william optics flt 132 vs takahashi tsa 120

[hubble space telescope]

hello everyone
any suggestions between these scopes? i dont know what is the best and after a long research i conclude to these telescope. I'm more in the direction
of the takahashi and the william optics but im still not sure…
any thoughts?
thank you!!!

Edited 27 Jul, 2018 14:09

[Rodd]

Depends on what you want to do.  Imaging  TSA visual  WO.

Rodd

[hubble space telescope]

most of the time astrophotography...

a lot of people tell me that takahashi is better then william optics, but why? i compare images between them and they look the same... why is takahashi is better then william?

thank you!

[Whirlwind]

Tak's have a reputation of, for the most part almost amateur perfect optics and consistently so.  This includes things like the lens cell.  Hence any optics that fail to meet their minimums are discarded.  This also goes for companies like Astro-physics.  Barring any QA issues you are guaranteed a good lens.  Some of the 'lesser' (and I say this in terms of public opinion of brands) tend to more mass market their optics and hence their minimums are lower.  That does not mean they make bad lenses, sometimes it is the lens cell that is the problem (old FLT132 lens cells were known to contract in the cold and cause pinched optics).  That means quality of the optics you get can be a bit more flexible.  You can get a great one, but you can also get an OK one and you won't know that until it arrives on the day.  You can mitigate that somewhat by having a telescope tested before it gets to you (e.g. ES Reid). 

Poorer figured optics (excluding any other mechanical issues) will distribute more starlight(photons) into the airy disc and hence in imaging terms means your light is spread out over a broader angle (that makes things like stars larger - effectively two very close stars might merge in a poorer figured optics).  However the airy disc also is larger for smaller apertures.  Central obstructions can also distribute more photons into the airy disc in telescopes such as SCTs but at the same time have larger apertures.

However this is all only purely theoretical when there are other factors to consider:-

Seeing - This blows up the size of your stars anyway.  Perfect optics are great in perfect sub-arcsec seeing conditions.  Otherwise your stars over large integration times are broadened anyway.  In the UK you probably won't get the benefit of those perfect optics.  On the top of La Palma you will.

Processing - You can hide a lot of issues with half reasonable processing skills.  There are tools that allow you to shrink your stars for example.  An image taken by someone with expert processing skills on a good telescope will always be better than an image taken with someone with OK processing skills and a 'perfect' telescope.

Other equipment - The best telescope in the world can't perform if you have a poor mount, filters for the telescope you are using.

Hence assuming you aren't located in perfect skies somewhere then I would suggest that you probably wouldn't see much of a difference (and if you did want to use it visually the FLT132 would probably be better).

However there are couple of other things to consider.  The Tak flattener (non-reducer) for the TSA120 is only a push fit which to me always seems a weakness as it leaves room for tilt in the system.  The WO does have a range of screw fit reducers/flatteners (that you can also adjust the backfocus on which I think is a real plus)

Also what mount do you have?  The FLT132 is a different beast in terms of weight for a mount 3-4kg might not seem much but it is the moment of the arm that counts and that makes refractors more difficult to mount well.  One of the advantages of the TSA120 is that it is very lightweight.

[hubble space telescope]

yeah you right it is depend on a lot of things, not only the OTA but the OTA is a very important component in the astrophotogra[hy setup...

and from what i understand from you is that takahashi is still a better choice... ?

[hubble space telescope]

hi everyone!
i just saw the TOA 130 that is also from takahashi and wondering which is better mainly for astrophotogaphy, TOA 130 or TSA 120?
thanks!!

[Barry-Wilson]

Neither is ‘better’ than the other for imaging.

There are a few factors for you to judge and weigh when considering what scope, ccd, and FL combination matches your imaging ambitions.

Do you want to image widefield targets like extensive nebula or small targets like galxies and planetary nebula or perhaps both, accepting compromises between image scale and FOV with different ccd pixel sizes and reducer/flattener permutations?

I am sorry if you clear in your objectives and my questions are not helping, however, from the questions you are asking it is not clear at all.

There are plenty of folk here who can help and there are great books such as “Making Every Photon Count” by Steve Richards (a regular and Mod on the forum) ?.

[hubble space telescope]

no, its ok! from every question and information, i collect more info about the purchase!!!

about the imaging targets.. i like something in average... kind of focal length that gets all the targets or most of the targets... from my experience (especially from videos and images that i saw) the area 913 mm focal length is my target... what do you say? its kind of "see it all" field of view?    

thanks!

[gorann]

Why just these two scopes? In that price range you could consider an Esprit 150 which is likely to outperform both of them and if you get it from FLO you can get it tested by Es before delivery. 

[Barry-Wilson]

The size of the image depends on

1. the size of the target in the sky
2. the focal length of the telescope
3. the pixel size of the ccd
4. the number of pixels in the ccd

There are on line tools, FOV calculators, that allow you to choose a scope, a focal ratio, a ccd and pixel size and a target to simulate what you record on your chosen ccd sensor.  See http://www.12dstring.me.uk/fovcalc.php.

HTH

[ollypenrice]

I would warn you that Takahashi's quality control has not been of the best in recent years. So I don't entirely agree with Whirlwind. I use a dual Tak FSQ106 rig and cannot fault the optics but they are both old instruments. However, Tak will sort things out. 

I'd say that Barry has given a good answer to your question. There are plenty of good apo refractors available and you need the right one for your camera and targets and you need a good example of the breed - which means you need a good dealer.

Olly

[hubble space telescope]

thanks barry! already knew this website but really thanks! i thinking to buy the nikon d810a and gorann - takahashi specific because almost every person that i asked in astronomy forum said that takahashi is the best company in refractors! 

 and olly - and what about the quality of the william optics flt 132?

thanks!!!!