Good Morning folks,

I have begun to use my new Canon EOS R for astrophotography.  Images to date have been wonderful.  However, the raw images would definitely benefit from the use of flat frames.  I am quire familiar with shooting flat frames with a CCD camera but have no idea as to how to shoot flats for the Canon EOS R.  I am hopeful that you might offer up the procedure that you use to acquire effective flat frames for a camera like the EOS R.

Thanking you in advance.

Clear skies,
Kevin Dixon

Kevin,

The purpose of flats is the same no matter the camera type, so the procedure is approximately the same.  I usually try and get a histogram that is centered about half way.  Needs to be exposed enough to show the fainter dust bunnies and donuts, but not so much that there is saturation.  Start with and evenly illuminated image field.  Two common ways are illuminated panel or sky flats with a t-shirt.

On a dedicated astrophotography camera [true CCD are rapidly being replaced by CMOS, the terms CCD and CMOS are more about the semiconductor manufacturing technology used, which is a whole other discussion] the exposure is totally manual.  That is to say, you at the operator, need to pick the correct exposure time to get the histogram to the desired position.

Depending on how you are using your DSLR there may be two different scenarios. 
1. DSLR is attached to a scope.  On a scope the aperture is fixed.  Use any of the automatic modes so that the camera automatically chooses the correct exposure time.
2. DSLR is attached to a compatible lens.  Using a lens will usually allow control of the aperture.  In this case use the Av mode and make sure the aperture is set to the same aperture as your light frames. 
Then set the DSLR to manual mode, use the same exposure time (and aperture) and take multiple frames.  You need enough frames for a good statistical average but larger numbers are not usually necessary.  I usually shoot 16, sometimes I do 32 if I have a large number of light frames.

I've never used IP Camera Control so I can't comment on exactly how to use IPCC to do this.  IP and IPCC are no longer supported (which is why the developer released them as free programs).  The EOS-R is a newer camera and I'm pretty sure that it is not supported by IPCC.  Double check the supported cameras list, http://www.mlunsold.com/ilcameracontrol.html.  Additionally, IP probably won't directly support the CR3 format, again check the features and specs, http://www.mlunsold.com/ILImageProcess.html.

However, if you can convert the EOS-R CR3 format to one of the types that IP uses (FITS, TIFF or DNG all work), then ImagesPlus program will work just perfectly fine for calibration, stacking and image processing.

John Schnupp, N3CNL
2007 R1200RT +68,100
1995 XLH 1200 106,495 (retired)
Georgia, VT
44.7675°N, 73.1592°

Thank you very much for the detailed information John.  I will be using an illuminated panel to create the flats.  The DSLR is attached to a Newtonian telescope.

I had read that I could set the camera to Av mode so that it chooses the proper exposure duration.  Have you found this to be an effective means to create effective flats?

Thanks again.

Clear skies,
Kevin

Kevin,

I would only use the Av mode for the first frame, note the exposure time that the camera picked.  Then I would manually set the aperture and exposure times in Manual. 
Using a light panel it should be fairly consistent but by manually setting the exposure you would not need to worry about the camera changing anything during the series of flats.

John Schnupp, N3CNL
2007 R1200RT +68,100
1995 XLH 1200 106,495 (retired)
Georgia, VT
44.7675°N, 73.1592°

While using AV mode will work, I prefer to use AV mode for a single
flat to get an exposure time. Once I have this, I switch to manual to
take the series of flats, using the exposure time from the AV one. If
you check the histogram from the AV exposure, you can also decide to
slightly increase or decrease the exposure time to place the histogram
hump exactly where you want it.

Phil

Thanks very much John and Phil. I really like that approach to determining the exposure setting for flats with the EOS R.

Clear skies,
Kevin