CCD 1 Class Announcement -- Please Read if Interested

Thanks, Scott, looking forward to your participation.

Happy New Year, Ed

Sure, it shoud be fine.

Ed

First, I should say to other potential CCD1 students that if you already have a monochrome CCD camera, even if it is a bit mismatched for your seeing and telescope, it most likely will still work for the course.  Use what you have.

Now, on to your question about desirable specifications for a CCD camera to use with a 14” SCT.

Pixel Size

You have a telescope with a long focal length, so you should avoid cameras with small pixels.  I also have a 14 inch SCT.  My camera has 24 micron pixels.  This is just about ideal for my normal seeing conditions, i.e it produces an image scale (1.34 arcsecs/pixel) that works well for the size of the typical stellar seeing disk at my observing site.  

I have also used a camera with 9 micron pixels with the 14 inch SCT.  To get an appropriate image scale for that camera required using a focal reducer and 2X2 pixel binning. i.e. setting the camera to use a “super pixel" composed of 4 smaller pixels.  This camera also worked very well with my telescope and seeing.  

I would recommend you look for a camera with pixels no smaller than 9 microns for the 14 inch SCT..

Cameras with large pixels (20-25 micron pixels) are rare in the used market, but cameras using the KAF1001e chip (24 microns) are still available new ($$$).   Cameras with 9 micron pixels are common, new and used.  

ABG (antiblooming) vs NABG (non-antiblooming)

Either will work fine for the courses and for doing normal photometry or exoplanet photometry.  All else being equal, the NABG camera would have the advantages of greater sensitivity and larger dynamic range.  I would not let this be a deal breaker if everything else about an ABG camera fits your situation.

Cooling

The cooling must be regulated, i.e. controlled by the camera and software to maintain a set temperature.  I have seen even some new budget cameras being sold with unregulated cooling.  This really should be a deal breaker.  Colder is better, but this is less important than regulation.

  Bit depth

16 bits (i.e. 65536 grayscale levels) is now considered the standard.  That said, I have a 12 bit camera (an SBIG ST-237) that I think would be fine in the courses if it were used with a short focal length telescope (~600-800mm FL).   If someone has an older computer (XP or earlier) with a parallel port, I’d be happy to see it go to a good home gratis.

For a CCD camera to use with your 14 inch SCT you should probably be looking for 16 bits.  Shortcuts here could mean other shortcuts you don’t know about.

CCD chip size

The physical dimensions of the chip and the telescopes effective FL determine the size of the field of view.  For the CCD courses I think you could get away with a FOV as small as  ~ 12 X 9 arcmin.  This is a small FOV by modern standards, but would work for the courses.

For a “keeper” camera to be used for photometry after you finish the courses, I’d suggest a minimum size of at least 18 X 12 arc minutes.  20 X 13 arc minutes would be better. I am happy with my FOV of 23 X 23 arcmin, but some would think this too small.

I find the easiest way to calculate FOV’s is to start with the image scale using the “206” equation shown on page 19 of the CCD Photometry Guide.  You can then calculate the size of each axis (in arc seconds) by multiplying the image scale by the number of pixels across each axis, and thus get to arc minutes for each axis when you divide by 60.  All this will be covered in CCD1.

If you are going to use a focal reducer to get the right image scale for your seeing, remember to use the FL produced by the FR in your calculations.

Here are some examples using older SBIG cameras and a focal length of 3690mm.  This is the effective FL of my C14 when using my STL1001e camera.  These cameras are no longer produced by SBIG, but they can be found for sale on Cloudy Nights and Astromart.  The chips used in the STL 1001e and ST 8xe cameras can still be found in current production cameras from SBIG an other manufacturers 

Camera             Pixel size             number of pixels each axis           effective FL           FOV          

STL 1001e          24 micron                         1024    X 1024                    3690               23’ X 23’

ST 9xe               20 micron                           512 X 512              FR 0.7X    2583         13.6’ X 13.6’

ST 8xe                9 micron                          1530 X 1020            FR 0.7X    2583         19.3’ X 12.2’

If you have questions you can contact me by going to my profile and clicking on the contact tab.

Phil

The CCD classes are taught via an AAVSO forum which is open only to class members.  The classes use discussion topics, and class exercises and assignments (i.e. making and discussing calibration frames)..  There are no on line meeting times.  Class members just check the class forum at their convenience and participate in the discussions by posting comments there. 

CCD1 students usually need to spend about an hour a day with the discussions (and posibbly a bit longer when doing exercises).  There may be quizzes, and there is a final exam.  CCD1 is designed for photometry beginners, but you should have a least some experience using a CCD camera before starting the course. 

The text book for CCD1 and CCD2 is the AAVSO CCD Photometry Guide which you can find here:

https://www.aavso.org/ccd-photometry-guide

CCD1 covers the first four chapters. 

There will also be a syllabus, but the discussions are wide open for questions.  I will post discussion topics and offer explanations or clarifications, but there are no official lectures.  I encourage students to ask questions, and these often lead to new discussions.  Two or three new topics or exercises are introduced each week.  All the topics remain open for continued discussion for the whole 4 weeks of the class.

Despite what you may have been told, CMOS cameras are not supported in the class.  If you are experienced using a CMOS cameras, you are free to use yours, but I will not be able tell you how to use a CMOS camera.  

For students without a suitable camera (a monochrome, temperture controled, CCD camera) , I will provide images you need for the course.

Students need to use their own software to analyzie images.  Examples of appropriate software are listed in the CCD Guide.

Phil

I don't think there should be a problem.    I usually don't get information about the class size until about one week before it is scheduled to start unless there is a problem.  You can sign up here:

https://www.aavso.org/choice-course-descriptions#CCD1

Don't be concerned if you don't hear back from AAVSO HQ right away.   People at HQ are starting to go out on holiday vacations, but we'll get you in.

If needed, you can contact me directly by clicking on the mug shot, then the "contact" tab.

Phil

Mike:

Monochrome CMOS are welcome in CCD1. The constraint is that I only have experience with the AS183 and may not know the technicalities such as optimal binning, gain and offset for your rig. 

Ed

dlee,

CCD1 is offered for mono cameras only, no one-shot color. If your ATIK 460EX is mono it should be fine. Note that to take full advantage you also need at least one photometric filter (Johnson V recommended). But if you have none you can use one of your AP filters (green for example) ot the images I will provide are learn the basics with that filter.

Ed

There were 15 slots. Apparently it sold out quickly.

Ed