Live Autofocus

[AndrewPearce]

Hi

I've been using Backyard EOS for a while now and it's been very successful when hooked up to my Canon 1100D camera.  I've now got an 800D and when running the software, I get the following statement in the log file "Unable to set LiveviewAutoFocusMode, current setting is assumed!".  I'm not able to frame and focus, yet all other functions of the software work for this new camera.  The AF is set to ON and the software is controlling the focusing.  However I'm not seeing a bright star in the frame and focus mode to allow me to finetune the focus.

Any ideas as to what I may be doing wrong?

Regards

Andrew Pearce

[astroman133]

Some of the newer cameras have "smart" LiveView autofocus modes that are not compatible with the Canon SDK and BYE. Unfortunately the Face+Tracking mode is one of those modes and is the default. Use the camera's menu to choose the various modes to see if one of them will allow LiveView to work with BYE.

[AndrewPearce]

Thanks for your quick response, it's appreciated.  The 800D is not a new camera so I'm presuming someone may have come across this before?  It has 3 LiveView autofocus modes - Face+Tracking (as you've mentioned), Smooth Zone and Live 1-point AF.  Changing to these other 2 modes doesn't seem to make any difference, I get the same error message.  Apologies for asking a dumb question, but I presume that you must have LiveView enabled in order for BYE to work?

[astroman133]

Yes, you must have LiveView enabled in the camera for Frame & Focus to work.

If you put the lens in MF mode and manually run it through the full focus range do you see the star at some point? The correct focus point should be at infinity.

LiveView exposures are very short and the camera's autofocus circuitry is unlikely to work when the image is mostly black or nearly so. Even a bright star will be just a dim dot.

[astroman133]

I should have said, that the error message that you are seeing is likely not be contributing to the ability to see the star. To test you could test the camera and lens with BYE at the kitchen table. If you set LiveView autofocus to the 1-point AF option, do you see a LiveView image on the BYE F&F screen?

[AndrewPearce]

Hi, yes I do see an image on F&F and the focus control works OK indoors even though I'm still getting the error message in the log file.  Last night I couldn't detect any bright stars.  With my Canon 1100D, I was able to easily detect Antares, Sirius, Alpha Centauri, etc as a dim dot which is all I needed to focus correctly. 

 

[astroman133]

If you are too far from critical focus, you will not see any stars.

[AndrewPearce]

Thanks for your help, the problem is resolved.  I found that reducing the brightness of the LCD screen made the stars much easier to see in the F&F mode.