72mm white light

[Size9Hex]

Pleasant white light views in the SW 72ED with Lunt wedge this afternoon. I’ve previously used an ST102 for solar, so was interested to see how the 72mm would get on. Nicer glass, but a lot less of it of course.

At 90x the seeing wasn’t great, with the view being seeing limited perhaps 90% of the time. When it settled, I could make out 9 small spots of varying shape/size in the current active region, the 9th being marginal. Checking afterwards, the view compared well with the spots in the SOHO image. In these seeing conditions, I didn’t miss the extra horsepower of the ST102, which in fairness has really delivered in the past on days with good seeing. Interested (and optimistic from experience so far) to see how the smaller scope fairs in better conditions.

The Oiii filter I’ve been using to tame the purple halo and sharpen up the ST102 wasn’t needed. I did try it to dim the glare, but preferred the view through the polarising filter despite having become accustomed to green white light(!?).

On a few occasions as the seeing settled, I thought I saw a fleeting grainy texture which I took to be not-quite-resolved granulation. Wasn’t sure anything would be visible at this aperture so I was happy to see it, assuming that’s what it was. Interested in the experiences of others on this.

The 72ED focuser was notably easier to dial in at high power than the ST102, which I thought helped make the most of the limited horsepower in the smaller scope.

With a low power eye piece, it was quick to find the sun by aligning the shadow cast by the dew shield onto the tube rings. No solar finder needed.

Overall, really impressed with the 72ED so far and solar seems promising too from today’s limited experience. Seems versatile and capable for a little’un!

Just a footnote... there’s no intention to bash the ST102 (which I think is good at what it sets out to do) in this post btw.

[Mark at Beaufort]

Paul an interesting report. I sold all my White Light kit over 12 months ago and I was looking at the SW 72ED to restart my interest. 

It seems a very good scope for the money. Do you think that the scope will cope with a much greater magnification?

[Knighty2112]

Wow! You must have 20/20 eyesight. I viewed the sun around lunchtime for about 20mins, but only noticed one spot in WL. Well done!  

[AdeKing]

1 hour ago, Knighty2112 said:

Wow! You must have 20/20 eyesight. I viewed the sun around lunchtime for about 20mins, but only noticed one spot in WL. Well done!  

I did slightly better but still only managed about 4 small spots in the current AR in WL

[Size9Hex]

52 minutes ago, Mark at Beaufort said:

Paul an interesting report. I sold all my White Light kit over 12 months ago and I was looking at the SW 72ED to restart my interest. 

It seems a very good scope for the money. Do you think that the scope will cope with a much greater magnification?

Thanks Mark. I think it’s a belter, albeit with realistic expectations needed given the aperture. It’s a bit short of inward focus compared to the ST102 and my dob, and won’t reach focus with my focal extender so 90x is the maximum I can get from it with my shortest eye piece. Hoping to find some time to solve this at some point because I suspect it will take more power, although I must state I’ve not tried it. I’ve detected at least one double star just inside the Dawes limit at 90x. At this mag, I can see the Airy disc when hunting doubles, so from this perspective (point sources), the resolution is starting to run out. But subjectively, I think it still seems very sharp at 90x on solar, Jupiter, lunar and I’m optimistic it’ll take more on some of these extended objects.

[Size9Hex]

1 hour ago, Knighty2112 said:

Wow! You must have 20/20 eyesight. I viewed the sun around lunchtime for about 20mins, but only noticed one spot in WL. Well done!  

Thanks Gus. Tiny speckles for sure, but there are quite a few of them up there in the current active region. Keep at it and I’m sure you’ll catch them. ?

Edit: just thinking about the seeing conditions too, most of time the smaller spots vanished and the larger spots kind of merged together, so if your seeing was any worse than here, it would have been tough.