Highburymark

Very nice - looks like you’ve done an excellent job

Very interesting - thanks Jeremy. Looks like the ED 1.5x is the most flexible of the extenders.

Useful to know optimum range from AP - didn’t know that. They certainly perform well above that power too - at least to my not perfect eyes.

It also begs the question, if there’s no benefit in Ha, why has Lunt moved to expensive ED doublets and triplets as base scopes for its entire range? The answer’s obviously because more people are attracted by a ‘do it all’ package than separate scopes for night and day, but I’m surprised Lunt hasn’t at least retained some of the cheaper, non-ED dedicated solar scopes in its range for the many people who already have an ED night scope, and don’t want a second. I use a TV85 (ED doublet) for solar and its excellent - never thought whether it’s particularly well corrected for hydrogen alpha though. Meanwhile Coronado SMIII “70mm” solar scopes use a fast and cheap achromat. Presumably pretty unpleasant for night astronomy, but corrected to perform well in deep red.

I really like the BBHS mirror too. My T2 Zeiss prism usually lives on the TV85 for solar work - haven’t had chance to test it with the TSA yet. Makes sense that you’re getting better results with the mirror because your scope is relatively fast. With my F/7.5, I’m not expecting any noticeable differences between the two diagonals, but we shall see. I’ve ordered a TOE 4 to replace my Delite 4, and complete the mini set.

Avoid the Coronado - Meade has just been bought by Orion, and they are reassessing the whole business. There is very patchy support for Coronado products at the moment. Lunt LS80 would be nice - though still pricey, particularly double stacked. Lunt has now moved to using modular ED refractors for their scopes which can also be used at night. Might be a few old model dedicated solar LS80s still available at stores. The etalons themselves haven’t changed. There’s also the interesting new Baader/Solar Spectrum Sundancer, which has just been released. Best piece of advice is to do your homework - solar scopes/etalons are very variable in quality, so one option might be to buy secondhand, when you can actually test the etalon first. Quarks in particular can be poor. Definitely not a decision to be rushed.

Hmm. The Solarscope DS 100mm filters are almost £30k in the EU!! Much less in the UK. Apart from the incredible price, I don’t think the Tak FC-100s are robust enough for two external 100mm filters (which can also be sourced from Lunt for about £15k.)

My only criticism of the excellent Barcon is its (grrr - why does spellchecker always want to change this to it’s?!!!!) limited power when used after the diagonal - think it’s around 1.65x. Using it with 25mm eyepiece to try and get up to much higher powers requires a huge stack. The Zeiss Abbé is better in this regard. The newer AP Baradv has a bit more punch than its predecessor too.

Excellent - thanks. I’m thinking it will probably work nicely with other non-Tak refractors too? I have a little TV85 that I’ll experiment with. Great that it doesn’t add to eyepiece stacks. F/11.25 TSA sounds like fun!

I saw a modest but very clear resolution improvement going from 50mm to 60mm, and then a more substantial jump going from 60mm to 70mm, where I am today, although the 70mm etalons are higher quality than the 60s I had. If you get a good LS80, no doubt you’d see significantly more detail. The only drawback with the LS80 is if you want to double stack, many (all?) owners report an annoying bright shadow around the disc. These can be lessened by fitting another internal filter, but need to be taken into consideration if buying the DS version.

Those light paths look right. Does sound like you need more out-focus. With T2 diagonals, easy option is to use Baader T2 spacers to find focus - either before or after the diagonal.

Jeremy - is it the 1.5x ED extender you have for the TSA rather than the Q 1.6x? I’d be interested to hear if there are any issues reaching focus with extender/TSA 120, either with or without BVs? I’ve got an ED 1.5x on order too - will mean I can use 25mm Zeiss OPMI microscope eyepieces on planets and the Moon, and double stars in single ep mode.

I’d definitely go for the Maxbright. It’s a top class binoviewer, nice wide and sharp views, with all the accessories you might need in the future to adapt it to different telescopes and targets. It’s every bit as good as the MkV in my experience, but lighter. I thought the main attraction of the Orion linear (and the other iterations of the same model) was ease of use without a barlow - more of a niche product for lower magnification observing.

The other suggestions look great too. Great thing about the DZ is it’s so light and easy to carry

Will have to measure it - not sure off the top of my head. Will try and report back tomorrow

Congratulations on a beautiful telescope. I used this Manfrotto case for the FC-100DC when I owned one - and still use it with a TSA-120. it’s well padded, decent value and perfect for a 4” scope. Available at many camera stores

Lots of atmospheric colour on Jupiter this evening. Is anyone using an ADC successfully? They look like another great lump of metal to add to the eyepiece stack, but are they effective for the planets?

Couldn’t disagree with that Dave. I’d be perfectly happy with the Vixen if restricted to one scope. Have yet to actually look through one, but it’s on my priority list. If I had dark skies at home, then a Newtonian would make most sense, but living with light pollution and requiring a travel friendly scope makes a 4” refractor the most flexible and satisfying compromise. Ideally, it would be aircraft friendly too - various options there, though looking at something a bit faster.

I found the answer to my own question in the most unlikely of places - aisle 4 of the local supermarket.

Jupiter’s colours have been so muted this year - that’s meant keeping powers at or under 200x has brought out the bands more. But it’s well worth trying higher mags if the image stays sharp

Fujis might be the safer bet ortho-wise at the moment. Thread on CN showing quality control problems with some recent Tak abbes. Although both Tak and Fujiyama lines appear to be made in the same factory, haven’t seen any complaints about the quality of Fujiyamas.

Thanks for all contributions to this thread. It’s turned into a very interesting comparison of high power planetary preferences.

Good point Louis, often the problem is with eyepiece centering. Though gradually more BVs that address this are coming into the market.

I can only echo everyone else’s comments. I use them pretty much 100% now for solar Ha and perhaps 75% white light, 75% lunar, and 25% for planets. I think dedicated single planetary eyepieces at high magnifications are preferable for planetary detail than barlowed binoviewers though. Agree with the comment about collimation - suspect quite a lot of pairs out there may not perfectly collimated, and as a result might not allow for easy merging, or for long sessions without eye strain. Although the use of binoviewers is very much down to personal preferences, and everyone’s unique physical capacity for two-eyed viewing, it seems we all use them for very similar reasons on equally similar targets.

Late replying to this, apologies. I think most conventional eyepieces still come to focus with the shortened tube. One thing though - If you’re swapping around from one ep to binoviewers regularly, you might need to adjust the balancing of the tube a bit - I had a heavy pair of binoviewers, and as you know the OTA is incredibly light. Good thing about the Tak tube clamps is they make adjustments easy