead pixels, but I find it rather easy to fix with photoshop (or any other photo retouching software) :wink:

When a laser is scanning the beam is always at full power at any point, it is just that it is only at that point for a very short tie.
Have a look at the info on Bills Pangolin site for the explanation if you don't understand why.

Jim

I stand corrected :wink: .

Under those circumstances, the laser CAN damage the pixels, even if scanning :P

Quote:

---

When a laser is scanning the beam is always at full power at any point

---

That applies to TTL I think. With analog, you can have less than full at any point. Sorry, I'm splitting hairs here :lol:

Actually, there is a difference.

Scanned beams can only irradiate the CCD for a brief period. A static beam will continuously cook the thing. So, depending on the power of the laser in question, you may or may not end up damaging the CCD with a scanned beam.

The information on the Pangolin site that Bill Brenner referenced in his other post deals with damage to the human retina. But the power limits are a lot lower for the human eye than they are for a CCD. Damage is a function of power level AND duration of exposure. It's just that because our eyes are *so* sensitive, it is possible to exceed the permissible exposure level and cause damage to our eyes even with a relatively modest-power-level laser and the shortest possible exposure based on the max scanner speed. (This is the main point Bill was trying to make - namely that you can NOT rely on fast scanning to protect your audience from eye damage, because even at medium power levels and fast scans, the total exposure is already high enough that you are in the danger zone.)

Some CCD's are no doubt very sensitive, but I have a 2.1 megapixel Fuji Finepix camera that has survived several direct shots (static beam for 2-3 seconds) from a 100 mw laser with no ill effects and no dead pixels. I woulnd't want to try the same trick with my eyes though!

Adam