60mm White Light solar

[Stu]

Have been meaning to try this for a while, the CoolWedge in my FS-60Q.

I was concerned about heat build up in the Q module, probably unnecessarily but I rigged up a UV/IR cut filter ahead of this lens just for safe measure. Not needed with the Sun this low, but perhaps will help on a hot mid summer’s day.

Inwards focus is always a challenge I find with the 60mm, especially with the Wedge which has a long light path and Binoviewers on top of that. I played around with a few options, eventually removing the 2” ClickLock so I could attach the MaxBright IIs directly to the CoolWedge II, which has that option. I had to use a x2.6 GPC, but with 25mm eyepieces this resulted in a decent sized full disk view but with plenty of surrounding sky. Adding extension tubes allowed me to up this so only around 50% of the disk was visible, giving significantly higher mag.

Seeing was pretty ropey in the gaps between clouds, but still good enough to see the large AR which is disappearing around the limb now, plus plenty more of the smaller ones. Even 3597, 3594 and 3592 showed as small spots.

Granulation was pretty much invisible, just a hint of mottling over the surface, small aperture and poor seeing the culprits.

Anyway, nice to have the option of a very compact scope for travel. I did try the 76 DCU aswell, finding focus with the same setup and that showed the same mage scale but more resolution at a very similar magnification due to the virtually matched focal lengths; 570mm vs 600mm for the Q

I’m intrigued by the prospect of using the 60Q as a small PST mod for travel too; it is f10 which is ideal, I just need to source a Baader Ha filter to sit ahead of the CQ optics and see if I can reach focus. It may need a cut down rear tube but I’ll see what happens.

Some pics for reference.

 

[Highburymark]

Agree that 60mm is too little for really satisfying WL detail Stu, but the 60mm PST mod sounds promising. Presumably you just swap over the etalon from your monster mod scope?
I still think 100mm is the sweet spot for white light in U.K. seeing - it’s the one thing I miss having moved to a TSA-120 from a 100DC. With the 120, I’d say 75% of sessions are compromised by seeing. But the other 25% certainly compensate. Marvellous views at 250x on very special occasions. Have you tried the wedge with your FS128 yet? 

[Stu]

2 hours ago, Highburymark said:

Agree that 60mm is too little for really satisfying WL detail Stu, but the 60mm PST mod sounds promising. Presumably you just swap over the etalon from your monster mod scope?
I still think 100mm is the sweet spot for white light in U.K. seeing - it’s the one thing I miss having moved to a TSA-120 from a 100DC. With the 120, I’d say 75% of sessions are compromised by seeing. But the other 25% certainly compensate. Marvellous views at 250x on very special occasions. Have you tried the wedge with your FS128 yet? 

Yep, probably needs a very good day to make it worthwhile, but useful as a very compact travel kit.

Simplistically yes, just need the back end from the other mod but I need to get the etalon at the right distance. It’s not just a case of measuring 600mm from the objective because of the CQ module, but I did find the focal point then the etalon needs to be 200mm ahead of that. Will give it a go at some point soon.

I have had a brief solar session with the FS128 but not in gods seeing, should be good anyway. I’ve also got a 120mm Celestron Omni XLT f8.3 which nearly went to Wookie65 but had a last minute reprieve so I’ll try that too.

Ludicrously enough, I also have a second 150mm f10 in the attic (don’t ask) which just needs a bit of fettling to get sorted. Might just try that for white light alongside The Beast! That would be a crazy setup for days of really good seeing!