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Tak TSA120 or TEC140?

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#1 swag72

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Posted 29 August 2012 - 02:07 AM

I am coming to a crossroads. I am selling my Skywatcher 120ED and would like to replace it with a quality refractor of a similar length. The Skywatcher really has never performed and I've had enough of it. There's not many people around that have experoience of both scopes, so I wonder if there's some folks on here who can offer some opinions.

It will be used purely for imaging and I'm not wanting to use any reducers on it. I'd like to use the native focal length. I currently image with an Atik 314L+ and don't see that changing. So hanging off the end is the camera and a Trutek manual filter wheel with an 8 filter carousel.

The mount is an HEQ5.

Perhaps you have some other ideas? I have searched the forum and have not really found many comparisons of the two scopes.

#2 orion69

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Posted 29 August 2012 - 02:32 AM

What was wrong with SW 120ED?

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#3 brianb11213

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Posted 29 August 2012 - 02:49 AM

What was wrong with SW 120ED?

Yeah, it's good enough optically for deep sky imaging ... the focuser isn't the greatest but upgrading to a Feather Touch rack & pinion would fix that for much less wallet damage than changing the whole tube.

If you want more light grasp / more focal length / less chromatic aberration, for deep sky imaging, you might well be better off with one of the relatively inexpensive small RC astrographs.

#4 swag72

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Posted 29 August 2012 - 02:51 AM

I've upgraded the focuser on the 120ED already. I've had someone compare the images of the 120ED and my small Pentax (scaled appropriately) and the 120ED is underperforming. Personally, I think optically it's a lemon.

#5 orion69

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Posted 29 August 2012 - 02:58 AM

Well, I can't help you to compare those scopes but I'm also thinking of upgrade. Like brianb11213 said SW 120 is pretty good optically (I have Equinox 120ED which I believe has same optics) but I want something faster and larger aperture. If I were you I'll go with TEC 140.

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#6 chris charen

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Posted 29 August 2012 - 03:55 AM

Personally, I think optically it's a lemon. [ED120]

In what way is it a lemon ? The consistency of the Synta doublets is well recognized. How does it star test ? does it show even illumination rings ? are there aberration's ? are you concerned with 'excessive' CA ?
When you say 'it never really performed' what were your expectations ?
Just interested to know why you rate your ED120 so negatively.

Chris.

#7 swag72

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Posted 29 August 2012 - 04:37 AM

Chris, I have never felt happy with the images that the 120 produced and initially thought it was the focuser, so upgraded that. Then I wondered if it was me, and my focusing abilities. Then I got a small Pentax and someone who works in the astro business compared the images from the Pentax and the 120ED - It's not giving the resolution that it should and is not producing sharp pictures. Perhaps it is me? But I do not like the scope and want shot of it! It's time to move on!!

#8 orion69

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Posted 29 August 2012 - 05:02 AM

I've upgraded the focuser on the 120ED already. I've had someone compare the images of the 120ED and my small Pentax (scaled appropriately) and the 120ED is underperforming. Personally, I think optically it's a lemon.


If small Pentax (75mm?) has more detail then SW120 (scaled appropriately) and images were taken correctly, then you have a lemon because 75mm scope (even Pentax) cannot compare to SW 120 (if working correctly), too much difference in aperture...

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#9 brianb11213

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Posted 29 August 2012 - 05:30 AM

If small Pentax (75mm?) has more detail then SW120 (scaled appropriately) and images were taken correctly, then you have a lemon because 75mm scope (even Pentax) cannot compare to SW 120 (if working correctly), too much difference in aperture...

Or, a marginal mount is working well with the smaller scope but really struggling with the bigger one.

You really need to check this out because upgrading your current tube to a bigger, heavier one - however perfect - will make matters worse rather than better if the mount is struggling.

Given good skies, AP performance is about 70% mount, 10% optics, 10% focuser, 10% camera.

#10 orion69

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Posted 29 August 2012 - 06:32 AM

Could you provide images for us to compare?

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#11 swag72

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Posted 29 August 2012 - 06:45 AM

Here's a dropbox download to a tiff file that has 2 layers, one the SW120ED and the other the Pentax 75. The images have been scaled appropriately and they are both Ha.

https://dl.dropbox.c.../Pentax_120.tif

#12 ken svp120

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Posted 29 August 2012 - 07:23 AM

I am coming to a crossroads. I am selling my Skywatcher 120ED and would like to replace it with a quality refractor of a similar length. The Skywatcher really has never performed and I've had enough of it. There's not many people around that have experoience of both scopes, so I wonder if there's some folks on here who can offer some opinions.

It will be used purely for imaging and I'm not wanting to use any reducers on it. I'd like to use the native focal length. I currently image with an Atik 314L+ and don't see that changing. So hanging off the end is the camera and a Trutek manual filter wheel with an 8 filter carousel.

The mount is an HEQ5.

Perhaps you have some other ideas? I have searched the forum and have not really found many comparisons of the two scopes.


Underperforming? Impossible. It says "ED" does it not!? :lol:

I will put in a vote for the TEC but that's only because I'm biased - I have used it for imaging. I have not used the Tak so I can offer you no comparison. However, I will kick around and see if I can find any of my monochrome images and will PM them to you or post them elsewhere and provide a link if I do find them. One recommendation I would offer is to join the TEC Yahoo forum and post your question there, you are likely to get a lot of well reasoned information from experienced individuals. Maybe see if you can find a Tak Forum as well...

Good luck - I'll be anxious to hear which one you end up with. I doubt you can go wrong with either.

#13 Waxing Gibbous

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Posted 29 August 2012 - 07:37 AM

TEC 140 - no question.
I owned a TSA 120 and it's not a million miles ahead of the EON 120. A brilliant scope, to be sure, but really not worth the premium over the EON IMHO.

I haven't owned a 140, but the example I had access to (for 3 nights anyway) was simply stunning - visually and mechanically.
The extra 20mm actually does make a difference and the fit and finish on the TEC is so much better, it's in another league. While the TSA120 would exhibit some very slight SA the TEC exhibited none.

An added advantage to the TEC is that their accessories, while not cheap, are still cheaper than Takahashi's by some margin.

#14 Texas

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Posted 29 August 2012 - 07:44 AM

I can see little advantage going from a 120 to a 120 even if the 120 you are going to is a Tak.
The TEC 140 as the alternative is a no brainer to me.

#15 brianb11213

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Posted 29 August 2012 - 07:55 AM

TEC 140 - no question.

On a HEQ5? (Same as Sirius).

My personal experience is that an HEQ5 is already struggling with a WO FLT 110 on it. Fine for visual, OK ish for lunar/planetary imaging, not good enough with a hydrogen alpha filter set as well. And that's sitting on a Berlebach Planet which is a great deal better at handling vibration than the stainless pipe leg tripod that's supplied with the mount.

A TEC 140 has a lot more momentum to control than a FLT 110 even with two kilogrammes of etalon hanging in front of the objective. For DSO imaging I think it would really struggle.

Again I think a EQ6 (Atlas) would be OK for a TEC 140 visually but I have real doubts about it being able to handle deep sky imaging at native focal length. Not that I can imagine why anyone would think of sticking a $5K tube on a $1K mount, the other way round makes far more sense to me for deep sky imaging.

BTW I looked at the images posted (with some difficulty as I'm not set up for multi layer TIFFs) and they look very similar to me. The 120 image is marginally softer than the Pentax but whether that's an optical issue, less accurate focusing, mount vibration or simply worse seeing is impossible to determine.

#16 swag72

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Posted 29 August 2012 - 08:05 AM

Yes I would be sticking with the HEQ5 - So the thoughts are for imaging that the HEQ5 simply will not be beefy enough for the TEC140? The HEQ5 is pier mounted in a obs if that makes any difference.

#17 orion69

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Posted 29 August 2012 - 08:11 AM

Yes I would be sticking with the HEQ5 - So the thoughts are for imaging that the HEQ5 simply will not be beefy enough for the TEC140? The HEQ5 is pier mounted in a obs if that makes any difference.


In my opinion HEQ5 is NOT good enough for SW 120 for AP either .

Knez

#18 swag72

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Posted 29 August 2012 - 08:20 AM

Cheers Knez - You sure know how to make my life complicated :)

#19 snommisbor

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Posted 29 August 2012 - 08:32 AM

If I was to have a choice between 2 scopes it would be the TAK TOA 130 and the TEC. Then you are more equal in your choice. The FOV is actually the same being the TAK is a 7.7. Plus you have the option to reduce it down. And they are comparably priced on the used market. I have looked through a TOA and it was incredible how color free it was. Now with that said I actually made the same choice between these 2 and went with the TEC. Mainly because of the extra 10mm and a little faster and a little lighter. But between those two you cant go wrong. If it is only between the TSA120 and TEC it is a no brainer TEC all the way.

#20 StarDust1

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Posted 29 August 2012 - 08:46 AM

I think both scopes are too heavy (and long) for HEQ5. The EQ6 is a much better mount for these scopes when imaging. The TSA102 will be better scope for your mount. It's lighter and shorter. I wouldn't put a TEC140 or TSA120 on an HEQ5 for imaging. For visual use the mount is excellent.

From my experience the TSA120 on an EQ6 works very well. Highly recommended when you are on the budget for an excellent mount.

How about a used EM200 and TSA102? It will be just above the price of a new TEC140. You should get round stars all the way with your Atik 314L+ and TSA102 without a reducer or flatner.

#21 swag72

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Posted 29 August 2012 - 08:54 AM

I did think about a TSA102, but it is not offering me a massively different focal length to my existing Pentax 75. If I don't get a different focal length, then I can't help thinking it won't be worth it.

#22 snommisbor

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Posted 29 August 2012 - 09:33 AM

Since you are doing nothing but imaging, why not get a FSQ106 or a NP101, or even the TEC110. Nice thing about the first 2 is you dont have to get a flattener and we are talking about a scope in weight that should work on your mount until you decide to upgrade it and would be an incredible AP scope. I have a TV101 and even when I use it visually the views are pretty awesome and I know there is a guy on here who wrote a review about his FSQ106 with a tele extender on it and it was a great visual scope at F/8. Lots of possibility with the FSQ.

#23 brianb11213

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Posted 29 August 2012 - 09:55 AM

I did think about a TSA102, but it is not offering me a massively different focal length to my existing Pentax 75. If I don't get a different focal length, then I can't help thinking it won't be worth it.

OK then, what about an AT6RC?

Longer focal length & a bit more aperture but much easier to mount than a f/7 ish 120mm+ refractor because it's shorter and lighter. To be perfectly honest I think it would be happier on an EQ6 but I think it could live with a HEQ5, especially if you have it "well tamed". And it's not that big an expenditure to find out whether you like it or not.

Yes, I know this is the refractor forum, but if the mount has to stay then neither the Tak nor the TEC might be the answer to the user's requirements & finding this out would be an expensive mistake.

If you really want to make a f/7 ish 120mm+ refractor sing, I think you should upgrade the mount first. (And then you might find that your existing 120 works a lot better.)

#24 jrbarnett

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Posted 29 August 2012 - 10:00 AM

I don't think either is a great choice for imaging at native focal ratio. The TSA-120 is a better fit for a light mount like the HEQ5. For *visual* I think the TEC is too much for an EQ6, much less trying to image with it on an HEQ5, though I have my doubts about how well an HEQ5 would handle the TSA-120 fully loaded for imaging, too. It's 12.6 pounds for the bare OTA, and on the long side to boot. Add rings and dovetail, and camera gear, and you have a fairly long large moment arm load in the saddle.

What was it about the Skywatcher that you didn't like? The answer to that might help those giving advice.

Regards,

Jim

#25 StarDust1

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Posted 29 August 2012 - 12:21 PM

Jim, from my experience the TSA120 works well on an EQ6 for imaging. The HEQ5 is a great portable mount, it's just too light for an TSA120.


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