Frequently Asked Support Questions

Q. How do I access a USB/Serial Converter about com6? A. Right click on My Computer to access Windows Device Manager. Find the LPT and Com port section and select the USB/Serial converter. Right click on the port and select properties. Using the advanced section of the driver port configuration select a new com port supported by the driver.

Q. Why does it take so long to download in RAW mode? A. The image is probably 12MB or more of data. That is a lot to move over USB. Try using the fast focus mode, or fast bin mode.

Q. Maxim/DL connects, but says "flushing" and no image shows up? A. This can be caused by selecting the EOS driver for both camera and guider. This is not supported, choose another guider that is connected or "None".

Q. Why won't my 20D/350 connect? A. Try switching from printer to PC Connect mode on the camera.

Q. The picture is B&W and dithered. It looks bad! Why?
This is the RAW, unprocessed image. The “dithering” is because each pixel has a different color filter on it. The Image must be processed before it will look good. First subtract dark frames, then use Maxim's ConvertRGB menu item to convert to color. Suggested RGB weights are in appendix A of the Release notes or Manual.

Q. Why won’t my camera connect? When I plug in the Parallel control cable it just starts shooting pictures and I can’t connect.
Because the Parallel port is uncontrolled before the driver starts up, the signals stuck on the parallel line might be signaling the camera to shoot. You should leave the cable disconnected until the driver is running and then plug it in. Otherwise the camera will be active when the driver tries to connect and it will not be allowed to control the camera.

Q. I tried to combine several images together. Now when I convert then to color, the color is all wrong!
You must calibrate the image first. Then color convert. Then stack the images. You can’t vary this order. Period. Or you will junk your images.

Q. My star profiles are flat on top in the fast readout mode. Why?
The fast readout uses significantly fewer bits for data (8 bits vs. 12bits). You just can’t get the range in those bits you need to show the range of star magnitudes. To focus pick a star and exposure times that prevent the star from maxing out the values thru the center. A star with soft edges means there is more range of data to compute the focus.

Q. Wouldn’t it be better if you stacked a bunch of JPEGS coming out of the camera? Why mess with these ugly B&W images?
JPEG has 8 bits per color. Using raw mode we get 12bits. We also can do Dark frame subtraction on a per Pixel level, rather than on an area averaged out around the pixel. The data is more accurate and with better processing it will look superior in the end. EOS Digital cameras don’t really have any RGB pixels. They are only one color at a time. Any format that combines colors together before calibration or cuts the bit depth will lose information, especially for the high dynamic range images from the heavens.

Q. It is really slow when I focus. What am I doing wrong?
There is a checkbox on the focus tab in the camera window. Set this to enable fast focus. It should be a couple of seconds instead of tens of seconds to download.

Q. Do you support firewire?
If your camera can talk to Canon tools thru firewire, it should work with the Driver.

Q. I don’t know what I did, but the camera is hung up. It is not showing any progress and the Start/Expose button is gray and it has been several minutes. What can I do?
If you cycle the camera driver disconnect then reconnect this often will clear up any issues. If that does not work: disconnect and power cycle the camera, then connect again. If that still does not work: reboot your computer and power cycle your camera. If you can reproduce a hanging situation please report it to

Q. My camera keeps disconnecting. I push a button and it goes back on. What is up?
The camera has a sleep mode, if you don’t use it, it goes to sleep. To keep it from doing that, use an AC adapter. You can also set the auto power off delay setting to OFF.

Q. When I try to expose an image the camera clicks and no image downloads. Why?
If you have a camera with the Mirror lock functionality, turn it off. This version of the driver is designed to work without the mirror lock for long exposures. Mirror lock will be available in version 2.

Q. All my exposures seem to take the same amount of time. Why?
If you have a camera that has variable stops (ie ½ 1/3 ) you need to set the stops to 1/3. This allows the camera to expose and a finer granularity. If you have the camera set to ½ the camera will ignore the time delay settings sent to it.

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