Lunt CaK B1200 + PST #1 yellow
Posted: Mon Oct 01, 2018 12:02 am
I was experimenting with a PST #1 yellow filter with my Lunt B1200 CaK. I was testing on a 70mm F/6.8 doublet. I only have an R2 Revolution imager, so no reasonable photos to show. I will try to attach iPhone shots of the R2 monitor.
Lunt with the yellow filter vs. Lunt without:
1. Gain had to be increased from 6dB to 18dB, so it was dimmer.
2. It seemed a little higher contrast between the active region and the rest of the disk, within the limits of the R2.
3. I think is could see more subtle variation within the active region itself.
4. I could not see the H-alpha filament in either one.
5. I could see subtle linear details in both, but perhaps better with the yellow filter but not sure.
6. There was a faint reflection with the yellow filter that I could tilt off axis. It only showed up at higher (e.g., 42 dB gain).
7. Prominences were visible only in the solo Lunt (at about 42 dB).
Some of the difference in contrast, perhaps, could be the change in brightness and the fact that the R2 has discrete gain settings. Maybe the dimmer version just lined up better with the R2's thresholds.
So I probably will not be able to tell much more unless I move up to a real camera and computer.
I may just sell the PST CaK, stick with the Lunt Cak and R2, and put my investment mostly into H-alpha because I am mostly visual.
George
Lunt with the yellow filter vs. Lunt without:
1. Gain had to be increased from 6dB to 18dB, so it was dimmer.
2. It seemed a little higher contrast between the active region and the rest of the disk, within the limits of the R2.
3. I think is could see more subtle variation within the active region itself.
4. I could not see the H-alpha filament in either one.
5. I could see subtle linear details in both, but perhaps better with the yellow filter but not sure.
6. There was a faint reflection with the yellow filter that I could tilt off axis. It only showed up at higher (e.g., 42 dB gain).
7. Prominences were visible only in the solo Lunt (at about 42 dB).
Some of the difference in contrast, perhaps, could be the change in brightness and the fact that the R2 has discrete gain settings. Maybe the dimmer version just lined up better with the R2's thresholds.
So I probably will not be able to tell much more unless I move up to a real camera and computer.
I may just sell the PST CaK, stick with the Lunt Cak and R2, and put my investment mostly into H-alpha because I am mostly visual.
George