Takahashi v APM optical quality

[Chris]

Hi Derek, just to confuse you more, I'll throw my thoughts into the mix 

You're a visual guy right? In which case I'm not entirely sure a triplet is the most practical of scopes? for visual all the above makes, APM, Tak, and Synta ED's are going to give pretty razor sharp virtually CA free views, with the former two perhaps having a more consistant Strehl by virtue of the QA you're paying for. 

If you have the mount for it, and like big aperture, then maybe think about being a beta for the new SW 150ED? I think this should be a low risk based on all the other ED's including first reports regarding the ED72. 

I'm not sure a large triplet would acclimatise as quickly, so you might end up not getting the most out of it unless you're out for hours or keep the scope in a shed/garage? 

A TEC140 would also be nice, or the APM doublet  

The Esprit's look wonderful for the money, but they are triplets with massively engineered focusers aimed more at the imager, although a beefy focuser would also help with the weight of a triplets lens cell. The 80mm triplet I had was very heavy! Stunning once cooled, but in there lies the problem. 

Even more confused?    

[John]

18 minutes ago, JeremyS said:

P2V has has an ex-demo one of these on offer for a while, but now sold.

Wasn't you was it John?

Nope, I've not had the pleasure of one of those as yet.

[ollypenrice]

I'd look out for a second hand TEC140. They go for around £4000 or a little less. They are optimally corrected for visual and have the highest QC you could ask for.

Olly

[DRT]

1 hour ago, Lockie said:

If you have the mount for it, and like big aperture, then maybe think about being a beta for the new SW 150ED?

That is definitely an option, Chris. I have an ED120 and the Evo150 now and have compared them side by side with a solar wedge and the extra detail visible through the 150 is significant. Translating that to an ED150 on the night sky is a tantalising prospect  

[John]

The nearest I've got to an ED150 was when I used to use 6" F/8 refractors with a Chromacor corrector. That corrected 90% of the CA and also the SA (spherical aberration) that many of the chinese achromats have. That more or less delivered ED doublet performance from the scopes. While the ED150 will undoubtedly offer more light grasp for deep sky objects the resolution difference over the ED120 might not be so great. We will see

 

 

[DRT]

2 hours ago, ollypenrice said:

I'd look out for a second hand TEC140. They go for around £4000 or a little less. They are optimally corrected for visual and have the highest QC you could ask for.

Olly

As this is a triplet would it give me the cool-down and weight problems mentioned by others in the above posts?

[Peter Drew]

4 hours ago, Stu said:

No, very different.

AP is AstroPhysics, US company founded by Roland Chretien.

http://www.company7.com/astrophy/index.html

APM is a German company founded by Marcus Ludes

http://www.apm-telescopes.co.uk/apm-history.html

Or even Roland Christen.   ?

[GavStar]

6 hours ago, DRT said:

As this is a triplet would it give me the cool-down and weight problems mentioned by others in the above posts?

I had a tec 140 and found cool down very quick. The fact that it’s oil spaced not air spaced makes it quicker to cool down. Within 30 mins I’m able to do high magnification.

I upgraded to a tec160 and have no issues with this one either. I’m visual only and have no problem with the weight. I use a couple of triplets for visual and think they are great.

[Chris]

8 hours ago, DRT said:

As this is a triplet would it give me the cool-down and weight problems mentioned by others in the above posts?

I know they are very well regarded, but I wrongly thought they were a doublet, Ooops. 

[Stu]

7 hours ago, Peter Drew said:

Or even Roland Christen.   ?

I needed a thanks and a laughing emoji for that Peter!  I’m going to blame auto correct for that one because I’m sure I looked it up first!

[ollypenrice]

9 hours ago, DRT said:

As this is a triplet would it give me the cool-down and weight problems mentioned by others in the above posts?

No, I doubt it. It's an oil spaced triplet so all the elements are effectively in physical contact with each other (via the very thin film of 'oil.') The inner elements can conduct heat effectively to the outer in contact with the air. Mine lives outside but there is a massive difference between daytime observatory temperatures and night time air temperatures. When I image with the TEC it is one of the most thermally stable telescopes I've used, moving relatively little during cooldown. It's surprisingly light for a big scope, too, and one with a seriously good focuser. TEC say 19lb or 8.6kg. The dewshield retracts fully.

Olly

Edit: I see that that lucky man Gavstar has already made this point! TEC160 eh? Woo Hoo.

[Stu]

14 minutes ago, ollypenrice said:

I see that that lucky man Gavstar has already made this point! TEC160 eh? Woo Hoo.

Olly, you just gotta look through it someday, stunning scope. I’ve never seen E & F stars in the trap shown so amazingly, they were just ‘there’, beautiful tiny pinpoints.

[ollypenrice]

28 minutes ago, Stu said:

Olly, you just gotta look through it someday, stunning scope. I’ve never seen E & F stars in the trap shown so amazingly, they were just ‘there’, beautiful tiny pinpoints.

I don't need to know this! I need NOT to know it!!!

?lly

 

[John]

My TMB/LZOS 130mm F/9.2 is an air spaced triplet but I don't notice a particularly long cool down requirement with it. Just a few minutes more than my ED120.

 

[Stu]

44 minutes ago, ollypenrice said:

I don't need to know this! I need NOT to know it!!!

?lly

 

Gavin and I are hatching a plan to visit, Olly. If this becomes a road trip then who knows!!

[DRT]

So I start out wondering whether to buy a 120 Tak or saving money by buying a 150 APM lens cell and within 24 hours you guys have got me looking at the TEC 160 ?

You can always rely on Team SGL to help make you more confused than you were to begin with ?

[Chris]

56 minutes ago, John said:

My TMB/LZOS 130mm F/9.2 is an air spaced triplet but I don't notice a particularly long cool down requirement with it. Just a few minutes more than my ED120.

 

If this is the case, disregard my advice Derek. Maybe triplets are more practical for visual than I thought. 

[Peter Drew]

3 hours ago, Stu said:

Olly, you just gotta look through it someday, stunning scope. I’ve never seen E & F stars in the trap shown so amazingly, they were just ‘there’, beautiful tiny pinpoints.

A routine observation in my C8, it is permanently in Tenerife though.  ?

[Stu]

19 minutes ago, Peter Drew said:

A routine observation in my C8, it is permanently in Tenerife though.  ?

Yes, you have a slight advantage in altitude over the UK down there! V nice  

[John]

4 hours ago, Lockie said:

If this is the case, disregard my advice Derek. Maybe triplets are more practical for visual than I thought. 

I did worry a little about cool down times when I was thinking about the TMB/LZOS Chris but I thought that the sheer optical quality would make up for a little more planning before observing. In actuality it's not been an issue at all. My Vixen ED102SS doublet needs 20-30 mins to produce the best high power images and the ED120 and TMB/LZOS are also at the upper end of that. For some reason best known to itself my Tak FC-100DL needs practically no cool down time at all. 

 

[GavStar]

Good to see other quality refractors such as APM, TEC and astro-physics discussed on SGL. (There has been a lot of Takky conversations recently! ?)Still virtually nothing about CFF though...

[John]

10 minutes ago, GavStar said:

Good to see other quality refractors such as APM, TEC and astro-physics discussed on SGL. (There has been a lot of Takky conversations recently! ?)Still virtually nothing about CFF though...

How many CFF owners are there on here ?

Taks were rarely discussed here a few years back, the reason was, I think, that very few members owned them.

Not much discussion of Astro Physics scopes either for that matter.

 

 

[25585]

3 minutes ago, John said:

How many CFF owners are there on here ?

Taks were rarely discussed here a few years back, the reason was, I think, that very few members owned them.

Not much discussion of Astro Physics scopes either for that matter.

 

 

AP scopes most usually discussed when a pre-owned example is on sale somewhere. 

WRT to Takahashi's, the FC doublets seem to have led the boom on discussion & ownership, followed by smaller models, with a sprinkling of FS & other models owner input. 

 

[Timebandit]

23 hours ago, DRT said:

Oh dear, what have I done?...

 

 

1 hour ago, GavStar said:

Good to see other quality refractors such as APM, TEC and astro-physics discussed on SGL. (There has been a lot of Takky conversations recently! ?)Still virtually nothing about CFF though...

 

Don't encourage me please Gavin. I have been very good the last few days and have not mentioned those Takky , I mean Takahashi scopes. ?

I will go an sit on my hands again?

 

[ollypenrice]

8 hours ago, Stu said:

Gavin and I are hatching a plan to visit, Olly. If this becomes a road trip then who knows!!

Free dinner for anyone bearing a TEC160!!!!

Olly