The first night out with the unmodified
camera was on a fairly clear night but when I would not normally
image, with the Moon at 75% phase. Because of the Moonlight I
kept exposures to a maximum of 60 seconds at both ISO 800 and
ISO 1600 for these test images. All of the images below were unguided.
using an Orion Atlas Mount with EQMOD. A photo of my deck
observatory setup with remote control can be seen here. My
purpose of testing the new camera was to learn its features and
verify that it was operating correctly before taking the camera
apart for the IR filter replacement.
Normally, I would use a barlow
for imaging the Moon with my Orion ED80 refractor. I already had
the Televue .80X focal reducer on the ED80 but imaged the Moon
with it since it was already set up and I was anxious to try some
deep sky imaging using the reducer. The
resolution of the 12.2 Megapixel Canon 450D imaging chip is 4272
by 2848 pixels. ISO setting was 100 and a 1/250 second exposure
was used to help freeze the poor seeing conditions. Here is the
Full Frame image taken:
One advantage of the 450D over
the 300D is its higher resolution, so crops of the original hold
up very well. Here is a CROP the above image around the
Moon which has been reduced to 1200X1200 pixel size:
Galaxies M81 and
M82 - Full Frame:
I would not normally image deep
sky objects with the Moon at 75% phase, so keep that in mind for
the following imaging results. ISO 1600 was used and 57 one-minute
exposures were median stacked. The dark band at the top is due
to reframing of the object during the exposures.
Here is a CROP the above
image that has also been reduced to 1200X1200 pixel size:
M13 Hurcules Globular
Cluster - Full Frame:
ISO 800 was used and 7 one-minute
exposures were median stacked:
M44 Beehive Cluster
- Full Frame:
This open star cluster was near
the Moon so I kept the exposures short at 35 seconds. ISO 1600
was used and 12 frames were median stacked:
Initial Test Comments:
Having imaged in the past with
the Canon 10D and modified Canon 300D, I was pleased with the
operation and first-light images of the 450D under a Moon-lit
sky. The camera tested well and I was later successful in taking
it apart to remove the IR cut filter; see modification procedure
here beginning on PAGE 1.
Some notes on my initial thoughts
after the first night of imaging with the new camera:
Auto Clean: Using the 450D's menu system, I disabled
the "Auto Clean" feature so that it does not do a cleaning
every time the camera is turned off. This was done to avoid any
problems taking flats.
USB Connection: What a welcome feature to have all camera
functions available via the USB 2.0 connection! Only one wired
connection is now needed between the 450D and the computer and
it is the USB cable supplied with the camera. No longer are special
cables needed such as the one I built HERE
for triggering the 10D bulb exposures that also required a USB
to RS232 adapter for my notebook computer without a serial port.
Battery: The 450D has a different battery than
the 300D and on the first night it lasted about 5 hours, even
when using the camera's live view feature. With all-night imaging,
especially if by remote control, an AC power adapter is preferred.
The part number for the AC adapter is ACKE5 and can be ordered
online from many sources.
Control Software: I no longer need to use DSLR focus or
Images Plus to change the camera's settings, for focusing and
taking bulb exposures, including interval exposures, since these
basic functions are now available in the software that comes with
the camera, "Canon EOS Utility". See next
page for details.
Viewfinder: After my first all-night imaging session
with the 450D, I was amazed at dawn when I realized that I had
not once looked through the camera's viewfinder. I will most likely
block it off with a cover for astro imaging to avoid stray light
entry. I never used the viewfinder because of the camera's "live
Live View: I used the 450D's "live view"
feature to center stars for the alignment procedure for my Atlas
Mount using EQMOD and also to help center objects to be imaged
in the imaging frame. On brighter objects this involves seeing
the object on the live view display and moving the mount to center
it. For dimmer deep sky objects this involves taking an exposure,
noticing its position relative to the center of the imaging frame
and then using "live view" in zoom mode to move the
star field appropriately.
Weight: I own the Canon 10D, 300D and 450D. The
weight of these bodies alone are 2.5, 1.5 and 1.25 pounds respectively.
The 450D body is the lightest of the three and is just slightly
smaller in size than the 300D. The lesser weight of the 450D is
an advantage for keeping the weight loading down on telescope
14-bit A/D processor: The 450D analog to digital (A/D) conversion
process is now increased to 14-Bit from 12-Bit allowing the camera
to record up to 16K colors per channel for smoother tonal transitions
and more accurate color gradations.
Image Transfer Speed: The 450D has a USB 2.0 connection, as
opposed to USB 1.1 on the 300D. The download of images from the
camera to notebook after capture was nearly a minute for the 300D
but only about three seconds for the 450D, and that is for a much
larger (15.32 MB) file.
Image Processing: The RAW (CR2) file size of the 450D (15.32
MB) presents an increased burden on image processing. I use both
a 2.8 GHz Pentium 4 notebook and a Core Duo T2400 processor notebook
and image processing was noticeably slower. The TIF files converted
from the Canon CR2 Raw files are each 72.3 MB in size! My older
version of Images Plus is not able to convert the RAW files. The
freeware Deep Sky Stacker does work with the 450D Raw files. Also,
the software provided by Canon with the camera, Digital Photo
Professional can be used to open and convert the Raw files.
Looks like I will be shopping
for another hard drive and maybe a faster computer:)
NEXT PAGE - Page 13
: Canon EOS Utility & Live View for Camera Control for Astro-Imaging