Auto-iris lens

[Scruit 0]

I have a no-name color 1/3" sony 480tvl ccd camera with a 4mm DC auto iris lens installed in my car. It does not have a mechanical ircut filter. Inside the garage under artificial light it sees colors normally, but outside in bright sunlight it sees everything as having a bright yellow/orange hue, especially reds and greens. Grass appears yellow, but even red cars appear yellow under direct sunlight. In the underground parking lot at work the car colors are all normal.

 

Do I need an IRCut lens?

 

EDIT: SOLVED!! Marzsit nailed it. The problem was I used an indoor camera that had no IRCut filter. Adding an IRCut to the lens corrected the colors.

Edited April 10, 2007 by Guest

[rikky 0]

First thing I would check is the colour settings of the camera, and switch between AWB and ATW.

[Scruit 0]

First thing I would check is the colour settings of the camera, and switch between AWB and ATW.

 

Camera is ATW and has no switch for AWB.

 

I tried adjusting the color settings on the DVR input and still never got close to the right colors. If I reset to factory defaults I find that the colors are normal indoors under artificial light, but messed up outside under sunlight.

[marzsit 0]

check if your camera can see the flashes from any ir remote control you have lying around the house. i'm thinking your no-name sony camera was made for indoor use and has no ir filter over it's ccd chip..

[Scruit 0]

I did that test yesterday - it CAN see the IR flickering on the remote control. I believe you are correct about the indoor rating. I had thought that indoor/outdoor ratings had more to do with changing lights levels and weatherproofing... So I mistakenly thought an indoor camera with an auto-iris lens would be ok inside a car as long as the storage/operating temps matched the temp inside a car (sitting in the sun, etc)

 

Sitting at a drive-thru this morning... The building cast a shadow over half of the maroon car in front of me. The part of the car that was in shadow appeared maroon and the area in the sun appeared yellow.

 

I have ordered UV/IR cut filter for the lens - should be interesting to see how that goes. That will also help with the fact that the camera occasioanlly has the sun in view while I'm driving.

[rory 0]

If its just a color only camera, it should have a "fixed" IR Cut Filter by default.

If they left that out, it was poor design on their part. All color cameras Ive used have fixed IR cut Filters, even the $50 color bullet camera. Note, this is color only, not Color/IR cameras, and not Exview Color cameras.

 

BTW, the yellow color is not related to the IR, so perhaps its something else.

IR issues would be washed out colors mostly the green shrubery, wont be yellow though. Did you look at it on a Color TV or CCTV Monitor yet?

[Scruit 0]

If its just a color only camera, it should have a "fixed" IR Cut Filter by default.

If they left that out, it was poor design on their part. All color cameras Ive used have fixed IR cut Filters, even the $50 color bullet camera. Note, this is color only, not Color/IR cameras, and not Exview Color cameras.

 

BTW, the yellow color is not related to the IR, so perhaps its something else.

IR issues would be washed out colors mostly the green shrubery, wont be yellow though. Did you look at it on a Color TV or CCTV Monitor yet?

 

 

That image is taken from a TV capture card attached to the DVR output. The car's LCD screen shows the same colors. I can hook it up to an actual TV to check it out. I know that the camera can 'see' the IR on a remote control, though.

 

 

I'll have to post examples tonight... I'm confused by the half/half car though - the half in shadow was normal and the half in sun was yellow. Seems to indicate the camera is reacting to the sunlight refelcting off the car. inside the parking garage this morning all the car colors were normal.

 

I can swap the lens for the old 4mm fixed iris lens and see if it still sees yellow.

 

Do the DC-Drive auto-iris cables use a standard wiring? The lens was prewired with the connector and I just plugged it right in. If the lens was opening too wide would it do this?

 

I did ty adjusting the 'level' on the camera, but that just made the yellow grass even more yellow, or made the image darker until I couldn't see it any more - but still yellow.

 

I help up color cards to the camera inside the garage yesterday and all the colors appeared normal. I put an old license plate which was red/white and blue on the hood of the car in sight of the camera - and I left it there as I backed out of the garage. Inside the garage the colors were bright but as I got outside the colors became very muted, but still visible as red white and blue - in the background the grass was still yellow. The weather forecast is calling for cloudy skies for the next few days so maybe I can see what the grass looks like when it's not under direct sun.

 

 

I also looked at gettnig a *true* day/night camera with mechanical filter and auto iris and I was getting prices like $400 back. All I need is a 12v camera that can look out of a car windshield, not be blinded by the sun, and see cars around me in their actual colors. Is that too much to ask?

[CollinR 0]

If its just a color only camera, it should have a "fixed" IR Cut Filter by default.

If they left that out, it was poor design on their part. All color cameras Ive used have fixed IR cut Filters, even the $50 color bullet camera. Note, this is color only, not Color/IR cameras, and not Exview Color cameras.

 

BTW, the yellow color is not related to the IR, so perhaps its something else.

IR issues would be washed out colors mostly the green shrubery, wont be yellow though. Did you look at it on a Color TV or CCTV Monitor yet?

 

 

That image is taken from a TV capture card attached to the DVR output. The car's LCD screen shows the same colors. I can hook it up to an actual TV to check it out. I know that the camera can 'see' the IR on a remote control, though.

 

I agree with Rory on his comments about color effects of IR, I haven't seen it represented as yellow specifically. Although it's not common to duplicate that either... I can see it possibly being percieved as yellow as the washout isn't a true white either.

 

"IR filter"s are not normally a hardline they curve. Light frequency vs % throughput. This means the specific filter used controls how much of what spectrum of light get through. Note the how much... some does get through. Just having an IR filter doesn't mean it can't see any IR at all.

 

IR on remote controls... If you see the light on the actual LED you haven't learned it all. Go in a dark closet or bathroom and see if it can be used to illuminate any distance. If it truely has no IR filter at all you will see that it illuminates a small closet pretty well.

 

I'll have to post examples tonight... I'm confused by the half/half car though - the half in shadow was normal and the half in sun was yellow. Seems to indicate the camera is reacting to the sunlight refelcting off the car. inside the parking garage this morning all the car colors were normal.

 

I can swap the lens for the old 4mm fixed iris lens and see if it still sees yellow.

 

Do the DC-Drive auto-iris cables use a standard wiring? The lens was prewired with the connector and I just plugged it right in. If the lens was opening too wide would it do this?

 

Some have different pinouts, I have never wired one up wrong or even had one that didn't use the default pinout. I think you should evaluate this before proceeding too much farther. I would definatley try swapping it too.

 

I also looked at gettnig a *true* day/night camera with mechanical filter and auto iris and I was getting prices like $400 back. All I need is a 12v camera that can look out of a car windshield, not be blinded by the sun, and see cars around me in their actual colors. Is that too much to ask?

 

Thats alot to ask, if you look at how complex your eye is... Lots of stuff going on to make your vision good under most situations.

[Scruit 0]

IR on remote controls... If you see the light on the actual LED you haven't learned it all. Go in a dark closet or bathroom and see if it can be used to illuminate any distance. If it truely has no IR filter at all you will see that it illuminates a small closet pretty well.

 

I can check that when I get home into the garage and close the door.

 

I can also park my car in the driveway after dark with the car/house lights all off and see if I can see the driveway lit up by the 850nm emitter on the license plate camera I have on the house. If I can see the glow then there is no IR filter... I know it can defintely see the emitter itself as I drive towards the house - looks like the porch light is on.

 

Some have different pinouts, I have never wired one up wrong or even had one that didn't use the default pinout. I think you should evaluate this before proceeding too much farther. I would definatley try swapping it too.

 

I'll check that tonight. I have the manuals somewhere so I can compare the pinouts.

 

 

Thats alot to ask, if you look at how complex your eye is... Lots of stuff going on to make your vision good under most situations.

 

I know it's a lot to ask - but I'm approaching the point now where the functionality is not worth the price. If I have reached the limits of what cheap hardware can do then so be it.

[Metal Shaper Man 0]

What about AWB, the circuitry in a color camera that allows it to yield perfect color pictures in different types of light It seems to me that there is just something wrong with that camera. I would replace it.

[phred 0]

........

All I need is a 12v camera that can look out of a car windshield, not be blinded by the sun, and see cars around me in their actual colors. Is that too much to ask?

 

All you need is a camera with 1million:1 contrast ratio.

 

A lens with 20 f stops.

 

Effective resolution approx 600 megapixels with a 130 degree field of view.

 

 

That should match the human eye but you still will not be able to look at the sun.

 

 

sorry for being a smartass but hope you see the point.

[Scruit 0]

 

sorry for being a smartass but hope you see the point.

 

Better to be a smartass than a dumbass.

[Scruit 0]

Two updates...

 

1) Here is a comparison of the Auto-iris lens versus a manual iris lens

 

 

 

THe manual iris lens is an accurate representation of the color of the grass and house. (The images were pixelated by the capture process for posting the pic to the web)

 

 

2) The camera lists the DC Auto Iris connections as:

 

(counter-clockwise from bottom left)

Bottom Left = 1: Damp - Yellow

Bottom Right = 2: Damp + Red

Top Left = 3: Drive + White

Top Right = 4: Drive - Green

 

The lens does not identify pin numbers, just colors of wires (the plug is molded on so there is no way to see what color the wires are)

 

Damp + Black

Damp - Green

Drive + Yellow

Drive - Red

 

 

Well, there's obviously something not right here. I have to try to figure out how to identify the pin numbers/colors in the lens now...

 

Making the assumption that the lens is wired correctly... I measured the resistance between the + and - of the damp and drive coils (top pair and bottom pair. The bottom pair, which should be the damp coil, measured about 700ohms, while the drive measured 200. There is no continuity between the top and bottom pins.

[Scruit 0]

Lesson for the day: When they say 'specifications subject to change without notice' they really mean it.

 

I opened up the lens to check the wiring colors - they don't match the manual. The wiring actually matches the camera, both drive and damp, and both polarities are correct. Confirmed lens operation by sitting in a dark garage and then turning the headlights on and off - The image bleaches out for liek 1/10 of a second before it adjusts to the new light level. When the headlights turn off the image goes black for 1/10th of a second before it adjusts up and you can see stuff again.

 

 

 

So, here is what I know so far:

 

- The camera sees colors normally under artificial light

- Under low sunlight colors are very light, tending slight to the yellow for grass

- Under high sunlight grass appears yellow

- In shade, car colors appear normal

- Sunlight reflecting off a car makes the whole car appear yellow

- LED brakelights appear as red

- Incandescent brakelights appear as white

 

- The Auto Iris lens sees grass as muted green, slightly yellow in late evening sun

- A manual Iris lens saw normal grass colors under the same conditions with the same camera

- The basic function of the DC auto iris is confirmed to be ok - it adjusts for sudden changes in lighting

 

 

 

Another thought: The manual says that the "Galvanometer" should be oriented to the left as you look at the camera. I had it at the top right. I adjusted the threaded section on the back of the lens to bring the 'galvanometer' bit to the left like in the manual. How important is this?

 

 

So it's definitely something with that lens on that camera. I don't have another DC Auto Iris lens or camera to try it with.

 

Some possibilities now:

 

1) The auto iris is not working correctly, even though it's fundemental operation appears to be normal. Maybe letting in too much light?

 

2) The lens is damaged/faulty in that there is a color shift as the iris opens to maximum

 

 

 

Is the IR filter in the camera or the lens? Could it be possible that the manual iris lens has an ir filter but the autoiris lens does not? I thought the ircut filter was in the camera (if at all)

[Scruit 0]

Current status: After adjusting the angle of the 'galvanometer' and adjusting the color settings while facing a store front (lots of posters in different man-made colors) I can see almost all of those posters in proper colors... Except one green poster that appears yellow... Other green posters and the shop's awning were ok - just this one poster. I wonder if the inks in the 'yellow' poster reflects light of different wavelenths than the other green posters - wavelenths that humans can't see but the camere can?

 

Grass still appears yellow, but man-made objects are almost all in proper colors.

 

The IR/UV filter will be here soon so I can see if that's the problem. If it doesn't fix it then I'll have to decide between a new camera-lens combination, or just accepting the yellow grass (at the risk of raising questings of the footage is used in court)

 

Does anyone have any recommendations for a low-cost outdoor camera that is 12v and has a 3.5 or 4mm Auto-iris lens (or c/cs mount)? This camera mounts behind the rear-view mirrors, so small size is important.

 

 

EDIT: I turned all the lights off in my garage and the camera was able to see objects lit by the IR from a TV remote control up up to 5' away. Even when the lights were on I was able to see the 'white' glow of the IR light from the remote control reflected off my arm that was 4' from the camera. I believe this means the camera has no IR filter, am I correct?

 

I don't plan to use this camera with IR lighting because it's in a car - If I'm driving then there will be daylight or headlights.

[phred 0]

Very possible you have a damaged CCD.

Sometimes the tiny wire connections give up.

Effects of this can vary from complete failure to false colour rendering.

[rory 0]

Change the lens, AI lenses are very inexpensive these days.

I had the Iris (so it seemed) go on a lens before, camera had been up for 5 years, just went bad, camera was still good, $40 lens fixed the problem.

[Scruit 0]

Very possible you have a damaged CCD.

Sometimes the tiny wire connections give up.

Effects of this can vary from complete failure to false colour rendering.

 

Hope not. I'm still clinging to the IR theory like a shipwreck survivor clings to a piece of broken wood.

[Scruit 0]

Change the lens, AI lenses are very inexpensive these days.

I had the Iris (so it seemed) go on a lens before, camera had been up for 5 years, just went bad, camera was still good, $40 lens fixed the problem.

 

That's the next step. I just want to see what impact the IR filter has first.

[Scruit 0]

Update: Problem is fixed. The IR cut filter makes the grass appear green (what a concept).

 

It also means the camera can no longer see the light from the IR illuminator on the front of my house.

 

I'll post pics a little later on when I get a chance download the images from the car dvr.

[Scruit 0]

Before:

 

After:

 

 

I just need to mount it permanently (so you can't see the black ring) and then adjust the focus/brightness/contrast again.

 

And yes, the house in the distance is slightly yellow in real life. No accounting for taste I guess.

[rory 0]

Well yeah, no IR Cut filter makes the green in grass and shrubbery etc, washed out green, but the color was yellow in your images which confuses us all. Also the images are kind of blurry which makes it more difficult to see.

[Scruit 0]

Well yeah, no IR Cut filter makes the green in grass and shrubbery etc, washed out green, but the color was yellow in your images which confuses us all. Also the images are kind of blurry which makes it more difficult to see.

 

The images are kinda blurry because I'm always messing about with the camera and lens trying to figure this thing out. I have no idea why the grass appeared yelloe, but holding that filter up turned it back to green. I dunno - I'm not an expert. I've been ripping my hair out on this thing for a few weeks now and I'm just glad to be on the home stretch.

 

THe images would be blurry if I captured them right from the camera but they're being recorded by the DVR first then replayed and then paused - and then a tv capture card is used to grab the paused image and save it to a jpg. There's a chain-of-custody I woudln't like to explain in court.

 

Thanks for you help and patience, rory. And all who provided opinions.

 

(Oh, and the cost of the filter and camera combined was about $100, so I probably would have been better buying the right camera back at the start, when you count the 4 or 5 hours I've spent farting about with it)

[rory 0]

No prob, Im sure you had fun either way