Tec140ED used vs TSA 120 new?

[johninderby]

I have to wonder about those that try a refractor that is optimised for visual use and then complain it isn't as good for imaging as a refractor intended for imaging. 🙄

As I’m a visual observer then I want a scope that’s optimised for visual.. 🙂 Love my Tecnosky 125 doublet. Impresses me every time I use it. A step up in performance over  the SW doublets. 

 

Edited September 24, 2021 by johninderby

[kirkster501]

TEC140 is a superb scope,  I love mine for AP (both DSO and solar/lunar) and visual.  It is wonderful.  Now, hand on heart, how many nights per year can we actually use the increased capabilities of this glorious scope compared to a less premium one?  Not many is the answer.

[Andrew_B]

3 hours ago, ollypenrice said:

It is primarily connected for visual, yes. Regarding its imaging prowess, there's an interesting debate. I've seen it dismissed by one CN poster as 'a glorified achromat,' an opinion I find incomprehensible.  What many imagers have found is that the blue correction is greatly improved by the TEC field flattener, though the official line from TEC is that this is not true. My own experiments with and without the flattener clearly suggest that it is true. A slight tendency to bloat on hot stars disappeared with the flattener, which is a prodigious bit of kit giving a vast, well illuminated field larger than any current amateur cameras can exploit. I love it as an imaging instrument. Some samples...

https://www.astrobin.com/full/335042/0/

https://www.astrobin.com/full/380941/0/

https://www.astrobin.com/full/419975/0/

We have two of them here with no discernible difference in performance.

Olly

 

Those are some great images and I can well believe that the flattener helps with blue correction because I'm pretty sure I've seen that mentioned as a property of some other flatteners and reducers.

Calling it a glorified achromat is pretty ridiculous. I've never read anything to suggest it's less than a superb visual apo or that it's actually bad for imaging, just that other exceptional scopes might be better.

[JeremyS]

1 hour ago, kirkster501 said:

TEC140 is a superb scope,  I love mine for AP (both DSO and solar/lunar) and visual.  It is wonderful.  Now, hand on heart, how many nights per year can we actually use the increased capabilities of this glorious scope compared to a less premium one?  Not many is the answer.

Very true, but some of us live for those rare nights and want to be prepared to use them when they do arrive 😊

[jetstream]

59 minutes ago, JeremyS said:

Very true, but some of us live for those rare nights and want to be prepared to use them when they do arrive 😊

AND

It seems that there are many many more reports of TSA120's taking high mag than others such as TEC's/LZOS

AND

What could the reasons possibly be?

[dweller25]

I would go for an air spaced scope as oil gets messy when it leaks 🥴

[jetstream]

11 minutes ago, dweller25 said:

I would go for an air spaced scope as oil gets messy when it leaks 🥴

For me it could be a real issue with the winter temps here, and can possibly be an issue for anyone anytime.

[Andrew_B]

1 hour ago, dweller25 said:

I would go for an air spaced scope as oil gets messy when it leaks 🥴

Also I wouldn't want to have to mess around changing the oil and the filter every 15,000 light years!

[Deadlake]

2 hours ago, jetstream said:

TSA120's taking high mag than others such as TEC's/LZOS

You mean TSA120 are so common 😀 Seriously I wish I had a good night’s seeing to give an accurate report and a BBHS mirror diagonal. Given I’ve almost got all the parts for using the AZ100 I predict clouds….

Edited September 24, 2021 by Deadlake

[John]

17 minutes ago, Deadlake said:

You mean TSA120 are so common 😀 Seriously I wish I had a good night’s seeing to give an accurate report and a BBHS mirror diagonal. Given I’ve almost got all the parts for using the AZ100 I predict clouds….

I was using 600x on tight double stars and to spot Triton last night with my LZOS 130. 240x seemed the best for Jupiter and 300x did well on Saturn. Your LZOS (and @Stu's) are very similar optical quality I think. If you get the seeing, pump up the power ! 

Hope you get some good sessions in with the scope soon

A question for TSA 120 owners if I may: We know that Canon Optron make the objectives for the Tak Fluorite doublets. Do Tak make their triplets (such as the TSA) themselves or is a third party optical house involved for those ?

Edit: Just found the answer from Roger Vine's review of the TSA 102: "The TSA-102’s lens is an air-spaced triplet made in Japan by Canon/Optron"

 

 

 

Edited September 24, 2021 by John

[Deadlake]

16 minutes ago, John said:

I was using 600x on tight double stars and to spot Triton last night with my LZOS 130

Do you think this is the limit?

[JeremyS]

15 minutes ago, John said:

I was using 600x on tight double stars and to spot Triton last night with my LZOS 130. 240x seemed the best for Jupiter and 300x did well on Saturn. Your LZOS (and @Stu's) are very similar optical quality I think. If you get the seeing, pump up the power ! 

Hope you get some good sessions in with the scope soon

A question for TSA 120 owners if I may: We know that Canon Optron make the objectives for the Tak Fluorite doublets. Do Tak make their triplets (such as the TSA) themselves or is a third party optical house involved for those ?

Edit: Just found the answer from Roger Vine's review of the TSA 102: "The TSA-102’s lens is an air-spaced triplet made in Japan by Canon/Optron"

 

 

 

Made by elves, virgins and pixies, John. And carried by unicorns.

[dweller25]

I only have eyepieces that go to x499 on my FS128 😢

But rarely go over x290 as my seeing just North of Manchester is generally poor 🙁

Edited September 24, 2021 by dweller25

[John]

11 minutes ago, Deadlake said:

Do you think this is the limit?

I've honestly no idea. Without using a barlow, my shortest fl eyepiece is 2mm. I don't use that very often but on the right sorts of targets and under the right conditions, the optics of the scope seem willing. With the Baader Q-Turret barlow I could get to 1350x - I might give it a go for a lark sometime

 

[ollypenrice]

2 hours ago, dweller25 said:

I would go for an air spaced scope as oil gets messy when it leaks 🥴

If it leaks. But it doesn't. And bacterial growth can affect air spaced lenses, too...

Olly

[jetstream]

49 minutes ago, John said:

I was using 600x on tight double stars

Dont you just love those .2mm exit pupils?

[jetstream]

7 minutes ago, ollypenrice said:

If it leaks. But it doesn't. And bacterial growth can affect air spaced lenses, too...

Olly

https://www.cloudynights.com/topic/640062-oil-spaced-apos-can-leak-if-improperly-stored-or-maintained/

[ollypenrice]

8 hours ago, johninderby said:

I have to wonder about those that try a refractor that is optimised for visual use and then complain it isn't as good for imaging as a refractor intended for imaging. 🙄

As I’m a visual observer then I want a scope that’s optimised for visual.. 🙂 Love my Tecnosky 125 doublet. Impresses me every time I use it. A step up in performance over  the SW doublets. 

 

The Tak FSQ106 is optimised for imaging but the TEC is a better imaging scope, albeit slower. Here is a pure log stretch of Alnitak, cropped, taken with the TEC in 10 minute luminance subs. As you can see, reasonably faint detail is already showing but, critically, Alnitak is cleanly split as a double. I can split it in the FSQ data as well - by layer masking different stretches together - but without fancy processing Alnitak is a big white blob. The TEC gives a clean split straight from the raw data, and note how close to Alnitak we can see structure in the nebulosity. Not many refractors can do this.

Olly.

[ollypenrice]

11 minutes ago, jetstream said:

https://www.cloudynights.com/topic/640062-oil-spaced-apos-can-leak-if-improperly-stored-or-maintained/

Life's too short to read all of a thread like that but by the end of page one I hadn't found a leaking TEC...

Olly

[jetstream]

2 minutes ago, ollypenrice said:

, Alnitak is cleanly split as a double.

Just curious as I know nothing about imaging- why is there a halo around Alnitak and why are some stars so big? This is the TEC or Tak?

[John]

11 minutes ago, jetstream said:

Dont you just love those .2mm exit pupils?

I'm actually not that keen on using ultra-high magnifications. When observing the planets I will always prefer smaller / sharper / more contrast over a larger image scale. I have found very high magnifications useful for some tasks though so it's good to have instruments that support that, when required.

 

[jetstream]

1 minute ago, John said:

I'm actually not that keen on using ultra-high magnifications. When observing the planets I will always prefer smaller / sharper / more contrast over a larger image scale. I have found very high magnifications useful for some tasks though so it's good to have instruments that support that, when required.

 

This 600x mag must have given you good star tests!

Edited September 24, 2021 by jetstream

[ollypenrice]

1 minute ago, jetstream said:

Just curious as I know nothing about imaging- why is there a halo around Alnitak and why are some stars so big? This is the TEC or Tak?

TEC. In imaging terms those stars are not big at all, they are very small. Similarly, in imaging terms that is as close to a halo-free Alnitak as you are ever likely to see. It is phenomenally well controlled. You're looking at a deliberately under-processed image, one to which only the simplest of log stretches has been applied, since my aim is to show the native optical performance of the TEC. To see why I think it's remarkable you'd need to look at other broadband images of the Flame Nebula. (Narrowband filters hold down stars in ways that broadband filters don't, but broadband give natural colour.) I don't want to link to other people's images and say, 'Look, your Alnitak is a big white blob,' but I think you'll find plenty of big white blobs out there if you look!

Olly

[jetstream]

31 minutes ago, ollypenrice said:

Life's too short to read all of a thread like that but by the end of page one I hadn't found a leaking TEC...

Olly

I brought this up because @Fedele lives in Italy I believe and might possibly have extremely high temps at times which might impact an expensive oil spaced refractor. Some might not find that link interesting but some just might, given the cost of these telescopes, IMHO.

[F15Rules]

54 minutes ago, ollypenrice said:

The Tak FSQ106 is optimised for imaging but the TEC is a better imaging scope, albeit slower. Here is a pure log stretch of Alnitak, cropped, taken with the TEC in 10 minute luminance subs. As you can see, reasonably faint detail is already showing but, critically, Alnitak is cleanly split as a double. I can split it in the FSQ data as well - by layer masking different stretches together - but without fancy processing Alnitak is a big white blob. The TEC gives a clean split straight from the raw data, and note how close to Alnitak we can see structure in the nebulosity. Not many refractors can do this.

Olly.

I freely admit that I'm not an imager and have no interest in imaging at all.

That said, I don't care what scope took that image, of whatever type or brand, it's optically a superb instrument, and I can only look at that image with admiration, both for the scope and the imager.

Great stuff, Olly.

Dave