Filter/Imaging Chip Assembly
The following diagram is on Canon's
web site and it shows the components of the filter/imaging chip
assembly. Use it for reference in the steps below. I have added
the label "IR Cut Filter" for the two filter pieces
Canon has labeled "Phaser-layer Infrared-absorption glass"
and "Low-pass filter 2". This is really just one filter
that has two sandwiched layers, so I will use "IR Cut Filter"
for these directions along with Canon's other labels.
We are going to remove and replace
the "IR Cut Filter" only. The "Low-pass 1"
filter will be left in the camera. It is an anti-aliasing filter
that Canon is using as a dust cleading surface and is explained
on Canon's web site as follows:
"Self Cleaning Sensor
Unit - A key element of minimizing dust is preventing it from
clinging to the front surface of the imaging sensor. To combat
against this, the EOS Rebel XSi features a Canon-designed Self
Cleaning Sensor Unit. The low-pass filter at the front of the
sensor shakes off dust automatically with ultrasonic vibrations,
removing dust from the sensor assembly. The EOS Rebel XSi has
a new coating on the front surface of the low-pass filter, to
increase its resistance to dust sticking to the sensor."
23. Remove one screw as shown below: ***550D For
550D see step 23A below instead.
only: Remove the three
screws shown below. Be careful; the filter assembly will now be
detached from the CMOS imaging sensor:
24. Lift the four corners of the "support
material" frame up with a small jewelers driver and pop the
metal frame off. Be careful not to scratch the filter.
Pietschnig note: "I was surprised by the springiness of the
"support material" frame. It jumped off without warning,
luckily landing on the
table and not on the piezo filter. A hint which suggests to hold
it down could probably be helpful here."
25. The removed "support material"
frame is shown below (on left). Remove two screws as shown from
the assembly: ***550D Skip this step for 550D.
You may want to remove Low Pass filter #1 at this point as explained
in STEP 28, instead of later to avoid touching it during the next
26. Now we will separate the filter assembly
from the CMOS imaging chip. The black filter assembly is held
on to the surface of the imaging chip by a thin strip of double-sided
black tape (except
for the 550D). This adhesion
can be weakened by using an exacto razor knife. I used a flat
"Chissel" type razor and patiently pryed between the
black plastic frame and the metal base, all around the unit as
For the 550D, there is no
need to cut the black filter assembly off the imaging chip. It
is not adhesived on. There are three pins that position the frame
correctly. Just lift it off, put it in a sealed container and
continue at Step 28.
27. Go slow here and be patient. Work the
razor blade around the sides of the frame and corners, applying
slight prying up pressure. After a few tries, the plastic frame
will begin to loosen from the metal frame and you will hear the
crackle of the glue of the adhesive tape gasket becoming undone.
When the parts separate, be careful not to get the front surface
of the CMOS imaging chip dirty. Put the CMOS imaging chip into
a sealed container to keep dust-free as you continue to work on
the filter assembly.
28. Lift the "Low-pass filter 1"
out of the unit; it is not secured. I used a jewelers driver to
lift one corner and it came out easily.
29. Remove the original IR Cut Filter (blue
glass) from its frame. It is glued in the plastic holder at the
four corners. I used a razor knife to loosen the glue in each
corner. Then I pryed the glass up at each corner and the glass
broke. No problem since this glass will not be used again since
it is being replaced with the Baader UV-IR-Cut filter (or clear
glass if desired...or nothing at all). There is a thin black tape
gasket between the filter glass and the black plastic frame. It
lifted up in one corner so I pushed it back into place with the
Photo of 550D
by Skyler: Another really handy item was Nitrile gloves. They
keep the insides of the camera clean w/o leaving my finger oil
marks on components and they were just great when I popped out
the glass that you showed in your example. I could push on the
filter from the other side with the gloves on - one or two fingers
at a time and one side at a time with a gentle prying and pushing
motion. Since you have more surface area with your fingers, the
chance of the filter breaking is minimized. Could not have done
that w/o breaking the filter otherwise.
30. Glue the replacement Baader filter into
the plastic frame by using very small drops of silicone glue in
each corner. Be sure to use a glue that doesn't outgas as it may
affect the optics. Do not use much glue here so that it doesn't
run into the field of view. I left the glue dry overnight to be
sure it was well cured. Below is the plastic frame with the new
Baader filter glued into place.
the FULL SPECTRUM MOD leave the plastic frame empty. Be sure to
transfer the black rubber seal from LPF#1 to the plastic frame
if it is still attached to LPF#1.
The dissassembly and filter replacement
is now completed. I used a rubber ear syringe blower bulb to remove
dust from all optical surfaces. If there is any dust on the Baader
replacement filter you can flick it away with a camel hair brush
or the end of a microfiber lens cleaning cloth. On the next page,
you can continue to follow re-assembly directions that should
be easy since you'll be going through the above process in reverse.
Next Page - Imaging
If you completed the modification
and would like to let me know how it went for you, you can contact
me at the following email address:
I will add any comments to the
modification instructions that might be helpful to others and
a link to your site if you wish.