Laser beam photography project - help required finding the right laser.

[kingphoto]

Hi there,

I've been really impressed with some of the beam pictures on here, especially brucemir's pictures which are incredible!

Last night I joined the group and introduced myself. For those of you who missed the introduction, 'Hello' from the UK. Just so you know, I have read most of (I hope) the stickies and beginners advice to try and get up to speed with laser safety, physics etc. As I am new to all this I am sure there are gaps in my knowledge and I hope I won't upset any of you regular posters.

I am a photographer wanting to use lasers for a new, personal, photography art project. I have already done a controlled test at night using moonlight to illuminate the landscape. This was done in a remote location with what I suspect was a Firedragon II, 532nm Green, 200-400mW? laser. The results were amazing and I am looking to push the project further. Safety is paramount and I was very careful wearing safety glasses, ensuring laser beams were always terminated and never pointed at aircraft, people etc. I also informed the local Police station of my activities.

I am about to ask a bunch of questions and I hope this is OK. There doesn't seem any point in beating around the bush as I feel you need the full details of what I am trying to do - to be able to offer advice. Hopefully this won't upset anyone on the forum or be conceived as inappropriate.

So...I was hoping you could help me find the best lasers to continue the project.

Budget: I was hoping to pay around £100-150.00 pounds sterling per laser, including shipping and any optical devices to help with beam diameter/divergence.

Output power: The Firedragon I used last week was loaned and I really need 2 lasers of the same strength to photograph beside each other. As suggested, the lasers power was suspected at being 200-400mW. I don't think I need this much power and could probably halve the output power. This is a little difficult when I don't actually know what it was. Is there anyway of identifying the different output powers of these Firedragon lasers?

Beam Diameter/Divergence: I am looking for a laser with a large beam diameter of between 3-4mm. Whether this is achieved by the laser itself or with a focusing device/beam expander (like dragon lasers that doubles the beam diameter) I am not sure. I also require the laser to have a very low/tight beam divergence, or I guess a way of controlling this with a lens like DL's beam expander. What my photography tests showed was when you point the beam over a large distance the beam naturally expands in the distance creating the opposite effect of perspective. Ideally I would want the beams diameter to be at its widest close to me and narrowing as it got further away so it made sense visually and matched perspective in the landscape. Is this possible?

Operating Temperature: The Firedragon seemed to perform very well in very cold/freezing conditions. There was actually frost on my bags during the shoot. I would need another laser that was capable of achieving this ie being switched on at 0 degrees Celcius (maybe even up to -5 degrees Celcius) without it damaging the laser/diodes. Or, if this is inadvisable, a recommendation on the sturdiest laser and a solution ie keeping lasers in pockets until they are ready to turn on/battery operated warmers perhaps? I guess in summer I would need the opposite qualities, something that cooled quickly and was able to be turned back on when I was ready to shoot again.

Duty Cycle: Ideally i would really like to be able to turn this laser on and off when I like it. I don't really want to be restricted by operating times. In saying that, if this means that the laser is prohibitively expensive then I will probably make the compromise. What I do have in my favour is the fact that these photo's require very long exposure times of 4-10 minutes. The camera I am using then takes the same amount of time to produce what they call a black frame to reduce noise. So in effect, the laser will need to be on for approx 4-10 minutes, then can be off for the same amount of time for this process to take place.

I hope that covers everything. Any questions please fell free to ask. All I would ask is that you don't share my picture (if the link has worked) as this is just a test and I would rather keep it to the forum.

Thanks in advance for any assistance that you can give me.

Cheers, Mark
http://www.markkingphotography.com

 

[gozert]

Thanks for the loads of information you gave, this makes helping you out way easier.

For 100-150 pounds per laser you can definitely get something nice. The thing is though, low diverging lasers usually don't go well with a thick beam diameter, so I suggest you to get a beam expander with the lasers.

What came to my mind first was Jetlasers. They currently have a 150mw 520nm (green) direct diode laser. This means that there aren't any crystals used to achieve the 520nm color, and that the beam diameter is a bit thicker than the standard 532nm lasers. This one is currently 250$, but I know an easy trick to get over 50$ off. You can PM me for the details on that.

Then there is also the 445nm laser from Jetlasers, which starts at 1.6W for 250$. Although this is a lot more powerful, there won't be that big of a difference since green lasers are way more visible to the human eye than blue lasers are. I calculated that the beam of a 1.6W 445nm is about as bright as a 180mw 520nm. So that's pretty close. Again, for this laser too, you can save around 50$ by this one simple trick.

These lasers together will be about 330 pounds, excluding the 50-60$ that you can get each laser cheaper for.

You will however need one or two beam expanders, depending on if you're going to use them together to keep the divergence low. These expanders are around 100$ each. However, I think you're fine with just one expander since the 520nm will be less divergent than the 445nm. Also, both of them come with an adjustable focus.

What you should not forget is that you may want to get yourself a good pair of goggles too.


LaserBTB also has many nice lasers, but as far as I know they don't fit any beam expanders.




Oh, and also. I took a look at the photo's on your website and must say that I'm pretty amazed. They look great!

 

[brucemir]

very nice beam shot

 

[kingphoto]

Thanks for the loads of information you gave, this makes helping you out way easier.

For 100-150 pounds per laser you can definitely get something nice. The thing is though, low diverging lasers usually don't go well with a thick beam diameter, so I suggest you to get a beam expander with the lasers.

What came to my mind first was Jetlasers. They currently have a 150mw 520nm (green) direct diode laser. This means that there aren't any crystals used to achieve the 520nm color, and that the beam diameter is a bit thicker than the standard 532nm lasers. This one is currently 250$, but I know an easy trick to get over 50$ off. You can PM me for the details on that.

Then there is also the 445nm laser from Jetlasers, which starts at 1.6W for 250$. Although this is a lot more powerful, there won't be that big of a difference since green lasers are way more visible to the human eye than blue lasers are. I calculated that the beam of a 1.6W 445nm is about as bright as a 180mw 520nm. So that's pretty close. Again, for this laser too, you can save around 50$ by this one simple trick.

These lasers together will be about 330 pounds, excluding the 50-60$ that you can get each laser cheaper for.

You will however need one or two beam expanders, depending on if you're going to use them together to keep the divergence low. These expanders are around 100$ each. However, I think you're fine with just one expander since the 520nm will be less divergent than the 445nm. Also, both of them come with an adjustable focus.

What you should not forget is that you may want to get yourself a good pair of goggles too.


LaserBTB also has many nice lasers, but as far as I know they don't fit any beam expanders.




Oh, and also. I took a look at the photo's on your website and must say that I'm pretty amazed. They look great!

Hey, thanks so much for your reply yesterday and especially the comments on my work. It is always nice to hear positive feedback.

I have just checked out the '150mw 520nm (green) direct diode laser' from Jetlasers and it certainly fits the bill as far as beam diameter goes. Would having a wider diameter affect the distance ti was able to travel? Would the internal focus on this laser act like a beam expander and enable me to reduce the divergence?

I have just emailed Jetlasers these questions, but would be interested to hear your opinion too on how it would cope with operating in cold temperatures (ideal 15-35 degrees C) and what the duty cycle of these would be/maximum operating time?

Thanks also for the heads up on the discount - that sounds very interesting and I will def PM you regarding how to do this if I decide this laser is the one to get. Is there any time restriction on the discount?

Any further help greatly appreciated. Thanks, Mark

 

[kingphoto]

very nice beam shot

Thanks so much. Its just a first test with no retouching done so I am confident I can get the balances a bit better when I do the real thing.

 

[kingphoto]

Hey, thanks so much for your reply yesterday and especially the comments on my work. It is always nice to hear positive feedback.

I have just checked out the '150mw 520nm (green) direct diode laser' from Jetlasers and it certainly fits the bill as far as beam diameter goes. Would having a wider diameter affect the distance ti was able to travel? Would the internal focus on this laser act like a beam expander and enable me to reduce the divergence?

I have just emailed Jetlasers these questions, but would be interested to hear your opinion too on how it would cope with operating in cold temperatures (ideal 15-35 degrees C) and what the duty cycle of these would be/maximum operating time?

Thanks also for the heads up on the discount - that sounds very interesting and I will def PM you regarding how to do this if I decide this laser is the one to get. Is there any time restriction on the discount?

Any further help greatly appreciated. Thanks, Mark

Hi there, I have a couple more questions and was wondering if you could help again? I know you originally mentioned this laser, the 150mw 520nm (green) direct diode laser. Unfortunately they only have a 50 and 70mW laser in this colour available and Gray doesn't know when/if he will be getting any more powerful ones in. Gray did say that the 520 was visually brighter than the 532. However, when I did this test [http://lsrtools.1apps.com/relative brightness] it seemed to be the other way around. What were your thoughts? The laser I used for my test has been metered and measured 170mW (532nm). I am also worried that if I get the jetlaser 520nm with the beam expander (and expand to approx 6-8mm) that the divergence will then be awful, especially with the rectangular/oval beam. I really need as tight a beam as possible, ideally a tapering beam but I know I am probably asking way too much.

That kinda swings me back to the O-Like wide-beam 532nm/100mW that you recommended. This looks like it would do the job as far as divergence goes, but is probably 2-4mm to wide. I really want something around 6mm diameter at the aperture. is there anyway that you know of that I could reduce the beam diameter on this laser, with another cheap lens of even a smaller aperture that I put on the front of the laser? I am not sure what this would do to the beam and if it reduce the quality in anyway?

As always and thoughts and suggestions greatly appreciated. Thanks, Mark

 

[kingphoto]

Thanks for the loads of information you gave, this makes helping you out way easier.

For 100-150 pounds per laser you can definitely get something nice. The thing is though, low diverging lasers usually don't go well with a thick beam diameter, so I suggest you to get a beam expander with the lasers.

What came to my mind first was Jetlasers. They currently have a 150mw 520nm (green) direct diode laser. This means that there aren't any crystals used to achieve the 520nm color, and that the beam diameter is a bit thicker than the standard 532nm lasers. This one is currently 250$, but I know an easy trick to get over 50$ off. You can PM me for the details on that.

Then there is also the 445nm laser from Jetlasers, which starts at 1.6W for 250$. Although this is a lot more powerful, there won't be that big of a difference since green lasers are way more visible to the human eye than blue lasers are. I calculated that the beam of a 1.6W 445nm is about as bright as a 180mw 520nm. So that's pretty close. Again, for this laser too, you can save around 50$ by this one simple trick.

These lasers together will be about 330 pounds, excluding the 50-60$ that you can get each laser cheaper for.

You will however need one or two beam expanders, depending on if you're going to use them together to keep the divergence low. These expanders are around 100$ each. However, I think you're fine with just one expander since the 520nm will be less divergent than the 445nm. Also, both of them come with an adjustable focus.

What you should not forget is that you may want to get yourself a good pair of goggles too.


LaserBTB also has many nice lasers, but as far as I know they don't fit any beam expanders.




Oh, and also. I took a look at the photo's on your website and must say that I'm pretty amazed. They look great!

Hi there, I have a couple more questions and was wondering if you could help again? I know you originally mentioned this laser, the 150mw 520nm (green) direct diode laser. Unfortunately they only have a 50 and 70mW laser in this colour available and Gray doesn't know when/if he will be getting any more powerful ones in. Gray did say that the 520 was visually brighter than the 532. However, when I did this test [http://lsrtools.1apps.com/relative brightness] it seemed to be the other way around. What were your thoughts? The laser I used for my test has been metered and measured 170mW (532nm). I am also worried that if I get the jetlaser 520nm with the beam expander (and expand to approx 6-8mm) that the divergence will then be awful, especially with the rectangular/oval beam. I really need as tight a beam as possible, ideally a tapering beam but I know I am probably asking way too much.

That kinda swings me back to the O-Like wide-beam 532nm/100mW that you recommended. This looks like it would do the job as far as divergence goes, but is probably 2-4mm to wide. I really want something around 6mm diameter at the aperture. is there anyway that you know of that I could reduce the beam diameter on this laser, with another cheap lens of even a smaller aperture that I put on the front of the laser? I am not sure what this would do to the beam and if it reduce the quality in anyway?

As always and thoughts and suggestions greatly appreciated. Thanks, Mark

 

[gozert]

Hi there, I have a couple more questions and was wondering if you could help again? I know you originally mentioned this laser, the 150mw 520nm (green) direct diode laser. Unfortunately they only have a 50 and 70mW laser in this colour available and Gray doesn't know when/if he will be getting any more powerful ones in. Gray did say that the 520 was visually brighter than the 532. However, when I did this test [The Premier Free Hosting Site brightness] it seemed to be the other way around. What were your thoughts? The laser I used for my test has been metered and measured 170mW (532nm). I am also worried that if I get the jetlaser 520nm with the beam expander (and expand to approx 6-8mm) that the divergence will then be awful, especially with the rectangular/oval beam. I really need as tight a beam as possible, ideally a tapering beam but I know I am probably asking way too much.

That kinda swings me back to the O-Like wide-beam 532nm/100mW that you recommended. This looks like it would do the job as far as divergence goes, but is probably 2-4mm to wide. I really want something around 6mm diameter at the aperture. is there anyway that you know of that I could reduce the beam diameter on this laser, with another cheap lens of even a smaller aperture that I put on the front of the laser? I am not sure what this would do to the beam and if it reduce the quality in anyway?

As always and thoughts and suggestions greatly appreciated. Thanks, Mark

I would indeed go for the 532nm if you have the chance to do so. It's a bit brighter compared to 520nm, and the divergence is way better. You could check out Dragonlasers too. They have decently priced 532nm Spartan lasers, of which I own one. It is of great quality. It has a low divergence and for sure is overspec. They offer beam expanders too.

6mm at aperture is going to be hard though, my widest was a 445nm 2.4W which was around 4mm at aperture.

 

[kingphoto]

I would indeed go for the 532nm if you have the chance to do so. It's a bit brighter compared to 520nm, and the divergence is way better. You could check out Dragonlasers too. They have decently priced 532nm Spartan lasers, of which I own one. It is of great quality. It has a low divergence and for sure is overspec. They offer beam expanders too.

6mm at aperture is going to be hard though, my widest was a 445nm 2.4W which was around 4mm at aperture.

Hi there, Thanks for the quick reply and additional advice. I agree with your thoughts on the 532, the divergence seems to be around 50% better which suggests that I should go with that wavelength. What put me off the Spartans from DL was Adam's concerns about them not operating very well in the cold. Also, their BE is only 2x, so I would theoretically only be able to double the beam diameter to 4mm. If I found a good 532 laser with a 3mm diameter and a 2x beam expander I would be in business!

That takes us back to Jetlasers. They are more expensive but do a 10x beam expander. Their 520's diameter is 3mm, the 532 only 1.3mm. Apparently they both have the same divergence of around 2mRad. Would you still be wary of the 520's divergence despite JL's claims that they are the same. I know this wavelength has problems with divergence as I have read this several times elsewhere. I think JL's 532 sounds like it would maybe be the best option if I can use their BE to expand 4x-5x and then try to correct the divergence with the BE's focus. Do you or anyone else on the forum have experience with using their BE's to achieve something like this?

Once again, thanks so much for all your help and advice. Cheers, Mark

 

[Shakenawake]

1. the larger the lens used to focus a laser, the wider the initial beam will be, but the farther away it can focus to a point, so tapering the beam over a long distance will require a beam expander or large focusing lens, which is basically the same. in general, beam diameter is inversly proportional to divergence, the wider the initial diameter, the lower the divergence

2. yes 532 is a bit brighter per mW than 520, grey must have gotten mixed up.

3. diode lasers need to be kept cool so a colder outside temp should result in a longer duty cycle

4. a 100mW 520 build should have no problem being on that long in a decent heatsink and in such low temps

can you provide more info on the types of pics you are wanting? did you know that for many exposure lengths, even a very short laser burst will show up? in fact for powerful lasers one doesnt want overexposed in pictures, this is pretty much necessary if you want to, for example, capture stars, dark sky, and the laser beam

sounds like a build using an osram PL520 or osram PLP520-B1 and incorporating a beam expander (somewhere between 5X and 10X) is what you want

looks like jetlasers has changed their site recently, they used to have 50-150mW or so 520s available

 

[kingphoto]

Hi there, thanks for the help, much appreciated. Can you clarify this for me in layman terms, "in general, beam diameter is inversly proportional to divergence, the wider the initial diameter, the lower the divergence"? I think you mean that if I increase the beam diameter with a beam expander, it will also increase the divergence/make it worse...?

Thanks for clarifying that a 532 is slightly brighter than a 520, I thought that was the case. Do you still think the 520 is the way to go...with it having a reputation for a worse divergence/oval/rectangular beam dot etc? If I can get a 532 to work in cold conditions that would be great...but spring is here so temperatures will soon be warming up. So something that covers a low of 0-20+ degrees would be perfect.

I see how cold helps the duty cycle. I would be looking for duty cycles like 1-2 mins on, 1 min off type thing. My exposures are around 8-9 minutes long and the laser would be on for a proportion of that exposure. The tests i did were with a 532nm/170mW green. I would want something around this power as it gives me the flexibility to adjust the laser exposure times and also add beams in different places during the exposure - thus reducing the need for multiple devices.

The picture at the beginning of the post kind of represents what I am trying to do, except the laser beam would be more solid and 3-5x wider. I am taking these photo's using moonlight as a light-source.

Apart from the Jetlaser, However, currently their most powerful 520 is 70mW. Would a custom build be possible and if so would this be prohibitively expensive?

Thanks, Mark

 

[Shakenawake]

Hi there, thanks for the help, much appreciated. Can you clarify this for me in layman terms, "in general, beam diameter is inversly proportional to divergence, the wider the initial diameter, the lower the divergence"? I think you mean that if I increase the beam diameter with a beam expander, it will also increase the divergence/make it worse...?

no, the opposite. imagine holding two straight lines up to your eyes, the farther away they are from eachother (wider beam diameter), the farther away you can precisely make them cross at a specific point

Thanks for clarifying that a 532 is slightly brighter than a 520, I thought that was the case. Do you still think the 520 is the way to go...with it having a reputation for a worse divergence/oval/rectangular beam dot etc? If I can get a 532 to work in cold conditions that would be great...but spring is here so temperatures will soon be warming up. So something that covers a low of 0-20+ degrees would be perfect.

the low power 520 diodes i listed have good divergence compared to the higher power 1W ones, beam expanders will only improve this. the 520s will always be more stable under various circumstances than 532s

Apart from the Jetlaser, However, currently their most powerful 520 is 70mW. Would a custom build be possible and if so would this be prohibitively expensive?

the hard part would be finding a member that can build a custom unit which accomodates a beam expander

 

[kingphoto]

no, the opposite. imagine holding two straight lines up to your eyes, the farther away they are from eachother (wider beam diameter), the farther away you can precisely make them cross at a specific point



the low power 520 diodes i listed have good divergence compared to the higher power 1W ones, beam expanders will only improve this. the 520s will always be more stable under various circumstances than 532s



the hard part would be finding a member that can build a custom unit which accomodates a beam expander

Thanks so much for your help. It is all very helpful and I appreciate the time taken to explain things further. Cheers, Mark

 

[kingphoto]

Hi guys, I read somewhere on this forum that we shouldn't include batteries in our orders from China, as sometimes this is what holds them up when they go through customs. Is this the case? I noticed that a laser I just purchased from O-like has a battery included...should I get them to take it out? Thanks for any guidance you can give me. Cheers, mark

 

[chipdouglas]

that is pretty true. order your batts from ebay with a quality charger. try nitecore chargers.

Michael.

 

[SteveT]

Hi guys, I read somewhere on this forum that we shouldn't include batteries in our orders from China, as sometimes this is what holds them up when they go through customs. Is this the case? I noticed that a laser I just purchased from O-like has a battery included...should I get them to take it out? Thanks for any guidance you can give me. Cheers, mark

UK customs often open packages that contain batteries for closer inspection. Best to avoid shipping a laser and batteries together; as this gives scope for 'officials' to power up your 'flashlight.' I had a laser confiscated not so long ago although I did receive my batteries.