Louis D

I bought a pair of vintage binoculars form a professional restorer, and he used NyoGel to lubricate them.  I assume it was one of the heavier damping varieties like 774H.

2 hours ago, Ricochet said:

The disassembled eyepiece is not a 5 element SWAN, but a 4 element WA. Trying to match the WA lenses to the specification for the SWAN is what has lead to the misidentification of the number of lenses in the lower group. 

That makes sense.  Very similar looking externally, but different internally:

I did have to laugh at WO's ad line for the 20mm SWAN: The ultimate 1.25” SWA eyepiece.  From the context within the ad, it probably should have said The ultimate compromise 1.25" SWA eyepiece.  However, that wouldn't have sounded so grandiose.

2 hours ago, John said:

Sounds a similar performer to the William Optics SWAN 20mm but at a better price. Fine in slow refractors, maks, SCT's etc.

 

And quite similar looking when disassembled:

Two upper singlets and what appears to be a lower doublet, although the author claims it to be a triplet.

I had a quick look at the skies with the SVBONY 20mm through my field flattened AT72ED.

It is nicely sharp in the central 50% of the field of view, though I wouldn't say pin sharp just yet.  It then gets more astigmatic as you work your way to the edge.  It had about twice as much astigmatism at its 68 degree edge as did either the Paradigm (BST Starguider) or Meade HD60 18mm at their 60 degree edges.  The Paradigm and Meade seemed to be a bit sharper in the central portion of the field as well.

The field was close to flat.  Of course, with so much edge astigmatism, it's difficult to judge best focus there.

The extra 8 degrees of field in the SVBONY didn't seem all that noticeable.

Faint stars looked similar in all.  Bright stars seemed to wink out at the field stops well enough in all of them.

The SVBONY had vignetting before the edge.  Perhaps the last 5% of the field.  It was slight but noticeable.  I take it that the designers pushed the old 66 degree design another 2 degrees to 68 degrees by enlarging the field stop without altering the lens design.

It works surprisingly well with eyeglasses.  I didn't have any problems taking in the entire field while resting my glasses on the folded down eye cup.

There were no indications of SAEP (kidney beaning) that I could discern.

Next I'll have to try it in my 127 Mak at f/12.

Overall, it's surprisingly good for what I paid for it, but it is not sharp across the field at f/6.

Having a 90mm FPL-53 triplet, I would probably err toward the 125 FPL-53 doublet just because cool down time will be much shorter than for a triplet.  It's pretty annoying having to wait 30 minutes or more to use high powers after taking the triplet outdoors while waiting for it to acclimate.  There will always be some color at high power with any refractor.  It just goes with the territory.  However the tightness of star points and their airy discs allows for easier viewing of tight doubles as compared to a reflector even with the minor residual color.

3 hours ago, Broadymike said:

Thanks all for your answers. Think its looking like I'll end up with both  lol. 

Think it will be the rigel quickfinder that seems to fit the bill as far as price and quality goes. Just now need to start looking for a RACI. So any recommendations there would be appreciated. I'll keep an eye out on the for sale ads on here too. Don't want anything cheap and nasty but do have to consider budget. 

The GSO made 9x50 RACI is probably the most recommended one out there.  It's surprisingly well made for the price.  I think I paid $50 shipped for my used copy last summer.

1 hour ago, Hiran said:

Hi everyone . I have celestron 7-21 zoom eyepiece . I tried to connenceted to camera t ring and found the tread are different. T adapter got 42mm and zoom lense got 38mm. How did it fit ststaightaway to sony t adaptor ? Has it got 38mm thread ? it would be realy helpfull If anyone can tell how to attach these two 🙏🙏

 

That's a different Celestron zoom.  I'm sure it's an M37 thread since M38 is not an industry standard.  You could look for a T-thread (M42) to M37 adapter or step-down ring.  Make sure it has a 42x0.75 thread (T-mount) and not a 42x1.0 thread (Universal mount).

1 hour ago, Starslayer said:

Yes, lanyard needs ordering. 

Make sure it has a way to keep them from swinging forward while not on your face and hitting the scope or mount if you lean over to view.

The fact that you can focus on trees closer than infinity, which is where stars focus, indicates you're short of adequate in-focus when wearing eyeglasses which I presume are set for distance correction.  I'm guessing you're myopic (near-sighted) which allows you to focus the stars closer than infinity without eyeglasses.  I might have that backwards.  I'm nearsighted and have to confess I've never checked which way I have to move the focuser to achieve focus without glasses.

It seems bizarre that a 6" SCT lacks enough focus accommodation for infinity focus with a BHZ.  What diagonal are you using?  Have you tried reaching focus with glasses but without the diagonal (straight through viewing)?  This would buy you 60mm of in-focus with a 1.25" diagonal removed from the optical path.

3 hours ago, Robindonne said:

Indeed. But if the stolen value exceeds the rent, does it also exceeds the costs of the procedure.  A lawyers hour equals an 8” dobson.  

You could always look up what forms need filled out and where to file them.

3 hours ago, Starslayer said:

Is this maybe different with Nate being in NM not Surrey?  😉

The biggest loss for those of us fairly far south (NM and TX) are the northern skies.  Circumpolar objects never get very high in the sky, so they never get out of the murk.  I haven't seen the Little Dipper clearly in years.

47 minutes ago, cutepetgroomer said:

We were paying on it .. but we’re out of state when someone was caught going into said unit so the owner of unit decided not to charge us for last few months to make up for their slack in watching it better .. someone apparently fooled a new employee that it was my husband.. wasn’t discovered until husband called to make payment as usual 

Unless the cost of forgiven rent exceeds the value of what was stolen, I'd be going after them legally for this.

27 minutes ago, pointedstick said:

On the other hand, I haven't had amazing experiences looking at the Messier objects. The Hercules Globular Cluster is just a dim blurry smudge. Other globular clusters are not so thrilling either. Bode's Galaxy is practically invisible. I haven't been able to see any nebulas.

The best views will require you to either get up around 3 in the morning or wait another month or two.  The summer Milky Way is coming.

I recommend pushing the magnification up to around 200x to resolve large GCs like M13 and M22.  You may need to buy a Barlow to increase your magnification.  150mm should be enough to begin to resolve them.

If you missed the Orion nebula, you've missed the brightest emission nebula.  Try looking for M17.  It looks kind of like a cigar at first.  You might also be able to see M16 or M20.

Try looking for M57 and M27.  Again, crank up the power on these small planetary nebula (PNs).

Start looking for M6, M7, NGC 6530 within M8, and other open clusters.  They're quite beautiful.

I assume you've already bagged the Double Double since you mentioned Alberio.

Being in NM, you should be far enough south to get good views of Sagittarius and Scorpius which have a lot of objects.  Scan back northward along the Milky Way toward Cygnus for more objects.

I captured some images with the field flattened AT72ED while using the following eyepieces:

• Meade 5000 Plossl 40mm: 61° AFOV, 27mm of usable eye relief, and a 43mm diameter eye lens
• Agena UWA 80° 30mm: 81° AFOV, 18mm of usable eye relief, and a 38mm diameter eye lens
• Meade Silvertop Plossl 9mm: 48° AFOV, 5mm of usable eye relief, and an 8mm diameter eye lens

I chose them because the first two have long eye relief and large eye lenses while the last has short eye relief and a small eye lens, and they present a range of AFOVs from 48° to 81°.

I took the images with my trusty Samsung Galaxy S7 and with a Canon Rebel T3i (600D) mounting Olympus Zuiko 21mm f3.5, Olympus Zuiko 50mm f1.4, Sigma 50mm f1.4 EX DG HSM, Vivitar Series 1 90mm Macro f2.5 (otherwise known as the Bokina lens), and Canon 18-135mm at 18mm/f3.5 lenses.

I chose them because the phone represents the baseline I've taken most of my eyepiece AFOV images with, the 21mm is fairly fast while being quite compact, the Zuiko 50mm is fast and compact but a bit poorly corrected, the Sigma 50mm is fast, bulky, and very sharp, the Vivitar is considered one of the finest macro lenses ever produced (though there is a bit of purple abberation at f2.5), and the Canon zoom because it's my everyday lens on the DSLR.

Below are the images grouped by eyepiece.  The Vivitar produced too much image scale with the 9mm Plossl, so I substituted the zoom at the very end.  I was a bit too tired at that point to go back and use it with the other two eyepieces for reference.

If you select them and view at full resolution, you are getting the exact resolution I was getting for each image.  There was no resampling.

Capturing edge images was a royal pain.

After capturing all these images, I wasn't quite sure what I was supposed to be looking for, so I @vlaiv will look at them tell me if they reveal anything.

I know I much prefer capturing the entire image in one go with the camera's phone.  It's quick, easy, and very repeatable.

Well, if you weren't paying rental fees on the unit all those years, consider the losses as payment toward unpaid rental fees.  It might have been the owner pilfering the cream of the crop on you.  If you were paying rental fees, the owner had no right to change the lock, and you've probably got a legal case against them.

Welcome to SGL.  I remember when I was about 6 years old that I first wanted to be an astronomer and then a paleontologist as well.  I guess it comes with that particular age.  Now that I've taken up astronomy in my later years, I guess it's about time for me to take up paleontology next. 😉

Search for "wheeley bars" and "scope buggy" for off the shelf solutions.

You could build a wheeled dolly out of wood and caster wheels, and then put cups for each tripod foot on it spaced appropriately.  Next, tighten cargo straps or heavy duty bungee cords down from the center of the tripod to hold the tripod firmly to the platform.  If the whole thing still seems top heavy and tipsy, put a 40 pound bag of sand or steel plates around the center of the platform to move the center of gravity lower.  You can even add corner jacks to avoid lifting the tripod off the dolly.

9 hours ago, Don Pensack said:

The Altair would be a noticeable upgrade, but a caveat: It has a very long eye relief.

Even with the eyecup raised, which you would do if not wearing glasses, it is possible to get too close to the eyepiece and get blackouts therefrom.

You do need to "hover" over the eyepiece.

With its M43 eye cup thread, you could probably add a Morpheus eye cup extender and M43 threaded eye cup if that became an issue.

9 hours ago, Tiny Clanger said:

However , I missed the  RDF for those bright things ... and now the shoe was full of RACI, and no way was I dismantling the mak to drill holes in it

I bought one of these off of ebay to allow for a 9x50 RACI, RDF/QuikFinder, and GLP to all be mounted simultaneously in the single finder foot.  They're quite sturdy and allow the RACI to almost be mounted in line with the altitude axis which is best for balancing purposes.

Vendor thread on CN about APM zoom eyepiece 7.7mm-15.4mm , 75° Constant FOV.

CN discussion thread about it in eyepieces forum.

Basically, it's still in development by Markus Ludes and his Chinese counterparts.  They're trying to finalize the ergonomics of the design it seems.  The optical design seems pretty stable.

4 hours ago, rwilkey said:

2" ep's are generally used for low power, why the hell would you want to Barlow a low power ep, that defeats the object of buying low power ep's.  I got rid of my 2" almost as soon as I bought it.

For fun to change things up.  I love the enormous eye lenses and long eye relief of my giant 2" eyepieces when wearing eyeglasses.  It's very relaxing to use them because I don't have to touch the top of the eyepiece with my eyeglasses to take in the entire FOV.  It's nice to use them at a larger image scale once in a while with a telecentric Barlow/magnifier.  Don't use a non-telecentric 2" Barlow with widest field 2" eyepieces.  They'll hard vignette ruining the whole experience.

19 hours ago, Shimrod said:

As a consumer you don't have the option of not paying VAT, so surely a discount of 30% is just that.

It is if you're an American.  It's basically voluntary to pay sales tax on imported items (except through ebay and other onine marketplaces).  We never pay VAT on imported items, and the sellers don't have to collect American sales tax, so the sales are basically tax free unless we voluntarily remit sales tax to our governing authority.  I guess Americans buy so little via direct imports that the taxing authorities can't justify creating a bureaucracy to collect it.  That, and any items under $800 are duty free.

As such, it's often cheaper for me to buy items from the UK/Europe/Australia/Japan and ship them here than it is to buy them locally.  Returns are a pain, though, if anything goes wrong.

I've noticed that UK/Euro prices are competitive with US pre-tax prices even with the ~20% hidden VAT included.  That's what makes them so cheap when cross-importing because VAT goes away and nothing else gets added.

Get a 50mm RACI finder.  The field of view of 127 Maks is insanely narrow.  The finder will help you get your bearings after putting the scope on target using a RDF or Telrad/QuikFinder.

6 hours ago, lee g said:

Hi do you use a solar continuum filter with the Hercules wedge.

No, I don't own one.  I did try my green Optica b/c line filter without any additional ND or polarizing filtration because the line filter cuts out so much light.  I didn't spend a whole lot of time with them, but I didn't notice any "Aha!" moments with any of them.

I did buy a SVBONY ND3 filter to put on the eyepiece.  It almost makes the image too dark.  I guess an ND2 filter would be about right if I could find such a thing.  I'll go back to using the included variable polarizing filter for now.  If I set it to about ND2 and then rotate the eyepiece, I can get additional polarization due to the polarization effect of the wedge itself on the incoming light.

I put a UV/IR cut filter on the front of the wedge and didn't notice any particular heating of it when I removed the wedge.  It reflects rejected wavelengths rather than absorbing them, so I think that helps prevent heating.

Optica b/c line filters from their 1978 catalog.  The band-passes are labelled violet, blue, green, yellow, orange, and red (from left to right in the diagram below) on the filters themselves.