DIY Sony A100 infra-red conversion

Dragos (aka "DeX") has kindly offered to allow Dyxum to host an article which describes the conversion of a Sony A100 to take infra-red images. The article originally appears on Dragos' flickr account. I thank Dragos for the effort he has put into this outstanding essay. We hope it will be of use to our membership. And now for the (not so) Fine Print Disassembling a camera is not for the faint-hearted. You do so at your own risk, both in terms of rendering your camera inoperable and in terms of physical injury. Please read the descriptions carefully. If you're not sure, ask questions or leave well enough alone. Frank

DIY Sony A100 infra-red conversion (by DeX)

I've learned a lot from this forum so now it's my turn to give something back. For those of you that own a dusty A100, here is a do it yourself a100 infrared conversion tutorial (original article can also be located here).




Why convert a camera to IR? ... because it is simply awesome!
You get to see the world as you have never seen it before and it really allows for some amazing creative possibilities.
But more on that in another article that I intend to write soon enough.

First off go get yourself a 49-52mm Hoya R72 filter off e-bay if you intend to convert the camera to IR only, or some clear filter if you want to have a full spectrum camera.
Don't use a UV filter because you might want to try UV photography with it... I went for the R72 filter because I prefer seeing what I'm framing and I clearly wanted an IR camera, nothing more.
Also there are many IR filter types, the R72 is really the most popular because it gives good balance between color and out-of-this-world look.
When it arrives, get the following tools ready:
- small philips screwdriver
- small flat head screwdrivers
- masking tape
- glass cututer
- pliers & soft cloth (for breaking glass)
- rocket blower

Even if you don't have the tools, it shouldn't be more than 50$ (or € or gbp) for the whole conversion and it only takes a couple of hours if you're really slow, careful and scared.
The more tinkering-disposed people here could easily do it in about half an hour.

Now let's start:

What you need first of all is to get the glass out of the r72 filter and then practice cutting some glass before cutting the actual filter.




Before doing anything with the filter, make sure you put masking tape on it. It is also very helpful if the masking tape is aligned on both sides.
The glass from the filter is held in place by a circular spring. Look for this dent and then try to get one of the spring's ends out with a small screwdriver.




Once you have that end out, just pull the rest of the spring out and let the glass fall gently out of the filter.



Practice cutting 22x30mm rectangles out of glass before getting to the 30€ filter. Make sure you get the feel of it.
The hot mirror we will be replacing is actually 21,5x29mm but there is a lot of margin for error and if you cut too much, you can always sand off the extra glass.
What may also happen is that the edges of the cut will be rough, so you want them to be as far from the CCD as possible.




Once the filter is cut into shape, set your work area with bins or other containers.
It is crucial to know which screw went were and this is good practice for any tinkering you might do on stuff with small parts.
Use the service manual too as it gives very helpful insight on how to assemble/disassemble your camera.




First remove the viewfinder rubber by pushing it upwards with your thumbs.

Rear cover removal: 9 screw in total.
- 4 underneath
- 2 under the CF card cover
- 1 to the left
- 2 under the viewfinder cover thing
This should be it and you should now be able to remove the back cover. The LCD will stay in place.








Keep the screws head down, neatly organised so that you remember their placement exactly.
Removal of the LCD is done by pulling on the orange flexible circuit board at left of the LCD, then flipping it down and pulling on the thicker orange flexible PCB (printed circuit board).



Important!
Before proceeding further you need to discharge the flash capacitor. If you don't do this you risk getting shocked and as a reflex you'll throw the camera, most probably breaking it, as well as your heart
The flash capacitor is in the grip so we need to remove the front cover as well.

Front cover removal: 7 screws.
- 2 under the flash
- 2 above the lens mount
- 2 to the side, on the grip, right after the rubber
- 1 under the lens mount, on the bottom.



To discharge the capacitor, put a light bulb, or a 330Ohm resistor between these two contacts.
It would be ideal to check with a voltmeter if the thing is discharged or not. It should be about 230V when charged so be careful !




Underneath the LCD you can see the cooler board as I call it. Completely detach the LCD then unscrew the 5 screws keeping this metal board in place.
It uses some sort of thermal conductive sticky foam to stick to the processor so you may encounter some small resistance.




Next we need to remove the power board.
This one is held in place only by the bottom screw and a connector that "clicks" it into place.
Be sure to remove all the cables highlighted in red, then unscrew the screw and lift the board, starting from the bottom.




Almost everything is out of the way now, we only need to flip the main board to get to our precious CCD.
In order to do this you need to remove all the cables and flexible PCBs highlighted in red. Once that's done, unscrew the 3 screws holding the motherboard in place.
Everything that is in the green rectangle can stay connected as it does not interfere with your job.




Once the main board is free to move, flip it like this and surprise surprise, there's the CCD.
You may want to ask somebody for help with the main board, so that he/she keeps it flipped while you work on the CCD.
Unscrew the 4 screw holding the CCD in place, flip the CCD and voila.




Be careful when removing the CCD, especially for the slider tensioner marked here in orange.
It has a spring and the tendency to go for a walk.
Maybe someone can tell me exactly what the importance of this part is because I'm not sure I reinstalled mine correctly, although everything seems to work :D




Close up of the beautiful image taking machine. Thank you quantum physics for making this work !
More seriously now, you need to remove the two black frames that are over the hot mirror. This will be trivial but the next step isn't.
The glass is stuck onto the CCD with some sort of black glue tape.
You will need to use a hobby knife or flat screwdriver as a lever and starting from the corners, pry off the glass from the CCD.
If you do it nicely, the black glue will stick to the plastic and you'll be able to reuse it to stick your own IR filter on the CCD.




This is how the CCD looks after the surgery. You can see that I've rather savagely cut the IR filter but this seems to be no problem as the edges are anyway masked by the black frame things.
The CCD in itself is quite a bit smaller than the glass so you have some serious room for error.

Now you just put everything back together and it should work without any special adjustments.
I, for instance, have managed to misalign my CCD while applying too much force when screwing it back into place so I had to realign it using the 3 screws of the SSS assembly.
If anybody else has this issue, I'll give details on how to solve it without fancy equipment.




I have also corrected the AF so that it works with most of my lenses perfectly.
If you are a frequent tele-lens user, you might want to do this too. If there's enough request I'll also show how to do that too.


And now for the shots of success, post conversion:







A word about dust:
I know it is important to do this in a rather clean environment to avoid getting dust between the filter and the CCD, but I did it in a dusty student's room, armed only with a blower and some microfiber cloth.
I do have some really small dust in the thing but it is not noticeable unless you shoot at F32 (it is very small). So in most real-life usage, this is, for me at least, not a problem.

Acknowledgement
Now last but not least I'd like to thank two people who's prior experience helped me a lot:

Edinator describing the process.

and

Pete Ganzel how to disassemble the a100

Dragos

Edited by Frankman - 20 May 2011 at 11:04

Frank,

For me, reading this article is much fun than just to think to do :)

Thank you Dragos (and Frank)..

LesPaul & maewpa: Thanks, it really is easier than it looks. The hardest part for me was to overcome the fear of breaking the camera or the filter while cutting it. I had to open this camera twice as I had a small problem and the second time I did it, it was a breeze. Then again, you can find a a100 for about 150-200$ on e-bay so it's not that high of a risk

For more visual reasons as to why convert your A100 you can take a look at my constantly updated IR gallery or Edinator's. I'd love helping somebody out with the conversion and see it was successful afterwards, that would definitely make my day

Edited by DeX - 20 May 2011 at 11:56

This is great, thanks! The examples are stunning. I've been considering having my old KM5D converted so I'd have reason to use it again. I don't know whether I'd want full spectrum or just IR though...hmmm.

Dragos, Thanks for an excellent well written article. As soon I get the time the A100 is coming off the shelf for some surgery. Great pictures as well!

LesPaul, to answer some of your questions:
- The false color comes from the sensor's color filters frequency response (it's a bit technical but I hope you'll understand):

Visible light is between 400 and 650-700nm. Blue is 450nm, Green is 550nm and red is 650nm. From 650 onwards you have infrared. As you can see in the graph above the color dyes used in the CCD bayer color matrix do not perfectly filter red (650nm) blue (450nm) and green (550nm). Near visible infrared starts from 650nm onwards and as you can see, both the blue and the green color filters let some IR light pass, in different quantities between 700 and 850nm. The red filter lets all of the IR pass through it. This difference in IR response for the 3 channels creates the impression of color. From 850nm onwards, all three filters (red, green and blue) let the same amount of IR pass so what this means is that using a low pass 720nm filter (like the hoya) will give you a bit of color but using a deep IR 850nm filter will essentially produce black and white images. I will try to explain all of this more simply and clearly in a future article.


- You need to replace the hot-mirror in front of the CCD for two really good reasons:
1. Having a piece of glass in front of the CCD means that you'll be able to clean that without scratching the CCD
2. Removing the filter will create a shorter optical path, affecting your focus. If you take out a 3mm thick hot mirror, you should put back a 3mm thick piece of glass as to minimally disturb the optical path.

smcabbott: I would personally only convert live view cameras to full spectrum (nex, SLT). If you do it full spectrum then you need to put the IR/UV filter in front of the lens and it defies the purpose of a SLR to not see what you're framing or where you're focusing.

Thank you all for the positive feedback, I'm really glad.

What a great tutorial.

I had an A200 converted by Advanced Camera Services in the UK. If I'd had access to this excellent tutorial posted up by Dragos then I may have given it a try myself and saved some money. Having said that converting the camera to 720nm infrared has been the best decision I've made in the last 12 months. The A200 is the first camera I pick up over my conventional A700 when I'm out shooting and its a lot of fun to use.

Post processing the RAW files that you get out of camera is another lesson and I'm looking forward to the next tutorial to see if I can learn something new.

George