Range Report Artificial light for a CED M2 chrono

[ReaperDriver]

Has anyone tried to use some kind of artificial light to get the M2 to work better in lower light conditions? I've found that about the only negative to the CED M2 (and I'm sure its not unique to that brand or model) is that later in the day towards dusk - I can't get consistant readings (or none at all) out of it as the sun starts to get low on the horizon.

I know they make an IR screen set to alleviate this - but I'm not looking to spend an extra $150 on that right now (I would have to add the optional battery pack where I shoot). Has anyone tried glow sticks, chem lights, battery powered lights or some other kind of light so see if you can extend your chrono'ing a bit latter in the day?

eta: I'm not talking full on dark, just dusk where its plenty light enough to shoot, but apparently not enough to get light into the sensors to accurately detect the bullet.

 

[ChadTRG42]

Re: Artificial light for a CED M2 chrono

A florescent light will not work, since the light flickers. You could try a normal incadecent (SP?) light bulb, and see if it works. I think they sell a light source for this, IIRC. But, the best option is the IR screens. I have shot them in total darkness and picked up every shot. They are awesome.

 

[ReaperDriver]

Re: Artificial light for a CED M2 chrono

A florescent light will not work, since the light flickers. You could try a normal incadecent (SP?) light bulb, and see if it works. I think they sell a light source for this, IIRC. But, the best option is the IR screens. I have shot them in total darkness and picked up every shot. They are awesome. [/quote

Damn, I was afraid you were going to say that.

 

[dmgreene]

Re: Artificial light for a CED M2 chrono

ReaperDriver I was wanting to ask the same question. I am wondering how bright the lighting would have to be. I was wanting to make something that would run off of 12 volts so that power could be supplied from any vehicle. I wonder if something like automotive tail light bulbs would work? I like to squeeze a penny where I can so that I can squeeze the trigger more. Anybody tried anything like this?

 

[338LM]

Re: Artificial light for a CED M2 chrono

I had lighting problems with my CED M2 also at different times of the day. I bought the IR screens/battery pack and we are talking a major improvement.
I know you did not want to hear that.

 

[ssgp2]

Re: Artificial light for a CED M2 chrono

I also delayed the purchase of the IR because I am a cheap bastard

But after calculating the amount of time and money I spent figuring out the best loads.
Coming back home with only half of the data is a wasted day at the range

The IR is worth the money

 

[mattmcg]

Re: Artificial light for a CED M2 chrono

After using the CED M2, I finally got fedup with the inconsistent readings due to a long shade that occurs in the afternoons at my local 100yd range. Went with the IR screens and haven't had a problem since! Very consistent and definitely takes the light source out of the equation.

Expensive I know but just put it on your Christmas list!

 

[Grump]

Re: Artificial light for a CED M2 chrono

I have gotten reliable readings with automotive HEADLIGHTs at a distance of about 6 feet.

It would be nice to have quantified Lumens values to calculate from.

IF I were to bother with artificial light, I'd just mount a pair of heatshields to a couple of junkyard headlight socket (small halogent--does anyone use sealed beams any more???), and mount them on a piece of 1/2-inch square tubing rigged to hang next to the screens, shining upwards to the bottom of the diffuser screens.

Estimated materials costs: $50 max. I could do it fast enough for it to be a financial gain compared to the $150 overcharged for the OEM unit.

 

[ssgp2]

Re: Artificial light for a CED M2 chrono

Before purchasing the IR, I was thinking about installing some chemlight on the screen.

I don't know if it would work do....

 

[Grump]

Re: Artificial light for a CED M2 chrono

Just my calibrated and photo-experience and chrono-experienced eyes here, but my sense is that you would need a dozen or more chem lights per screen to even have a CHANCE of that idea working.

Compared to the IR overpriced option, a person could just buy a pair of big flashlights and two pocket mirrors, and duct tape them to the unit (lights horizontal on each side, mirrors to reflect up to the bottoms of the diffusers). If it weren't cold out now, I'd try it and let you know how it works with a PACT unit... I have a nice and bright 5-D cell unit, what else is laying around here?????

 

[Jumper]

Re: Artificial light for a CED M2 chrono

I put together a set of IR LED screens for my M2. They run off of 12V. I used an extra set of screens I had on hand ($20) and ordered the LED's ($10 + shipping). LED's are cheap. I strung 17 of them down the center of each screen in a straight line centered directly above the sensor. I need to diffuse the light a little more because its a little too sensitive to shot placement. I'm sure a High intensity chem light placed on top of the sky screens would would well also.

Reference using artificial light to shine up at the bottom of the diffuser screens, it probably wouldn't work. The light source has to shine down. If light reflects off the bottom of the bullet as it crosses the sensor, the sensor doesn't see it. The sensor detects the shadow of the bullet as it passes by. Its the same effect as placing the skyscreens above snow. If too much light is reflecting up from the snow the shadow of the passing bullet is cast upward not downward where the sensor can detect it.

 

[dmgreene]

Re: Artificial light for a CED M2 chrono

I read that the CED IR light is not visible to the human eye. This may be a stupid question but how in the crap do you know if the lights are working or not?

Jumper where did you get the LED's from.

 

[Jumper]

Re: Artificial light for a CED M2 chrono

I use a digital camera. Most any digital camera or cell phone camera can see in the IR light range and they pick up the light emitted from the IR LED's. CED's IR skyscreens have a green LED that illuminates to let you know its working. Here is what the camera sees when you point it an an IR light source (these are the IR LED's on my homemade screens).

http://i139.photobucket.com/albums/q295/1Jumper10/P1000959.jpg[/img]]IR Skyscreens as seen from a digital camera

I got my IR LED's here Electronic Goldmine

 

[dmgreene]

Re: Artificial light for a CED M2 chrono

Thanks for the info. Do you remember which LED's you used? How many of these can be wired in series? I like the camera trick. Will they show up in the camera in broad daylight?

 

[Jumper]

Re: Artificial light for a CED M2 chrono

The camera can see them in broad daylight. Its just a little fainter. If I were to do this project over again I would probably use different LED's. Like I said in my first post, the diffusion isn't perfect and I have to be careful with shot placement.

Figuring out how many LED's in series you can run depends on your supply voltage and the forward voltage of your LED's. There is some calculations involved but its pretty straight forward. If you are tempted to try this I can give you some advice. PM me or just reply to this thread.

 

[ChadTRG42]

Re: Artificial light for a CED M2 chrono

Very cool!!!

 

[RECKON SO]

Re: Artificial light for a CED M2 chrono

I have also got flickering shade problems where I use my chrono, I bought the IR light screen set and built a sort of dog house out of pvc and strechted a small tarp over it so that the whole sensor unit is under the same shade the same way every time. I cant prove that this helps a lot but I figured that I would take out as many variables as I could, plus I can clock rounds in the rain and not get water all in my sensors. Since the IR light purchase I've got alot of confidence that the speeds I am clocking are the best I am going to be able to get with resources I've got.

 

[Jumper]

Re: Artificial light for a CED M2 chrono

I have been trying several different ways to use artificial light with my CED Millenium... short of paying $75 for the screens from CED. The set of screens I built pictured a few posts up worked OK but they were sensitive to shot placement. This told me I was probably needed to diffuse the light better. Tried several types of diffusers but none worked. I have since tried shining intense IR light up at the bottom of the skyscreens the way PACT uses IR light with their chrono. Not much luck. It seems that the light on both screens has to be equal and very uniform. No light or dark spots. So, I ordered some IR LED's and I'm going to try again. I've learned quite a bit about LED's since undertaking this project. The new LED's I have on order are 50 degree, 880nanometer LED's. I'm going to pack them closer together and try and close up any gaps in the light curtain. The 50degree angle should help with this. the 880nm range is supposedly ideal for sensors. I've also made some diffusers out of Lexan that might work.

For anyone who has the IR screens from CED I think I may have learned a trick that might help with getting consistent results. If you cover the sensor with a FLAT (no curves to act as a lens) IR filter it should ignore most other ambient light and only use the IR light from the screens. Assuming the light emitted from the screens is equal, the light on each sensor will be equal. This should make it so you don't have to worry about a passing cloud, direct sunlight, time of day etc. If someone wants to try it and post back here I'd be interested to see if it works. To make an IR filter, disassemble any unneeded computer floppy disk and cut a piece to cover each sensor.

 

[dmgreene]

Re: Artificial light for a CED M2 chrono

Let us know how the new LED's work out jumper. So are you saying with the filters cut out of the disc that it will block all light except for IR light?

 

[Jumper]

Re: Artificial light for a CED M2 chrono

Yes. You can use exposed camera film as an IR filter too. But there is not much of that around anymore these days. Just make sure the filter is flat. Any bends will make it act as a lens and you don't want that.

 

[Jumper]

Re: Artificial light for a CED M2 chrono

Success! I finished putting together the second version and tested them today. The chrono read 12 out of 12 shots of .22LR anywhere I shot within the skyscreens. It did not work with the IR filters over the sensor. Here is a shot of the screens taken with a Sony Nightshot camera.

Here is another. Notice the shadow of the sensor on the floor produced by the IR lights.

I took photo's in every step of the build process so I could post them if there is interest. But it was a lot of detailed work. Lots of soldering too. In hindsight, I would probably have been further ahead to buy the IR screens from CED and use my own power supply. But these are pretty cool too and they only cost about $40. and some time.

 

[Sightersdelite]

Re: Artificial light for a CED M2 chrono

In recognition to Jumper who pointed me in the right direction in setting up my IR lights for the CED M2.

You may have to register but here is the link with some more info:

http://www.airrifle.co.za/showthread.php?p=265695#post265695

 

[Fred_C_Dobbs]

Re: Artificial light for a CED M2 chrono

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: dmg264</div><div class="ubbcode-body">I read that the CED IR light is not visible to the human eye.... </div></div>
By definition, all infrared light is invisible to the human eye. It is a longer wavelength (and hence a shorter frequency) than the color with the longest visible wavelength, which is red. Infrared is Latin for "below red," a reference to its frequency.

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Jumper</div><div class="ubbcode-body">Yes. You can use exposed camera film as an IR filter too.... </div></div>
It has to be <span style="text-decoration: underline">un</span>exposed E-6 (AKA Ektachrome) or 120 (medium format) transparency (slide) film. Developed but <span style="text-decoration: underline">un</span>exposed E6 or 120. But it also serves as a 1 f-stop filter so you'll lose half the intensity of your light source. Easier just to buy an IR filter from Edmund Scientific.

 

[coues7]

Re: Artificial light for a CED M2 chrono

Should I cancel my 35P order....great great info Jumper!!!!

 

[memilanuk]

Re: Artificial light for a CED M2 chrono

Interesting thread... I have one of the earlier CED Millennium chronos, and I sprung for the IR screens and battery. Kind of had to, as where I'm at we're in a large valley and get a lot of temperature inversion (i.e. high fog/low clouds) that keeps it light enough to see, but not enough direct light for reliable chrono use about three months out of the year.

The problem I have the rest of the year is that the way our firing lines are laid out it always seems like the sunlight is angling in from the side and I get some inconsistent reads and/or no reads, even with IR screens.

Anyone here built a 'box' for the sensor heads? I'd read about a setup used by some USPSA or IPSC shooters where they had two CEDs in a box with incandescent lamps wired up as light sources so they shot through the box and the velocity / power factor numbers were averaged from both chronos. I don't need a two-chrono setup, but the idea of a semi-permanent box setup to provide a more consistent lighting environment does appeal to me. I'd have to upgrade my wimpy tripod, though as such a box would probably act like a sail and launch it across the range...

 

[BigDKC]

Re: Artificial light for a CED M2 chrono

My M2 came with a couple of files on the cdrom that had the dimensions for their chrono box. Though I think their intentions are for the IR screens, I'm sure other lighting could be adapted.

I couldn't find these files on their website so I uploaded both to my webspace:

Here is the pic file:
Chrono Box Gif image

And here is the PDF file:
Chrono Box PDF file


**ETA**
Another thought I had for those not wanting to buy the battery packs, couldn't you use an extension cord and one of those cheap power inverters to run the screens off your truck? Most people have them these days, if not I'm sure you could buy one a lot cheaper then the battery packs.

 

[Fred_C_Dobbs]

Re: Artificial light for a CED M2 chrono

Forget building boxes. I went to Target today and found a 28" long translucent plastic storage box that was about a foot deep. You could use one like it to make a housing for the whole shebang, eliminating the need for the diffusers and their supports in the doing. It would make moving the chrono a PITA but you guys are headed that way anyway. Using an all-encasing box cuts to the chase, gives you a measure of protection from rain and would dramatically reduce the influence of any external light sources if you spray painted the inside black.

Turn the lid upside down and cut a hole in the center so that when you attach the M2's mounting beam to your tripod, the lid is trapped in between. Cut a round hole fore and aft just big enough to allow the base of the sensors to fit through when attached to the mounting beam. Then cut an arch of whatever size suits your fancy through both ends of the box proper for your bullets to pass through. Attach your IR light source to the bottom of the box, which will be the top of the inside of the contraption once you've got it all hooked together, exactly opposite from the circles you've cut in the lid.

So to put it together, you attach the sensors to the mounting beam. Screw the beam onto the tripod with the box lid trapped between them and the bottom of the sensors fitting into their cut-outs. Turn the box proper upside-down and fasten it to the lid. Turn on your IR light source and align the box with your gun-target line and you're in bidness.

I made one like this for my Shitting Chrony as a makeshift diffuser and umbrella (I get caught in the rain a lot). No IR source, I attached the diffuser screen from a fluorescent lighting fixture to the bottom of the box, which was the top when assembled. It worked like a prince, except my tripod wanted to do cartwheels whenever there was a decent crosswind, and that was quite a bit smaller box than the M2 would require. I never used it much because it was too bulky to haul to the range and back, and my Shitting Chrony stayed broken more than it worked.

 

[Trovan]

Re: Artificial light for a CED M2 chrono

I thought IR filters filtered (blocked) IR light. Wouldn't this be the opposite of what you want? Help me understand this.

I have the IR screens and I have found that any cardboard on top of the screens helps to stop ambient light interfere with the IR. When I am using the IR screens in a lighted condition, I get some false readings. When I block the sunlight, the screens work great. CED told me thatthey use a box when they use theirs at matches for the same reason.

 

[Fred_C_Dobbs]

Re: Artificial light for a CED M2 chrono

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Trovan</div><div class="ubbcode-body">I thought IR filters filtered (blocked) IR light. Wouldn't this be the opposite of what you want? Help me understand this....</div></div>
There's IR-passing filers and there's IR-blocking filters.

 

[wadebrown]

Re: Artificial light for a CED M2 chrono

I work with optics and electronics and it always surprises me that the chronographs companies do not buy sensors with sensitivity outside visible light and into the infrared, and couple these with matched IR LEDs. Granted, there is infrared light in sunshine but less of it than visible.

I have worked with many of the chronographs mentioned and have usually seen effects of the position of the sun if I am not using an external light source. I built a 4 foot long triangular box for my Chrony and use LEDs on the top as the light source. With the box shielding any direct sunlight and using the LEDs as the light source provides velocity values that are very consistent. It takes a little more time to set up, maybe 3-4 minutes more, but the results are well worth it.

wade

 

[Fred_C_Dobbs]

Re: Artificial light for a CED M2 chrono

Here's the data sheet for the CED M2's photosensor.

According to one poster at the forum Sighterdelite linked to, this sensor is most sensitive at a wavelength of 940 nanometers. The visible spectrum ends about 750 nm, which, if true, would mean this sensor is partial to infrared light.

 

[Ed-G]

Re: Artificial light for a CED M2 chrono

I have a Shooting Chrony and bought two of these lights to try. I need to figure out a away to get them on and off the defusers. If they don't workout the pair was only $12.


http://www.opticsplanet.com/s/EZ-FL-EvLLFl-EVLL21S/

 

[Jumper]

Re: Artificial light for a CED M2 chrono

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Sighterdelite</div><div class="ubbcode-body">In recognition to Jumper who pointed me in the right direction in setting up my IR lights for the CED M2.

You may have to register but here is the link with some more info:

http://www.airrifle.co.za/showthread.php?p=265695#post265695 </div></div>

Very nice write up Sighter! And a very nice build! It seems that 940nm LEDS are the ideal choice.

The more I use my set the happier I am with them. No more waiting for a sunny day or better light conditions, just plug in the screens.

With Fred Dobbs info about filters, I may build a 940nm set and try the filters again. Not that they seem to need it, just that the filter should have worked and it didn't and that bothers me.