[HOWTO-WIP] Infrared photography
 

So I decided a few weeks ago to try my hand at removing the IR filter on the N900, because IR photography is awesome.

I ordered a module on ebay, so I wouldn't break my current one.
I broke the one I bought, and broke my original one when I was removing it from the phone.

45 minutes later, disassembling and reassembling the phone twice (because after doing it once, the N900 doesn't turn on until you disassemble and reassemble again), I have a working infrared camera on my N900- other than the broken autofocus and damaged sensor from scratching it when removing the IR filter.

http://i.imgur.com/sOxpo.png

The light (in the "Light off" image) is from a 1.2v 20mA IR LED. I'll take some day pictures tomorrow, when it's day. Once my new module comes in, if I don't break it again I'll have nicer focused pictures.

Re: [HOWTO-WIP] Infrared photography
 

great thingy dude .

Re: [HOWTO-WIP] Infrared photography
 

http://i.imgur.com/2rIUw.jpg

Found a piece of broken filter from where I took it out to compare before/after, top is holding piece of the filter infront of the LED and the bottom is without it.

Re: [HOWTO-WIP] Infrared photography
 

It would seem not many people find IR too interesting.

Re: [HOWTO-WIP] Infrared photography
 

Is there a reason you are using 940nm LED's?
You should get a better night picture with a lower frequency.
The only benefit of using higher frequency IR is to make it more invisible to humans.

Re: [HOWTO-WIP] Infrared photography
 

How much was the spare camera?

Re: [HOWTO-WIP] Infrared photography
 

isn't it the other way round? Seems more intuitive to assume a frequency higher on a band below visibility is more visible than a frequency far off the visible range.

/j

Re: [HOWTO-WIP] Infrared photography
 

IR photography is awesome.Used to have an old camera and hacked it for this purpose :)

Re: [HOWTO-WIP] Infrared photography
 

No, although I do apologise were I said frequency I actually mean wavelength.
I deal with infra-red and cameras as part of my job.

Humans can see light between ~380nm and ~740nm.
IR covers from there to about 1mm.

IR LED's come in different wavelengths
I install these at work, the 850 is slightly visible (has a glow) whereas the 940 is invisible to the naked eye.

Using 850nm compared to white light reduces camera efficiency by ~25%, whilst at 950nM it can be reduced by over
60%.

Also less applicable here is the problem of focus shift, which is were a fixed lens camera becomes blurry while using IR.
The lower wavelength IR's reduce this effect.

Re: [HOWTO-WIP] Infrared photography
 

So actually "yes", since higher wavelength means lower frequency ;-)

/j

Re: [HOWTO-WIP] Infrared photography
 

@azkay
I'd like to answer your question from other thread rather here.
using several LED in series, with a smaller series-resistor, genarally yields better efficiency on same supply voltage.
with 70R resistors you should be safe to use 3 pcs LED specified as 1.3V@20mA in series, on a supply voltage of 5V. BTW aiui the datasheet says the LEDs can handle up to 100mA continuous forward current, I'd maybe go for 50mA.

OTOH sixwheeledbeast has quite some point with his suggestion to use LEDs in the 850nm range. For those you should get specifications and redo the math.

/jOERG

Re: [HOWTO-WIP] Infrared photography
 

Well OK, but nobody corrected me.
You don't measure frequency in distance and you don't buy IR LED's by frequency.
Yes, you are correct that wavelength and frequency oppose each other in the scale of waves.

Also if possible try even lower wavelength like 740nm, they will be even more visible but you will get better images and spread of light at close range.
Also different LED cases make a difference as to how even the light is spread, they can be bought in a variety of "spread" angles

Re: [HOWTO-WIP] Infrared photography
 

Absolutely awesome! I was fighting with camera module 2 weeks ago (resulting in broken autofoxus in two camera modules - it works ok only for up to ~14 cm, don't want to focus on further objects, even via manual adjust, as per fcam or camera-ui from cssu), as night-vision via N900 was idea that "struck" me more than a year ago.

To be honest, after looking @ camera module internal, I haven't balls to try removing filter. It seems, that your first attempt resulted in ruined (scratched) sensor, but You know (now) how to do it properly.

Could You share Your experiences here, as detailed as possible? Some guide for removing (replacing by regular glass?) IR filter in N900's camera module would be great :)
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OTOH, how You have destroyed original module by removing it (what happened)? Also, do you think that it's possible to fix broken autofocus on such module (or problems like ones I've described, with ~14 cm max focus distance), or module looks too delicate?

/Estel

Re: [HOWTO-WIP] Infrared photography
 

Not much reason, was just looking for something and I hadn't played with it before so I went with 940nm.

My fourth module just came int today.
First one I ordered I broke the autofocus, I started dismantling from the top up. After that I broke the original one trying to take it out, so I had IR without autofocus. The third one I got a few weeks ago I did perfectly, but the phone was giving me an "Operation failed" when I tried to use the camera. I got my fourth one today, tried it before touching it- worked fine. So, the third one was faulty- too bad I didn't test it first to get a refund.

Took it apart perfectly, took out the IR filter and put it back together and it works with autofocus, though as you said it doesn't seem to focus too well on further away things. I havn't tried replacing where the filter was with glass, might have to try it.

Basically, now it's working fine but not for landscape type photos, I still have a little noise on the sensor but it's probably dust/glass particles which I could probably clean out later if I can bother with it.

Hard to not make a mess trying to cut out glass filters with screwdrivers and knives, lol.

Here is a picture of how I took apart the faulty one- same as the working one.
http://i.imgur.com/p755G.jpg

I pretty much just used a small flat screwdriver on each corner and twisted it slowly to break the seal/glue stuff, then I used the edge of a flat screwdriver/sharp knife to cut the edge of the filter slowly as to not go through into the sensor, then when it cracked I used a needle to snap the glass off away from the sensor.

Also bought 720 and 950 dslr filters to cut out and modify into the case.
Not sure where I'll find .5mm piece of clear glass to replace the old filter with.

Re: [HOWTO-WIP] Infrared photography
 

Looks very good, I think I have nice use case for my "broken" camera modules.

BTW, oddly enough, my module refused to focus on objects further away than ~14 cm after only removing it from N900's mainboard, not after disassembling it (I've disassembled it later, when I knew, that I had nothing to loose). In fact, even when adjusting manually, I can not get it to focus further away.

IDK if it's the same in Your case, maybe not. While reading through pages about modifying cameras for IR, I've found information, that replacing IR filter with non filtering glass is required to keep autofocus working - it may be related to Your problems.

Best way to check it, is to use fcam or CSSU'ish camera application - use manual focus, and see, if You can get sharp view on far away objects. It would be very useful to know.

/Estel

Re: [HOWTO-WIP] Infrared photography
 

I tried it with fcamera an hour ago, focus set to >5m outside is still blurry. Anything within a few meters is fine, though.

Guess it's the problem with not having the glass there.

Re: [HOWTO-WIP] Infrared photography
 

Unfortunately, no. glass helps only to regain *autofocus* - You should be still able to focus manually, though. It looks like same problem as mine - it's just that mine blocked @ 14,77 cm, and Yours at 1m or so.

What troubles me, is that this "damage" may occur even, when just removing camera module from slot, without actually disassembling it. No clue WTF - it looks very sturdy, and it's held in slot via regular, mechanical thigie' lock - can't imagine what may get destroyed, when carefully disabling this lock and removing module :/
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As for Your question where to get 5mm square of glass - cut it out from bigger one, of course. You just need to find piece of clear glass with reasonably similar thickness, then carefully cut it, using glass cutter toll. They're very cheap, fortunately (tools, not glass).

/Estel

Re: [HOWTO-WIP] Infrared photography
 

The autofocus on mine still works, it's just blurry at distance. I can still see it go in focus/out of focus on things.

.5mm, half 1mm thickness lol.
I think I read somewhere awhile ago that plastic works as a makeshift alternative, just won't be as good as glass. Can't hurt to try.

Re: [HOWTO-WIP] Infrared photography
 

Also, don't forget that the focus point is different in IR photography (although if you deal with this stuff you obviously know this). Maybe the autofocus needs to be "shifted" a bit to adjust to IR?

Keep on trying, IR is awesome.

Re: [HOWTO-WIP] Infrared photography
 

Agreed, you may get focus shift depending on the "wavelength" of the IR's; as I mentioned in more detail above.

You will find the autofocus will be setup as white light. So with higher wavelength IR and/or the further from the object you are; the more the focus shift will need correcting.

Re: [HOWTO-WIP] Infrared photography
 

Interesting mod, useful to take photos of animals at night with an IR spotlight :)

Re: [HOWTO-WIP] Infrared photography
 

Neat idea - small screen, put into binoculars-like mount, connected to N900's TV-OUT, and bundled with powerful pack of IR diodes. N900, of course, with IR modified camera module.

Result:
N900 turn-able into NightVision set, with surprisingly good quality/price ratio. All You need is to replace day-photo module to prepared IR one (require ~20 gram small screwdriver with two tips) - can be done in 3 minutes, when You gain experience with quickly assembling and disassembling device - and, plugging binocular's plug into TV out.

With some smart construction, whole set may be extremely lightweight, ultra-portable (to the point of always having it with Yourself), and non-requiring another, dedicated N900 (compatible with main device Youi're using everyday.
---

Crazy idea for my personal variant of custom body replacement - mechanism for camera module quick-swap, without need to disassemble whole body. Just "click", and camera module is removed. Another "click", and 2nd one is back in place :)

I don't think it would meet widespread usage, but for me, personally, it's another overkill feature.

/Estel

Re: [HOWTO-WIP] Infrared photography
 

I do not, this is my stepping stone into the world of IR.

Re: [HOWTO-WIP] Infrared photography
 

Is this possible to do with the N900? Or would it be a hardware problem? Basically, what must be done to get this clear?

http://i.imgur.com/92CcG.jpg

This is with FCamera at >5M

http://i.imgur.com/3JV6P.jpg

Re: [HOWTO-WIP] Infrared photography
 

As I've said earlier, manual focus settings have nothing do with it - Your camera module just got damaged during removal/mounting. All of quoted things are related to *auto*focus. When You set focus manually, to "infinite" (>5m), You should get good results, no matter what. Unless Your camera module canmt physically - move lens as requested, which is, sadly, the case here.

As said earlier (again) I have no idea why focus mechanism is so fragile - I got same problem on my camera module, without opening it, at all. Just removing it from motherboard was enough to damage it.

It's, probably, the case, why service manuals say "never use the same module after removal" (like they do with screws). I'm quite sure, that with enough care and luck, one can remove module safely. Same applu for dedicated module removals, which are exorbitant'ly overpriced.

The thing is, that I have no freakin' idea why it get damages so easidly on the first place - dedicated removal tool doesn't perform any magic, it just disable two mechanical locks, and pull module off. The same should be achievable without removal tool, and despite looking at module from every angle, I just can't find a way it could get damaged, when so carefully removed, as I did.

Yet, it is screwed, both in my and Your case. Which is major roadblock for now, as we need to find non-damaging way of replacing it (by avoiding touching some fragile part, etc - need to first identify, what is directly responsible for damaging it).

/Estel

Re: [HOWTO-WIP] Infrared photography
 

Got it,

http://i.imgur.com/DSdfH.jpg
I put in a .5mm clear plastic square in place of where the filter was originally.

Re: [HOWTO-WIP] Infrared photography
 

But what have changed? You're implying, that focus started to work as it should?

No matter what, great photo!

Re: [HOWTO-WIP] Infrared photography
 

Focusing always worked, it would just be out of focus for distant objects, the focusing still happened. Replacing the original IR filter with a clear "filter" fixed the focusing problem at distance.

The particles on the sensor is annoying, though.

Re: [HOWTO-WIP] Infrared photography
 

Hey guys,

I dont have an N900(I have an N9), this is damn interesting, Anyway, just wanted to share some wishful thinking ..

I remember during the old days when I had an N73, there was an add-on Flash accessory(PD-2)

Just had me thinking, it would be nice to have on my phone and if its possible to have a flash, it might be possible to have a camera module as well... But that would take software and some major mods to the OS itself I assume.

Edit: Even if this idea might not be totally practical... there are other things that must be possible in this direction...

Re: [HOWTO-WIP] Infrared photography
 

Unfortunately, original camera modules for N900 are quite impossible to disassembly.

Following azkay's photos, I just did a run on tearing down my faulty module (nothing to loose, as it was screwed already) - first of all, pictures doesn't match, original module looks quite differently.

Second, it's not humanly possible to disassemble it from downside and remove filter, without literally tearing it down. It's made "Chinese way" - once for eternity.

I suppose, that azkay modified it successfully on replacement module, so it's probably possible to use those. They're not original, of course, and that bring possibility of worse picture quality for normal photos - but, for NightVision, it shouldn't matter. I might give it a try, after finishing replacement body project - it might be feasible to use original module for normal photos, and modified replacement one for night vision.

/Estel

// Edit

just a wild guess, but I might have found reason, why focusing mechanism got damaged during removing module. Moving focusing lens occur due to copper spiral on moving part, which is enclosed in magnetic field of camera module's case. Actually, case contain 4 neodymium magnets, and copper spiral on lens is connected via ultra-thin wire, to module base (where matrix is located). When in use, copper ring becomes electro-magnet, and it strength is controlled by module, which result in ultra-precise control of lens distance.

Now, Using advice from this very forum, I've used shaving blade (old type) broken into two, to disable locks, that keep module in place of N900's motherboard. Such blades are heavily prone to magnetic power. It's possible, that their effect on magnetic field cause lens to move out of it's defined range, bending part of *very* delicate spring mechanism, that is part of force, controlling lens position (spring push into one side, and electromagnetic copper ring into another).
---

After tearing down whole module to pieces (literally0, I can't see anything else, that could get damaged during removal. So, again, it's a guess only, but I suspect that using non-metallic (plastic, ceramic) thin things to disable locks, should grant safe removal of module. I would avoid using anything metallic to remove it, and keep than in mind during storage (outside N900's body).

/Estel

Re: [HOWTO-WIP] Infrared photography
 

My original N900 module was the same as this one, the first 2 I took apart completely from top up which is how I broke the autofocus on those, ruining the coil.

You basically have to do it from the bottom up, between the sensor and the lens assembly it's just glued on.

Re: [HOWTO-WIP] Infrared photography
 

Hm, in case of module, that I'm 10000% sure was original, IR filter was on top of sensor, protected by *mold* plastic case. It;s just like that You need to break this plastic all-together, to remove filter. Quite low chances of not scratching sensor matrix :/

Also, there is another caveat - ultra-thin copper wire, than connects base PCB (with sensor) to copper ring. It's super-easy to break it, while un-glueing base of module. Not to mention that - at least in my case - this glue was stronger than plastic itself, i.e. parts of plastic break more easily than parts of glue holding them together... 0_o
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Also, I'm quite surprised, by how Your module looks, externally (from photos). It's totally different from what I've removed from genuine N900 - I'll post photos later.

/Estel

Re: [HOWTO-WIP] Infrared photography
 

Well done. Ive been wanting to try this on my N900 for a while.

Ive been shooting IR on an old sony H9 for a couple years now. Recently tried modifying a cheap little micro cam and was successful. I didnt have any old film so used a floppy disk as a permanent IR pass filter. Still getting some visible light through. But was just an experiment to see how easy it was to remove the hot filter out of the camera module.

What plastic did you use to replace the hot filter ?

Are you using anything as a IR pass filter ?

If I had the time, money, design and craft skills. I would make a new back cover with rotating lens cover. That could switch between "off/covered" for when not shooting, "hot filter" for shooting normaly and "IR pass filter" for shooting IR.

Re: [HOWTO-WIP] Infrared photography
 

It is exactly what I plan to have in my private, "exclusive" wooden N900's body - except for fact, that I want only "off-covered/ on-clear", without hot IR filter. It'as due to fact, that I want to design simple mechanism for quick replacement of camera module (no idea, if external hot IR filter would be enough, to make one "universal" camera module, for shotting both normal photos, and IR ones, when using IR pass filter?).

As it's niche of a niche ;) I don't plan to offer body replacement's complicated by additional system (for quick camera module replacement), but as I have to project it anyway, I'll gladly share designs on Free license. Don't hold Your breath, though, as it all have to wait until base design for body replacement get finished.

Of course, considerable donors/pre-order supporters have special rights, any if any of them is reading this thread and interested, no problem on making their units modified for support of IR photo/NightVision filters, and quick camera module replacement :) (although it, also mean waiting little longer, as "base" units need to be finished first, before I start to create "variations" like this one, mainly for myself ;)).

/Estel

Re: [HOWTO-WIP] Infrared photography
 

I just replaced the IR blocking filter with a clear piece of plastic.
I also tried holding 740nm and 950nm filters in front of the lens, but the picture seems the same without them anyway, unless there's no other light.

Re: [HOWTO-WIP] Infrared photography
 

Ok, I finally had chance to test bunch of oryginal N900 camera modules, and - guess what - there are two types of them! One is easily disassemble'able, and it's the on on azkay's photos. The other-looking one is, OTOH, utterly impossible to open without breaking it to pieces, so if you got that type, don't even try. Unless you're better than me and figure out a way, then, by any means, share it with us.

In other case, it's required to get same-looking module as azkay's, to do successful disassembly and IR filter removal.

/Estel

Re: [HOWTO-WIP] Infrared photography
 

Sorry for double posting, but it's "other department" news, after some time:

I've finally decided to do this mod properly. Indeed, with some patience, removing only lower part (with sensor) from rest of module was easy. No risk of broken ultra-thin cables, as lowest part have micro 2-pin connector, so everything fragile goes away with upper part of module.

Now, removing the Ir filter - that's another story. I thought about de-glue'ing plastic thingie that keeps it in place, but it's so tightly attached to PCB, that I was afraid of ripping sensor along. Sadly, cutting Ir filter (which is glass, not plastic), was only possible choice.

Holding sensor upside down (very important, to prevent gravitational fall of Ir filter glass dust into sensor), I've patiently weakened it using shaving blade, but it wasn't possible to remove it as one part - ended up breaking it in one place, and *carefully* removing remaining parts, everything with sensor upside down.

I'm perfectly sure that I haven't touched sensor itself, not scratched it, and after assembling module again, I got nice IR pictures. Hoever, I see many glass-dust particles on resulting image (without upside-down trick, it would be 2-3x as much). I've also got focus shift, which should be fixed, after I get hold on small piece of pure glass, to put it in place of IR filter. It seems to me, that the closer thickness of that replacement glass is kept to original filter's one, the more correct focus, but I may be wrong (any optics-knowledgeable people here?).

Now, i'm thinking about a way to removes that glass-dust from sensor. Cleaning with anything is a no-go - even using finest things, it leaves sensor in worse shape than before (tested on sensor from another, non-functional module). I got idea of sucking it via vacuum (for example, abusing vacuum cleaner on lowest sucking power, and making some adapter, that will allow me to safely vacuum'ise sensor without risk of touching it by anbything). Maybe someone here got better ideas?

/Estel

Re: [HOWTO-WIP] Infrared photography
 

Don't suck, blow. Try those squeezy things that were used to clean old cameras. I don't know how they were called, but they have a rubber thing like a balloon which you squeeze and it blows air through a straw. I think it will do a better job than suction. (judging by how blowing the dust out of a cpu cooler requires much less powerful motor than sucking it in)

Re: [HOWTO-WIP] Infrared photography
 

Yes I think using compressed air to blow is safer than sucking air with a vacuum :)
Keep up the good work!

Re: [HOWTO-WIP] Infrared photography
 

Thanks for advices, I'll certainly consider it. Hoever, I'm a little bit worries - sensor is *extremely* vulnerable to scratches, and I'm afraid, that while blowing, moving glass-dust particles could damage it. That's why I thought about some delicate sucking ( :cool: ) that would make particles de-attach sensor, without risk of touching it again/moving around. Just leave and never came back.

OTOH, I'm worries that sucking can damage sensor too (basically, it seems, that *everything* can damage it, it's so vulnerable thingie). will need to carefully consider all available options.

/Estel