Sunkwang SK-B140XP IR Cut filter

[funkedup 0]

Hi

 

My name is Trev and I am new to the forum.

 

I have recently purchased the above camera, and would like to permanently remove the IR cut filter from this.

 

I was wondering if anyone could give me any information on how to go about this please?

 

Many thanks

[funkedup 0]

I would also like to point out, I am a total newbie to CCTV products.

 

I have bought this camera as an experiment, for a project that I am working on.

 

I have removed the camera board from the front housing, and taken off the motor cover.

 

Underneath, we have this

http://i1120.photobucket.com/albums/l493/funkedupRapid/e6e86254.jpg

 

One filter is slightly magenta, the other is slightly cyan.

 

Could you please give me any info on what each of these filters are for please?

 

 

Many thanks

[SEANHAWG 1]

The blue one is the IR filter. The clear one probably does nothing, its just clear. This camera appears to have a mechanical ICR filter which means it lets in IR at night but blocks it during the day. Why would you want to remove this?

[funkedup 0]

Because I am only using it in the dark.

Also, I am stripping the camera back to basics. I would like to make it smaller.

 

Thank you for the information though.

 

I have another question.

 

Can anyone recommend any Hi-res 2.5-3" LCD test monitors.

Or even something like this?

https://www.esdsec.co.uk/CCTV/Service-Monitors/Psg-Pro-Focus-Cctv-Set-Up-and-Focus-Monitor-3440

 

I am sure this is a trade customer only item, but I would like something along these lines if possible.

 

Cheers

[SEANHAWG 1]

Because I am only using it in the dark

It would work fine then. There would be no IR filter in the way.

[Soundy 1]

Default operation of this camera would be to move the filter away and switch to B&W mode in the dark. Removing the filter completely will only affect its daytime (color) image. Entering the camera settings and locking it in "night" mode would have the same effect.

[funkedup 0]

You will have to forgive my ignorance on this, as I am totally new to this sort of technology.

 

I am intending on making this camera a NV spotter, with the assistance of a small DVR screen and some IR light.

 

This is to be used for hunting, possibly as an add on to my rifle scope.

 

This is a big thing, here in the UK at the moment.

 

If you google 'Nitesite' this is similar to what I would like to achieve.

 

As it will only be used in the darkness, am I correct in thinking that I could just remove this complexity altogether, by just removing the filters?

 

If I wish to use this add on to record during the daytime, then the filters would have to be left in the camera.

 

I have never used one of these before, so bare with me

 

Thanks for the information.

[Soundy 1]

As it will only be used in the darkness, am I correct in thinking that I could just remove this complexity altogether, by just removing the filters?

 

Well, yes... but at the same time, it could just be left alone - in the dark, the camera will automatically switch to B&W mode and move the filter out of the way. The camera should also have an option to lock it in night mode all the time.

 

If you've already got it apart, then no harm done, but in the future, disassembling the camera to remove this isn't necessary to achieve your goals. I understand you're also trying to shrink the size of the whole assembly, but keep in mind that to be able to focus properly, the sensor should maintain its relative position to the lens mount - removing the ICR may allow you to place the sensor closer to the lens mount, but then you may not be able to focus properly, or depending on the lens, the back end of the lens may contact the sensor, damaging one or both.

 

If I wish to use this add on to record during the daytime, then the filters would have to be left in the camera.

Not necessarily. These sensors are sensitive to IR; however, IR light on a color sensor can adversely affect the white balance, resulting in odd color tints, and in some cases could adversely affect the exposure. IR cut filters are implemented on color cameras to counter this, but are not needed on B&W cameras, which is why the latter usually tend to have better low-light performance. Cheap "day/night" cameras are simply color cameras with no IR cut filter... "true day/night" cameras use the movable filters like you have there, to achieve the best of both worlds.

 

So yes, you can still use the camera day or night with the filter removed, the color will just look a little strange in the day.

[funkedup 0]

Excellent, thanks for your reply.

 

I have looked at the front mount of the Camera, and the circuit has a cover, which encased the filters and the little motor for this. when the lens (16mm Fixed Iris, manual focus) is screwed into the housing, it touches the cover that held the filters.

 

So, I could possibly, mount the lens ring onto that cover.

This will reduce a lot of weight as the front and back of this camera is cast and quite heavy.

 

I am not too bothered about the colour, but I will try it without the filters first, then maybe put them back for some further tests.

Thing is, it may take a knock or two whilst hunting, so the less there is to go wrong, the better.

 

Does anyone have any experience of some tiny DVR's with screen, that can cope well with low light cameras?

It would be nice to be able to record my trips, but not necessary.

 

Ideally I would like a viewfinder (with Hi Res can be B&W) as this would reduce glare.

It would be nice to get the unit set up with a separate output jack, to add a DVR (without a screen).

 

We use PAL over this side of the pond too.

[cctvmann 0]

im still having trouble understanding why you needed to take a camera to bits only to find out it can work in night mode via settings in the cam menu. seems a bit pointless destroying a camera and spending money as a waste. but hey ho your curiosity i guess!

[funkedup 0]

Less to go wrong when I am out in the field.

It may take a bang and shift a filter, or the function may malfunction.

So removing the filters, will eliminate the chance of this happening.

 

I may add them back in, if I decide to use the unit in both daylight and dark conditions.

 

Also, the box is quite long, for what is inside, what is from stopping me, cutting the box and reducing the overall length of the unit by about half?

 

Along with ditching the cast front and rear ends and and remaking these out of delrin, or some other light weight material.

 

Please bare in mind, this will be hanging off the ocular lens end of a £500 riflescope.

 

Any weight saving and shrinking is a positive.

[Soundy 1]

Your best bet, really, would be to look for a small B&W camera, since you really don't need color for this purpose, and a B&W camera would reduce a lot of the additional electronic complexity as well.

 

Edit: something like this might be better suited - it's small (4-1/4 x 3-3/4 x 4-1/2"), light (about 10oz), and still gives you a C/CS lens mount: http://www.pelco.com/sites/global/en/products/camera-solutions/range-presentation.page?p_function_id=15006&p_family_id=20012&p_range_id=2859

 

[funkedup 0]

That looks ideal.

 

As this camera I have, is only my test bed, I am always keen to learn about other possibilities.

 

I see that is smaller, so could be what I am looking for, but what lux does that work to?

Ideally something around 0.0001 would be perfect, but I understand this type of camera comes with a price tag $$$$$$$

 

I would also like to try a board cam, but again, I am still on my first project, to see if I wish to invest any more time and money into it.

 

I understand that I am going to need some form of IR illumination, as I am going to be shooting out to around 60yds and scanning fields at around 90-100yds.

I do not wish to use lasers for the illumination, although some do over here, but this tends to be less advantageous of say an 850nm IR Led.

 

Does anyone have any recommendations of a good small (PAL) compatible viewfinder or screen?

 

Pleeeeeeeease?

[Soundy 1]

I see that is smaller, so could be what I am looking for, but what lux does that work to?

Ideally something around 0.0001 would be perfect, but I understand this type of camera comes with a price tag $$$$$$$

That one says 0.4lux color, 0.08 B&W.

 

I would also like to try a board cam, but again, I am still on my first project, to see if I wish to invest any more time and money into it.

I was going to suggest that, but the catch with a board cam is that almost all of them use M12/M13 lens mounts which greatly limits your lens options, and I'm guessing you probably want something with a pretty substantial focal length.

[funkedup 0]

As the focus of the camera will actually be on the reticule of my rifle scope, the lens I have is a fixed iris 16mm lens. The F stop plays a factor in the amount of light transmitted, so the lower f stop the better.

 

I then use the focus wheel on my scope to bring the target into focus.

[Horizon 0]

Funkedup, it sounds like you're after a Watec 902h camera. These are black &white only. It's available as either a small cased camera, or a board camera. Low light is claimed to be 0.0003 lux. I've bought one to see how well they work, and their low light claim appears to be true. Another neat feature is that it doesn't use sense-up, so moving things don't get motion blur.

I got mine second hand, no idea what these are worth new. Try Ebay?

Also, the CCD imager on them suffers from dead pixels. Buying a camera with half a dozen dead is considered acceptable, so it pays to check before you hand over your money.

There are other cameras available. Some can do colour. Have a look on some of the video astronomy forums.

[funkedup 0]

Yeah, I know about the Watec. That is what people are using over here.

 

Some have 1/3" CCD and some have 1/2" CCD, obviously the bigger the better.

 

I bought this cam as a cheap alternative, to see how I get on with my experiments.

 

This is about the cheapest possible way for me to make a bit of DIY NV and at the same time, gain some experience and knowledge.

 

Some test pics

 

Camera in dark room

 

Camera in dark room using remote as an illuminator

 

Camera in dark room, using remote as illuminator, pointing beam through ocular lens of 4x40 tasco scope.

 

This pics were taken with the cam rigged up to my TV.

Throwing some IR light at this is going to improve it no end.

Just need to find out what wavelength the remote is, it must be around 940nm.

 

I think an 850nm LED illuminator will give me plenty of distance and maybe even 940 at around 3w will be pretty bright and covert.

 

obviously these pics are not the best, but it has given me an idea of the capability.

 

I have now replaced the filters, to see if there are any gains, as I may get a better picture quality.

Edited March 17, 2012 by Guest

[Horizon 0]

Hi again funkedup.

Dealextreme is an interesting site to have a look at. They have 3watt Luxeon/Cree style LED modules, or "InfraRed IR Drop-in Modules" to fit into torches. These LEDs give a red glow, so not ideal for stealth use, unless you want to mess around with filters. It should give you plenty of light for the Sunkwang.

I've been tempted to use these with my CCTV cameras, but haven't found the time

[funkedup 0]

Hey, yeah, i have been looking at these.

but first I am going to try a 10 degree 12v 50w halogen spot, with a 850nm camera filter. Just because it is a bit cheaper.

 

I know these get hot, but they will only be on for short bursts of time, I will use a spotter to scan the fields.

 

Right, I have my day scope adapter made up now, the camera shortened and have ordered a EVF

 

it is the same as this on the bay

380422270957

 

I just don't understand how I am to wire this to the power supply (5v I think) and to the coaxial cable from the cam.

 

I have this

 

Also, when looking at the connector block, how do I identify pin 1, as this could be on either edge.

 

From what I see, pin 1 is 5v +, Pin 2 is -, Pin 3 is vid input

 

But does pin 1 share 5v + with vid +?

 

Pin 4 is for horizontal sync, what does that do?

 

Any help appreciated.

[Horizon 0]

Hey there. Any chance of a better copy of the schematic. It's a bit small to see clearly.

Based upon what I can see, this EVF drives a small CRT (not the LCD listed in eBay). The circuits will be completely different, including the ICs. Did you get the one on eBay, or the one matching the schematic?

 

For the schematic, I'm not certain that this needs 5 volts, it could need higher. You've checked the datasheet for that IC (KA something something)? What's its part number? The datasheet will say what voltage the IC needs, which is what you need to apply to pin 1.

Video would go between pins 3 (vid) and 2 (gnd). There appears to be a 270K (can't read it clearly) resistor next to the capacitor connected to pin 3. It's too high to correctly terminate the video signal - if this EVF is the only thing connected to the camera, connect a 75 ohm resistor between pins 2 and 3 for termination. It'll make the video look better.

Not sure why the horizontal signal on pin 4 is being sent back to the camera. At a guess, if it was connected to ground (edit: or maybe to the power on pin 1 - hard to tell. Need to see the datasheet), it would turn off the extra-high voltage to the CRT. It would allow you to turn the CRT on and off quickly, without having to wait for the CRT filament to warm up. You should be able to leave this disconnected.

[funkedup 0]

Cheers for the info, I love this forum!

 

As I am just dabbling in electronics, it is very helpful for me to pick up some general information.

 

I have spoken with the seller regarding this, and he has informed me that for my use, it will be tricky to set up, but he has told me that he has another.

 

He will be sending the schematic for this along with the viewfinder.

 

This guy is in Latvia though, and he has offered an associate of mine the same viewfinder, so i am a little dubious to whether I will receive anything to be honest!

 

I am getting excited now, as I have received my filter, I have gone for an 850nm

My dimmer switch for my lamp is in the post

 

I have a circuit to restrict the current from 12v-5v for the viewfinder (USB only has a 5v output)

 

for this lamp (need a case made up as a bit of a shroud to reduce light spill and hold the filter)

it is going to be an adapted lightforce lamp

 

using one of these battery packs

[funkedup 0]

Illuminator is finished

 

 

 

Everything is wired up now and working well, I just need to get it all put in a neat and tidy box.

 

I am possibly going to move the OSD to the RH of the box, if the wiring looms allow, that way I can change the settings whilst I have the rifle in my shoulder and am looking through the viewfinder. Rather than plugging it into my TV.