4" Tak vs Mewlon 180c

[PatientObserver]

While I wait for my FOA-60Q to arrive, I have been considering what scope I should mount on the other side of my Rowan AZ75. Like the OP, the Mewlon 180C is one of the scopes I am considering. I am a new astronomer, and I live in the Northeast of the USA, so my main concerns are collimation and cool down time (the temps can drop substantially at night here). The former I can learn. Will passive cool down be an issue?

Having owned the Mewlon 180C for a while now, are you still pleased with the scope?

[JeremyS]

1 hour ago, PatientObserver said:

While I wait for my FOA-60Q to arrive, I have been considering what scope I should mount on the other side of my Rowan AZ75. Like the OP, the Mewlon 180C is one of the scopes I am considering. I am a new astronomer, and I live in the Northeast of the USA, so my main concerns are collimation and cool down time (the temps can drop substantially at night here). The former I can learn. Will passive cool down be an issue?

Having owned the Mewlon 180C for a while now, are you still pleased with the scope?

I have a Mewlon 210 and I think the cool-down time of Mewlons is overstated. It really depends how you store it and the delta with outside temp. Similar considerations for a Newtonian.

[MalcolmM]

1 hour ago, PatientObserver said:

While I wait for my FOA-60Q to arrive, I have been considering what scope I should mount on the other side of my Rowan AZ75. Like the OP, the Mewlon 180C is one of the scopes I am considering. I am a new astronomer, and I live in the Northeast of the USA, so my main concerns are collimation and cool down time (the temps can drop substantially at night here). The former I can learn. Will passive cool down be an issue?

Having owned the Mewlon 180C for a while now, are you still pleased with the scope?

Very very pleased!

Cool down - no problems, I keep it outside in a plastic box for a couple of hours before observing. Caveat is my climate is possibly less severe than yours. Some on this forum use a battery powered fan I believe to help cool down.

Collimation - no problems yet! Collimation was perfect out of the box, I have not needed to touch it. Though it might be a bit tricky, I'm sure it's doable with a bit of patience and so far in my experience, it would seem to keep Collimation very well. The finder was also spot on out of the box. 

I have had no dew problems either which is a big benefit of the open tube. 

Potential future purchases for you 🙂: a 2" Masuyama 32mm eyepiece gives great widefield (for a 2m focal length scope!) views. Other wide field eyepieces are available 🙂

Also I use a pair of Maxbright binoviewers with the Mewlon and they genuinely give an almost 3D view! Highly recommended. 

FOA-60Q ... Great choice. It's a truly beautiful scope to look at. The views through it aren't bad either 😀 

Malcolm 

[PatientObserver]

26 minutes ago, JeremyS said:

I have a Mewlon 210 and I think the cool-down time of Mewlons is overstated. It really depends how you store it and the delta with outside temp. Similar considerations for a Newtonian.

How large does the temperature delta need to be to be a problem?

[PatientObserver]

23 minutes ago, MalcolmM said:

Very very pleased!

Cool down - no problems, I keep it outside in a plastic box for a couple of hours before observing. Caveat is my climate is possibly less severe than yours. Some on this forum use a battery powered fan I believe to help cool down.

Collimation - no problems yet! Collimation was perfect out of the box, I have not needed to touch it. Though it might be a bit tricky, I'm sure it's doable with a bit of patience and so far in my experience, it would seem to keep Collimation very well. The finder was also spot on out of the box. 

I have had no dew problems either which is a big benefit of the open tube. 

Potential future purchases for you 🙂: a 2" Masuyama 32mm eyepiece gives great widefield (for a 2m focal length scope!) views. Other wide field eyepieces are available 🙂

Also I use a pair of Maxbright binoviewers with the Mewlon and they genuinely give an almost 3D view! Highly recommended. 

FOA-60Q ... Great choice. It's a truly beautiful scope to look at. The views through it aren't bad either 😀 

Malcolm 

Thanks for the response. Glad to hear you are still pleased with it.

I would like to avoid active cooling if possible, but could use a small battery pack powered fan if needed. Mostly hoped to keep things simple.

I just started researching binoviewers. The Maxbright seem to be highly rated. I will keep that in mind for a future purchase.

[dweller25]

27 minutes ago, PatientObserver said:

How large does the temperature delta need to be to be a problem?

If I bring the M180 out of a 20’C house temp out into a 5’C garden temp, the scope - with active cooling - takes a good hour to cool before I can do high power planetary.

[HollyHound]

2 hours ago, dweller25 said:

If I bring the M180 out of a 20’C house temp out into a 5’C garden temp, the scope - with active cooling - takes a good hour to cool before I can do high power planetary.

I have similar results… I usually don’t do any critical observations until an hour, although the scope is usable after 45mins. It’s one reason I usually mount the M180C alongside the FC-100DZ, so I can observe with that during that hour 👍

[HollyHound]

2 hours ago, PatientObserver said:

Thanks for the response. Glad to hear you are still pleased with it.

I would like to avoid active cooling if possible, but could use a small battery pack powered fan if needed. Mostly hoped to keep things simple.

I just started researching binoviewers. The Maxbright seem to be highly rated. I will keep that in mind for a future purchase.

I haven’t used active cooling yet, but I’ve heard it can make a difference in reducing  ool down times 🤔

The MaxBrights are great on the M180C… I use mine with a pair of Hyperion Zooms (8-24mm) and they’re fantastic on lunar and planetary 😀

[PatientObserver]

I should note that the other scopes I am considering are all refactors: Takahashi FC-100DZ, Takahashi TSA 120, or an Agema SD 120. I am even debating putting the deposit down on the Agema and then purchasing the FC-100DZ or the Mewlon 180C while I wait.

Edited May 18, 2023 by PatientObserver

[The60mmKid]

I've owned an FC-100DC and Mewlon 180C concurrently. When the Mewlon reaches ambient temperature, the seeing is average or better, and you're observing something that doesn't require too wide an FOV, the Mewlon trounces the 4" refractor. In my experience, though, the 4" refractor may be preferable when any of those three conditions is missing. The views through the Mewlon while it's cooling are almost unavoidably horrible because, at f/12, most eyepieces yield a pretty high magnification. Also, the effects of the central obstruction are visible when the seeing is poor since more light is going into the diffraction rings. And I wouldn't use the Mewlon for viewing open clusters and the such because coma is pronounced in the Dall Kirkham design. I didn't enjoy using a 40mm XW in it for this reason. A 48mm Brandon, with its narrower FOV, is brilliant in the Mewlon, though.

When the seeing was good and the Mewlon had (finally, after much waiting) reached thermal equilibrium, the views it provided of double stars and planets were utterly stunning. I can remember sitting spellbound at the eyepiece observing Saturn, Izar, Delta Cygni, and Zeta Herculis.

Edited May 7, 2023 by The60mmKid

[The60mmKid]

I'll also add that the difference in mounting requirements is worth considering. I'd be happy to use a 4" Tak on an alt-az mount. I'd much prefer a driven EQ mount for the Mewlon since, again, f/12 means you're often cooking at high heat.

[MalcolmM]

Just to add a differing experience to @The60mmKid.  What he says is true, the Mewlon is known as a Lunar/planetary scope; coma and long focal length!

However, with my Masuyama 32mm (which itself is reputed to be bad at the edges), I can just about fit the Pleiades into the FOV and I don't notice the aberrations. This may be because I'm not looking for it, or my eyes are not sensitive enough, or I am just looking at the overall view/context but whatever, I really enjoy the views.

I actually have enjoyed the Mewlon with the 32mm very much by pairing it with an FS60CB plus 28mm Erfle on a Giro Ercole (manual AltAz). I use the CB as a finder and observe open clusters and galaxies. The light gathering of the Mewlon is significantly more than the 4" Tak.

@PatientObserver, two different experiences from two different users 🙂 I think the Mewlon compliments the 100DC and/or FOA-60Q brilliantly. My only caveat; I'm a self confessed Takophile 😀

Malcolm 

 

[dweller25]

17 hours ago, PatientObserver said:

While I wait for my FOA-60Q to arrive, I have been considering what scope I should mount on the other side of my Rowan AZ75. Like the OP, the Mewlon 180C is one of the scopes I am considering. I am a new astronomer, and I live in the Northeast of the USA, so my main concerns are collimation and cool down time (the temps can drop substantially at night here). The former I can learn. Will passive cool down be an issue?

Having owned the Mewlon 180C for a while now, are you still pleased with the scope?

I did have to collimate my Mewlon two years ago when it arrived, the procedure is the same as an SCT - - you just use small  tweaks, recenter the star and repeat until finished, once done it stays put 👍

Cooldown has been a bigger issue for me as I store the scope indoors. Initially I put a USB fan on the front spider and blew air onto the primary, that was OK but occasionally you could see little air tremors at high power - this was warm air bleeding from the mirror to the primary baffle and then into the light path.

So now I have rigged up an additional fan for the baffle, this is just a 2” extension tube with a 40mm USB fan that pulls air through the baffle, cooling it and the central core of the mirror at the same time.

Once fully cooled the Mewlon is almost refractor sharp with surprisingly high contrast - it is quite a sight.

 

Edited May 7, 2023 by dweller25

[The60mmKid]

7 hours ago, MalcolmM said:

Just to add a differing experience to @The60mmKid.  What he says is true, the Mewlon is known as a Lunar/planetary scope; coma and long focal length!

However, with my Masuyama 32mm (which itself is reputed to be bad at the edges), I can just about fit the Pleiades into the FOV and I don't notice the aberrations. This may be because I'm not looking for it, or my eyes are not sensitive enough, or I am just looking at the overall view/context but whatever, I really enjoy the views.

I actually have enjoyed the Mewlon with the 32mm very much by pairing it with an FS60CB plus 28mm Erfle on a Giro Ercole (manual AltAz). I use the CB as a finder and observe open clusters and galaxies. The light gathering of the Mewlon is significantly more than the 4" Tak.

@PatientObserver, two different experiences from two different users 🙂 I think the Mewlon compliments the 100DC and/or FOA-60Q brilliantly. My only caveat; I'm a self confessed Takophile 😀

Malcolm 

 

An interesting point. The long focal length of the Mewlon is easy on eyepieces, so the astigmatism of the wide Masuyama (which I quickly parted with after popping it into my FC-100) is probably significantly reduced. Now that you mention it, I recall that I did enjoy the Mewlon for smaller open clusters. M11 was brilliant. But I'm picky about sharpness at the edges, so I didn't enjoy the views of the Pleiades and Double Cluster through the Mewlon. As our experiences demonstrate, these are individual preferences!

[The60mmKid]

If I still had the Mewlon, what I'd try is a low-power, wide-field eyepiece equipped with a Baader MPCC. If it worked, that would be something.

But this thread is evoking some fond memories and making me wonder if there's a Mewlon 210 in my future. After all, I have a Losmandy GM8 on a heavy wooden tripod singing the siren song, "We could hold a larger scope!"

Edited May 7, 2023 by The60mmKid

[MalcolmM]

2 hours ago, The60mmKid said:

The long focal length of the Mewlon is easy on eyepieces

I didn't think of that. You could be right. 

Go for a 210, it's a crime to have mount crying out for a bigger scope 😀 I would be very envious, as I already am of @JeremyS's

Malcolm

[Mr Spock]

There's a wait for the 210. The 180 is listed as 20-25 days and the 21 as 90-120 days 

[Stu]

2 hours ago, The60mmKid said:

The long focal length of the Mewlon is easy on eyepieces

I’m going to be dreadfully pedantic here, and just mention that it’s the slow focal ratio rather than the long focal length that makes it easy in the eyepieces. An f3.3 32” dob has a long focal length (2682mm) but will be pretty hard on eye pieces.

http://www.sdmtelescopes.com.au/scope-showcase/sdm100-32-f3-3/

I know you know, and that’s what you meant but, but, but….. I did say I was being pedantic 😉

 

[The60mmKid]

27 minutes ago, Stu said:

I’m going to be dreadfully pedantic here, and just mention that it’s the slow focal ratio rather than the long focal length that makes it easy in the eyepieces. An f3.3 32” dob has a long focal length (2682mm) but will be pretty hard on eye pieces.

http://www.sdmtelescopes.com.au/scope-showcase/sdm100-32-f3-3/

I know you know, and that’s what you meant but, but, but….. I did say I was being pedantic 😉

 

No, no... I appreciate corrections when they're warranted. I'm moving to England soon, so I should probably improve my English 🤭

[mikeDnight]

1 hour ago, The60mmKid said:

No, no... I appreciate corrections when they're warranted. I'm moving to England soon, so I should probably improve my English 🤭

That depends on where abouts in England you're moving to. Sometimes we don't even understand each other. 

[PatientObserver]

5 hours ago, MalcolmM said:

I didn't think of that. You could be right. 

Go for a 210, it's a crime to have mount crying out for a bigger scope 😀 I would be very envious, as I already am of @JeremyS's

Malcolm

Besides the extra mass, I much prefer six diffraction spikes to four. As such, I have not long considered the Mewlon 210. This is good for my budget, so I will consider it a win. 😉

[PatientObserver]

I started this journey planning on only purchasing a couple scopes. Here I am still waiting for my first to arrive, and now I already want four.

[HollyHound]

16 hours ago, PatientObserver said:

I started this journey planning on only purchasing a couple scopes. Here I am still waiting for my first to arrive, and now I already want four.

You only want four Taks... you're not trying hard enough 🤣

Edited May 8, 2023 by HollyHound

[MalcolmM]

1 hour ago, HollyHound said:

You only want four Taks... you're not trying hard enough 🤣

This Takitis is very contagious!

Malcolm 

[PatientObserver]

On 08/05/2023 at 13:59, MalcolmM said:

This Takitis is very contagious!

Malcolm 

So far I have resisted further advances of the disease known as Takitis ... I instead decided to place an order on an Agema SD 120. It was a little less expensive than a Takahashi TSA-120, and I get to spilt the cost into two payments. All the reviews I have read indicate it is a quality scope. I will have to wait for it to be built, but that will allow me to exclusively use my FOA-60Q for awhile. Although I am currently in remission from Takitis, I am aware that it may return in the form of a Mewlon in the future.