Hi, I have a LS50THa 50mm with a B400 filter and I am not overly impressed with the visual views. I do see prominences and some detail but you really have to look. Also I have had zero success imaging with it with a ZWO 120MM and ZWO 120 MC camera. Would upgrading the blocking filter to a B600 improve the views or just increase the FOV?
Lunt LS50THa With B400 Filter
Posted 09 February 2018 - 01:43 PM
It would just increase the FOV. It can take time to get used to the view, and it generally is more subtle that the overly contrast enhanced images you see posted here and elsewhere. Double stacking will greatly improve contrast, but decrease your image brightness.
Simulated view of SS v DS, click to enlarge.
Use the mono camera and add color in processing.
Edited by BYoesle, 09 February 2018 - 01:46 PM.
Posted 09 February 2018 - 02:30 PM
I have exactly the same optical system (no camera) and like you, this is taking some work to get good views of the solar surface and any edge events. It is not easy and finding the sweet spot for the tuner is tough.....I am experimenting with different eyepieces (best views are somewhere between 15 and 10mm) and have just purchased a Vixen 8-24 zoom to see if that helps find the best image. I found that I could find an edge event at one location (eg. 1000 hr on the solar disk) but if I moved solar image around, it may disappear if not almost right in the center of the image. I need to put the solar edge about in the middle of the view, and then move the image around so that the edges all come through the center of the view. Amazingly, other edge events show up when they get to the center.
I have considered double stacking, but not sure yet. I have also considered going to the Quark filter system so that I could use larger scopes, but am put off by the power needed to run the filter, and that it can take 5 min or more after a tuning adjustment for the image to stabilize.
Also, I can't do much right now, because I live in Fairbanks, Alaska and the sun is still so low even at local noon that it is lost in a mush of air turbulence, trees, etc. Waiting for another month or so for it to get higher in the sky.
I will follow this conversation to see other ideas.
Posted 10 February 2018 - 07:46 PM
Let me know how the Vixen 8-24 zoom works. I have a 20mm plossl, 13mm Orion Stratus and and 8.8 Explorer Scientific UWA. The smaller eye relief of the plossl seems better on the scope.
I took apart the pressure tuner and I noticed the gasket was worn in one area. Explorer Scientific is sending me a new one. I will let you know if that makes a difference.
I was looking at that Quark filter system vs a double stack also.
Posted 10 February 2018 - 07:49 PM
. Explorer Scientific is sending me a new one.
Correction, Lunt is sending me a new gasket not Explorer Scientiic
Posted 10 February 2018 - 08:51 PM
OK....let me know about the new O ring....though mine seems to hold pressure (tuning) once I set it. It will be about a month or so before I bring the scope out again for the spring as I wait for the sun to get some altitude...I will let you know what I see.