Louis D

13 hours ago, cajen2 said:

It didn't come out well in the photo (awful cheap phone) but the little one is the Hyperion 2.25x zoom.

Did you mean Barlow rather than zoom?

8 minutes ago, Littleguy80 said:

Plus I may have been able to pick up some fainter ones with this filter. 

Again, using the blinking technique with stray ambient light blocked by a hood, and using a long eye relief eyepiece to fit the filter between your eye and the eyepiece, makes confirmation of faint comets (or bright comets in murky skies) easier.  The comet coma will be the only thing not dimming with the filter.  Interestingly enough, I find the comet disappears as I keep staring through the filter at it and have to blink it again to get it back.

Possibly, but it seems most folks jump from 70mm or 80mm to 100mm for their second scope if staying within ED scopes.  Not many make the jump to 90mm without expecting a massive improvement in optical quality to compliment the subtle increase in aperture.  That's what I was doing when I went from a 72ED to a 90mm FPL-53 triplet.

You're right, it's a great grab and go or travel sized scope.

6 hours ago, Vulisha said:

As an owner of 127, 127 definitely! brilliant little scope! 

And i think in newer they fixed primary mirror size, but I might be wrong. Just read that online somewhere. 

I've heard that about its 150 big brother, but not about the 127.

Agreed.  I bought used Synta 127 Maks for myself and my grown daughter for $200 each pre-pandemic.  Even now, they still trade well below their new prices due to how many of them compete for the same secondary buyers.  Both still have perfect collimation.  Remember, the 127 is really about 118mm of clear aperture because Synta used 127mm primary mirrors, when in fact they need to be slightly larger to capture the meniscus's slightly diverging rays.  The JOC (ES/Bresser) version doesn't have this issue, but has a longer focal length.

What do you like viewing with them most?

For the out-travel case, I generally just don't insert the Barlow all the into the focuser.  I just insert it until the eyepiece pops back into focus and tighten it down.

Here's a post of mine from a similar thread 2+ years ago covering various lens cleaning formulations:

Thousands Oaks also sells a few varieties of solar film that render the sun yellow-orange.

3 hours ago, Jbagwell97 said:

Yes, last thing i want to do is blind myself with somthing cheap or not suited for purpose.

Another problem noted with the Chinese made solar filters is that they mount the film in a stressed manner leading to loss of resolution.  Wrinkles don't matter, but stretching tightly does.  It looks nice and flat, but that's actually detrimental for films.

Another unknown with the Chinese made solar filters is how well they filter out of visual band light (UV and IR).  I haven't seen any independent spectrographs of any of them, but have seen plenty of them for Baader, Thousand Oaks, and Solar Skreen (example below).

Another alternative is a Lunt, Hercules, or other brand of 1.25" Herschel wedge.  Their back focus requirement is much less.

There are various 33mm diameter 0.5mm thread pitch step rings out there.  You might be able to jobber several step rings together to get to a usable thread size for an adapter.  However, it may add too much distance to be of any use for pupil matching as Don has pointed out.

8 hours ago, FLO said:

I suspect 'military grade' and 'aerospace' are American-style marketing speak

No, the dude I bought it off of actually works for an aerospace company that makes CF tubing.  Being the head tube maker, he was able to make an appropriately sized tube to replace the original aluminum tube off hours.  It's not hyperbole that he made it to the same spec as the stuff going to various aerospace contractors.

9 hours ago, Mandy D said:

Unless it's a focal extender!

It still does a similar job, only better.

Or a 1.25" Tele Vue Paracorr.  But they're so rare, I didn't think it worth mentioning.

All this assumes 1.25"-only.

My frac's CF tube is military grade (from a US company that makes them for the aerospace industry).  No blemishing from the rings on it.

You can identify a Barlow lens by it having an eyepiece holder at one end with a setscrew and a lens at the other end that inserts in the focuser.

I've got a CF tube with some scratches I plan to fill with clearcoat and polish out.  What polishes did the manufacturer recommend?  There are dedicated CF polish kits out there, but they're not cheap.  I've got metal polishing compounds for jewelry, but I'd hesitate to use them on clearcoat paint.

4 hours ago, Shimrod said:

My eyepieces have been despatched

I read that initially as they've been destroyed. Whoops. 

You might want to inquire over on Cloudy Nights as well.  Being US based, you might have better luck there.  There are certainly quite a few Porta-Ball users over here who could help you out.  Unfortunately for you, I'm not one of them.  As I recall from star parties, it's actually a fairly simple scope to assemble and collimate, so don't be too concerned about the complexity of this undertaking.  One odd thing about them is that the primary mirror collimation knobs come up alongside the mirror because the backside of the mirror cell is inaccessible due to the ball construction.

BTW, don't be tempted by low ball offers to sell that scope.  They are worth many thousands of dollars and are still in demand on the secondary market.

2 hours ago, Don Pensack said:

But for fainter objects, the difficult with this technique is that the filter is essentially a mirror and reflects back so much ambient light the objects become invisible.

You are correct.  I was thinking about that when I wrote that.  However, I still found it effective to confirm comet ZTF using that off-spec Zhumell OIII filter.  It was the only part of the sky that didn't dim.  When attached to the eyepiece, it wasn't as effective because the blinking response wasn't activated in my brain.  I could sort of detect it by sweeping past its position in that case.  It's similar to how I can't see a camouflaged animal until it moves, then it's obvious.

If you have a long eye relief, low power eyepiece, try the blinking technique with the filter between your eye and the eyepiece.  This is how I've been comparing filters for false color reduction on achromats.  It's easier to see subtle differences between filters when you rapidly move them in and out of the exit pupil.  You can even try stacking filters this way to see if one is more dominant than another.  For instance, an HB or OIII should look the same with a UHC stacked ahead of it since the UHC should typically be passing both HB and OIII.

3 minutes ago, TheThing said:

Hopefully, just a quick query.  I've got a set of bino viewers and have picked up some pairs of eps now.  I'm intending to use them with a 127 mak for '3D' views of the moon.  Do I need to use a diagonal with them or will they reach focus without?

It should reach focus either way, but you're going to end up with a stiff neck without a diagonal unless the moon is really low to the horizon.

 Also, I assume that I can put a Barlow in front of the bino viewers and not have to purchase pairs of barlows?

Correct.  It's best to use a single Barlow ahead of the binoviewer.  It will also keep the focus closer to the nominal design distance.  Even without the Barlow or a 1.25" diagonal, you'll be operating at a longer focal length to reach focus due to the BV's 100mm+ optical path length, but still a much lower FL than with the Barlow.

Thanks.

See inline comments.

1 hour ago, Clarkey said:

@vlaiv - I would be happy to buy and forward on at cost. I think you can be trusted😆 I assume this one:

SVBONY SV191 Telescope Eyepiece 9-27mm Zoom lens 1.25inch Super-Wide Angle FMC 714559019061 | eBay

I am guessing it would be about £10 to send from here to Serbia.

Doesn't it seem like the 9mm circle should be 50% larger in diameter than the 27mm circle in this ad photo?

Many folks with 127 Maks are trying to get to wider true fields of view rather than higher powers by using Barlows.  I switched to a 2" visual back and put a 2" diagonal on mine to massively increase the true field of view by using widest field of view 2" eyepieces.  Sure, there is some light falloff beyond the field fully illuminated through the 27mm rear port, but the human eye has difficulty noticing it.

Are these threads under the eyecup?  Most of these threads tend to be either M37 or M43, depending on the width of the eyecup.  The 30mm UFF is different from most others because it has such a large eye lens.  I think it has an M45 thread.  Measure the width of the threads with a ruler, and see if it is closer to 37mm or 43mm to figure out which it is.

2 hours ago, Don Pensack said:

The factory size and the number of customers they can sell an eyepiece to as a private label product determines how many can be made in a batch.  It could be 100 or 500 depending.

It's definitely hard to make back your R&D costs on such small production runs.  The only reason smartphones are reasonably priced for what they do is because their R&D costs can be amortized over tens of millions to hundreds of millions of units.  Imagine what astronomy tech would be like if practically everyone around the world owned astronomy equipment.