SW Evolux ED or WO Zenithstar 61 Apo

[badhex]

13 minutes ago, bomberbaz said:

If I could convince FLO to do so on a sale or return basis I might well do so 😉

There are some good points raised and in particular one does make me wonder is SW's inability to state the glass type.

I am going to do a paper based side by side checking stats, product details, comments basically anything I can pull up about the OTA's regarding both to see if I can break my impasse on decision. 

Steve, there's a good run down of the features etc. in the SW webcast when it was released. It is a video by SW themselves and therefore obviously biased, so of course take it with a pinch of salt, but very informative nonetheless. 

 

[FLO]

On 21/06/2022 at 13:16, badhex said:

There have been absolutely tonnes of posts both here and CN debating why SW no longer talk about glass types, and their main point is that the designs are essentially their IP and give them the competitive edge which allows them to achieve high quality at reasonable costs to the consumer - a point which I think is fair. My best guess would be that they are using an equivalent - if not better - glass from a different, less well respected glass manufacturer and matching optical designs so they aren't paying Ohara FPL53 prices.

I suspect this has more to do with Chinese manufacturers preferring to source glass from Chinese glass companies, whereas Taiwanese manufacturers tend (at least historically) to source from Ohara, Hoya (both Japanese) and Schott (German). 

Currently I do not believe Chinese telescope and glass manufacturers outperform those from Taiwan / Japan / Germany (sorry, John) but I do believe the Chinese can manufacturer glass of equal quality. The Evolux and Esprit series demonstrate this. 

HTH, 

Steve 

[badhex]

1 hour ago, FLO said:

I suspect this has more to do with Chinese manufacturers preferring to source glass from Chinese glass companies, whereas Taiwanese manufacturers tend (at least historically) to source from Ohara, Hoya (both Japanese) and Schott (German). 

Currently I do not believe Chinese telescope and glass manufacturers outperform those from Taiwan / Japan / Germany (sorry, John) but I do believe the Chinese can manufacturer glass of equal quality. The Evolux and Esprit series demonstrate this. 

HTH, 

Steve 

Thanks Steve. This makes total sense from a socioeconomic point of view. As I only had best guesses to work from, I didn't want to make a statement I couldn't back up and was struggling to find a succinct way to put it, but this is in a roundabout way what I meant by 'less well respected'. To be clear, this is not an opinion I hold, but reading elsewhere on the internet it seems that there is not so much love for Chinese manufactured optics and glass, which I think is a bit unfair given what we've seen with previous SW products for example.

[FLO]

16 minutes ago, badhex said:

Thanks Steve. This makes total sense from a socioeconomic point of view. As I only had best guesses to work from, I didn't want to make a statement I couldn't back up and was struggling to find a succinct way to put it, but this is in a roundabout way what I meant by 'less well respected'. To be clear, this is not an opinion I hold, but reading elsewhere on the internet it seems that there is not so much love for Chinese manufactured optics and glass, which I think is a bit unfair given what we've seen with previous SW products for example.

I saw what you did 😉

My response was carefully worded too 😄 

There is too much talk these days about ED glass types. The ED lens is only one part of the optical design. It depends heavily on the quality and compatibility of the matching Crown lens. And of course there is the lens cell (the mechanical structure that holds the optics). It is hard to manufacture a cell able to reliably hold optics in alignment, across a range of temperatures. Some big names have tried and failed and, even now, some continue to struggle with this part of the optical design. 

Steve 

[great_bear]

On 20/06/2022 at 14:38, bomberbaz said:

I am torn between the two OTA's

I take it you've seen there's one up for sale here on SGL?

 

[bomberbaz]

32 minutes ago, great_bear said:

I take it you've seen there's one up for sale here on SGL?

 

I had yes although it appears someone has now registered an interest anyway. Only other thing is I am on with a red theme, my OCD itches away at things like that. 

Thanks anyway Jeremy 😃

[Elp]

Ah but shouldn't it be dark when you're out with it?

[Skyline]

10 hours ago, bomberbaz said:

I had yes although it appears someone has now registered an interest anyway. Only other thing is I am on with a red theme, my OCD itches away at things like that. 

Thanks anyway Jeremy 😃

I understand fully. It makes all the difference and it looks good as well.

[Stu1smartcookie]

On 21/06/2022 at 16:50, FLO said:

There is too much talk these days about ED glass types.

Sorry to revive this but i think the statement is quite interesting .... Sure , i agree there is too much talk about ED glass types , but , when its used as a marketing tool , surely it HAS to be investigated as to whether its worth something . 

 

On 21/06/2022 at 16:50, FLO said:

The ED lens is only one part of the optical design.

But a quite important part ? 

 

[great_bear]

3 hours ago, Stu1smartcookie said:

Sorry to revive this but i think the statement is quite interesting .... Sure , i agree there is too much talk about ED glass types , but , when its used as a marketing tool , surely it HAS to be investigated as to whether its worth something . 

 

But a quite important part ? 

 

I think the key point is that ED is not a 'better' kind of glass - it's just glass with a different refractive index. The balancing of glasses of different indexes is a key tool to make sure the different wavelengths of light converge as closely as possible. There may be other emerging techniques in the optical designers toolbox that Sky-Watcher and others might not necessarily want to divulge.

The main thing the customer cares about is the performance of the scope overall. Agreeing on industry-standard, unambiguous ways of measuring, reporting and comparing scope performance is probably the thing to focus on (no pun intended). 

[Stu1smartcookie]

15 hours ago, great_bear said:

The main thing the customer cares about is the performance of the scope overall.

Agree with this but unless there is comparisons made ( fairly ) People have to go with the advertising blurb . I think , and this applies to me , people are led by claims of " superior quality glass " etc . Advertising works ... and due to the fact we have always been told that the best glass gives the best results its no wonder we see it as a deciding factor . 

 

15 hours ago, great_bear said:

Agreeing on industry-standard, unambiguous ways of measuring, reporting and comparing scope performance is probably the thing to focus on (no pun intended). 

🤣 i would have used that line too ... but i certainly would have intended 🤣

[FLO]

On 20/09/2022 at 13:13, Stu1smartcookie said:

Sorry to revive this but i think the statement is quite interesting .... Sure , i agree there is too much talk about ED glass types , but , when its used as a marketing tool , surely it HAS to be investigated as to whether its worth something . 

But a quite important part ? 

You have quoted only the first line of my post. Here it is in full: 

On 21/06/2022 at 16:50, FLO said:

There is too much talk these days about ED glass types. The ED lens is only one part of the optical design. It depends heavily on the quality and compatibility of the matching Crown lens. And of course there is the lens cell (the mechanical structure that holds the optics). It is hard to manufacture a cell able to reliably hold optics in alignment, across a range of temperatures. Some big names have tried and failed and, even now, some continue to struggle with this part of the optical design. 

Hope that helps 🙂

Steve