I obtained my first image of the sun today with my QHY10 attached to my Sky Watcher Equinox Pro 80mm OTA on Manfrotto video mount.
Initially I tried to obtain an image with a solar filter made from Baader film – but still far too bright and unable to reduce intensity even with lowest exposure length possible in Nebulosity 4.
Added in Hershel wedge – intensity better – required Herschel wedge, polarising filter on maximum setting on camera after wedge, AND also solar film on end of scope! However, I was not able to obtain focus with the wedge in place – insufficient back focus on the telescope.
Finally, I changed over to my Daystar Quark Hydrogen filter on the scope with 1.25 inch diagonal (insufficient back focus for 2 inch diagonal) and the images below show the settings on telescope and Nebulosity that allowed me to obtain a reasonable image, close to focus – best position for focus turned out to be 8.5-9mm on the image scale on the focuser tube on the Sky Watcher Equinox Pro 80mm OTA.
Following this session, I noted that when I use the Quark visually, an eyepiece is inserted into an adapter at the end of the Quark and this sits a certain distance from the Quark body. Therefore, it would seem sensible to assume that the camera sensor needs to sit approximately the same distance from the Quark body as the eyepiece focal plane is located when an eyepiece is used visually. When I purchased my QHY10 second hand, it did not come with the QHY adapter but with one from another manufacturer which appears to have an inbuilt extension tube and this may mean that it is not possible to bring the QHY10 to focus on the Quark properly as it is too far away from the Quark. I need to get to grips with ‘backfocus’ and the correct distances required for the camera to each optical device I attach it to. Perhaps this information can be found in the camera instructions or looking for on the internet for diagrams showing the optical train / metal back focus for the camera and how to attach it.
Following image shows Nebulosity 4 frame and focus in action: