On March 21, 2011, I purchased a Canon T3 (1100D) from my local
Walmart for $599. The kit included a newer version (II) of the
18-55mm IS zoom lens that Canon has been providing with earlier
models. Other than minor cosmetic changes on the lens, the new
Version II of the lens seems similar to the old version. According
to Canon: "The major changes are the shape of the zoom ring
rubber grip and the tapered area at the front of the lens."
Canon is marketing the T3 (1100D) as a replacement for the
XS (1000D), that had been the lowest priced DSLR in its lineup
since 2008. The chart below has
some key specifications for the T3 that can be compared to four
Canon models popular for astro imaging at this time:
Notice that the 1100D has the same number of effective pixels (12.2 million) and same
pixel size (5.2µm) as the 450D. This would point to Canon
using the same sensor as for the 450D but according to Canon,
the 1100D has a 12.6 megapixel sensor and the 450D has a 12.4
megapixel sensor. Hopefully Canon has retained the good characteristics
of the 450D imaging sensor that has performed so well for astro
imaging. Some other differences between the models are as follows:
cleaning: The 1100D has no automatic sensor cleaning function
as the other camera models. This is not a disadvantage for astro
imaging. This was most likely deleted to keep the price down.
There is no piezoelectric element to generate ultrasonic vibrations
that attempt to knock dust off the front most filter. For astro
imaging, most users keep that feature's auto mode disabled anyway
since it might change the flat fields used for calibration. Having
cleaned many Canon cameras, I find the auto cleaning function
very ineffective anyway since it works only on the loosest of
debris. The piezoelectric system is set up to capture the dust
under a sticky black gasket around the front most filter and the
dust can become dislodged or even smeared onto the filter if a
wet cleaning is done. That is why I do not re-use the sticky gasket
when I do Full Spectrum modifications with clear glass and prefer
to clean cameras using a simple blower bulb cleaning instead.
The 1100D does
have a menu function that allows manual cleaning of the front
filter, by which the flip mirror goes up for cleaning, as in other
models. It also has the "Dust Delete Data" function
as other models.
The 1100D is a tad heavier than the 1000D, 450D and 500D but lighter
than the 550D. The 1100D is also a little larger than the 1000D
by 4mm in width, 2 mm in height and 16mm in thickness:
I found that even
though the 1100D is larger than the other models, it still fits
well inside Version
III of my Whole Camera Peltier Cooler.
1100D uses the new DIGIC 4 processor, while the 450D and 1000D
use the DIGIC 3 processor. The ADC of the 1100D, like the 450D
is 14-bit as opposed to 12-bit of the 1000D. Some astro imagers
prefer the 14-bit processing but it is difficult to discern differences
in astro images taken with 12-bit versus 14-bit cameras. Although
the 450D and 1000D's highest ISO setting is 1600, the 1100D has
ISO ranges up to ISO 6400.
and Movie Mode:
The 1100D has in-camera video capture that is absent on both the
450D and 1000D models, even though all three have the liveview
function. Some software developers have created video capture
software that allows video to be recorded from the 450D and 1000D,
if a computer is used with a USB 2.0 connection. I would expect
as the new Canon SDK gets in the hands of software developers
that they will upgrade their software to provide a similar feature
for the 1100D. The 1100D however, can do video capture to SD card
or computer "out-of-the-box" using the latest version
of Canon's "EOS Utility"
that comes with the camera. "EOS Utility" is really
all one needs for remote control of the 1100D for astro imaging.
Using it, all camera parameters can be adjusted, liveview can
be used for framing and focusing and multiple exposures can be
sequenced. I noticed that the camera ISO can be changed when in
liveview mode but not when in movie mode. Being able to set the
ISO while in liveview mode is a good feature for brightening stars
used for focusing. The 1100D camera white balance settings can
be adjusted for movie mode. That is a welcome feature because
it is useful for color correcting videos captured with modified
cameras, since the Custom White Balance (CWB) feature can be used
for video. The 1100D lacks the movie crop mode of the Canon T2i
model. The movie mode of the 1100D allows recording 1280
x 720 HD video, at either 25 or 30 frames per second. Movies are
captured as .MOV files using the MPEG-4 format. Movie mode should
be useful for planetary, lunar and solar imaging.
Camera Back LCD Display: The camera back LCD
display of the 1100D is a 2.7 inch TFT color monitor and sized
in-between the 450D and 1000D displays. The displays of all three
models are 230,000 pixel:
1100D takes yet another different type battery than earlier models.
It uses a new LP-E10 battery that is a 6.4Wh unit providing about
700 shots per charge. That is 200 shots more than the 1000D with
a full charge. One thing I don't like about the new LP-E10 battery
is that all its contacts are exposed instead of recessed as for
the batteries of other models. A new power supply (battery eliminator)
is therefore needed and the battery charger provided with the
camera is also different than that of other models.
Functionality: The grip of the 1100D is very
smooth and has no area of textured rubber layering as in other
models. I would prefer a less slippery grip to avoid camera falls.The
SD card slot has now been repositioned to the bottom of the camera,
inside the battery compartment. For other models the card slot
is on the side. I prefer a side mounted card slot because it is
easier to remove the card when the camera is being used on a tripod.
Some camera-back buttons have been repositioned from earlier models.
There are three ports on the 1100D. The remote timer connector
is the same as other recent models....hurray! The mini-USB connector
is the 11-pin connector of the newer models with in-camera video
so that one connector can share both USB 2.0 and Audio/Video functions.
The 1100D has a built-in mic but no external microphone jack.
Dark Frame Noise Testing:
My first testing
with this camera model was to take a 5 minute dark frame at ISO
1600 as was done in previous
I have done for the 450D, 500D, 550D and 1000D. Camera settings
were adjusted to be similar to those used for testing those other
models and the settings info from Canon's DPP for the 1100D dark
frame test image is below:
Below are the
histogram displays using Canon's Digital Photo Professional software
for the initial 5 minute ISO 1600 dark frame exposure of all 5
Canon models for comparison.
The image below compares the initial 5 minute ISO 1600 dark
frames of all 5 Canon models. RAW dark frame files were converted
to 16-bit TIF files using Canon's DPP software and the TIFs were
then cropped at center to 200 X 700 pixels:
For the above cropped TIF dark frame images, image pixel standard
deviation values for luminosity were recorded using Images Plus
for all 5 Canon models and are displayed in the graph below:
The true test
of dark frame noise is how the camera performs over time while
capturing long exposures and as the camera heats up. I do plan
to test the 1100D (T3) camera in the same manner as was done for
the other four Canon models over a period of two hours. (see
Summary: Based on my initial time
with the new 1100D camera model for only a few days, these are
the key features I found most applicable for astro imaging:
Features that I did not like:
I'll be updating this page with more dark frame noise and sensitivity
test results, and hopefully initial deep sky images soon.
4, 2011: Comparison of 450D (XSi) and 1100D (T3) over
two hour period with peltier cooling.
Based on the dark frame tests above, the low noise performance
of the Canon 1100D (T3) tested very close to that of the 450D
(XSi) when single dark frame exposures were compared. This time,
I tested both cameras in a Version
III Whole Camera Peltier Cooler that I recently finished building.
5-minute dark frames were taken continuously over a two hour period.
A 15 second delay was used between the exposures at ISO 1600.
I measured the camera
temperature using the cooling chamber probe and also recorded
the EXIF temperature readings from the RAW dark frame files over
the two hour period and plotted both below:
The above plot
shows that the cooling chamber cooled the camera body at the same
rate and degree for both camera models. A 43 degree Fahrenheit
temperature drop was achieved for the 1100D (T3) and 42 degrees
for the 450D. The plots for the EXIF recorded camera temperature
show the 1100D heating up more during the first 15 minutes, most
likely because of its additional in-camera video/audio circuitry.
After the initial 15 minutes, both cameras cool at nearly the
same rate with the 1100D staying about 5 degrees warmer than the
Using the Canon
software "Digital Photo Professional", all Full Frame
RAW files were converted to TIF files and the histogram luminosity
value using "Images Plus" for image pixel standard deviation
was plotted in the graph below. The standard deviation values
for the 1000D trend higher for the first few minutes in line with
the increasing internal temperature of the 1100D, but after 30
minutes of continuous exposures, there is a crossover in the plots.
At 30 minutes the image pixel standard deviation for the 1100D
goes lower than that of the 450D and stays lower for the remainder
of the two hour period.
Images Plus was
used to crop the dark frames at two hours of cooling to 400 X
400 pixels at center. The cropped images were both adjusted in
Photoshop levels and curves using the same action and then converted
The 1100D dark
frame crop does appear to have less noise than the 450D crop.
Additional test results for comparisons
of the Canon Digital
Rebel T2i (550D), T1i (500D), XSi (450D) and XS (1000D) can be
For discussions on DSLR modifications
and cooling for astro imaging, please consider joining the DSLRmodifications
Yahoo Discussion Group HERE.
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