Baader Maxbright II - advice needed

[RobertI]

Bit of a long one this, but I’d appreciate some help.

I’m now looking to get Baader Maxbrights while the special offer is still on. I’ve been reasonably happy with the William Optics for solar system use, but I think the wider apertures, better eyepiece holders and improved connectivity of the Maxbrights should hopefully provide benefits. In particular I am hoping to improve deep sky BV observing by allowing lower power, wider FOV observing with my 102ED. So I would like to check a few things:

Connectors

I have this prism diagonal - it’s a 1.25” with a male and female T2 connector and 28mm free aperture. I think this provides the shortest light path possible. FLO offer this Maxbright package which includes a 2” nosepiece with T2 male thread and 1.7x GPC.  So I am assuming the configuration would be:

1. The male T2 thread of diagonal attaches to the female T2 thread of the BV (GPC goes in between)
2. The female T2 thread of the diagonal attaches to the 2” nosepiece
3. The 2” nosepiece goes into the focuser drawtube - no 1.25” converter required hence reducing light path

Is this right? Do I need to buy anything else? How to I ensure the BVs are at the correct orientation if I am screwing in directly?

Back focus

I am assuming this will all reach focus ok? Has anyone tried with a 102ED like mine?

Eyepieces

The only pair of eyepieces I have are the ones that came with the WO BV, but these don’t make use of the full 25.5mm aperture of the Maxbrights. I have the following eyepieces, which ones should I double up on (ie: buy another) to get my nice low power views or should I get a brand new pair (😱)?

• Morpheus 17.5mm (76 degree FOV but higher power than the WO eyepieces)
• Hyperion Zoom (narrow AFOV at 24mm)
• ES 24mm 68 degree (quite wide diameter, suitable for BV?)
• 32mm Plossl (narrow AFOV)

Thanks for making it this far and any thoughts appreciated. 🙏

Edited September 3 by RobertI

[Saganite]

That is all you need Robert.  I used a WO for a good few years, but the BM II is just in a different league. You will not be disappointed....

The 1.7 GPC will reach focus easily as it did in my VIXEN ED103s.

Edited September 3 by Saganite

[globular]

Connectors:
You have it spot on.  The collet on the BVs allow for changing orientation.

Back Focus:
With the 1.7 GPC I think you'll be fine. If your main aim is wider FOV then you might want to try without a GPC (or a lower powered one) - but I don't have your 102ED to know if there is enough back focus for that. The BV is about 110mm without a GPC and is about 80mm with the 1.7 GPC. (Which has been given a silly name, as it magnifies more like 1.5 than 1.7).  Your prism diagonal is about 40mm back focus. The baader equivalent prism can save another few mm if you need them.  I have both and rate the baader slightly better quality and slightly shorter path and slightly wider aperture - but it's by no means necessary (unless you need to save a few extra mm of back focus).

Eyepieces:
The 1.7 GPC will give similar magnification to your WO 1.6 one - slightly less I'd wager, depending on where you mount them. So, if you need to use it for back focus reasons, you'll need to go longer fl EPs to get a wider view.
I went with a pair of UFF 24mm 65° and they are excellent. They also focus at the shoulder so don't require any extra valuable back focus. Their field stop is 25.9mm so you can't really go any wider without starting to introduce some issues.
I do wonder what the new Ursa Major Flatfield 25mm 65° would be like - they are very cheap but might be worth a try?

Enjoy!

[Richard]

I use a pair of 24mm Panoptics for low power binoviewing. They are one of the few pieces of astro kit I’ve bought new (well over 20 years ago I think) and haven’t ever felt the urge to part with despite my constant search for the ‘perfect’ refractor/eyepiece combination. Despite reports that they do not, both my current CZAS binoviewer and my old MB II did ‘sort of’ suffer from vignetting with 24mm Pans, but it is more a lack of clear-cut field stop and doesn’t really bother me.

I had a pair of 19mm Pans before the 24s and they were also lovely, and a bit smaller and lighter. Neither are cheap but I’m very happy with mine.

Initially tried 32mm TV Plössls but they were just a bit too wide for my inter-pupillary distance to accommodate.

I also have a pair of 10mm UFFs which work very well for slightly higher-power views.

Edited September 3 by Richard
.

[Saganite]

I sold my 24mm Pans after several years of use and replaced with 19mm Pans and they fit my scopes well, but I often look at the 24mm UFF'S........Hmm

[Richard]

1 minute ago, Saganite said:

I sold my 24mm Pans after several years of use and replaced with 19mm Pans and they fit my scopes well, but I often look at the 24mm UFF'S........Hmm

I preferred the 19s in some ways, but I’m a little too obsessive about having the widest AFOV possible. I’d have both 19 and 24mm pairs but I really need to stop reading reviews and buying kit based on them, and use what I have a little more instead, if only the weather picks up!

I found that there were several different ‘breeds’ of UFF, and mixed reports about the different focal lengths within each make. I found some APM 10mm UFFs and I’m very pleased with them for the price. Apparently they are not so good in fast scopes, I use mine in scopes between f/6 and f/20.

[RobertI]

44 minutes ago, globular said:

I went with a pair of UFF 24mm 65° and they are excellent. They also focus at the shoulder so don't require any extra valuable back focus. Their field stop is 25.9mm so you can't really go any wider without starting to introduce some issues.
I do wonder what the new Ursa Major Flatfield 25mm 65° would be like - they are very cheap but might be worth a try?

That’s a good steer thanks. I have to say the Ursa Major FF are just the right size and at only £39 each, got to be worth a punt?

[paulastro]

Excuse my ignorance, but can someone  tell me if the 1.7 GPC will work with my Celestron 8inch Starsense Dob, or would I need something else? - I''ve used a x2 barlow element screwed into the nosepiece of my MB Mk 1 binoviewer up to now.   Same for my refractots, except my Askar 103 triplet which I can just remove the detachable tube section.

 

[RobertI]

17 minutes ago, paulastro said:

Excuse my ignorance, but can someone  tell me if the 1.7 GPC will work with my Celestron 8inch Starsense Dob, or would I need something else? - I''ve used a x2 barlow element screwed into the nosepiece of my MB Mk 1 binoviewer up to now.   Same for my refractots, except my Askar 103 triplet which I can just remove the detachable tube section.

 

I’d be interested to know this too, I have a 12” dob on hire during November, so wondering if BVs would work.

[RobertI]

Thanks for the information everyone, I’ve now ordered the Maxbrights! 🥳 Not in stock so might take two to three weeks. Just got to decide on best eyepiece(s) for low power viewing now. Also need to think about best way to achieve around 170x for planetary viewing. 

[Saganite]

At f7 in your 102ED and a GPC 1.7X that would be a pair of 7mm eyepieces or thereabout, but I don't have a pair even close .  Others will make suitable suggestions I am sure .... 

[Highburymark]

On 03/09/2024 at 12:09, paulastro said:

Excuse my ignorance, but can someone  tell me if the 1.7 GPC will work with my Celestron 8inch Starsense Dob, or would I need something else? - I''ve used a x2 barlow element screwed into the nosepiece of my MB Mk 1 binoviewer up to now.   Same for my refractots, except my Askar 103 triplet which I can just remove the detachable tube section.

 

Can’t answer your question Paul, but as you may be aware, the 1.7x GPC is actually only 1.5x - so will give noticeably lower powers than your current barlow

[paulastro]

22 minutes ago, Highburymark said:

Can’t answer your question Paul, but as you may be aware, the 1.7x GPC is actually only 1.5x - so will give noticeably lower powers than your current barlow

Many thanks Mark, that's very helpful.  I didn't know it was  x1.5. In all the years I've used a binoviewer for the Moon and planets I've always roughed it with a barlow 😊.

[Saganite]

47 minutes ago, Highburymark said:

Can’t answer your question Paul, but as you may be aware, the 1.7x GPC is actually only 1.5x - so will give noticeably lower powers than your current barlow

I didn't realize that either.  Do you happen to know Mark if the 2.6 GPC is higher or lower than 2.6x ?

Thanks 

Steve

[Highburymark]

2 hours ago, Saganite said:

I didn't realize that either.  Do you happen to know Mark if the 2.6 GPC is higher or lower than 2.6x ?

Thanks 

Steve

It’s slightly under at 2.5x Steve. Seems odd for that most precise of brands, Baader, to give imprecise information on its GPCs - though I also understand the Morpheus AFOVs are all slightly different too.

[bosun21]

I used to use a pair of 17.5 Morpheus eyepieces in mine which gave great views. I found them a little bulky for my liking so changed to 18mm UFF's, again great views.

[RobertI]

Tonight I worked out the magnification provided by the 1.7x GPC with the Maxbrights and it appears to be 1.6x. The method I used was to time how long for a star on the celestial equator to cross the FOV. I’m assuming the 25mm eyepiece has the stated 65 degree AFOV.