Takahashi TSA102S refractor

[Sunshine]

That's it! all this Tak talk has me turning myself inside out for first light. It will be -11,  feeling like -20 but, I am now getting ready to take my scope out, wish me luck!

Edited February 11, 2021 by Sunshine

[Sunshine]

Having said that and, having little experience with refractors, I will ask what may be a silly question. When bringing my scope in from the cold, can dew form between the triplet elements and cause issues? 

[jetstream]

Just now, Sunshine said:

Having said that and, having little experience with refractors, I will ask what may be a silly question. When bringing my scope in from the cold, can dew form between the triplet elements and cause issues? 

The wife made me a "scope coat" out of an old quilt years ago and with a velcro'd opening. I used this for my 10" for years. I would wrap the TSA102 up really well to slow the warm up down and maybe leave in a cool basement or somewhere like it.

[Sunshine]

17 minutes ago, jetstream said:

The wife made me a "scope coat" out of an old quilt years ago and with a velcro'd opening. I used this for my 10" for years. I would wrap the TSA102 up really well to slow the warm up down and maybe leave in a cool basement or somewhere like it.

What I have done in the past when rarely out in the cold, I would move scope from outside quickly into my cold storage in basement to allow for a gradual warm up. This should be ok, I guess, I just

wasn't sure if refractors with spaced elements were higher risk of water droplets forming between elements.

thank you!

[jetstream]

8 minutes ago, Sunshine said:

wasn't sure if refractors with spaced elements were higher risk of water droplets forming between elements.

yes they can be, these scopes are not sealed purged and nitrogen filled.

Would a Pelican 1740 be a good addition for you?

 

[mikeDnight]

36 minutes ago, Sunshine said:

Having said that and, having little experience with refractors, I will ask what may be a silly question. When bringing my scope in from the cold, can dew form between the triplet elements and cause issues? 

If you check your lens by shining a red torch at it at the end of your observing session, and if its dew free, you can cap it and bring it inside. It shouldn't dew up!  If there is dew on the lens at the end of your observing session, bring the scope in while its uncapped and leave the cap off. The moisture will evaporate over night, after which you can cap it the following morning. Moisture on or between the elements only becomes a problem when its prevented from evaporating by being trapped inside by the lens cap. You might consider a dew heater strip or an extended astrozap dew shield as a means of offering added protection.

 

[Sunshine]

Well the stars have not aligned for me, in the time I left the scope out to cool, maybe an hour or so, when I eagerly stepped outside, the sky went from clear to clouded!!. I saw [removed word] ALL!! as my British friends here would say, except for one star, a 5 min look at Polaris as it was in somewhat of a clearing. Twas still hazy but i did manage a couple of minutes on this one star, doing a quick star test with my 5mm XW revealed beautiful concentric defocused rings, a beautiful snap focused Polaris and, a cool blue beautiful colour. Otherwise, I was back inside in only 10 min as the sky completely clouded.

Scratch this attempt, better luck next time.

Edited February 12, 2021 by Sunshine

[jetstream]

2 hours ago, mikeDnight said:

If you check your lens by shining a red torch at it at the end of your observing session, and if its dew free, you can cap it and bring it inside. It shouldn't dew up! 

Mike I respect your opinion greatly.

But its a different ball game over here. Bringing that scope inside from -20c etc will cause moisture problems.

[Sunshine]

1 hour ago, jetstream said:

Mike I respect your opinion greatly.

But its a different ball game over here. Bringing that scope inside from -20c etc will cause moisture problems.

To be clear, the forecast was -11 but feels like minus 21. Having said that, I did follow what Mike said and thankfully had no issues, not a molecule of H2O formed on the lens, I checked for moisture before bringing it in, there was none. Before bringing it in I capped the objective with shield extended in order to trap cold air and once inside it did not fog up at all after peeking inside the cap even after 20 min. Maybe if it truly was -20 ambient temp it may have fogged up? I was actually quite taken aback when it didn’t fog up at all. What surprised me most was I skipped the step of bringing it into my cold storage straight away, I brought it into my +23 degree home. How it didn’t fog up the least bit is beyond me. My 115 Eon would fog up in slightly warmer temps. I’ll leave that up to the dewologists here on SGL to figure out.

Edited February 12, 2021 by Sunshine

[Deadlake]

So how cold does it have to be before you have to consider this, presume function of humidity as well. Number of ponds and streams around where I live as well. Is @mikeDnight red light test is as good as any to see if there is water present? I can feel moisture on the tube when I take my refactor in, so guess that implies there is a enough water around to cause issues if not allowed to evaporate.
 

Hopefully will not have cold nights like this for some time, doesn’t seem to improve the seeing which is not what I expected.

[mikeDnight]

It's rare these days that I'll stay out long enough in sub zero temperatures for my lens to dew.  Going back to the time i had my NP101,  I remember sitting on a deckchair ankle deep in snow and sweeping the sky for two or three hours. My next door neighbour called to me over the low garden wall "Youre mental you are! I've always known you're simple"!!  (She's a sun worshiper)!   I replied to her with some witty comment, but after she'd gone, I realised that although my body was as warm as toast, the cold night air I was breathing was making me wheeze. That was back around 2007/2008. Since then I've been careful not to let the cold affect me like that anymore. Now I'm more a creature of comfort and relish the milder spring nights. Perhaps I'm just getting soft as I get older.

[Deadlake]

5 minutes ago, mikeDnight said:

It's rare these days that I'll stay out long enough in sub zero temperatures for my lens to dew.  Going back to the time i had my NP101,  I remember sitting on a deckchair ankle deep in snow and sweeping the sky for two or three hours. My next door neighbour called to me over the low garden wall "Youre mental you are! I've always known you're simple"!!  (She's a sun worshiper)!   I replied to her with some witty comment, but after she'd gone, I realised that although my body was as warm as toast, the cold night air I was breathing was making me wheeze. That was back around 2007/2008. Since then I've been careful not to let the cold affect me like that anymore. Now I'm more a creature of comfort and relish the milder spring nights. Perhaps I'm just getting soft as I get older.

What about a dome observatory, better than a roll off? How much protection dies a dome give against breathing cold air???  

[mikeDnight]

17 minutes ago, Deadlake said:

What about a dome observatory, better than a roll off? How much protection dies a dome give against breathing cold air???  

Brilliant idea!  I've actually thought about constructing a dome for my observatory rather than the run-off roof I have at present. Although it will still need to be cool, it will offer a little more protection from cold winds, and will aid in maintaining dark adaption. I think this might be a project for this spring! ☺

[paulastro]

38 minutes ago, mikeDnight said:

It's rare these days that I'll stay out long enough in sub zero temperatures for my lens to dew.  Going back to the time i had my NP101,  I remember sitting on a deckchair ankle deep in snow and sweeping the sky for two or three hours. My next door neighbour called to me over the low garden wall "Youre mental you are! I've always known you're simple"!!  (She's a sun worshiper)!   I replied to her with some witty comment, but after she'd gone, I realised that although my body was as warm as toast, the cold night air I was breathing was making me wheeze. That was back around 2007/2008. Since then I've been careful not to let the cold affect me like that anymore. Now I'm more a creature of comfort and relish the milder spring nights. Perhaps I'm just getting soft as I get older.

In plain English Mike, you mean you're just a big softy 😄.  If you think you're getting old now, by the time you reach my age you'll be in a state of hibernation most of the time 🙂.

[Deadlake]

1 hour ago, mikeDnight said:

Brilliant idea!  I've actually thought about constructing a dome for my observatory rather than the run-off roof I have at present. Although it will still need to be cool, it will offer a little more protection from cold winds, and will aid in maintaining dark adaption. I think this might be a project for this spring! ☺

I’m tempted too, but more around the time taken to setup each night. Just going out and powering it up is more attractive. Out of interest if you have an observatory why limit yourself to a 4”?

Edited February 12, 2021 by Deadlake

[JeremyS]

1 hour ago, mikeDnight said:

It's rare these days that I'll stay out long enough in sub zero temperatures for my lens to dew.  Going back to the time i had my NP101,  I remember sitting on a deckchair ankle deep in snow 

It’s not Blackpool, Mike! Should’ve worn something on your feet

🤣

[garryblueboy]

15 hours ago, mikeDnight said:

It's a different language this side of the pond, isn't it!  A fiver is £5. A tenner is £10 etc. 

Don’t forget Mike a Pony & a Monkey 😀😂

[paulastro]

2 hours ago, JeremyS said:

It’s not Blackpool, Mike! Should’ve worn something on your feet

🤣

Yes, clogs!

[Guest]

16 hours ago, johninderby said:

Here are a few:

A pony means £25 

A monkey means £500

Bangers and mash – cash

Pavarotti – he was a famous tenor so a Pavarotti is a tenner (£10)

Must not forget that a grand is a £1000😜

[Sunshine]

Here our $1 and $2 coins are always referred to as the Loonie and twoonie, because of the loon bird present on the one dollar coin. There is no loon on the two dollar coin but we still call it the “twoonie” lol, the twoonie is a pretty coin, I think so. When introduced many years ago the middle would occasionally pop out as the metal alloys had different expansion rates but it was fixed.

Edited February 12, 2021 by Sunshine

[Sunshine]

Back on topic, has anyone snapped up the 102 from the OP? doubt it is still available.

[dweller25]

18 minutes ago, Sunshine said:

Back on topic, has anyone snapped up the 102 from the OP? doubt it is still available.

It’s not for sale at the moment @Sunshine as I am still mulling things over - I would definitely wait for Coronavirus issues to reduce before doing anything.

[Guest]

What a lovely telescope. I long for the night that I will get the chance to look through a Tak refractor. I have owned an ED 100 f9. The views were very good indeed. Wonder if there is an opinion from someone who has experienced the views of both and how much better the Tak is over the ED 100 f9? Or indeed how close the quality of view is between them. I would still like to own a Takahashi if the opportunity presents.

[dweller25]

14 minutes ago, Grumpy Martian said:

What a lovely telescope. I long for the night that I will get the chance to look through a Tak refractor. I have owned an ED 100 f9. The views were very good indeed. Wonder if there is an opinion from someone who has experienced the views of both and how much better the Tak is over the ED 100 f9? Or indeed how close the quality of view is between them. I would still like to own a Takahashi if the opportunity presents.

I have owned both, as you would expect the Tak was better in terms of contrast, sharpness and build quality and was able to go to much higher magnifications, but the SW100ED is great for the price.

Edited February 12, 2021 by dweller25

[F15Rules]

12 hours ago, Sunshine said:

To be clear, the forecast was -11 but feels like minus 21. Having said that, I did follow what Mike said and thankfully had no issues, not a molecule of H2O formed on the lens, I checked for moisture before bringing it in, there was none. Before bringing it in I capped the objective with shield extended in order to trap cold air and once inside it did not fog up at all after peeking inside the cap even after 20 min. Maybe if it truly was -20 ambient temp it may have fogged up? I was actually quite taken aback when it didn’t fog up at all. What surprised me most was I skipped the step of bringing it into my cold storage straight away, I brought it into my +23 degree home. How it didn’t fog up the least bit is beyond me. My 115 Eon would fog up in slightly warmer temps. I’ll leave that up to the dewologists here on SGL to figure out.

People often say that Taks are overpriced, but you're paying for the additional premium engineering as well. For example, the Tak lens cells are a work of engineering art, often collimateable and as far as I'm aware always constructed with a heat sensitive cell which expands or contracts with the ambient temperature to ensure that you don't get pinched optics, for example, where the lens elements get squeezed too much by the metal cell not expanding or contracting at the right rate relative to the doublet or triplet optics in the objective.

On my FS128 (fluorite Fraunhofer doublet), the dewshield is fixed, not  sliding..it threads onto the blue painted collar on the OTA (see photos)..on the rear of the blue collar there is a tiny grub screw, almost invisible, which has to be loosened before you can unthread the objective cell from the white OTA tube (see photos).. this prevents you from unthreading the objective cell from the tube by accident. The dewshield end cover/cap is like a cast aluminium manhole cover, so solid, and yet, with it's felt surround, just a perfect, snug friction fit into the dewshield. The focuser knobs are finely machined solid aluminium..and so it goes on. 

If you want the best build and engineering, it costs serious "wedge" !!( money/cash to our Canadian friends 😂), but you can immediately tell, when handling a Tak, how much thought has gone into it's creation👍👌.

Dave

Edited February 12, 2021 by F15Rules
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