New Laser Build for Night Vision

[Vandis2]

I'm a newb and glad to be on the forum.

Am trying to put together a relatively high powered focusable Laser illuminator good to 300+yds for the economy and fun of it all.
I just bought and am waiting to receive an infrared EJ230 bullet camera from Kt&C and the specs indicate that its SONY 960H CCD sensor is calibrated for ~850nm IR spectrum light radiation.

From what I have learned from videos and others, and if my memory serves me right, this EJ230 camera loses sensitivity and brightness to IR illumination exceeding 900nm (i.e. 940nm IR flashlight).
But what happens within the chip sensor when exposed to reflected light illumination at longer than 850nm wavelengths, specifically at 808nm?
Would this wavelength generate brighter images?

The reason I ask is because I am looking to pay considerably money for an 850nm laser diode or module, which begins to defeat the whole purpose of the build.

In looking for a high powered 850nm diode or module, I have discovered that the most common mass produced IR industrial laser diodes over 300mW, and the most available, seem to be the 808nm diodes.
Hence prices are very low internationally relative to the 808nm diode, as most of you know.
For example on ebay an 850nm-300mW diode sells for $54 whereas an 808nm 300mW sells for only $3.
And a full laser module with heat sink (808nm-800mW) can be bought for less than $100 whereas a similar 850nm is almost 4x that cost.

Can anyone give an educated guess as to what my 850nm camera will give me when recording illumination generated at 808nm wavelengths as verses 850nm?

And BTW, I do know of the safety risks involved in using high powered IR laser illuminators over IR LEDs.

 

[jaybeez]

I'm having trouble googling up the specs on that sony ccd. I looked 3 places and got 3 different specs. all the commercial digital nv devices I'm aware of are daylight and ir sensitive. that's actually one of the benefits of this technology in its early stages. if that is the case with this ccd, then 808nm should work to illuminate just as well as 850 or visable light. 850nm visability isn't especially amazing for digital as far as I'm aware. its actually typical of digital (once the ir filter is removed).

in my experience, lasers make terrible illuminators, but excellent designators, but granted I haven't much experience with lasers and digital.

eagle tac makes a rediculously powerful led iluminator, osram based iirc that's quite affordable. I have $7 leg with a filter that works to 100 yards.

what is your project or need? I might have other suggestions.

 

[jaybeez]

i just watched this video review on that camera, the user used it in daylight and night, so any wavelength light up to its max sensitivity should work to illuminate, 720 808 840 850 ect.

EJ230 Night Vision Camera Review & How To Adjust - YouTube

 

[Vandis2]

Jaybeez

Roland of "Rolaid's Bench" the author of the youtube video you linked actually answered that question for me on his youtube channel. He said,

I have used it with 808/850/915/940 and the camera does well with all. That being said as you move up the 'scale' the sensitivity of the Sony CCD to that frequency drops off so you need more power to get the same results. This equates like this: 850nm is about 2x as visible to the CCD as 940 so you will need aprox 2x the Lumens @ 940nm.
First decide your need for 'invisibility' and then plan your lighting for the range max.​

I am likely going with an 808nm diode module from 300-500mW.

Regarding the specs on the Sony 960H chip that is featured in the EJ230 camera you can see them here:

http://www.ssesa.com/pdf/1105.pdf

and the camera specs here:

KT&C Co., Ltd. :: View topic - KPC-E230 / EJ230

 

[jaybeez]

are you trying to make a rifle scope like rolaid's?

because while his setup looks ingenius, it has some major drawbacks

 

[Vandis2]

Yes I plan to mount the camera behind my 50mm scope on a Rem700 .243.
What drawbacks do you see?
There is a necessary trade off for the economy of the build!

 

[jaybeez]

-12v power for the camera
-? v power for the lcd display
-loss of light transferance through the scope, this is a big one, expect a huge decrease in efficiancy
-mounting everything together and standing up tobthe recoil, .243 is a medium cartridge but it shoots light, still quite the investment for something that may not hold uo to higher recoil
-still need an illuminator and power for it
-a large lcd display will illuminate you and spook game and trash your eye's adaptation to the night
-its going to be heavy
-its not particularly safe to shoot with night vision without good illumination, digital won't see anything at night without supplimental illumination of some type, and laser illuminators that I have seen provide to narrow of illumination to be safe for shooting with in digtal. especially a caliber that can travel as far and flat as .243.


I dont see a huge cost savings with this set up over something like a used pulsar n550. the performance gained with the sony ccd will be lost when using a cheaper scope.

what scope was rolaid using? it looked expensive. and rolaid is hunting with a pellet gun. at really close range.

 

[jaybeez]

something nice about a real scope like the pulsar n550, if you pick it up used, you can resell it for what you have into it usually. real intensifier based nv, while expensive, holds its value well.

rolaid's setup, is a bunch of expensive used electronics and bits when he's done with it.

people speculate that one day digital will be the end all be all of nv, but it has a long way to go.

 

[Vandis2]

-12v power for the camera
-? v power for the lcd display
-loss of light transferance through the scope, this is a big one, expect a huge decrease in efficiancy
-mounting everything together and standing up tobthe recoil, .243 is a medium cartridge but it shoots light, still quite the investment for something that may not hold uo to higher recoil
-still need an illuminator and power for it
-a large lcd display will illuminate you and spook game and trash your eye's adaptation to the night
-its going to be heavy
-its not particularly safe to shoot with night vision without good illumination, digital won't see anything at night without supplimental illumination of some type, and laser illuminators that I have seen provide to narrow of illumination to be safe for shooting with in digtal. especially a caliber that can travel as far and flat as .243.
I dont see a huge cost savings with this set up over something like a used pulsar n550. the performance gained with the sony ccd will be lost when using a cheaper scope.
what scope was rolaid using? it looked expensive. and rolaid is hunting with a pellet gun. at really close range.

Good points, you know what you are talking about.

Let me respond, as I have thought about this too:

-Scope light transferance loss: You have a point as there will be light loss. Though my scope is excellent, a Nikon Monarch 4x16-50mm. I can see better in the dusk thru it than with my natural eyesight. At night without additional ambient light the camera will detect the scope image just fine.

-Illumination: I am using a 500mW focusable 3oz laser module illuminator <$70 that will outshine an LED flashlight at a fraction of the weight and price?

-Spooking: Hunting wild hogs on private land in the middle of nowhere in the middle of the night from a fixed bench rest at 150-200yds, I will be in a blind of sorts so not much visible light reflection to spook anything

-Weight: The $35 5" HD LCD monitor is only a few ounces, the EJ230 camera and laser about the same. And it all comes off in one piece leaving me with the scope still sighted in for day hunting.

-Recoil: The monitor is made for a vehicle, the camera is sturdy and the laser as well. My gun is already close to 10lbs (a heavy benchrest bipod) so recoil is less than a sport barreled gun, but may have to adjust things periodically.

Camera $110
Monitor $35
Laser $70
Cables, picatinny rails, etc. (running everything off my 12V vehicle battery) $25

Total build cost <$250 and a lot of fun
Price for a new Pulsar N550 $1200

 

[jaybeez]

well, spend a couple more bucks and run the video out to a portable hardrive and post the testing videos and hunting videos.

 

[Vandis2]

You are right.
With a $20 USB video cable device one can run the IR camera feed directly into a laptop instead of the monitor.

Sabrent USB 2.0 Video/Audio Capture DVD Maker Adapter - USB 2.0, MPEG Encoder, Plug-n-Play at TigerDirect.com

Good idea!

 

[jaybeez]

well I was actually suggesting the rifle mounted monitor and a laptop or hardrive in addition to it. the pulsars and some thermals have a seperatr video output so you can record to a portable hardrive. the youtube videos of many digital nv devices are recorded this way, giving higher quality than you would get from looking into a smal lcd in the real world.