Canon Digital Rebel XSi (450D) Modification

by Gary Honis

Page 13 - Canon EOS Utility & Live View for Camera Control when Astro-Imaging

Removal of IR Cut Filter for Astrophotography

Canon EOS Utility:

The Canon 450D comes with a "Canon EOS Digital Solution Disk" that contains the camera driver and a number of software programs for the camera. "Digital Photo Professional" is one of the programs for viewing files and also converting RAW files to other image formats such as TIF files. For imaging I have done in the past with the Canon 300D, remote control operation of the camera was possible using Canon's "Remote Capture" software supplied with the camera. The Canon 450D comes instead with camera control software called "EOS Utility". For astro imaging, an advantage of the new "EOS Utility" software is that long exposures via the bulb setting are now possible using the supplied USB 2.0 cable for connecting the camera to a computer. "EOS Utility" also operates the "live view" feature of the 350D which is a very easy way to achieve a good focus.

I operate the scope and mount on my deck observatory via an ethernet connection over power line from a 50 inch plasma Hi-Def TV in my recroom. The Canon "EOS Utility" software worked well over the remote connection. Here is an overview of the camera's operation:

With the USB cable connected between the 450D and the already booted computer, turning the camera on will open the window "Canon EOS Digital Rebel XSi". In this window, the "EOS Utility" icon can be selected and then the "Camera Settings/Remote Shooting" icon to open the remote control program seen on the left.

The image on the left shows the settings I used to take flat frames. The window shows battery strength and how many more images can fit on the camera's SD card. The round button at the top is the shutter button and below it you can specify the save directory for the images. The second section of the window shows "M" for manual mode and the number "5" which is the exposure setting of 1/5 second.

On the display to the left, the camera has been set to Bulb mode for long exposures.

The ISO setting is 800 and the images will be saved in RAW format. The icon to the right of "RAW" is showing that the current setting for saving images is to both computer and camera SD card. Below this icon is a small "stopwatch" icon. If you click on this, the following "Timer shooting settings" window will open:

The "Timer shooting settings" window can be used to take multiple exposures in bulb mode including a delay setting and timer interval. I used the above settings to take 5 images, each 1 minute long with a 15 minute delay time. After clicking the "Start" button, the following window will appear during the exposures:

Live View: The third icon at the bottom of the main window as shown below starts the Live View operation:

A "Remote Live View window" opens as shown below:

The display in the Live View window above has a rectangle that can be grabbed and moved anywhere on the display. Clicking on the rectangle will open a new window that Canon says is "enlarged at 100% (actual pixel size) in the Zoom View window" as shown below:

I have not found a way in the Canon EOS Utility Software to adjust the Zoom magnification of the Canon Zoom View feature. It would beneficial to have the ability to adjust the zoom amount for focusing on astro objects such as stars, planets and lunar features. So, I have been using non-Canon display magnifier software programs to further enlarge the zoomed image on the computer display for more accurate focusing. Here is an example using the freeware "Virtual Magnifying Glass" that can magnify up to 32X:

After setting focus using the zoomed section of the image, the Live View windows are closed and image exposures can be taken. Although the examples above were for focusing on the Moon, focusing on stars or planets is also possible (see below).

Other Parameters:

Clicking on the "Preferences" button opens the following windows where parameters can be set:

With "Digital Photo Professional" selected as a linked software in the above window, when an exposure is taken, the image is displayed as a thumbnail in Digital Photo Professional where it can be further analyzed.

Lunar image taken on 4/16/08 using the above settings with an Orion ED80 refractor and 2X barlow reduced to 1200X 1200 pixel size:

Live View Focusing and non-Canon Magnifying Software:

With my older modified Canon Digital Rebel 300D, my preferred method of focusing for astro imaging was by eye through the viewfinder using a 2.5X varimagnifier. I had also kludged together a webcam system using the varimagnifier for easier focusing on a computer display as detailed Here. Although I also used DSLR focus for camera control and timed exposures with the 300D, its focusing routine of using still images transferred from the camera to computer using the slow USB 1.1 connection was awkward to use and took a long time. The "Live View" mode of the Canon 450D provides a real time video of the subject and in a fixed zoomed view, but for easier focusing I found that a higher zoom magnification is helpful. Windows XP has a built in magnifier tool under Start/ All Programs/ Accessories/ Accessibility/ Magnifier. It is a very basic magnifier. Fuller featured display magnifiers are available as freeware. Here is one that I also tried:

Magnifying Glass - Magnifying Glass 1 is a simple utility that zooms region of screen under mouse cursor. This utility differs from many others by set of unique features various contrast modes, various position modes and transparency.

Magnifying Glass Features:

In the example below, the subject was the star Regulus and a 127mm Triplet Refractor was used for imaging. On the left is the "Remote Live View Window" with Canon's Zoom View selection box in white centered on the Field of View. The star Regulus appears near the center of the selection box. It is dim in the example below because I had adjusted the star's brightness to avoid overexposure in the Canon Zoom View window. On the right is Canon's Zoom View window enlarging the white boxed area. The square area labeled "Magnified Glass inverted view" is the focusing display uisng the Magnifying Glass software for an additional 4X magnification. I used the "inverted" mode as an aid in focusing and this window can be moved anywhere on the display to select a star or feature for closer inspection. The "corner tracker" mode is used here that is using the red highlighted corner as the pointing device.

Also shown at the the of the display is a 4X magnified view of the star using the Windows XP built in magnifier tool. This tool can magnify between 2X and 9X and also has an "inverted" mode, not selected here.

My experience with webcam focusing for astro imaging has been with using video focus software such as QCfocus. Details on how it uses a star's PSF and full width at half-maximum (FWHM) measurement to achieve focus can be seen Here. Hopefully in time, such software features will become available for the Canon cameras equipped with live view including control of ASCOM focus controllers.

I tried some other freeware magnification utilities and although they had some great features for focusing, most would only function for still images and not for video streams such as the Canon live view display.


To My Astrophotography & Digital Imaging Home Page

Starmaster Telescope Eyepiece Astronomy Astrophotography Meade Celestron Televue Eyepieces Telescopes

Starmaster Telescope Eyepiece Astronomy Astrophotography Meade Celestron Televue Eyepieces Telescopes