Deadlake

1 hour ago, Nikodemuzz said:

Exactly, I have read similar comments. And given that the light gathering difference is only about 15%, I wouldn't expect there to be a significant difference. Which further underscores my comment about the factors favoring the TSA-120 seem heavier.

I think you would get a difference for imaging if you went with a faster scope, but you are going for F7.5 scopes which are relatively slow. magic fluorite dose not help you there. 

By the way, both of those scope where on my shopping list but got crossed due to availability of faster scopes.

Everything for Vixen going through Bressner is a bottleneck. Pre Brexit but during the pandemic the SXP2 I bought took about two weeks to arrive. I knew it was in stock, just the shipping. The latest scope I’ve bought in Janauary sourced with parts  from Germany and America still has not arrived. Brexit is more of an issue I hear then the pandemic. Also constant issues with logistics (for all orders the dealer is procuring). I think this the new normal. For the next large orders I’m going to try RVO as they will accept a deposit and charge when on route to them.

Just now, dweller25 said:

I’m sure @JeremyS has a handle on the situation 😂

@JeremyS he does like to get a good handle indeed. 😀

3 minutes ago, dweller25 said:

It’s just the same as an SCT

BUT it remains stable 👍

Compared with a Celestron maybe? If so, you should tell @JeremyS as he is not sure of the advantage of Takahashi over Celestron SCT'S yet. 😀 
 

Just now, dweller25 said:

??????
Perhaps I expressed myself badly.

In my opinion there is no need to buy expensive collimation tools to collimate a Mewlon 210.

All that is required is a night with good seeing so you can see the in focus airy disk, a cheap 7mm Orthoscopic eyepiece (x303 and a narrow field of view) and you are good to go.

Make VERY small changes and do not worry about the squeaking noise - really !

This may help too....

 

I was joking. Reading some CN posters experience with collimation is sounds  a mystery any one gets it to work. 😀 

8 minutes ago, dweller25 said:

Best tools/method....

Good seeing, 7mm eyepiece and a star 👍

Show off. 😀

3 hours ago, Fedele said:

tell me the options...ah, i know yet the stars 🙂

This is mentioned al lot on the CN thread, Information on the Takahashi Mewlon 210 and Mewlon 250

 Hotech Deluxe CT Collimator

However there must be other options?

A Mewlon is on my list, just wondering what I need to buy as well.

13 hours ago, Fedele said:

But the one for 250 etc don t work for 180?

Apparently not, but there are other options.

I think thesis covered here:

Information on 210 and 250 Mewlons

9 hours ago, jetstream said:

Are you sure the SCT's are including the total obstruction including the baffle? I think the Mew180 is 30%.

9.25 is 36% by diameter and 13 % by area

https://www.celestron.com/products/c9-25-optical-tube-assembly-cge-dovetail

in specification tab, however no description of measurement.

The Mewlon 180 is around 30% and the 250 around 28%. Which would explain contrast differences. However on CN its reportedly bigger around 32% for both,....

12 minutes ago, jetstream said:

Diameter.

Both the C9.25 and Mewlon 210 are around 33%...

5 hours ago, jetstream said:

Check out the true, not advertised central obstructions between them. Then maybe check out some generic MTF's based on average SCT and Mewlon specs...

For visual, a central obstruction of less 22 % you’ve mentioned in the past, presume you mean by area?

9 hours ago, dweller25 said:

1985 - Astro Systems (Bedford) 8.5" F/5 Newtonian - A brilliant first scope - should have kept it - sold
1988 - Beacon Hill 6" F/8 Newtonian - Hinds optics, very nice but kids came along so no time - sold
2007 - Celestron 102SLT refractor - not really good at anything - sold
2008 - Celestron C9.25 SCT - very disappointing - sold
2008 - TAL 125R - very nice but too much CA - regretfully sold
2008 - Skywatcher 127 Maksutov - a bit too small - sold
2008 - Skywatcher 8" F/6 Dobsonian - superb optics - should never have sold it - sold
2009 - Skywatcher 120ED refractor - pinched optics - returned
2009 - Takahashi TSA102 refractor - 4" perfection - KEEPER
2009 - Helios 6" F/8 refractor - too much CA - sold
2009 - Takahashi FS128 refractor - superb scope - KEEPER
2010 - Celestron C102ED refractor - excellent lightweight travel scope - should have kept it - sold
2010 - Skywatcher 180 Pro Maksutov - would not cool down - sold
2010 - Skywatcher 8" F/6 Dobsonian - disappointing optics - sold
2010 - Skywatcher 10" F/5 Dobsonian - superb optics but this scope did my back in, otherwise a keeper - sold

2012 - Takahashi Mewlon 210 - this brand new scope from Tak Europe was actually three years old! and had bad mirror shift - returned
2012 - Celestron C8 SCT - Nice optics but the OO 8" was better - sold
2012 - Orion Optics 8" F/6 Dobsonian 1/10th wave - superb optics - Awkward viewing angles affected bad back - sadly sold.
2013 - Intes Micro 715 Maksutov - Superb optics - views matched the FS128 - sold

2014 - Orion Optics OMC200 F/20 Maksutov - Carbon fibre beauty - would not cool down - sold

2014 - Lunt 60 H-Alpha solar scope - always at work when the Sun came out! - sold

2014 - Skymax 127 Maksutov - still a bit too small! - sold

2017 - Tal 100RS - New old stock - had a tilted lens cell and an out of true focuser - sold with full disclosure.

2018 - Celestron C6 - very light and good optics - close to but not better than my 4” APO - sold

2019 - TS 6” Classical Cassegrain - never dewed up - close to but not better than my 4” APO - sold

2020 - Takahashi FC100DZ - very lightweight 4” APO  - great for my bad back - KEEPER

 

My taste in scopes is changing as I get older....

Viewing from the rear suits my back.

Quick cooldown suits the highly variable Lancashire climate

I appreciate the views unobstructed, high optical quality optics provide.

My back likes lightweight scopes.

I am becoming a refractorholic 😂

Are APO only keepers?.?

1 hour ago, JeremyS said:

Wow I scanned 572 posts in that CN thread. It wasn’t particularly frothy, though .

I even saw our own @dweller25 in there.

But I saw no compelling arguments in favour of the M210 cf a C9.25

The points I took away where:

1. The Mewlon was sharper over the SCT's by owners of both.
2. The TSA120 was competitive unless you has a night of exceptional seeing.
3. Mewlon better at not dewing, then a SCT.
4. Unsure which was harder to collimate, the SCT of Mewlon. 
5. Mirror shift, both SCT and a Mewlon seem to get sent back.

With point 2 how much bigger do you need to go to get some benefit or all seeing/temperature delta related?

PS: Mewlon is green, matching colour scheme.

4 hours ago, JeremyS said:

I have same dilemma. I have a very nice C9.25 but wonder how a Mewlon 210 would compare. Considering the C9.25 is mainly for deep sky, it probably has an advantage 

We could just ask John Bobben on Do I need a Mewton 210, yes!, he has both after all, I think the Mewlon is sharper. If I  was using the scope as just a light bucket, then the C11 would be ok, however for planets when seeing allows a larger aperture the Mewlon takes the lead. The Mewlon is not dew prone as the C9.25 or C11, however some loss of aperture which makes tricky decision.  

If AP is you main use a 130mm/F6 LZOS is worth a look. Speed always helps for capture and not too heavy when compared with other scopes.
You can also get a phenolic tube option which will not dew and more temperature stable (better than aluminium) for maintaining focus.  
 

11 minutes ago, jetstream said:

Me too.

The Mewlon 210 is attractive, however hard working out worth over a C9 or C11 (comparable price).

49 minutes ago, John said:

If it wasn't for CN we would not have this thread. Markus Ludes (APM) posts there but not here.

It's a different style of forum to SGL but there is much to be gleaned from it if you have some patience.

 

 

Indeed, the mirror of this thread on CN is funny to read. As one of the poster's said on CN, "How CN this thread is". 

Have you done first light, x234 magnification I see. Is the Tasco the best 3" refractor ever..... 😀 

Since its parfocal even more interested. What a waste of time on CN. 

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.

27 minutes ago, Louis D said:

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.

Saw the CN thread, scan read it as so much *froth*. Thought I ask the question on SGL as I thought it would not cause *noise* until we got a definite answer. 

6 minutes ago, Nigella Bryant said:

Probably other manufacturers will step in, perhaps UK built scope's, mount's like in the 70's. 

The cost of living is on the up as well in the Far East, I suspect in the end it will meet in the middle. Issue is the twenty/thirty years in between where an equilibrium was being found.

37 minutes ago, Louis D said:

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 didn't plan for a long outage, the longest our village has been without electricity is a week over xmas five years ago. Luckily it was just half the village, the pubs where still operational and cooked everyones xmas lunch where they could. Having a second car helps if one is used as a generator. Interesting idea about using PHEVS to generate energy to store overnight. 

16 hours ago, Louis D said:

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.

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.