Type of refractor to use with a wedge?

[Bill E.]

I would like to get around a 100mm refractor to use with a solar wedge. I am a bit confused on single,doublet and triplet .I understand it is the number of lenses and somehow the more you have the more correct the light is in the eyepiece ,but is important to have one over the other when used mainly with a solar wedge?

[Bill E.]

Rusty,I want something a bit more compact. I want to tandem mount and complement a Lunt 80. Maybe a f6-f7 ?

[solarchat]

Bill, it sounds like the Exp Sci 102mm APO is the scope for you. I use it at every outreach event and I can't say enough good things about it. Not the doublet but the APO

[Cschur]

I think most of the short refractors are around f/6 - f/7, so if you have a specific length in mind, you can calculate the aperture pretty straightforward. An "ED" achromat is an in between cost you many also consider. They are far better as far as color correction goes than a regular achromat, yet no where near as expensive as an apocrhomat with three or more lenses. Im lookin at the Explore Scientific 127 for the future, it looks like a great deal of quality for the price.

[Derek Klepp]

Bill I often use a 100mm ED doublet purchased second hand. It sits well in tandem with either of my Ha scopes. It also doubles as my Birdwatcher and grab and go. I think it was one of the very first Williams Optics releases. It is also identical in parameters to the Lunt 100 so when moving the camera image scale is the same.I also have a 127mm APO with Japanese glass as opposed to Chinese 127mm. The views are better but the added weight means slower set up and less stability on my HEQ5PRO mount. I also have a Meade 80mm APO but with the wedge there are focus issues. I can only get focus with certain eyepieces(In my case Meade UWA's). Like Rusty I would love to go to 150mm F15. I think this would be spectacular for WL wedge views. However a substantial mount would be needed.

[marktownley]

I think a 100mm f7 is the way forward for you.

I currently have a 70mm f6 and a 127mm f9 frac and want a 100mm to bridge the gap. There are numerous times when the 70mm is fine seeing wise and the 127mm is just too much; though have to say personally are tempted by a 100mm f10/11...

[swisswalter]

Hi Bill

at my site 100 at F/8 ist just the one I can use most of the time, anything above is seldom to very seldom used

[Bill E.]

Well,Thank you, I appreciate all the input. You have given me a bit to think about. Now I will do my homework. I will post what direction I end up going. : : : : :

[Suncityan]

Here's another interested bystander.

I am looking for something to go along with my Coronado SolarMax 60, thank you for the insight (have a solar wedge needing a place earn its keep).

Thanks

[marktownley]

Again, I think a 100mm is the way forward with this...

[Suncityan]

That physical size instrument would fit the mounting capacity here. I also read where one should try for a three lens design.

Now I'm wondering if anyone would like to suggest one 100mm brand over all many the offerings out there? Guess they could be categorized by price/quality/accessories. (Sort of a cost per mm for what you get comparison.)

Thank you

[astrodanco]

For public outreach I'm currently using an SV80ED with a Lunt wedge and a Baader solar continuum filter. It works quite well, but I think a 100mm or so objective would work even better. A little more focal length wouldn't hurt either.

But when I see the images taken by the guy who has a full aperture Baader film filter over his Edge HD 14, it makes me want to ditch the wedge and buy a large sheet of the Baader film for mine too. (Too large to haul around much though.)

[Suncityan]

Your words, " full aperture Baader film filter over his Edge HD 14" makes me want to dig out the long retired Celestron C-8 in the back of the closet. It is one of the first black tube versions purchased almost thirty years ago - hadn't thought about putting a full aperture filter on it.

It is bulky but maybe there would be a way to mount it on the EQ and then mount the 60mm Ha scope on it instead of a tandem mount plate as is presently being considered. The mount plate presently being designed will be large enough for two small refractors. It would be a challenge to come up with an acceptable mount plate and scope configuration that would allow easy set-up and take-down.

The 'observatory' (very stout pier bolted to the concrete deck on the south side of the house) is easily accessible, just walk out the study door with the equipment.

Wonder if anyone on this forum has mounted two very dissimilar scopes as suggested above and would share their experience, Tommy

[astrodanco]

You can mount them side-by-side. I've done that with a Nexstar 8SE OTA, an 80mm refractor OTA and an ADM Accessories DSBS-DUAL. Or you can mount the 60mm scope on top of the C8. Put an ADM Accessories DC8 on top of the C8, an ADM Accessories VDUP4, VDUP7 or VDUP11 on the bottom of the 60mm and an ADM Accessories DV-SAD inbetween them.

[Suncityan]

Well goodness - that is too easy....

Seems there is an adapter on that site for just about any scope(s) mounting configuration.

Looking at what is offered there it seems as if a set of radius blocks, RB-OTA, a set of adjustable rings, DR-75, and an appropriately sized dovetail bar in between would be a solid mount for the 60mm Ha scope onto the C-8.

Maybe another set of radius blocks mounted on the bottom surface of the C-8 tube would give a very solid way to mount the two scope assembly onto the flat mounting plate on the EQ mount. The original adapter plate between the C-8 tube and the mount was not solid at all.

Think I understand that is a way those adapters could be put to good use here.

Thanks for the suggestion!

[marktownley]

Wonder if anyone on this forum has mounted two very dissimilar scopes as suggested above and would share their experience, Tommy

I've mlounted my Coronado SM40 and my C8 side saddle before with no issues, just a case of getting the balance right...

[Suncityan]

Thanks for the reply!

I wonder if you found the C8 to be a good scope to view in ole sole in white light.

Where I'm coming from here is trying to decide wether or not to purchase a 100mm refractor and use a wedge or if since the C8 is already in my arsenal get a full aperture filter and use it. I would like to see granulation if possible.

A refractor would cost anywhere from $800 US to four or five times that amount and compared to that a filter would be a minuscule amount.

[marktownley]

[quote]I wonder if you found the C8 to be a good scope to view in ole sole in white light.

It's a great scope when seeing conditions allow; sadly from where I live this is only a couple of times a year @ 8" aperture. 100mm is usuable much more - infact is likely to be my next scope purchase. The trick is using as much aperture as you can get away with on a regular basis.

[Suncityan]

Very good statement, "The trick is using as much aperture as you can get away with on a regular basis."

The reason the C8 has spent most of its life in the closet is the atmospheric stability has not been good here on a regular basis. This was when DSO viewing; however, seeing when viewing the planets was much better. It would be a relatively (relative to the cost of a refractor) inexpensive test to get a blocking filter for the C8, mount it solo and see what happens.

Sort of like trouble shooting a computer, it's best to concentrate on ridding one bug at a time.