Louis D

Assuming it's a small chip imager, the added extension doesn't really matter.  Besides, when you focus at infinity at night, the extra extension shouldn't be needed.

The coma corrector needs to be spaced a specific distance from the imaging chip, 55mm in your case.  You need to figure out what combination of spacer rings accomplishes this.

Being a purely visual observer, that's about the limit of my knowledge of imaging.  Perhaps you should ask in the Getting Started With Imaging forum.  You might get more replies there.

7 meters is pretty close for a Newt.  You might need 2" or more extension to bring the image to focus.  Put a low power eyepiece in the fully racked out focuser and lift it up and out of the focuser while maintaining alignment, looking for focus.  Start with a tree or chimney outside a window and then work your way closer and closer with high contrast objects until you know where 7m focuses with your scope.

I'd probably get a RACI finder for low power views to complement the long focal length of the Mak.  Trying to find your way around the sky with the Mak alone is difficult due to its narrow field of view.

As far as home brew cleaning solutions go, here is Arkansas Sky Observatories' cleaning solution and methodology.  They're the only ones recommending a tiny amount of Kodak Photo Flo as a wetting agent.  It's a combination of propylene glycol (25-30%) and octylphenoxypolyethoxyethanol (5-10%).  Even without it, I'm sure their solution would work well.

1 hour ago, Alien 13 said:

I find saliva or a hot breath will shift most gunge..

Alan 

IIRC, Roland Christensen of Astro-Physics espouses the virtues of saliva on a clean fingertip for its enzymatic action on organic crud like tree sap.

2 hours ago, Spile said:

I am struggling with the concept that complex  = more ingredients = better. The thread posted shared personal views so is opinion. Nothing wrong with that but opinion isn't a laboratory test is it?

Like Don says, and in my experience as well, a purely alcohol solution doesn't work as well as an alcohol/soap/ammonia solution on things like tree sap spots and greasy stains.  A purely alcohol solution does work well as a final cleaning pass to remove all remaining cleaning residue from the more complex cleaners.  Like telescopes, there's no one best cleaning solution for all purposes.

For really gunked up old lenses, I disassemble the eyepieces, lay a folded towel in the bottom of the kitchen sink to safely catch a dropped lens, and then hand wash each lens with dish detergent with my fingertips.  It can take several passes to get it all off.  Then I followup with the lens cleaning solutions to get rid of any spotting or streaking.

As far as eyepieces, do you have astigmatism in your eye?  Check your eyeglass prescription for CYL or cylinder.  If it exceeds 1.0 diopter, you might want long eye relief eyepieces at lower powers so you can wear your eyeglasses at the eyepiece.

If astigmatism isn't an issue, there are many good options including the ES-68/82 lines.  There are also the Nirvana 82 and their other brandings if you want ultrawides.  The UFF line at 18mm and below is also a good choice.

If astigmatism is an issue, the Morpheus line is better corrected than the Hyperion line.

The 24mm APM UFF is a good choice whether or not you have astigmatism.

The 30mm APM UFF is an excellent choice for a near widest field 2" eyepiece whether or not you have astigmatism.

The APM UFF line is now sold under many other brands as well.

I wouldn't buy an 18mm and a 25mm.  They're just too close in power with your Dob.  If you don't get the 2" eyepiece, get the 25mm and skip the 18mm.

If you do get a 30mm 2", I'd skip the 25mm and 18mm and get a 12mm to 16mm eyepiece for general mid-power viewing.

Lastly, I would get a 5mm to 8mm eyepiece for high power viewing.  With a 2x Barlow, you can get some higher/highest powers with the mid and higher power eyepieces.

I recently picked up a used ES FE 2x, but haven't had a chance to try it out under night skies.  It would probably be best for a 24mm/25mm eyepiece to avoid vignetting.  If I ever get a chance to try it out, I'll report back on it.

I've had a TV 2x for over 20 years.  It certainly works well, but isn't spectacularly better than other vintage options.  It's certainly high priced today.

Since the Vixen isn't sold (or ever been sold) in the US, I know nothing of it.  It might be very good based on my experience with Japanese made Barlows.

If you follow the used market, my vintage favorites are the following Japanese made Barlows:

Orion Deluxe: very long (not an issue for Newts), but the cleanest image with no light scatter even at highest powers.

Meade 140 APO (3 elements): Mid length, basically identical to the TV with just a hint of scatter at highest powers.

Celestron Ultima/Parks Gold Series/Orion Shorty Plus (3 elements): Again, basically identical to the Meade and TV, but short and compatible with refractors.

All three of these regularly show up in the US for under $50 in the astro classifieds.  Similar performance new generally runs over $100.

The only modern Barlow I own is the GSO ED 2" 2x which is great for general usage, but it is not at the same level of polish as those above.  There is noticeable scatter at high powers, so I generally use it with a Tele Vue Panoptic Barlow Interface to make a poor man's 2" 2X Powermate.  I then use my 2" low power eyepieces in the combo just for fun some nights to change things up.

I also have the Orion 2" Deluxe 2x which is very long, but similar to the 1.25" version in scatter.  However, it is incompatible with the TV PBI, so it's not very useful with long focal length 2" eyepieces unless you live with the hard vignetting.

I have no idea if any of today's Chinese or Taiwanese made 1.25" Barlows have the same level of polish as the vintage Japanese Barlows I mentioned above.  Perhaps others have compared them to yesterday's best.  Starting out, I'm sure some of them would work well enough even if not being at the highest levels of polish.

It's going to depend on your tolerance of false color which way to go.  A regular short tube achromat is okay for dim DSOs but terrible for bright solar system objects.  An FPL-51 doublet would be the most cost effective G&G scope.  It will be nearly color free except at high powers.  An FPL-53 doublet will improve this a bit, but at a cost.  I would avoid triplets because of their extended cool down time.  Going from 70/72mm to 100/102mm greatly increases the tube size and mounting requirements, so be aware of this.

Check this post of mine that shows the various popular cleaners' ingredients.  ROR and Zeiss are actually more complex cleaners than BWF.  BWF might make for a good final pass since it's purely alcohols based.

Make sure to buy a telecentric 2" magnifier if you're insistent on using widest field 2" eyepieces in them.  Otherwise, you'll get severe vignetting that actually looks more like a hard cutoff of the field like a smaller field stop.  That said, I would just get an affordable 1.25" Barlow for starters since it's rare to double up 2" eyepieces except for those which are 2" due to being huge like the ES-92 and ES-100 series.

The flex tube wouldn't be my choice for solar viewing due to the open tube.  You would need to make sure any light shroud is light tight and well sealed around the extension rods.  On the other hand, it does allow binoviewers to come to focus by not extending the rods as far as normal.  The Arcturus BV requires about 4 inches of in-focus.  If you can't shorten the optical tube, you generally need a Barlow lens or OCS/GPC to reach focus in a Newtonian.

Either an SCT or Mak would have no problem reaching focus with a BV thanks to their moving mirror focusing method.  However, the focal length grows somewhat in so doing.

A refractor with a removable tube section can also work well.  TS-Optics and others have offered some in the past and might still offer some.

I have an Arcturus BV, and the OCS/Barlows that come with it are terrible.  I use the optics section of a vintage Meade 140 APO 2x Barlow screwed into the BV nosepiece to reach focus in many of my scopes.  It operates at 3x in this configuration.  A vintage Celestron Ultima 2x Barlow also works well.  They were also sold as Parks Gold Series (GS) and Orion Shorty Plus 3 element, IIRC.

The BV used natively in my 127 Mak pushes out the focal length to about 1700mm or more, but that is still far less than tripling it to 4500mm with the Barlow to reach focus.

Yes, you need a full aperture solar filter for white light viewing with most telescope designs.  A refractor can use a Herschel wedge instead for greater clarity.

The QuikFinder is so light and has such a small footprint, it should be mountable just about anywhere on it.  The Telrad would require a lot more real estate to mount.

Could you carry it backpack style with the tripod hooked on the side or behind?  A large internal frame backpack might fit it:

I just came across this low cost option that might work for you.  It's the EZ Push To Kit.

With a 355mm focal length, you're going to get wide true fields of view with most eyepieces.  Assuming you're going to use a 1.25" diagonal with it, a 32mm Plossl would get you to 11x and a TFOV of about 4.5°.  To nicely frame the 0.5° wide moon, you'd need something like a 5mm BST Starguider for 71x and a 0.85° TFOV.  To explore the moon in detail, I'd probably get a quality 2x or 3x Barlow because quality eyepieces below 5mm start to get expensive fast.

For DSOs, you might want to add something like the 8mm BST Starguider for 44x and a 1.35° TFOV.  Combining these three eyepieces with a 2x Barlow would yield 22x, 88x, and 142x as well.  That last power might only be useful for splitting doubles or for teasing out lunar details.  Remember, 60mm isn't going to pull in a lot of light on dim DSOs or provide a lot of detail on small objects.

Well, I know the ServoCAT systems are well regarded.

I would probably attach it directly opposite the altitude pivot point to affect balance as little as possible.

18 hours ago, cajen2 said:

Nobody has told me, but is the Williams Optics version exactly the same as the APM?

Optically the same, ergonomically different.  The WO has a broad, twist up eye cup whereas the APM and Stellarvue have tapered tops culminating in a traditional flip up-down eye cup.

IIRC, the RQF projects/focuses the circles at about 6 feet, not infinity, so there is some parallax with the sky if you move your head side to side.  Perhaps this difference in focus with respect to the sky makes them look odd?  My 20 year old copy has always had sharp circles, but I can't rule out a design change somewhere along the way, either.

I bought one of these for my daughter's scope, and it seems to work fine.  A bit bright with a slightly opaque window, but it gets the job done.

Aside from the APM/Lunt/WO 110 degree 3.5mm and 4.77mm/5mm eyepieces mentioned above, I would go with the 3.5mm/5mm Pentax XWs or Morpheus 4.5mm.  The XWs and Morpheus are very eyeglass friendly.  However, if you don't mind tipping your head and rotating it to capture the view from edge to edge, you could probably make the 110s work for you for planetary viewing.

1 hour ago, Deepblue12 said:

Louis

Came to that conclusion myself last night, i'm an inpatient [removed word] (not the best trait for Astronomy) and think i was just looking for a shortcut

Thanks

I'm at the point I enjoy comparing the views through different eyepiece/scope/Barlow/filter/CC/flattener combinations now.  It can make the same old showpiece objects look compellingly different.

1 hour ago, cajen2 said:

Sorry, less exclusive / expensive selection!

No need to be apologetic.  I've been at this for over 20 years, so I've been collecting little by little.  I'm at the point in life where I have the time to get out more, but my back and neck often ache too much by the evening to even think about hunching over an eyepiece for hours at a time.  I'd love to shave 25 years off my body, but that's not happening.

What's important is to get outside with what you've got available and make the most of it.  What good is a sports car if it sits in the garage year-round for myriad reasons?  It's better to have a utilitarian vehicle that gets used every day.

1. I always start with either my decloaked Meade 5000 SWA 40mm or Pentax XW 40mm (depending on the telescope) to scan the skies to enjoy a rich star field or two and then center objects for higher powers.
2. Next, I tend to jump up to either the 12mm or 17mm ES-92 to have a closer look.  Often times, I spend most of the night with them.
3. If I want to get an even closer look, I tend to pop in my trusty old Pentax XL 5.2mm.  If it is too much, I'll back off to the Pentax XW 7mm or even Morpheus 9mm.  If I think the skies are steady enough, I might pop in the Pentax XW 3.5mm.

So, not so much three most used eyepieces as three most used eyepiece focal ranges.  I don't find myself using the 22mm Nagler T4 or 30mm APM UFF all that much except in the 127 Mak where I need to downshift focal lengths a bit thanks to its long focal length and high f-ratio.