I am not saying TV telescopes are cheap... I cannot afford any.. but the NP127 is a FLAT FIELD scope that has 4 ELEMENTS... obviously it costs more than the TEC140. That scope is better corrected (that means smaller more pin point stars ACROSS THE FIELD) than the TEC140.
Bro..I have seen through both scopes before while I was in Houston, Texas. I spent a lot of time on both. I know what I am talking about. Regardless what TV claims that 127 is to be, it has ZERO significance at the eyepiece. The TEC was brighter, as sharp, resolve more and the focuser was a beauty. Period. It doesn't matter how many elements that TV has or theoretically how good it is. It just could not justify the extra $2000 over the TEC no matter how you cut it. I have been in this hobby for 22 years now and I have seen enough scopes to tell the difference.
The TEC has more aperture, it would be brighter and it would have more resolution. That is physics. What I am talking about is the flat field of the NP127 and the correction across the field. Some people may like that kind of view that's why they buy it. Some buy them probably because it is 'made in USA'. However, one cannot deny that the NP127 can achieve a larger true field and a flatter one if mated to other eyepieces with flat focal planes. Which is the primary design of that scope..
Every design has their pros and cons. I do not think it is right to put down the real benefit of a certain design and ignore them totally. I speak from the point as an engineer. As a consumer, yeah it is not worth the money and neither would I buy it at that kind of price. Also, must you put in '22 years belt' into your statement? The more years the heavier the weight is it?
The TEC has more aperture, it would be brighter and it would have more resolution. That is physics. What I am talking about is the flat field of the NP127 and the correction across the field. Some people may like that kind of view that's why they buy it. Some buy them probably because it is 'made in USA'. However, one cannot deny that the NP127 can achieve a larger true field and a flatter one if mated to other eyepieces with flat focal planes. Which is the primary design of that scope..
Every design has their pros and cons. I do not think it is right to put down the real benefit of a certain design and ignore them totally. I speak from the point as an engineer. As a consumer, yeah it is not worth the money and neither would I buy it at that kind of price. Also, must you put in '22 years belt' into your statement? The more years the heavier the weight is it?
You go take a look at that TEC, using a Nagler or a Pentax and see if it is as flat or not. If you can detect curvature on the TEC using your eyes, then you must have super eyes because I can't see any. I spent two nights on both scopes (actually with a Tak FS102 also) and I do not see what so great about TV design which requires 2K more. Maybe a photographer would appreciate more but not me.
Yes, that 22 years is to tell you that I have own and seen enough scopes to know what I am talking about when comes to comparison (not trying to be arrogant or anything but you need to know I am NOT comparing them casually. I know my stuff and what to compare and look out for). When I say ZERO signifiicance, it means zero significance at the eyepiece no matter what flat field they are talking about. I don't pay for theory. I pay for the views I see. No point telling me a wonderful design that requires more $$$ but doesn't translate to any visual practicability.
i think field flatness of a scope for visual obbing is a little bit of bullshit la. it's quite impt for photographic purposes. but for visual ob, i think astig and coma far outweight field flatness.
putting in any of televue's nagler, radian or panos, u will often realize that u cannot tell the diff between a scope that is completely flat or a scope that's not flat. but it's very obvious that the faster scope tend to be not so well corrected at the very last bit of the field. astig and coma will often creep in at the very last 5-10% of the fov, and refocusing often does nothing to help the image.
back to the issue of photographic, i think both scopes have superb images taken thru them. the tec140 has it's own ff, costing only abt usd600. end of day it's up to individuals to choose which scope they wan to work with. the much faster np127 or the bigger tec140.
The owner of the NP-127is that I tested almost wanted to sell off this scope after comparing with the TEC. He was cursing like mad for the extra $$$ that he paid with basically no difference to the field visually. For photography he could have use the TEC FF anyway. But because TEC need to wait, so he end up holding onto the 127.
I think he went for a used TEC140 after that. And that 4" FT focuser was a beauty, beauty, beauty. Pictures doesn't do any justification to this focuser. Need to see one and operate one to appreciate it.
MooEy wrote:i think field flatness of a scope for visual obbing is a little bit of bullshit la. it's quite impt for photographic purposes. but for visual ob, i think astig and coma far outweight field flatness.
putting in any of televue's nagler, radian or panos, u will often realize that u cannot tell the diff between a scope that is completely flat or a scope that's not flat. but it's very obvious that the faster scope tend to be not so well corrected at the very last bit of the field. astig and coma will often creep in at the very last 5-10% of the fov, and refocusing often does nothing to help the image.
back to the issue of photographic, i think both scopes have superb images taken thru them. the tec140 has it's own ff, costing only abt usd600. end of day it's up to individuals to choose which scope they wan to work with. the much faster np127 or the bigger tec140.
~MooEy~
Is it? I can see Field Curvature in my telescope with different eyepieces. I have yet to see a scope that is COMPLETELY FLAT like an LCD panel. Most views through eyepieces are like looking at a CRT screen which is curved. There is a 'P' eyepiece when placed onto my scope shows 20% FOV (outside) that is out of focus (and I mean it is really out of focus.. you see blur )..who say field curvature cannot be seen? Also, some P eyepieces compared to the T eyepieces have different field curvature signs.
the astro club i belong to ,a few guys have the tv 127 and 2 guys have the tec 140,looking through scope many times my nod goes to the tec.the build quality of the tec is very good.just the over all views through the tec really out did the tv.
current scopes,tak fs152 c6rgt,wo 110.sv 80/9,orion 10" dob,sv115.
