Re: Splitting hair


Aug 23, 2005

 


----------------------------

#8074 Aug 23, 2005

There is a very interesting post on refractors Yahoo group #14821, it

has Ronchi/Null tests for number of well known and some not too well

known refractors, it is worth a visit.

What caught my attention most was the knife edge test showing surface

smoothness on these refractors. Three rferactors showed very smooth

surface, Tak 130 TOA, Zeiss 130 APQ and TEC140. The Tak 152 doublet

showed much smoother surface compared to the much overpriced 150FCT.

The Zeiss 150 APQ although fairly smooth did not match the surface

smoothness of 130APQ. The 160AP shown on the test showed some minor

concentric zones, according to Roland that particular unit was not a

production model.

Most of the zones, pits or turned edges that are seen on this tests

are minor in nature and should not affect the performance, we are

splitting hair here.



Thanks,

Vahe



----------------------------

#8076 Aug 24, 2005

Vahe;



I agree a very interesting thread and now both Markus Ludes and Yuri

have posted on it. Markus includes a link to a German language

version of the pictures and some of the info.



Rich Wood



--- In tec-scopes@yahoogroups.com, "vahe352" vahe@f...> wrote:

> There is a very interesting post on refractors Yahoo group #14821,

it

> has Ronchi/Null tests for number of well known and some not too

well

> known refractors, it is worth a visit.

> What caught my attention most was the knife edge test showing

surface

> smoothness on these refractors. Three rferactors showed very

smooth

> surface, Tak 130 TOA, Zeiss 130 APQ and TEC140. The Tak 152

doublet

> showed much smoother surface compared to the much overpriced

150FCT.

> The Zeiss 150 APQ although fairly smooth did not match the surface

> smoothness of 130APQ. The 160AP shown on the test showed some

minor

> concentric zones, according to Roland that particular unit was not

a

> production model.

> Most of the zones, pits or turned edges that are seen on this

tests

> are minor in nature and should not affect the performance, we are

> splitting hair here.

>

> Thanks,

> Vahe



----------------------------

#8077 Aug 24, 2005

Comment, All well and good, but remember, the REAL test is that of a well focused view of planet or DSO :-).  As one of the masters (competition) has pointed out on many occasions, even with the best that star testing has to offer (which is superior to Ronchi tests, he adds), the information can be misleading and only gives the observer the ability to judge up to diffraction limited, or so.  TEC, AP, TMB and Tak are all significantly better than these tests are capable of measuring.  Or at least, that's what I've gleaned from the expert/s ;-) Mark   -----Original Message-----From: Rich Wood astronut1001@...>To: tec-scopes@yahoogroups.comSent: Wed, 24 Aug 2005 16:42:04 -0000Subject: [tec-scopes] Re: Splitting hair

Vahe;

I agree a very interesting thread and now both Markus Ludes and Yuri have posted on it. Markus includes a link to a German language version of the pictures and some of the info.

Rich Wood



--- In tec-scopes@yahoogroups.com, "vahe352" vahe@f...> wrote:> There is a very interesting post on refractors Yahoo group #14821, it > has Ronchi/Null tests for number of well known and some not too well > known refractors, it is worth a visit.> What caught my attention most was the knife edge test showing surface > smoothness on these refractors. Three rferactors showed very smooth > surface, Tak 130 TOA, Zeiss 130 APQ and TEC140. The Tak 152 doublet > showed much smoother surface compared to the much overpriced 150FCT. > The Zeiss 150 APQ although fairly smooth did not match the surface > smoothness of 130APQ. The 160AP shown on the test showed some minor > concentric zones, according to Roland that particular unit was not a > production model.> Most of the zones, pits or turned edges that are seen on this tests > are minor in nature and should not affect the performance, we are > splitting hair here.> > Thanks,> Vahe



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----------------------------

#8078 Aug 24, 2005

Mark;



True but none the less ANY readily visible error in the Ronchi tests

of scopes from well known Apo manufacturers is a bit surprising to

me. I would think that it has to affect the Strehl ratio to some

extent, at least slightly decreasing contrast.



Rich Wood





--- In tec-scopes@yahoogroups.com, pandrolmb@a... wrote:

> Comment,

>

> All well and good, but remember, the REAL test is that of a well

focused view of planet or DSO :-). As one of the masters

(competition) has pointed out on many occasions, even with the best

that star testing has to offer (which is superior to Ronchi tests,

he adds), the information can be misleading and only gives the

observer the ability to judge up to diffraction limited, or so.

TEC, AP, TMB and Tak are all significantly better than these tests

are capable of measuring. Or at least, that's what I've gleaned

from the expert/s ;-)

>

> Mark

>

> -----Original Message-----

> From: Rich Wood astronut1001@y...>

> To: tec-scopes@yahoogroups.com

> Sent: Wed, 24 Aug 2005 16:42:04 -0000

> Subject: [tec-scopes] Re: Splitting hair

>

>

> Vahe;

>

> I agree a very interesting thread and now both Markus Ludes and

Yuri

> have posted on it. Markus includes a link to a German language

> version of the pictures and some of the info.

>

> Rich Wood

>

>

> --- In tec-scopes@yahoogroups.com, "vahe352" vahe@f...> wrote:

> > There is a very interesting post on refractors Yahoo group

#14821,

> it

> > has Ronchi/Null tests for number of well known and some not too

> well

> > known refractors, it is worth a visit.

> > What caught my attention most was the knife edge test showing

> surface

> > smoothness on these refractors. Three rferactors showed very

> smooth

> > surface, Tak 130 TOA, Zeiss 130 APQ and TEC140. The Tak 152

> doublet

> > showed much smoother surface compared to the much overpriced

> 150FCT.

> > The Zeiss 150 APQ although fairly smooth did not match the

surface

> > smoothness of 130APQ. The 160AP shown on the test showed some

> minor

> > concentric zones, according to Roland that particular unit was

not

> a

> > production model.

> > Most of the zones, pits or turned edges that are seen on this

> tests

> > are minor in nature and should not affect the performance, we

are

> > splitting hair here.

> >

> > Thanks,

> > Vahe

>

>

>

>

>

>

> Yahoo! Groups Links







----------------------------

#8079 Aug 24, 2005

What Ilike about the TEC is that I never have to justify it after somebody testsit. Wes-----Original Message-----From: tec-scopes@yahoogroups.com[mailto:tec-scopes@yahoogroups.com]On Behalf Ofpandrolmb@...Sent: Wednesday, August 24, 2005 12:40PMTo: tec-scopes@yahoogroups.comSubject: Re:[tec-scopes] Re: Splitting hair

Comment, All well and good, but remember, the REAL test is that of a wellfocused view of planet or DSO :-). As one of the masters (competition) has pointed out onmany occasions, even with the best that star testing has to offer(which is superior to Ronchi tests, headds), the information can be misleading and only gives theobserver the ability to judge up to diffraction limited, or so. TEC, AP, TMB and Tak are all significantly better than thesetests are capable of measuring.  Or at least, that's what I've gleaned from the expert/s ;-) Mark   -----Original Message-----From: RichWood astronut1001@...>To:tec-scopes@yahoogroups.comSent: Wed, 24 Aug 2005 16:42:04-0000Subject: [tec-scopes] Re: Splitting hair

Vahe;

I agree a very interesting thread and now both Markus Ludes and Yuri have posted on it. Markus includes a link to a German language version of the pictures and some of the info.

Rich Wood

--- In tec-scopes@yahoogroups.com, "vahe352" vahe@f...> wrote:> There is a very interesting post on refractors Yahoo group #14821, it > has Ronchi/Null tests for number of well known and some not too well > known refractors, it is worth a visit.> What caught my attention most was the knife edge test showing surface > smoothness on these refractors. Three rferactors showed very smooth > surface, Tak 130 TOA, Zeiss 130 APQ and TEC140. The Tak 152 doublet > showed much smoother surface compared to the much overpriced 150FCT. > The Zeiss 150 APQ although fairly smooth did not match the surface > smoothness of 130APQ. The 160AP shown on the test showed some minor > concentric zones, according to Roland that particular unit was not a > production model.> Most of the zones, pits or turned edges that are seen on this tests > are minor in nature and should not affect the performance, we are > splitting hair here.> > Thanks,> Vahe



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----------------------------

#8080 Aug 24, 2005

Dito THAT Wes, You just have to be careful not to step on anyone's jaw ;-) Mark  -----Original Message-----From: Wes Bolin k5apl@...>To: tec-scopes@yahoogroups.comSent: Wed, 24 Aug 2005 13:55:41 -0500Subject: RE: [tec-scopes] Re: Splitting hair

What I like about the TEC is that I never have to justify it after somebody tests it. Wes-----Original Message-----From: tec-scopes@yahoogroups.com [mailto:tec-scopes@yahoogroups.com]On Behalf Of pandrolmb@...Sent: Wednesday, August 24, 2005 12:40 PMTo: tec-scopes@yahoogroups.comSubject: Re: [tec-scopes] Re: Splitting hair

Comment, All well and good, but remember, the REAL test is that of a well focused view of planet or DSO :-).  As one of the masters (competition) has pointed out on many occasions, even with the best that star testing has to offer (which is superior to Ronchi tests, he adds), the information can be misleading and only gives the observer the ability to judge up to diffraction limited, or so.  TEC, AP, TMB and Tak are all significantly better than these tests are capable of measuring.  Or at least, that's what I've gleaned from the expert/s ;-) Mark   -----Original Message-----From: Rich Wood astronut1001@...>To: tec-scopes@yahoogroups.comSent: Wed, 24 Aug 2005 16:42:04 -0000Subject: [tec-scopes] Re: Splitting hair

Vahe;

I agree a very interesting thread and now both Markus Ludes and Yuri have posted on it. Markus includes a link to a German language version of the pictures and some of the info.

Rich Wood

--- In tec-scopes@yahoogroups.com, "vahe352" vahe@f...> wrote:> There is a very interesting post on refractors Yahoo group #14821, it > has Ronchi/Null tests for number of well known and some not too well > known refractors, it is worth a visit.> What caught my attention most was the knife edge test showing surface > smoothness on these refractors. Three rferactors showed very smooth > surface, Tak 130 TOA, Zeiss 130 APQ and TEC140. The Tak 152 doublet > showed much smoother surface compared to the much overpriced 150FCT. > The Zeiss 150 APQ although fairly smooth did not match the surface > smoothness of 130APQ. The 160AP shown on the test showed some minor > concentric zones, according to Roland that particular unit was not a > production model.> Most of the zones, pits or turned edges that are seen on this tests > are minor in nature and should not affect the performance, we are > splitting hair here.> > Thanks,> Vahe



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----------------------------

#8081 Aug 24, 2005

--- In tec-scopes@yahoogroups.com, "vahe352" vahe@f...> wrote:

The 160AP shown on the test showed some minor

> concentric zones, according to Roland that particular unit was not a

> production model.

> Most of the zones, pits or turned edges that are seen on this tests

> are minor in nature and should not affect the performance, we are

> splitting hair here.

>

> Thanks,

> Vahe



I agree that those zones will not affect performance, and I bet Roland

knows how to fix this small problem - just by filling the air gaps with

an oil!

(-:

Yuri







----------------------------

#8082 Aug 24, 2005

--- In tec-scopes@yahoogroups.com, "vahe352" vahe@f...> wrote:

> There is a very interesting post on refractors Yahoo group #14821



Thanks alot, Vahe. Now you have given me yet ANOTHER group to monitor

as if I needed it. :D



Best Regards, Milt



----------------------------

#8083 Aug 24, 2005

Well Yuri, I guess that you can gloat over this one, but you also know

that the tables could have been turned the other way. For any of the

top apo manufaturers, and that includes TAC, TEC, TMB, TV, Zeiss, AP

etc etc, you will always find a distribution curve. If you take the

best one of any of these they will always test much better than the

worst of any of them. It's the luck of the draw which one gets picked

for comparison. Just look at the examples from Tak, Zeiss or Televue

who had 3 or more lenses tested. Each manufacturer had quite a range.

Personally I have done similar tests on all my competitor's optics

including some of yours and have found similar distribution. That does

not mean that they did not meet all the maker's specs, nor does it mean

that any of them did not perform superbly under actual observing

conditions. Every telescope maker allows himself some error budget, and

no matter how much time is spent on each optic, not every last will be

at the very top of that budget.



So count yourself lucky that yours was a good one with no minor faults

that anyone can take issue with, rightly or wrongly.



Rolando

--- In tec-scopes@yahoogroups.com, "yuri80226" tec@t...> wrote:

> --- In tec-scopes@yahoogroups.com, "vahe352" vahe@f...> wrote:

> The 160AP shown on the test showed some minor

> > concentric zones, according to Roland that particular unit was not

a

> > production model.

> > Most of the zones, pits or turned edges that are seen on this tests

> > are minor in nature and should not affect the performance, we are

> > splitting hair here.

> >

> > Thanks,

> > Vahe

>

> I agree that those zones will not affect performance, and I bet

Roland

> knows how to fix this small problem - just by filling the air gaps

with

> an oil!

> (-:

> Yuri



----------------------------

#8085 Aug 24, 2005

--- In tec-scopes@yahoogroups.com, "uncarollo2" chris1011@a...>

wrote: > Well Yuri, I guess that you can gloat over this one, but you also

know > that the tables could have been turned the other way. For any of

the > top apo manufaturers, and that includes TAC, TEC, TMB, TV, Zeiss,

AP > etc etc, you will always find a distribution curve. If you take the

> best one of any of these they will always test much better than the

> worst of any of them. It's the luck of the draw which one gets

picked > for comparison. Just look at the examples from Tak, Zeiss or

Televue > who had 3 or more lenses tested. Each manufacturer had quite a

range. > Personally I have done similar tests on all my competitor's optics

> including some of yours and have found similar distribution. That

does > not mean that they did not meet all the maker's specs, nor does it

mean > that any of them did not perform superbly under actual observing

> conditions. Every telescope maker allows himself some error budget,

and > no matter how much time is spent on each optic, not every last will

be > at the very top of that budget.

>

> So count yourself lucky that yours was a good one with no minor

faults > that anyone can take issue with, rightly or wrongly.

>

> Rolando





Well Roland, I would agree with most of your post, except the gloat -

there wasn't any, but I was friendly teasing you with an oil!

As per luck - I have to say that it is not a case, of coarse there is

a "learning curve" for any new product, but all other issues are

mostly related to a couple of things: our opticians hands and glass -

that is why we were "lucky" in first run when we did 35 of 40 planned!

Regards, Yuri



----------------------------

#8086 Aug 24, 2005

--- In tec-scopes@yahoogroups.com, "yuri80226" tec@t...> wrote: > --- In tec-scopes@yahoogroups.com, "uncarollo2" chris1011@a...>

> wrote:



> Well Roland, I would agree with most of your post, except the gloat -

> there wasn't any, but I was friendly teasing you with an oil!

> As per luck - I have to say that it is not a case, of coarse there is

> a "learning curve" for any new product, but all other issues are

> mostly related to a couple of things: our opticians hands and glass -

> that is why we were "lucky" in first run when we did 35 of 40 planned!

> Regards, Yuri



I use the best glass there is, same as you. We both get it from the

same place. You are lucky to have such good opticians.



We shall meet again another time and another place.



Rolando



----------------------------

#8087 Aug 24, 2005

Yuri;



When it comes to optics and business some people have little or no

sense of humor, unlike you. ;-)



Rich Wood









--- In tec-scopes@yahoogroups.com, "uncarollo2" chris1011@a...>

wrote: > --- In tec-scopes@yahoogroups.com, "yuri80226" tec@t...> wrote:

> > --- In tec-scopes@yahoogroups.com, "uncarollo2" chris1011@a...>

> > wrote:

>

> > Well Roland, I would agree with most of your post, except the

gloat - > > there wasn't any, but I was friendly teasing you with an oil!

> > As per luck - I have to say that it is not a case, of coarse

there is > > a "learning curve" for any new product, but all other issues are

> > mostly related to a couple of things: our opticians hands and

glass - > > that is why we were "lucky" in first run when we did 35 of 40

planned! > > Regards, Yuri

>

> I use the best glass there is, same as you. We both get it from

the > same place. You are lucky to have such good opticians.

>

> We shall meet again another time and another place.

>

> Rolando







----------------------------

#8088 Aug 24, 2005

--- In tec-scopes@yahoogroups.com, "uncarollo2" chris1011@a...>

wrote:

> We shall meet again another time and another place.

>



This has the makings of a spaghetti western. We can call it

'A Fistful of Apos.'



:-)))



----------------------------

#8090 Aug 25, 2005

--- In tec-scopes@yahoogroups.com, "uncarollo2" chris1011@a...> wrote:

> We shall meet again another time and another place.

>

> Rolando



Yes, why not. Usually it happens in Florida, I may try to go to one of

yours in IL, but not sure which one to go after Astrofest was splitted

in two pieces...?

Regards, Yuri



----------------------------

#8091 Aug 25, 2005

I am too busy for Astrofest this year, but Florida Star Party is in

the plan for next year. We will get together with Markus and have a 3

way arm wrestling contest (one beer in each arm and winner must drink

all 6 glasses).



Rolando

--- In tec-scopes@yahoogroups.com, "yuri80226" tec@t...> wrote:

> --- In tec-scopes@yahoogroups.com, "uncarollo2" chris1011@a...>

wrote:

>

> > We shall meet again another time and another place.

> >

> > Rolando

>

> Yes, why not. Usually it happens in Florida, I may try to go to one

of

> yours in IL, but not sure which one to go after Astrofest was

splitted

> in two pieces...?

> Regards, Yuri



----------------------------

#8092 Aug 25, 2005

Roland and Yuri, that should get funny , but I am a foul office guywith not much power left. So please allow me to replace me by my WORKER Matthias, he has enough training in Colone with drinking and lifting beerglases , okay? :-) Markus----- Original Message -----From:uncarollo2To: tec-scopes@yahoogroups.comSent: Thursday, August 25, 2005 4:41PMSubject: [tec-scopes] Re: Splittinghair

I am too busy for Astrofest this year, but Florida StarParty is in the plan for next year. We will get together with Markus andhave a 3 way arm wrestling contest (one beer in each arm and winner mustdrink all 6 glasses).

Rolando

--- In tec-scopes@yahoogroups.com,"yuri80226" tec@t...> wrote:> --- Intec-scopes@yahoogroups.com,"uncarollo2" chris1011@a...> wrote:> > > We shallmeet again another time and another place.> > > >Rolando> > Yes, why not. Usually it happens in Florida, I maytry to go to one of > yours in IL, but not sure which one to goafter Astrofest was splitted > in two pieces...?> Regards,Yuri



----------------------------

#8093 Aug 25, 2005

Hey, what about this western production "APO CORRAL"

Its nice to have a good sense of humor now that it is raining all

over the place.

Best regards to all and specially to the duelists.

Eric. (M.xico)













--- In tec-scopes@yahoogroups.com, "wilcoxmilton"

wilcoxmilton@y...> wrote: > --- In tec-scopes@yahoogroups.com, "uncarollo2" chris1011@a...>

> wrote:

>

> > We shall meet again another time and another place.

> >

>

> This has the makings of a spaghetti western. We can call it

> 'A Fistful of Apos.'

>

> :-)))



----------------------------

#8095 Aug 25, 2005

--- In tec-scopes@yahoogroups.com, "APM-Telescopes Markus Ludes"

anfrage@a...> wrote: > Roland and Yuri,

>

> that should get funny , but I am a foul office guy with not much

power left.



For those not versed in colloquial German, I think Markus did not mean

foul as in rotten, but the German word faul which means basically lazy

and out of shape. In any case I don't think it takes too much training

to lift 2 beer glasses, something they practice over there quite often,

yes? Mathaias would be unfair since I have seen him lift 14" Mak-Newts

like they were grab 'n go scopes.



Rolando


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