Next stage of my video eyepiece construction completed today, ready for testing hopefully tomorrow evening which is predicted to be clear.
In the first photo, the components are connected and working. In the second photo, I have assembled everything into single unit. The photo below shows the video eyepiece with lens on it rather than 1.25 inch telescope adapter.
Very poor conditions today with lots of high cloud, but the opportunity to see 2 sunspots at the current low activity level was not to be missed!
AR2739 is the 2 small spots on the left.
AR2738 still dominates the show but is now approaching the end of its transit. The white light image now shows some detail.
In order to see features on the sun in the presence of its extreme glare, Ha scopes and the like select out a very narrow band of frequencies with an (expensive) filter called an etalon.
In order to do this the etalons have to be “tuned” by various methods. To use them visually you need a very good contrast, and sometimes 2 etalons are used – the so called “double stacking” to narrow the bandwidth (and double the expense!) and improve the contrast. This can show breathtaking visual views.
However this only improves the contrast – not the spatial resolution, I believe. Resolution is controlled by the scope aperture.
Now, when imaging, you can readily improve contrast by signal processing with “Curves” and the like, as long as your camera has sufficient dynamic range. Tuning is therefore a lot less critical, and “double stacking” probably unnecessary.
Have I got this right? Any comments?
Due to other committments, only had chance to image AR2738 (in its entirity) and the nearby prominences this morning.
Roger suggested this project at a RAG meeting and kindly sent me a list of required components. The project is to produce an electronic eyepiece based on PD camera with small screen next to it so that observers can get the benefit integrated video images with their improved limiting magnitude over the eye at a glass eyepiece whilst retaining the “At the telescope” experience and not requiring user to carry lots of kit into the field. The mantra is simple, easy and effective, with the visual observer in mind at all times. The components required include the PD camera, which I already had, 7 inch LED screen, a 12V to 5V converter, various connectors and small 12V battery to power it all.
Main task is to add in converter and connect all so that single 12V power connection with power both PD camera and the 5V screen as well.
I successfully achieved this today. Next step will be shrinking it all down into a neat package and working out how I am going to attach the screen to the PD camera.
Quite a lot of activity this morning but AR2738 still dominates the show. The white light split in still clear but seems no bigger.