Pssst...Wanna See Some Ronchi Pics?

Here's a website with comparative Ronchi test photos for refractors. The
main site is he

http://homepage3.nifty.com/cz_telesco/

The refractor tests are he

http://homepage3.nifty.com/cz_telesc...acter_test.htm

The page is in Japanese, but you can check the file name by right clicking
on the pics and choosing properties. Here my list of the scopes tested,
from top to bottom:

Zeiss C63/840 Doublet type ACHROMAT
Zeiss C80/500 Doublet type ACHROMAT
Zeiss C80/500 Doublet ACHROMAT
Mizar 8cm F8 Doublet type fluorite APOCHROMAT
TeleVue 8.5cm F7 Two/two group composition SD APOCHROMAT
ADVIX 10cm F15 Doublet type ACHROMAT
ZEISS AS 100/1000 Doublet type semi APOCHROMAT
VIXEN 10.2cm F9 Doublet type fluorite APOCHROMAT
TAKAHASHI 10.2cm F8 Doublet type fluorite APOCHROMAT
TAKAHASHI 10.2cm F10 Doublet type fluorite APOCHROMAT
William Optics (Russian optics) 10cm F8 Triplet type SD APOCHROMAT
ZEISS APQ 100/640 Triplet oil-spaced fluorite APOCHROMAT
ZEISS APQ 100/640 Triplet oil-spaced fluorite APOCHROMAT
TeleVue 10.1cm F5.4 Four/four group composition SD APOCHROMAT (TV101)
TeleVue 10.1cm F5.4 Four/four group composition SD APOCHROMAT (NP101)
NIKON 10cm F12 two-lens type ED APOCHROMAT
PENTAX SDP 10.5cm F6.4 Four/four group SD APOCHROMAT
PENTAX 10.5cm F9.5 Doublet type SD APOCHROMAT
PENTAX 12.5cm F6.4 Four/four group SD APOCHROMAT
BORG 12.5cm F8 Doublet ED APOCHROMAT
TeleVue 12.7cm F5.2 Four/four group composition SD APOCHROMAT
TAKAHASHI 12.8cm F8 Doublet type fluorite APOCHROMAT
TAKAHASHI 13cm F7.7 three-lens type ED APOCHROMAT
ZEISS APQ 130/1000 Triplet oil-spaced type fluorite APOCHROMAT
TEC 14cm F7 TRIPLET composition oil-spaced type ED APOCHROMAT
Chinese 15cm F5 Doublet type ACHROMAT
Chinese 15cm F8 doublet type ACHROMAT
TAKAHASHI 15.2cm F8 Doublet type fluorite APOCHROMAT
TAKAHASHI 15cm F7 Triplet type fluorite APOCHROMAT
INTES-MICRO-- 15cm F8 Doublet type ED APOCHROMAT
ASTRO-PHYSICS 15.5cm F7 Triplet oil-spaced ED APOCHROMAT
ZEISS APQ 150/1200 Triplet oil-spaced type fluorite APOCHROMAT
ZEISS APQ 150/1200 Comparison of NULL TESTER and an interferometer test
ASTRO-PHYSICS-- 16cm F7.5 Triplet air-spaced type APOCHROMAT

Remember the scope description is *above* the test photo. I am interested
to hear what you Ronchi aficianados think of this data.

Ed T.

Ed T wrote:
Here's a website with comparative Ronchi test photos for refractors. The
main site is he

http://homepage3.nifty.com/cz_telesco/

The refractor tests are he

http://homepage3.nifty.com/cz_telesc...acter_test.htm



Wow - that Zeiss as100 looks like a piece of junque, and the foucault
pic on the APQ, what's with that diagonal scoring?

And that Pentax 12.5 f/6.4 ed! It looks terrible! I wonder what stars
look like through it - zonal, poorly corrected, you can see the
concentric circles from the mechanical grinding. Am I mistaken here?
That lens looks like...well, crap.

The Intes has a pretty scary figure, too.

Lot of surprises. Who woulda guessed that an AP155 had dog biscuit?

What an interesting site. WHo did the testing?

Thanks for the look - Chris

"starburst" wrote in message

What an interesting site. WHo did the testing?

Thanks for the look - Chris

I think its a group of fairly sophisticated amateurs in Japan, but machine
translating Japanese is frought with danger. You end up with a fair amount
of nonsensical text.

The null test is quite harsh, even on excellent lenses a 1/10 wave ripple
looks like a canyon.

Head over to the Yahoo refractor group for a little more discussion, I
posted there as well.

Ed T.

You know, Mr. T, considering the activity going on right now on the
thread "How long for AP160" below, the silence on this thread is
deafening. I don't think folks who have shelled out big money for an apo
want to see these tests, nor do they want to comment on them.

I've gotta say, though, that I'd love the chance to actually look
through all of these just to compare them to their ronchis and null
tests. There was an interesting site somewhere on the web where a coupla
amateurs took home the same three mirrors and tested them, and then
the results were tabulated and compared to interferometry. The
differences were starling. I understand the brilliant simplicity behind
foucault testing, but it seems that there's a lot in the eye of the
tester. And I'm beginning to believe that the only way to really test
optics is on a star under good seeing, you know?

Chris



Ed T wrote:
"starburst" wrote in message

What an interesting site. WHo did the testing?

Thanks for the look - Chris

starburst wrote in news:dehtcu$3pl$1
@geraldo.cc.utexas.edu:

You know, Mr. T, considering the activity going on right now on the
thread "How long for AP160" below, the silence on this thread is
deafening.

That's usenet. This thread isn't really controversial is it?

I don't think folks who have shelled out big money for an apo
want to see these tests, nor do they want to comment on them.

I did look and didn't find big surprises. Zeiss achros not too good, but no
miracle should have been expected, chinese achros very variable, top of the
line quite decent. Some disappointments, if I remember well - Japanese
doesn't help - in the 128 Tak, a russian apo and the williams flt 110.

As far as I am concerned the relatively poor Tak result isn't very
surprising.

Anything else stunning that we should look at?


--
Pierre Vandevenne - DataRescue sa/nv - www.datarescue.com
The IDA Pro Disassembler & Debugger - world leader in hostile code analysis
PhotoRescue - advanced data recovery for digital photographic media
latest review: http://www.pcmag.com/article2/0,1759,1590497,00.asp

I bet the tester has made a big , big mistake in testing the Zeiss APQ,
because the images he posted proove iut. They show color, which are
completly absend in the APQ. Such images can be done ONLY , if
the tester makes the mistake and do not test with the APQ with the in
the lightpath calculated Zeiss M44 stardiagonal prism. Removing
that diagonal prism resulting in chromaticle and spherical aberration
just like the images he show.

I dropped him a email in hope he can read english and reply to inform
him about
his mistake

if he understand, than hopefully he is able to repeaed the test or
write at least a notice about his fault

Markus


"starburst" wrote in message


Ed T wrote:
Here's a website with comparative Ronchi test photos for refractors. The
main site is he

http://homepage3.nifty.com/cz_telesco/

The refractor tests are he

http://homepage3.nifty.com/cz_telesc...acter_test.htm



Wow - that Zeiss as100 looks like a piece of junque, and the foucault
pic on the APQ, what's with that diagonal scoring?

And that Pentax 12.5 f/6.4 ed! It looks terrible! I wonder what stars
look like through it - zonal, poorly corrected, you can see the
concentric circles from the mechanical grinding. Am I mistaken here?
That lens looks like...well, crap.

The Intes has a pretty scary figure, too.

Lot of surprises. Who woulda guessed that an AP155 had dog biscuit?

What an interesting site. WHo did the testing?

Thanks for the look - Chris




--
Posted via Mailgate.ORG Server - http://www.Mailgate.ORG

Markus Ludes wrote:
I bet the tester has made a big , big mistake in testing the Zeiss APQ,
because the images he posted proove iut. They show color, which are
completly absend in the APQ. Such images can be done ONLY , if
the tester makes the mistake and do not test with the APQ with the in
the lightpath calculated Zeiss M44 stardiagonal prism. Removing
that diagonal prism resulting in chromaticle and spherical aberration
just like the images he show.

I dropped him a email in hope he can read english and reply to inform
him about
his mistake

if he understand, than hopefully he is able to repeaed the test or
write at least a notice about his fault

Markus


Hi Markus

Would the Williams lens they tested have a TMB designed lens?

"Mark S. Holden" wrote in news:HH0Pe.10875$1g2.3955
@fe05.lga:

Would the Williams lens they tested have a TMB designed lens?

How dare you! ;-)


--
Pierre Vandevenne - DataRescue sa/nv - www.datarescue.com
The IDA Pro Disassembler & Debugger - world leader in hostile code analysis
PhotoRescue - advanced data recovery for digital photographic media
latest review: http://www.pcmag.com/article2/0,1759,1590497,00.asp

Pierre Vandevenne wrote:
"Mark S. Holden" wrote in news:HH0Pe.10875$1g2.3955
@fe05.lga:


Would the Williams lens they tested have a TMB designed lens?


How dare you! ;-)


Still not over it ?

David wrote in news:dVcPe.4135$Sj1.3423@okepread04:

Pierre Vandevenne wrote:
"Mark S. Holden" wrote in news:HH0Pe.10875$1g2.3955
@fe05.lga:


Would the Williams lens they tested have a TMB designed lens?


How dare you! ;-)


Still not over it ?

You know, if people have the right to write pages and pages of sycophantic
prose about the gorgeous glossy white of of the tube their LZOS refractor
came in, I do have the right to keep a log of the decay of mine. Actually,
it does interest many people, judging by the traffic I get on my TMB page.
I guess being quite high in google helps a bit... and there is absolutely
nothing unfair on that page btw.

--
Pierre Vandevenne - DataRescue sa/nv - www.datarescue.com
The IDA Pro Disassembler & Debugger - world leader in hostile code analysis
PhotoRescue - advanced data recovery for digital photographic media
PhotoRescue, Winner of the 8-way comparative test of Computer Bild 07/2005