Introduction.

Before I started to make a mess with my Nikon P2 I already had a nice IR imaging capable camera. This was Sony DSC-F828. With only some minor obstacles to cope with it was a perfect tool for taking nice IR quasi BW pictures as long as it was my primary camera. The problem is that this thing is not that small so if you have a (D)SLR with 2 or 3 lenses already on board you may not want to have another one of similar kind just to take from time to some IR frames. The obvious thing would be here to have a small IR capable camera and by this I mean capabilities at least of the same order of magnitude as the F828 so at least such IR sensitivity to allow for reasonable shutter speeds (no tripod shutting). As for the F828 it is done this way that the camera has some "night modes" where the IR blocking filter (typically present in all digital cameras) is removed. In other words I was looking for a camera that has or may easily have this filter removed. If you google a bit here and there you can find a number of such cameras with nice description how they were converted or even few of companies providing this kind of services.

Unfortunately most of these cameras (if not all of them) fall into one of the following categories: DSLR and hybrid (meaning a big and expensive guys) or slightly smaller but still expensive (Canon PowerShot G5, etc) or still not that small, cheaper but at the edge of extinction (Canon PowerShot G3, Olympus Camedia C2/3/4xx). So the basic choice is here either to have somebody modified for you your expensive camera and pay for this often 1/3 of its price or take a risk that something may go terribly wrong (likely will) and you end up having an expensive piece of junk and some pricey but pretty useless piece of experience.

What is not for me entirely clear is why nobody (at least I am not aware of and judging from the Internet) tries to modify an inexpensive and small cameras to have a nice and hassle free add-on to the regular set. Are they not IR capable or what? The quality should be surely sufficient as typically IR photos are not of the cutting edge sort anyway.

I had a Nikon Coolpix P2 that served me as a very last resort backup camera. It was not that cheap camera (say economy plus) but mostly because of its wifi capabilities that are quite pathetic in this case by the way. Well but surely it is a small pocket size thing. There are number of similar in size and much cheaper Nikon cameras like Coolpix L4 or more recent L11 that very likely can be also adapted the way similar to the described below.

You will need:

1. A Nikon Coolpix P2 camera. The P1 model only differs by the number of pixels so likely all what I included below is also directly applicable. The L4 model seems to be also of similar kind (the CCD integrated with the lens unit). A 2nd hand P2 seems to be buyable for ca USD 150-200, L4 should be much cheaper.
2. An IR passing visible light cutting filter. I have a used Hoya R72 filter but you may want to check on Internet – there are some other possibilities including overexposed color negatives or non-exposed slides. Bear in mind that if you decide to use a filter significantly different (e.g. in terms of base material and thickness) from the original one you may end up having some troubles with the auto-focus system.
3. A small philips type screwdriver.
4. A small knife used to undo 2-3 odd screws.
5. A tweezer.
6. A glass cutting knife and sandpaper if you decide to use the above mentioned Hoya filter.
7. A soldering iron if you have shaking hands and you are not lucky enough.

The good thing about the P2 camera is that it is pretty straight-forward to take it apart and then put it back together. You really do not need to use any repair manual (although it is always useful to have). There are no hidden screws no “traps”, hidden holding notches, nothing of this sort. The only tricky part is with a large number of screw types so make sure you number them somehow to know what screw goes where. If you careful enough you also do not need a soldering iron. What is only needed is some basic technical skills.

I am not going to describe in details the whole disassembly procedure for the reasons mentioned earlier (it is pretty straight-forward). Just a basic order of disassembly and some remarks:

Taking the main components apart

1. Remove the battery, the card and the wrist strap.
2. Remove all the external screws from the housing – there are at least 2 screws with 3 “arms” only (typically 4 – a cross)
3. Gently remove the front and back part of the housing.
4. Now, read this: Beware of the capacitor (Figure 4, A shows the spot with uninsulated connectors)! Even after long time of not using of the camera there is a quite high charge over there. I am not sure whether this is enough to do any real harm but it is definitely enough to feel it well and call it very unpleasant experience (yes, I touched the connectors). Not to mention that if you are doing something at the time of being shocked this something may be thrown away in the best case scenario. In the worst case you may destroy the electronics on the main pcb board - surely it is more vulnerable to the electric charge than the human body.
5. Disconnect the back, housing ribbon from the main-board. Before pulling out the ribbon unfasten it gently (a flat lever-like bar)(Figure 1). This applies to all such types of the connector.
6. Remove the wifi section.
7. Remove the LCD screen. Be careful with the two wires (red and black) connecting the LCD to the board (Figure 2, C). You will need to manipulate quite a bit with the whole camera before you manage to take what necessary apart and these two wires can get easily broken apart from the board (it actually happened to me and I had to solder them back).
8. Remove the LCD screen holder (the metal chassis below the monitor, Figure 2, A). The screen is only attached by two metal "hooks" (Figure 2, B).
9. Remove the top plastic part, various parts on the front of the camera (including the flash unit). Take a note how the wires from the capacitor are placed in the top plastic part (Figure 4, B). Figure 3, shows the resulting mess.
10. Disconnect the battery housing: The battery housing (actually the assay terminal battery, Figure 5) with its 3 pin connector is soldered to the main board. I did manage to unscrew two associated and connecting screw without soldering this part out - there is enough space to do this having the screw-driver heavily tilted.
11. You should end up with the lens unit separated from the rest of the camera (Figure 6).

Figure 1	Figure 2
Figure 3	Figure 4
Figure 5	Figure 6

The lens unit, the filter and the filters replacement.

You may disassembly everything whatever place you like but take extra precaution before taking apart the lens unit. I know that this is a common sense thing but people do not realize how much rubbish is flying around in the air. After you undo 2 screws holding the CCD board together with the lens housing (Figure 7) you will have the sensor exposed to this rubbish. There is still a filter right in front of the sensor but likely it is close enough to have bigger dust particles visible if they got deposited onto this filter.

The most tricky thing for the whole project was actually to cut the IR filter with reasonable accuracy and limited number of scratches on its surface. I did it with a simple silicon carbide knife. I cut it off a bit larger and then patiently ground away (using wet sand-paper) all the excess material to fit the size of the Nikon filter. Perhaps a better idea is to seek a professional glass-cutter help and visit some related workshops.

Figure 7. The lens unit with the CCD board on top.	Figure 8. The original IR blocking filter.
Figure 9. The Hoya filter placed inside the lens housing.	Figure 10. The rubber spacer (B) and the Hoya filter (A) below.
Figure 11. The CCD board.

• All the ribbon connectors - ensure you put the connector deep enough into the socket.
• Figure 3, spot C - if you put the parts together in this area in wrong sequence you may end up disassembling back almost everything put together so far.

• As it might have been expected there are some problems with the auto-focus system. Fortunately it seems that the problems are very limited. In some focal lengths (and actually with some motives) the camera complains it can not get focused (red square indicator) but even in such cases it takes sharp pictures.
• In terms of exposure the system tends a bit to underexposed the pictures but nothing really serious.
• The “hot-spot” a kind of brighter area in the middle of the picture resulted from an internal reflection from the lens is visible but not too extensive. This is at least the case when the colors are not altered.

Grey mode, contrast enhanced.

More sample pictures [here].

(c) Marcin Debowski