Light spectrum

Adam · Post by **Adam** » Wed Dec 15, 2004 10:42 am

McEve, that reply wasn't from the company that sells the submersible camera was it? What would be the point of selling a submersible camera that doesn't work under water?

As for infrared imaging not working under water I don't know what they are talking about. Only the other day I was watching a wild life programme about squid and quite a bit of footage was taken with a night vision camera.

I may have got the wrong end of the stick, was your enquiry about something else? Please explain.

McEve · Post by **McEve** » Wed Dec 15, 2004 10:56 am

This company didn't sell submersible cameras. Night vision cameras don't use IR, they enhance the exsisting light, so for them to be used there needs to be *some* light, moonlight or simply starligh is enough for that kind of camera.

I don't know if the Zebra would feel safe enough if I let some light in....

Adam · Post by **Adam** » Wed Dec 15, 2004 12:25 pm

You know the guy that puts things together and reads the instructions afterwards, I'm afraid that's me. I must get out of this habit, I have now read the datasheet for the camera properly. You are right some night vision cameras do not generate IR but rely on whatever little light is available. This is not the type of camera you should be looking at, that said the amount of light required is so little that you or I would consider it to be dark. If you have a second look at the datasheet for the camera that I suggested you will notice that the manufacturer says;"Built-in high sensitive IR LEDs enable it to picture at total darkness."
That would suggest to me that it is capable of producing IR light in order to capture images at very low Lux levels, 0.1 to be exact.

Cameras that can function at a Lux level of 0.0(total darkness) have in built IR LEDs presumably to generate a light source. At these sort of light levels images will be in black and white, they can also look green to us depending on the camera used.

As an idea to take the guess work out of all of this you may want to consider getting hold of a Lux meter. You will then be able to judge appropriate lighting levels for yourself and then purchase a camera to suit your needs.

I use one at work occasionally to perform desk risk assessments for people complaining of eyestrain when using their PCs. There's a big drive on Health and Safety in the work place at the moment and this is fast becoming a popular request. The meter I use at work has a range of 1 to 20,000 Lux and an accuracy of +/- 5% so I doubt if it would be sufficient for this sort of application. I belive they can be hired for a nominal fee, or you could borrow one from a professional photographer if you know one.

McEve · Post by **McEve** » Tue Dec 21, 2004 9:04 pm

I found a person that has done IR filming under water, so I don't know what the salesperson I got the reply about IR not working under water got that from

And I also bought a camera on his recomendations

It was delivered today, so now all I have to do is figure out a way to get the film streamed to the computer somehow. It's only got a video out, (RCA or BNC cable) so I have to think of something clever.... I think I got a really old video card lying around with a plug that will fit this kind of cable, but I will have to see if that works at all.....

I disturbed them when doing a water change today, to tail is in the cave - unfortunately not the one I have custom made with a glass at one end - the male still prefers his old cave, even now that it's moved to a different location.

Adam · Post by **Adam** » Fri Dec 24, 2004 3:23 pm

Hi McEve, I did suspect that the salesperson you talked to was mistaken.

Where did you get your camera from if you don't mind me asking?

You might be better off getting a video capture card, I think you may not have the right inputs on a conventional graphics card unless it's one of those all in one top end cards.

Your male is obviously wary of the new cave or he just prefers his old one regardless of the fact that the location has been changed. You may end up having to remove his old cave if he refuses to use the new one. I would give it some time before doing this though.

McEve · Post by **McEve** » Fri Dec 24, 2004 10:30 pm

Hi Adam - merry christmas

I bought the one on the top of this page:
http://www.rfconcepts.co.uk/cameras2.htm#IR%20Cam

I do need a TV-card for it, but that's ok, I have two alternative solutions for it, so they'll be online in IR in the not too distant future

I'll give him time to see what he prefers, but the way it looks now he still prefer his old cave. If the fish doesn't mind the IR it won't matter too much though, as the camera I bought is water proof down to 30 meters

I will spy on him and will outwit him sooner or later so that I can get the footage I want

ps, pictures belonging to my posts and profiles are offline for a couple of days, I've turned off all the computers for the holiday - and what a difference it made - I have an ear deafning, but blessed, silence in the house now

McEve · Post by **McEve** » Sat Jan 01, 2005 11:44 am

IR does work in water! I now have a picture on the TV from a submersed camera, now I have to get the picture on the computer and streaming it

It's rather cool to watch the fish from this perspective!

So far I haven't been able to get the TV in options I had available to work, but I haven't given up just yet

Adam · Post by **Adam** » Sat Jan 01, 2005 1:53 pm

Happy new year McEve,

Great news about the camera.

Now hurry up with the streaming and get some pictures posted. If you were in the UK you could have my video capture card that's just lying around collecting dust, another impulse buy I'm afraid.

What's the hold up I still can't see anything yet.................

McEve · Post by **McEve** » Sat Jan 01, 2005 3:36 pm

I'm hurrying I'm hurrying

The video capture card I had didn't work with this camera, so I'm not quite sure how I'm going to get it to work... It's using a phono cable, which I now have connected to an adapter to make it go in through the scart on the TV.

The video capture cards don't have scarts, so I have to try something else. Any idea?

McEve · Post by **McEve** » Sun Jan 02, 2005 3:18 pm

I got the IR up and running. The quality is not very good unfortunately, and I don't know how it will be like for dialup users.

I'll have to add more IR light, maybe moon light to make sure the quality is good enough, but so far it looks like this

McEve · Post by **McEve** » Tue Jan 04, 2005 9:31 pm

My project have encountered another unespected obstacle.

The male is now guarding eggs, so I put the IR camera into the main tank, about 15 cm from the entrance to his cave, and pointing into it. I turned the lights off, and could see everything that happened inside the cave

Oh joy! Until I noticed that he was thrashing about, pressing up against the inner most wall, backing out swishing his tail towards the camera, speeding inside the cave again, thrashing about some more - he just didn't keep still one moment and did seem very stressed! It didn't take more than 1-2 minutes of this before a thought occured to me - I think they can see the IR light!

A quick search on google revealed this link

"The high-powered lights used too much voltage and the infrared light appeared to have some effect on the fish, indicating that some fish may see that spectrum." Really?!

It didn't even occur to me before I saw the males reaction!

Back to the drawing board

Adam · Post by **Adam** » Wed Jan 05, 2005 12:43 pm

HI McEve,

That's a real bummer

, trust zebras to be one of the few fish that can see IR light. If you think about it though it makes perfect sense as they are primarily a nocturnal fish. The only thing I can think of doing is to increase the distance between the camera and the male zebra's cave as the light is obviously spooking him. Perhaps with time he will become accustomed to the light.

McEve · Post by **McEve** » Mon Jan 10, 2005 6:18 pm

He panicked enough to eat the eggs

That's what I get for mixing hobbies