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04-26-2013, 12:09 PM   #31
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QuoteOriginally posted by ripit Quote
Where would you even find a class 1 laser? Looking around the lowest I see are 1mw or <1mw which would make them class 2, but even those are generically labeled class 3a as they are also <5mw. It would seem the maximum that can be readily sold in in the US and at least some other countries is class 3 so I wonder if that is why they genrically label them as class 3a? I don't see anything that claims to be class 1 devices except for contained lasers such as a cd player (they are class 1 because they are contained, not because they are low power if I understand right).
I haven't shopped for a laser poiinter recently but a few years back the dollar store sold class 1 lasers so I would assume they are still available? Maybe a place like dealextreme would have some.

Normally labels are accurate, though it is possible that some manufacturers don't test them and just label them higher than required to avoid problems.

04-26-2013, 09:16 PM   #32
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QuoteOriginally posted by bdery Quote
I haven't shopped for a laser poiinter recently but a few years back the dollar store sold class 1 lasers so I would assume they are still available? Maybe a place like dealextreme would have some.

Normally labels are accurate, though it is possible that some manufacturers don't test them and just label them higher than required to avoid problems.
I'm thinking a lot of the cheap chinese ones (from places like deal extreme, meritline, ebay, the dollar store) are just throwing the higher rating on there to be safe and or reduce liability. There are several on ebay that say 1mw but say class 3a, and I even saw one that the warning label said 1mw but also said less than 5mw and class 3a. They don't say they actually are 5m, they just say <5mw class 3a. There were others on ebay where the listing said 1mw but the warning label said less than 5mw and class 3a. I have not seen a single one anywhere that is class 1 or 2.
04-27-2013, 01:33 PM   #33
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I'm going to do a little more research but I'm thinking the laser I got is probably going to be safe (with the pattern cap on). Of course being off ebay, its not as described (seems thats the way my luck has been lately). It was supposed to be a 5 in one laser with 5 pattern caps but I only got one. It was supposed to be 5mw but the laser is about the same brightness as the other ones I have that I suspect are 1mw. With the pattern cap on, it projects a 11x11 grid. That means that it is split into 121 dots. When you turn the cap, each dot splits into 5x5 grids so each group of dots is 25 dots (total of 4235 dots). About 70% of the dots are bright (on each group of 25, the outer dots are dimer and on the entire pattern, the outside groups are dimer). In daylight but in the shade of the house, with it in the 121 dot pattern, pointing at the sidewalk, the dots are visible to about 12 feet (slowly moving it away and watching the dots, when they get 12 feet away they become so faint the can not be seen). Outside in the shade with the dots spread, at 3-4 feet, 90% or better of the dots can not be seen. All disappear by about 5-6 feet except for one bright dot in the center that disappears at about 8 feet. Inside with lights off but daylight through the windows (curtains closed in one of 2 adjoining rooms they are visible but not really bright. When shooting through a lens to spread them they are not visible inside past maybe 10 feet even when condensed to 121 dots. .

Any opinions?

Edit.

A couple of points I forgot. Each individual dot doesn't seem to change size with distance like its spreading but they get noticeably dimer even with a few feet of distance change indoors. The entire pattern spreads fast and seems to be equal to distance (at 4 inches the entire pattern is 4 inches,. at 2 feet the entire pattern is 2 feet). I have 37mm +1, +3 and +4 macro filters. I had discounted them with a single beam laser as they were not strong enough to have enough effect but might be of use with these weaker dots if I wanted to spread them a bit. I wish there were some easy way to measure the intensity of the beams (especially that one stronger dot in the middle though it doesn't seem much too much stronger.

Last edited by ripit; 04-27-2013 at 01:43 PM.
04-27-2013, 05:17 PM   #34
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After testing it out (and recharging the batteries) I am no longer certain it is safe (though I still think there is a chance it is). I had a couple of other thoughts. I could use a hole to block most of the grid (I don't need a huge grid that paints the whole room). A neutral density filter apparently does a good job reducing the power of the beam (and could be screwed together with a macro filter to spread and defocus the beam). A polarizer seems to get rid of stray light (not much effect for safety other than a little ND effect but it provides a cleaner image for the camera to see). I wonder if there is a local college or something that I could coax into measuring the laser output for me?

04-29-2013, 05:39 AM   #35
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QuoteOriginally posted by ripit Quote
It was supposed to be 5mw but the laser is about the same brightness as the other ones I have that I suspect are 1mw
Your eyes might not be able to tell the difference in brightness with sufficient accuracy for any reliability.

QuoteOriginally posted by ripit Quote
Each individual dot doesn't seem to change size with distance like its spreading but they get noticeably dimer even with a few feet of distance change indoors
Then they do change size but again your eyes are not the best tool to measure that.

QuoteOriginally posted by ripit Quote
A neutral density filter apparently does a good job reducing the power of the beam
Yep, just like with any light source.

QuoteOriginally posted by ripit Quote
A polarizer seems to get rid of stray light (not much effect for safety other than a little ND effect but it provides a cleaner image for the camera to see)
Most (if not all) of these lasers are polarised by nature.

QuoteOriginally posted by ripit Quote
I wonder if there is a local college or something that I could coax into measuring the laser output for me?
That would be a 2-minutes measurement with the right sensor. Maybe some electronic parts store could do that too.
04-30-2013, 08:25 PM   #36
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In case anyone is interested, I haven't done much else with the lasers I have. I can not go much further in the direction I wish with the parts I have right now (If nothing else I need a lens(s) to get patterns that will work better). There seem to be many possibilities on how to do it. I have done a lot of reading though and posted on a laser forum about safety and this project too. Don't take anything I say as fact as I am still in the research phase, but rather take it as some of the possibilities. It only takes one mistake to hurt someones eyes and damage to the eyes from lasers is permanent and irreversible. Its a mistake you can not ever take back.

First, I am far from the first person to do this. Many people have done it and it seems to work very, very well. A single laser dot works sometimes but an array of dots works better, and based on what I have read, a line (easily done with a line or cross lens or a laser that already projects a line or cross) or a hologram (ranging from a ready bear to a no smoking logo and everything in between) will probably work much better (I can not confirm that myself yet but that is the direction I will be trying next). Many of the people that had good success used one that projected a star (perhaps star hologram laser pointers are more common). Oddly, many of the threads I ran across were in the earlier part of 2000 (perhaps the sony cameras did coax people into experimenting).

There are laser focus assists on the market now. This one seems to be a cheap $5 1mw green laser (single dot) for $150, lol. I had thought I had seen 2mw when I first saw it so maybe there are two versions or perhaps someone somewhere listed the specs wrong.

Deluxgear Pinpoint Focus Assist PP-FA

wansen rf-602 | eBay


I had also been wondering if there were some way to trigger it from the hot shoe. Surly there is some contact that would give the appropriate signal at the right time (just enough power to trip a small solenoid switch or something). I just now (a few moments ago) ran across someone that did that, though the laser stays on during the shot (I would prefer it turn off as you might photograph the dot).

AF Assist tool v2.0 log | adrian's domain

It would seem that a 1mw is safe in all regards (even if you shot someone in the eye on accident with a single beam though I wouldn't recommend it). That is assuming that it is really 1mw. A 5mw is safe (it is strong enough to cause damage, but the persons blink reflex will cause them to shut their eyes before it does). First big problem. The cheapo laser pointers on ebay are apparently sometimes under rated or over rated. In rarer cases, your 5mw laser could be a 25mw laser. Even if you buy from a reliable source or test the laser, lenses can make a 5mw dangerous (though kind of going in the opposite direction of what you would want to do with a camera which is expand the laser out to make a pattern). I'm sure there are other factors that could make a 5mw dangerous, When I asked in a laser forum, it was said that what I am trying to do would be safe with a 5mw laser (again, if it actually is only 5mw). Many also said that 1mw should be plenty though. I would agree, in most instances, 1mw should be plenty. I have a laser pointer that was about $50 at office depot (I bought it on clearance for about $10 if I recall right). Its probably a Chinese cheapo like the rest. Its labeled less than 5mw, class 3a, but it is substantially dimmer. These diode based lasers seem to pules brighter momentarily, then shine dimer, and may continue to dim if you leave it going (reduced output due to heat?). Leave it off for a while and it recovers. With the office depot laser pointer, right after the initial bright pulse, when shot through the tip that came with the 5mw green that splits it to about 4000 dots, it is barely bright enough it might work, and within several seconds, fades almost all the way gone (in dim room light). Fyi, it is not being split into 4000 beams. The gren laser did perhaps an 11x11 grid. The office depot laser does a 7x7 grid (smaller beam I assume), but thats still over 1000 dots (each dot expands to 25 dots). I have an nd4 and an nd8 filter handy (and should have others somewhere). The nd8 should cut a 5mw to .625 mw. I'll use a more powerful (5mw) one till I determine the image (holagram) or line I like, and then find and appropriate size laser (which likely could be a 1mw).

Fyi, if you want to go more expensive, you can build a laser module for $50 or less. If you go with a good quality laser diode (and I assume a good quality power board if its not built in), you can get ones that are going to be what they are rated (if I understand right). I would assume the rest of the parts (holder, heatsink, lenses and such) could be cheaper if you like). Then again since I am certainly over complicating things, I may just try getting a cheap laser level that projects a line or a cross (and has a tripod socket), and screw it to the camera, lol. I know they are both female mounts, should be easy to remedy. Cheap low power laser pointers that have holigraphic tips are reported to work quite well too.

Just a little insight to what I have found reading.

On a side note, I wonder how much of sony getting rid of the lasers was peoples perception rather than safety. They limited the shutter speed and then got rid of night vision because it could photograph through clothing. I guess those who modify cameras to do ir are a bunch of perverts, lol. Thats all the night vision on my sony v-1 is. It pulls the ir cut filter out of the way and uses an ir led light.
05-01-2013, 04:54 AM   #37
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QuoteOriginally posted by ripit Quote
within several seconds, fades almost all the way gone (in dim room light)
Maybe that's just the batteries?
05-03-2013, 04:15 PM   #38
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QuoteOriginally posted by bdery Quote
Maybe that's just the batteries?
I used fresh charged nimh batteries but perhaps the 1.2v rather than 1.5v is part of the issue, and of course the voltage is going to drop under load. I guess I could try with alkaline to see what happens. The 5mw green does the same but not as bad and it takes a lot longer to go really dim (also using nimh).

Just an update. With any of the lasers and any kind of array of dots, it misses focus a lot and struggled more even with the more powerful green laser. I just got a laser pointer I stumbled across at pet supplies plus for $3. Its one of the little mini ones with 5 tips. It is much lower power (I'm guessing 1 or 0.5 mw). Some of the tips were kind of a blur rather than an image. With those tips on the 5mw green they did give an image (I guess the laser that came with it was not powerfully enough for a good image on the cheap crappy lens tips). The butterfly did give a reasonably clear image with the cheap low power one. I went in the back bedroom (only room that is very dark during the day). I set my tamron 28-200mm to 200mm to get 5.6 minimum. It could not focus on anything anywhere in the room (not a single focus lock) with the exception of right on the vertical blinds and the couple of larger cracks of lights where the blinds were not hanging perfectly straight. It could not focus lock anywhere else, even once. With the low power cheap laser and the butterfly, not only could it get focus lock anywhere in the room, but it did it with ease most times and unlike the dots, it nailed focus every time. It seems with the right image you do not need much power.

Before I bought this one, I ordered this one on ebay.

Multifunction Laser Level Leveler with Tripod Vertical Horizontal Line Tool | eBay

Which should screw to the tripod mount easy with a piece of 1/4 threaded rod. I guess I'll have a couple to play with.

05-04-2013, 02:28 AM   #39
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Just a bit of an update. In near darkness or complete darkness, the low power red laser did fine at closer ranges (with the butterfly hologram). At a bit longer ranges (20+ feet) indoors it struggled a bit more with my 28-200mm at wide angle, but less when zoomed, despite that creating a slower aperture. I guess its magnifying the image for the AF to. Outside there are street lights but its still plenty dark. I intentionally picked dark areas. The low power laser struggled again at longer distances. Using the higher power green laser and the butterfly hologram, it was able to focus pretty well out to about 60 feet with the camera zoomed or at the wide end. At this distance the butterfly covered most of the side of a car so I don't know that particular one would be useful at much farther distances. I had no good places to test anyway (I'm betting someone might object to me shining lasers at their houses).

I guess for me what is more important is how it helps at indoor light levels. I'm thinking the low power would be plenty (the camera needs less help if there is light). Then again, the laser might be less visible to the camera if there is more light. I'm guessing it will help a lot but I think I want to try and figure out a mount next. I see no reason not to have a couple of lasers, or an adaptable setup. A higher power laser with a narrower focused hologram might be good for evening/night shooting of landscapes and such (if there is something within distance to focus on and you are not at the range yet where you can just set it to infinity). Of course that would not be a good one to be pointing at people at close range (or at people at all).

Can you tell I like building projects like this as much as I like getting something that helps my camera?
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