Just been wondering about the double stack Ha filters, and looking at Brians SM40 (Solar max40) and my PSM40 (PST Solar Max), they both look the same.
Here is a pic of mine.....
Now with doing some research on them, the front gold lens bit unscrews from the T max tuner (the black bit with the gold tuning wheel on it) which some retailers sell by itself for about $169......
Coronado say
Coronado H-Alpha Filters include a T-Max de-tuning device. Some events on the Sun, notably active flares and coronal mass ejections (CMEs), are extremely fast moving. If such features occur on the disc of the Sun, their high velocity towards the observer results in their wavelength being Doppler shifted shorter than Ha. The T-Max allows the user to de-tune the SolarMax slightly to bring such phenomena into better visibility.
So now I am wondering that if the T-max is just de tuner, then I wonder what it would be like just screwed onto the front of the pst without the T max bit?
(Will have to give it a go next time I see the sun).....
So, in efffect the filter should not need tuning if just fitted as a screw on filter....
I know the Solarmax II have a richview bit on the front, which does fine tune them, but they also have the T max aswell.....
Also in the Coronado instruction book (no I never got one supplied either) but downloaded it, the earlier PST double stack system had a front mounted tuning ring aswell, but the first PST's had a different filter set up and needed the double stack to be tuned to match the factory fitted one.
The later PST's with the blue coatings will accept the filter without being factory tuned, so they just screw onto the front.... Which is what makes me think the SM40 is the same as the PSM40......... And its also a bit odd that the PSM40 is now discontinued and replaced with the SM40.......
