Technical Help about A-1 & Infrared

[Tim Polster]

Hello,

I am in the middle of a project that needs to add shooting in the night.

I have read here that if one can remove the infrared cut filter from a video camera, the camera would be permanently be converted to an infrared-only camera.

We would like to do this to an A-1, but Canon is not allowed to give us any information as it will void the warranty.

So I wanted ask if anybody has any experience with this subject.

Also, if anybody has any technical documents or any information of a technical nature that might help us know if this filter can be reached and removed by a professional video technician.

Thanks!

[Chris Soucy]

Wouldn't it be an aweful lot easier (not to say cheaper) to simply beg, borrow or steal a night scope with the appropriate lens adapter?

Alternatively, buy an HV20, it does not have an IR filter and will thus work with IR illuminators at night.

I do believe that attempting to remove said fiter from an A1 (even if technically feasible, which I seriously doubt) would do more than invalidate your warranty, it'd probably invalidate the entire camera, permanently.


CS

PS. To test for the presence or otherwise of an IR filter on your camera, turn it on, make sure you can see the LCD, aim a remote control (any IR remote will do) into the lens and fire away. If there's a filter, you'll see nothing, if there's not, you'll see the led flashing.

[Tim Polster]

Thanks for your reply.

I am in a difficult situation with this.

The daylight part of the project will be shot on EX-1 or higher quality cameras.

When the night shooting topic came up, I knew I did not want to just throw anything together with a "night vision" claim and be done with it.

I feel a night vision scope with a lens adapter would not be up to the quality I am looking for.

The A-1 was our choice because of the Canon software that can remotely control the camera via firewire. And the A-1 has a nice image at a decent price to risk the IR filter removal.

The HV20 might be fine, but the Canon software does not control it remotely.

After seeing the "Planet Earth" IR segment in the Serengeti, I realized IR shooting with quality cameras can produce some very nice results.

[Chris Soucy]

It may well be that the EX1 itself does not have an IR filter (I'm presuming in ignorance that it is a CCD/ CMOS sensor thing).

That does still leave the control problem, unless Sony have a "Console" system of their own.

Do you happen to know (or can you find out) just what camera(s) were involved with the "PLanet Earth" shoot?

I'm going to stick with my original view that this filter is incorporated into the A1 optics in such a way that removal is impossible, thus I think your choices are:-

1. EX1 if there is no filter.

2. Whatever they used for "PE".

3. HV20 or other CMOS without a filter.


Good luck,


CS

PS. It might be worth asking the question regarding the EX1 over in the CineAlta forum, at least someone there will have one to hand.

[Tim Polster]

Thanks Chris.

The remote control is sort of the center of the camera choice as this is a wildlife scenario.

I think they used Varicams for the Planet Earth segment, and I would think the BBC would have technicians that could do whatever they need to a camera for a shoot.

My local tech was unsure about the placement of the filter as well.

He said if the filter is any way associated with the area around the chips, there will probably no way to get to the filter.

I thought I would post here and see if anybody has worked on these cameras and might know anything ect...

[Chris Soucy]

I vaguely remember reading somewhere that the filter is actually built into the sensors (or some related optical component) themselves as an integral component/ layer, thus rendering it impossible to remove without trashing the sensor.

I am, however, quite prepared to be proved wrong.

If the A1 is a non runner due to this, I suppose it comes down to just how much control, of what, you need for unattended operation?

The EX1 seems to be the logical contender if it has things like Lanc "sleep" mode (standby) and start/ stop, zoom, focus etc (and no filter, of course).

I can't imagine for night operation using IR illumination you would really need much else. Maybe a remote pan head would be nice.

What all these controls have in common is the ability to work over much greater distances than either cameras firewire cable would, letting you get even further away.

I've run a remote Canon XL1s over 200 metres away with just such a set up (including the pan head but excluding the IR illumination) and don't think 200 is maxing it out in the slightest.


CS

[Tim Polster]

We are looking into a remote pan head.

So you controlled a camera via lanc at 200 meters?

Did you need any kind of amplifier or repeater?

We could make this work along with a video feed to see where to point the camera.

[Chris Soucy]

Yep, used a decent quality cable (made it myself - not hard, 8 pattern double shielded) no repeater required.

However - obviously, all transmitters are different, as are cables, as are receivers. Testing this well before hand would be adviseable.

Buy the cable in 100 metre (whoops, yards in US) rolls, whack the appropriate stereo 3.5 mm connectors on each end and see how far it will work (beware, on the roll it works like crap due to the inductance, it has to be unrolled).

The remote pan head is no problem, no digital, only dc current, so I ended up using 3 pair phone cable of all things, the cheapest solution that had the cores (the head had tilt as well).

The video feed needs the best shielded cable you can muster as the "average to start" composite is pretty much shite after 200 metres of iffy cable. Still, you're hopefully only using it to point to the target, so quality really shouldn't be an issue.

The issue will be, I think, what to do with the IR illuminators. They need to be powered, that can't be hard. BUT, what about steering?

If you're panning the camera, you may want to consider panning the lights with the same head as well. Depends on the weight of course, and the limits of the remote pan head, but as long as you don't tilt, you may well get away with it.


CS

[Petri Kaipiainen]

As far as I know ALL sensors have IR filtering somewhere, or digital imaging as we know it would not work*. Sensors are inherently IR sensetive.

How they bypass the IR filtering in cameras with "night vision" with IR illumination I do not know, maybe in those amateur cams the filter swings away when shooting in "night vision" mode.

I would think that in cameras with no nv the filter is built in with the sensor to cut glass/air interfaces to minimum. Thus no way to circumvent this with better HD cameras unless prepared to huge costs.

*) IR focus point is different from visible light, if IR were not filtered digital pictures would look funny and be out of focus.

[Chris Soucy]

Well, I hear what you say, but the bottom line is, the HV20 (and presumably other camcorders) can see IR, as can both of my digital SLR's.

Whether there is a restriction as to what frequency/ wavelength I do not know, but the "IR remote in front of lens" trick catches 'em every time.

As for "all sensors" needing this, I do have to take issue.

There was a case a couple of years ago where a digital still camera (same type of sensor remember) which was NOT fitted with a filter of any sort could, actually, "see" straight through (thin) clothing to get a "heat signature" from beneath.

Needless to say, after this little "defect" was discovered, the company concerned recalled all affected units and fitted filters, for the well being of every female on the planet.

So, bottom line, I am not sure why the filters are necessary in some cicumstances and not others (but I'm positive someone's going to wade in and tell us!) but I am certain they aren't used on all camcorders.

Your * may well be relevant, but then again, maybe not. If you think about it, ordinary film is sensitive to IR light, and no special filters are used on film cameras. Ergo, I think "not" takes the field (for the moment).

CS

[Petri Kaipiainen]

Ordinary film is somewhat sensetive to UV, but not IR

Digital sensors are not sensetive to UV (and need no UV filters), but they are sensetive to IR and need to be always filtered (when shooting with visible spectrum).

[Don Palomaki]

The camcorders in question were early production Sony Handicams back in the 1990s when they first introduced their night-vision capability. After the discovery that it could sort of see heat signatures through clothing, Sony modified the filters to block the longer wave length IR. And no, it was not "x-ray vision", just something for 13 year old boys to get all hopped up about.

In the 3-CCD (or CMOS) camcorders the beam splitter typically also provides the RBG filter functions, so it is not clear to me how much IR really passes through the beam splitter block. If a significant amount does, it likely is only in the red beam, so for IR use, the camcorder would probably be demoted to 1-CCD performance. Also, because the beam splitter (essentially comprised of several prisms) typically has the CCD attached, it may not be possible to remove any IR filter that might be present without remanufacturing the block.

If you remove the IR filter, it would not become an "infrared-only camcorder" but would still see visible light as well as it did before.

The bottom line is you might be better off using a video camera designed for IR (maybe rent one) if you need night observation footage. And there are IR adapters available for camcorders; e.g., http://www.morovision.com/nightcameraequip.htm
They list an adapter for the XH-G1 (so it should fit the XH-A1) but the image shown is for the XL-H1. No doubt someone somewhere rents the units, but they are export controlled items.

Or if this is for a work of fiction, consider using the XH-A1 normally with reasonable levels of normal light and filter or process the image (including color substitutions) in post to give it an IR night camera look for the portion of the program that needs it. This has the added benefit of allowing you any your crew to see what you are doing during the shoot.

[Annie Haycock]

Becasue infra-red looks so obviously different from daylight filming, I have no problems with using a different camera for it.

So I'm now using the Canon for everyday stuff (if only I had time to go out every day and shoot!) and I use a Sony HVR A1 for infra red work.

I have two infra-red LED lights which are mounted on an arm so that one is to the left and slightly above the camera, the other to the right and on a level with the camera, which is mounted in the middle. The whole lot is mounted on a remote controlled pan and tilt head, so the lights point wherever the camera is pointing. I use this in a loft for filming bats.

When I get extension cables for the lanc, and the p&t head and the monitor, I'll be trying more distant things such as badgers and other creatures.

The infra-red lights can be run off 12v batteries where there isn't an option for mains electricity. My lights are bright enough for only fairly close subjects, but I've also seen gel lights in use. They also ran off 12v batteries, and being brighter, with a wider angle of light, produced a rather better picture than mine did, again using the Sony A1. That was stuff for a BBC film - and a Sony A1 was bought for that purpose. (I got mine on recommendation of BBC and other professional camera people)

I think the quality of light has at least as much to do with the quality of the result as does the quality of the camera.

[Chris Soucy]

I'm intrigued as to how you discovered the HVR A1 could "see" IR, Annie.

I've just checked the Sony web site and there is no mention of this feature/ ability.

Do you know for a fact that CMOS camcorders all have this ability or, er what?

Don't get me wrong, I'm firmly of the above belief, but have absolutely no way to prove it.

The only other machine I know for certain has this ability is the Canon HV 20, another CMOS camcorder, so I guess the question for the audience is:

Is every CMOS camcorder capable of IR?

Bats, huh! I like bats, amazing creatures, shame there aren't any here (well, if there are, they keep a pretty low profile!).


CS

[Annie Haycock]

Well, I was told it did infra red, saw a demonstration, believed it, and bought the camcorder! On the camcorder there is a switch marked NIGHTSHOT and when that is on, you can see whatever is illuminated by the infra red lights. In poor daylight or ordinary illumination, it finds enough infra red to give a black and white picture. There is also an enhanced nightshot mode which you can get through the menu, and which gives pretty awful results.

I posted a clip on Youtube for another purpose, but you can see the effect. This was filmed from a hide with a glass front, so you can sometimes see reflections in the glass, and you can hear other people using their stills cameras. There was some artificial light. We were waiting for pine martens, but the deer were causing too much disturbance, and then a badger came along.

http://www.youtube.com/watch?v=iuRDuZX4Nlw

Oh, and you do have bats in New Zealand - two species, your only native land mammals. One, at least, forages on the ground amongst the leaf litter. Unfortunately I didn't get a chance to see them while I was over there a few years ago.

My last post came up twice - I edited one to be ignored because I couldn't see how to delete it. Is there a way?