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AT 125 EDL doublet

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#51 peleuba

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Posted 02 August 2020 - 07:39 PM

Is anyone guaranteeing .95 strehl at a specific wavelength?  Or are they just finding the one wavelength in the visual range that happens to reach 0.95? lol.gif

 

Funny.

 

Astronomics guarantees the Strehl value at what wavelength I am not sure.  I just checked my interferograms on some other AT OTA's and I am unable to locate the tested wavelength.  So its probably red.

 

It would be nice if it were green, but it might be red.  And for those following along, there is no direct correlation between a strehl value in red and one in green,  In other words, you cannot simply do math to convert the Strehl in red to one in green.  For a mirror, YES.  For a lens, NO.  This is because of spherochromatism.  The longer the focal ratio the closer the numbers will be, but there is no direct conversion.


Edited by peleuba, 02 August 2020 - 07:42 PM.

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#52 Jon Isaacs

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Posted 02 August 2020 - 08:35 PM

One more thought:

 

If you are going to actually strip the coatings and refigure lens, it makes sense to start with the poorest lenses rather than the best because I am thinking you are basically starting over anyway. 

 

Jon


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#53 Jason B

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Posted 03 August 2020 - 08:46 AM

I think it's great that Astro-Tech picked up this series of FCD100/Lanthanum doublets.  We have two of the 102mm Stellarvue versions in our small group at Fox Observatory and both provide outstanding views.  I have not been a big test guy but I can say the views are outstanding, especially given the price.  I like the specs of the 125mm and see that one possibly in my future.  My other AT scopes have been outstanding so I would expect the same from this one.

 

I think it's funny how we nitpick the more affordable lines of scopes in thread after thread after thread like they are made to be on par with the premium brands.  They're not.  They are meant to give us the best performance they can for a given dollar amount and if more is expected, we need to save a little longer to get something that meets the expectations.


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#54 starryhtx

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Posted 05 August 2020 - 05:09 AM

Did we get a date of availability yet?



#55 Rollo

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Posted 07 August 2020 - 05:42 PM

I would love to own a AT 125 EDL doublet !   Sounds like a great scope for the money !   


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#56 sipster

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Posted 07 August 2020 - 11:03 PM

Anyone know when they are supposed to come in stock?

January  



#57 sipster

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Posted 07 August 2020 - 11:19 PM

Did we get a date of availability yet?

So far January.



#58 sipster

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Posted 07 August 2020 - 11:50 PM

I think it's great that Astro-Tech picked up this series of FCD100/Lanthanum doublets.  We have two of the 102mm Stellarvue versions in our small group at Fox Observatory and both provide outstanding views.  I have not been a big test guy but I can say the views are outstanding, especially given the price.  I like the specs of the 125mm and see that one possibly in my future.  My other AT scopes have been outstanding so I would expect the same from this one.

 

I think it's funny how we nitpick the more affordable lines of scopes in thread after thread after thread like they are made to be on par with the premium brands.  They're not.  They are meant to give us the best performance they can for a given dollar amount and if more is expected, we need to save a little longer to get something that meets the expectations.

I believe that is true to a degree. However, from a business  point of view , there is money  in volume  sales. You can sell a high quality  product  at a lower and smaller profit percentage  if you sell a thousand  units instead of a hundred  units.




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