I just received delivery of a Solar Spectrum RG-18 0.3A etalon. Mark at SS says the etalon is closer to 0.25A. The RG models are supposed to be more uniform across the entire field.
The day started out mostly sunny, but by the time the sun was visible and I was set up and ready with an eyepiece bam, clouds for miles. I did some yard work and kept an eye to the sky. I figured I would be able to get some visual in so I could make sure everything was working. It took about an hour and I was able to get a quick peek for about 2-3 minutes. I had to figure out the spacing to get to focus so that took a while. I went back to work an finally I could see that the clouds were thinning out enough that I would possibly be able to image. These are the first I completed processing but I was able to capture more. The visual is stunning! Details really come alive. Filaments were dark and well defined. There doesn't seem to be a noticeable sweet spot. There was a nice filaprom that I cant wait to process.
The following are images of AR 2816 using a CR-6 at F/45 at the etalon and F/23 at the camera (ASI174)
Different processing of the same image