Louis D

You could always initiate a dispute with your CC company and let them sort it out with the retailer.

35 minutes ago, Jiggy 67 said:

If you’re in a 6 you’re in a 6, I don’t think you can lower it.

As I said, it depends on where you are located.  If you're on the edge of an urban center as I am, 6 is probably the value at zenith.  Looking away from the urban center will have a better Bortle value.  Looking toward it will have a worse Bortle number.  As such, choose your targets when they are positioned in the darkest parts of your local sky.

If you're in the middle of either an urban center or dark site, then the Bortle value will probably be fairly consistent around the sky, and it won't matter when you observe targets.

Tripod thread standard: 1/4-20, which means ¼", with 20 threads per inch.

In my experience in Bortle 5/6 skies, your sky darkness will be highly dependent upon where the light sources are greatest.  My sky facing a city of over one million and a giant freeway interchange is closer to Bortle 8/9.  My sky facing open farmland is closer to Bortle 4/5.  Only overhead is Bortle 5/6.  Local lighting of a field won't impact sky darkness very much unless it's stadium level brightness.

Assuming you only have a 1.25" diagonal, I would recommend buying a 32mm Plossl.  The Astro Essentials and Revelation versions are both good and affordable.  It will provide the widest true field of view possible in a 1.25" eyepiece.  The 24mm end of your zoom is rather narrow, so the 32mm Plossl can help with locating objects and then centering them for the zoom.

A good OIII or UHC filter would be my choice for first filter purchase.  Astronomik and several others sell reputable versions.  Avoid the super cheap ones, they don't work very well in my experience.

If you want higher powers with your zoom, most folks here recommend the Baader Q-Barlow 2.25x Barlow as a decent performer for a reasonable price.

1 hour ago, vlaiv said:

Is that flattened or regular AT72ED. It has rather short focal length - field curvature must be strong in the young one .

ST120 will have quite a bit larger radius of curvature if we take 1/3 of FL of each to be approximate radius of curvature. If above is flattened field then I can only expect worse from ST120 unless I have young eyes that compensate for FC (I'm starting to need reading glasses when working on computer - so that boat is probably about to set sail).

It is field flattened with a properly spaced TSFLAT2 ahead of a GSO dielectric diagonal.  Notice that the Meade 5000 SWA 40mm had no problem with the field.

The AT72ED has a 430mm focal length and 143mm RoC.  Your ST120 has a 600mm FL and 200mm RoC, so it will be less severe on eyepieces.  It might need about 15mm less TSFLAT2 spacing than my AT72ED.  However, I've found that the same spacing for my AT72ED works just fine with my TS-Optics Photoline 90mm FPL-53 Triplet APO which has the same FL as the ST120.  Shortening it didn't seem to improve things visually.

1 hour ago, vlaiv said:

I wonder why 40mm one is no longer made.

It has best performance at the edge of the field of the three.

In any case, I can see 35mm having enough of field stop to give me 4° in ST120 (together with 7mm exit pupil) - good to know.

You would think TS-Optics could have had a production run made for them of the 40mm version since it is the most in demand worldwide.

The 35mm is going to struggle a bit at the edges in an ST120.  Here's how my 35mm OVL Aero ED looks at f/6 in my AT72ED:

Here's Ernest in Russia's review/test of the 30mm, 35mm, and 40mm versions of these eyepieces under the Levenhuk ED brand.  All versions are made by KUO and the 30mm and 40mm were originally designed by Thomas M Back as the TMB Paragon.

From his summary chart, the measured field of view is 66 degrees for the 30mm, so just slightly less than the claimed 69 degrees (the top row of the table needs shifted one column right):

On 26/02/2021 at 09:54, Boros said:

I tried the sponge thing, but have to confess didn't like the soft feel, just felt a tad vague to me.

There is that I'll agree; but on the upside, it dampens vibrations from your finger touching the focus knob.

Since the OP didn't really specify cost, I took the topic's debate to be between wide field and narrow field eyepieces in general.  At the high end, narrow field eyepieces like the ZAOs, TMB monos, TAK TOEs, and Vixen HRs still outperform their similarly or lower priced wide field competitors.

45 minutes ago, Deadlake said:

From Mr Ludes
 

here more factory news , my questions and factory answeres

Some advises and questions

1, what ist he eyerelief from top of mechanic at different focal length ?
7.7mm: eyerelief is 18mm
15.4mm:eyerelief is 20mm

 

2, can you do again dual barrel 1.25“/2.“ Like on XWA eyepieces ?
Yes, similar to XWA 1.25 and 2” barrel

 

3, can you engrave for astronomy use the focal length and not the power on the eyepiece ?
Yes, our other zoom eyepieces are with focal length.7.7，8.7，10.2，12.2，15.4

 

4, can you design the top to accept the Tele Vue Astigmatism corrector called Dioptricx > https://www.televue...._page.asp?id=54 ? more details here > https://www.widescre...-corrector.html 
This adapter should be easy to make, we plan to make this corrector on our eyepieces

 

5. Whats the body diameter ?
The diameter of the largest part (rubber grip) is 53.8mm, and the diameter of the remaining part is 53mm or so.

 

6. Will the new Zoom be parfocal on all length ?
It is parfocal at different focal length.

 

 

7. If you can do the eyeside with a conical shape you will increase very much the sales
1.25”barrel is straight, the top shape is conical like XWA
If you can do click stop zoom you gain another better sale
It's a little bit complicated and difficult to add to this device

 

The eyecup is similar to the 12.5eyepiece, fold-up.
We have designed two product style, the right one looks very nice.

OMG! 😲 32mm of in-focus will be required???  I've only got about 15mm of in-focus left on my Dob with a CC in place.  It would be fine in my fracs and Maks, though.

11 minutes ago, johninderby said:

I dedicate this to CN 😁

 

PONTIFICATE

Word forms: plural, 3rd person singular present tensepontificates, present participle pontificating , past tense, past participle pontificatedPRONUNCIATION NOTE:   The verb is pronounced (pɒntɪfɪkeɪt ). The noun is pronounced (pɒntɪfɪkət ).1. VERB

If someone pontificates about something, they state their opinions as if they are the only correct ones and nobody could possibly argue against them.

[formal]

Politicians like to pontificate about falling standards. [V + about/on]

[Also VERB]

Synonyms: expound, preach, sound off, pronounce  

I can't think of any recent US leaders who might fit that definition. 😁

3 minutes ago, johninderby said:

And have a nice hot cuppa. 🙂

Hot cuppa tea, coffee, hot cocoa, mixed drink???

1 hour ago, LDW1 said:

Try either the Svbony 8-24 or 10-30 zooms they are more than great for the price of less than $100 C ! They are very close to the Baader in performance for about 1/3 the price.

Svbony is having a 32% off sale on ebay US right now on them.

2 minutes ago, Mr Spock said:

We never get into a froth. I might raise the occasional eyebrow, or utter a faint 'hmmm' - but not very often 😜

Quintessential British stiff upper lip, I presume.

For me, it's the super short eye relief of orthoscopics at short focal lengths that really bugs me.  I have enough astigmatism that taking my eyeglasses off even at a 1mm exit pupil causes a noticeable drop in resolution for me.  As such, I stick with my Pentax XLs, XWs, and Delos.  I know I'm giving up a bit relative to TMB monocentrics, ZAOs, TAK TOEs and Vixen HRs, but I'm willing to live with it for comfort sake.  During the latest Mars opposition, I found much better resolution to be had with my entry level Arcturus binoviewers and 50 year old B&L microscope wide field eyepieces than with my best monovision wide field eyepieces.

At lower powers, it's simply no contest.  My 25mm Edscorp Abbe Ortho is simply no match for a 22mm Nagler T4 or 30mm APM UFF in edge to edge sharpness at f/6, especially when you figure in the vast difference in field sizes.

All the same issues being regurgitated over and over again on page after page of this CN thread.  Apparently, us Americans are in a much bigger froth over it than folks on the other side of the pond.

5 hours ago, PEMS said:

Likely a good idea to start at the 25mm simply for the wider views it will supply as that helps in finding things. An 8mm and perhaps a 12mm can follow later. One easy approach is, if it is possible, to buy one every month or something. The Starguiders look nice as a small set of say 4, (8mm, 12mm, 15mm, 25mm). Not sure the 5mm and 18mm would add a great deal.

Having all but the 3.2mm in the set, I would suggest 25mm, 12mm, 8mm, and 5mm making for powers of 48x, 100x, 150x, and 240x.  I tend to skip straight from widest field to mid-high power in a Dob of that focal length.  As such, the 18mm and 15mm get skipped and are too closely spaced in power at 67x and 80x, respectively, to either the 25mm or 12mm to make sense to buy them as well.  That, and they're both fairly weak performers compared to the 12mm and below.

I would pool the money saved on the 15mm and 18mm toward getting a 30mm APM UFF or equivalent (Altair/Meade/Celestron) in the future.

5 hours ago, PEMS said:

The one area Starguiders sort of fail in in not having a 6mm eyepiece. Sometimes it seems a 5mm is just a little too much magnification for scopes and at 5mm the eyepiece has to be fairly good as well as having to operate with a fast scope.

Perhaps under UK skies you might have a point.  240x is not an issue here in my part of Texas.  For 185x at 6.5mm, I'd recommend the recently discontinued Meade HD-60 if it can be found second hand.  I've measured mine to have a 64 degree AFOV, so it competes strongly with the older Pentax XL 5.2mm I have.  A zoom eyepiece coupled with a decent Barlow might also be a high power option for the OP.

17 hours ago, SamAndrew said:

I think the Sky Watcher price increases are in line with inflation, they've just chosen to do ten years worth of inflation rises in one hit 😄

I paid £549 for a Quattro 10S in 2011. It is now £729. 33% increase

2.5% inflation for ten years = £702. So not far off.

 

By keeping prices low for two decades, they've managed to push out almost all non-Chinese competition.  Now they can raise their prices to a sustainable level for themselves.  This is also happening in solar cells and rare earth metals production.

3 hours ago, Deadlake said:

I once plotted get a PHEV. You can run the power in reverse and power the house from the car. That way you don't have some machinery hanging around that you don't know its going to work until it's too late.

That might work for short term outages, but not for days long outages.  Our gas stations were running out of fuel due to lack of tanker truck deliveries because of the icy roads.

Modern generators automatically start and run diagnostics weekly, alerting you via wireless connection if there's an issue.  The biggest issues I've read about are when the starter battery dies and this check can't happen and making sure to have the engine oil changed/maintained.  I'm not concerned about natural gas not making it to our house because we had a continuous supply despite it not making it to all the critical NG generators.  Maybe we just got lucky?

I've read proposals to use PEVs in a distributed manner to store electricity generated at night for use in the daytime.  Of course, this presumes you don't want to use that electricity to actually drive somewhere and back each day.

I just had an epiphany.  At 15.5mm and 75 degrees, it will most likely have a wider true field of view than the typical 8-24mm zoom at 24mm and 44 degrees.  It will also be wider at the short end as well.  It should yield a very useful range of magnifications and TFOVs.

Adding a focal reducer to a Newtonian will probably just exacerbate the inherent coma of the desig, add field curvature, add other edge aberrations, and reduce back focus to such a point it may not be possible to bring most eyepieces to focus.

If you really want a fast Newt for wide field views, go with an f/3.9 astrograph with a TV Paracorr T2 instead.  The large central obstruction will limit its contrast for planets, though.

If the dewpoint is quite low outside compared to inside my house (often the case during winter here), I'll cap my eyepieces and close my airtight cases before bringing them in to prevent them from instantly dewing over.  If it's damp outside, I'll bring them in uncapped and open cased to let them dry out before storage.

The scope(s) are brought in uncapped in either case because they're not airtight.  I don't want moisture inside the house accumulating on them while capped and not temperature equalized.

Finders come off before bringing in the scope(s) to avoid catching them on the door frame.

I generally carry the scope(s) and associated mount in one go since they're under 50 pounds.

I'm thinking of getting a standby generator for the house instead of more astro gear since we lost power for days during the winter storm two weeks ago.

14 minutes ago, Deadlake said:

In seriousness where can I reserve an item, and pay when it is in stock? I cannot do that at Flo for instance..

I know Astro Physics keeps decades long waiting lists for when they restart production of certain in-demand scopes.  If they decide to restart a certain item, they will approach each list member in order, and ask if they still want to buy that item.  If they do, they ask for a 50% down payment to hold your spot in the line at that point.

Perhaps this could be the new normal for retailers with months long wait times for popular items.  If they receive word of an item due for unloading and customs, they could go back to the wait list and ask for down payments to hold their spot in line for a few more weeks while the item clears customs.