GOTO Kogaku 80mm F15 Triplet type Standard APOCHROMAT ( made in about 1975~1976 )
Lens cell: The highest -quality finishing , . among all refractors which I have seen until today ( Japanese refractors only )

In Japan, GOTO kogaku has been called ( Noble telescope company) from many years ago. ( Now, GOTO already stopped making small telescopes for amateur....)
The reason why GOTO kogaku has been called for it will be that GOTO kogaku has very long history about making Telescopes ( mainly refractors) . Actually, at 1976 year point, already
50 years long history, GOTO kogaku had.about making telescopes for amateur .

In fact, I have been knowing GOTO Telescope ( 80mm F12.5 doublet type semi-Apochromat )since I was only 12 years old.... ( I started watching star from 10 old , I was bought GOTO 80mm F12.5 doublet type semi-APO
from my father with Mark-X mount when I was only 12 years old . of course, my family was poor ,but I wanted GOTO telescope to my father strongly..... Now when I think of it, for child like me, too luxurious story....So I have been knowing GOTO
Telescope ( refractor ) best .....< About why I was bought such high-quality telescope , a Japanese person advised my father to buy GOTO for me. He was famous person as a astronomy school teacher in Japan.
His name is Masaaki Imai , He died in about 1990 Also he was famous observer of the variable star in Japan .... I still appreciate my father and teacher Imai .... This is story of possibility . If my first proper telescope was other one, I might not do this work............

In Japan , the word ( Noble) is not used very much . When I think of it, ( why everyone in Japan is calling only GOTO kogaku Noble? ) . I have been thinking many years long that GOTO kogaku was surely nice Telescope maker, but
( Noble ) word is really suitable ..? < From many years ago, In Japan there were many telescope makers , but only GOTO kogaku is called ' Noble'.....( about it, I may have written ,used this word somewhere.
here I apologize for it..) I have been having GOTO F12.5 doublet type sei-apo for about more than 20 years long, but I didn't notice it. Unfortunately..

This GOTO kogaku 80mm F15 Standard type triplet APO was sold with my 80mm F12.5 doublet type semi-APO at the same time, ( there were 3 different types , F8.25, F12.5, F15 for each objective lens) , doublet type semi-APO are not rare . a lot of numbers in Japan
,but Triplet type standard APO type are now super rare in Japan.
..................... This is strange things . Because this telescope performance is REALLY GREAT
However, not sold so much . WHY ? after I checked this great Telescope , This is serious mystery ........ 1 thing I remember that this cause existed. about it, I can't write here, so if I meet the opportunity, then I want to write it...

Anyway, about 40 years long was needed for getting this APO and watching stars by this Historic refractor since I got GOTO F12.5 semi-apo in my child hood...

In Japanese rainy season , I could meet only 1 night ,clear sky with very nice seeing ( 25/ July in 2019), it may be a great present from the God. When I say a result, ( That's Great ! ) it was far beyond my expectation ....

For the first time, I could understand why GOTO kogaku is called ( Noble company of Telescope ) to know this great performance of Triplet type Standard type APO.

Before writing my report about this Triplet type standard APO , I must write the meanings of ( Standard type ) GOTO named.

As a definition, APO Chromat seems to have 1 important element. ; IT is ; 3 color , achromatism. .When not using ED, Fluorire lens, for design of APO Chromat , always needs 3 optical glass.
When I watch GOTO kogaku catalog now, except this standard triplet APO, others are all adopted ED lens, fluorite lens.

The reason why GOTO named this refractor as a Standard APO , seems to be from such definition . ( used 3 optical glass and achieved the performance of APOCHROMAT ), it was not from using ED , Fluorite lens .

I think this is very interesting thing ...( Of course, there will be some refractors APO with 3 optical lens overseas, but as far as I know, only this GOTO in Japan . from many years ao.


An introduction got longer.... I think I want to write impression of this super rare 80mm F15 standard APO as possible in detail.

25/ July in 2019 , at last I could watch stars and take a picture of the Moon.

( seeing; 8~9/ 10 )


1, Antares 2, The Jupiter 3, The Saturn 4, Altair 5, The half Moon.

used eyepieces

1, Takahashi classic MC Or25mm , Takahashi classic MC Or7mm, PENTAX SMC O5mm, Nikon classic Or7mm, Televue Radian 4mm < If I say ideal, I should use GOTO
MH-6mm, MH-12.5mm. but now unfortunately no GOTO eyepiece . GOTO has much confidence for GOTO MH6mm ,12.5mm. please understand it.>

My strong impression; WITH Dignity !! This is the first time to watch such beautiful star with grace !! ---------------------------------- Only it. I can say.

Since I started to watch a lot of Japanese Telescopes , but such experience is my first experience to watch stars with grace !!

If I will say the feature of this scope , this expression is the best.( in It's vanity taste)
This telescope has almost no color aberration , perfect star image ( at high maginification ) like 171x ( Takahashi classic Or 7mm and Nikon ).

When I try to adjust focusing, I can see the inner image , out of focusing, everything Perfect ! Also, when I used Televue Radian 4mm ( 300X) , the just focusing
star image can be seen very sharp , clearly. This is really surprising thing .

When I watched the Jupiter, just the time, The great spot can be seen from earth. . I remember that the great red spot of the Jupiter became thin 1977.
So, since it, I have seldom been watching the great red spot of the Jupiter so clearly..
However, can be seen very clearly by this GOTO 8cm F15 standard APO.!
< a Japanese pro telescope seller is saying , ( No aberration refractor is ; difficult to watch the pattern of the Jupiter...) when I heard his comment, I thought ( maybe this is wrong...).>

Surely, The pattern of the Jupiter , when I use Takahashi TSA, TOA, looks thin. However, I have been thinking his opinion will not be correct..
However, I have no grounds from any experience, theory against it..

After all, from this GOTO 80mm F15 Standard triplet APO , I understand that ( even if I use refractor with almost no color aberration, I can watch the pattern of the Jupiter clearly,

This is proved by this GOTO 80mm F15 standard type APO.

When I watched Saturn, after all I could watch the pattern of the Saturn very clearly. It was very beautiful Saturn as good as Jupiter.

This GOTO 80mm F15 standard triplet type APO's lens coating is not MC coating.

However, the contrast of the image is very high.....

Diameter of the 80mm telescoope, limiting visual magnitude is 11.3 class star.

I remember the small satellites of the Saturn are all 11 class star except titan.

GOTO 's diameter is 80mm, so normally I will not be able to see them.
However, I could watch some at 7mm eyepiece ( Takahashi classic MC Or 7mm) , at 171X.

This also is surprising to me.

Anyway, this Telescope showed me Planet ( Jupiter, Saturn ) very clearly. The pattern of 2 big planets can be seen clearly, densely.


Next, I watched Altair. ( always I have been watching Altair especially for refractors . Because Altair has pale color , and we can see it at high position from Japan.)

There, I felt <So beautiful! with Dignity > !!

It was the first time to watch such beautiful Altair. This impression can not be expressed by any words .....

In the view field, Altair was shinning beautifully with the best dignity.......................................

( Of course, star image in itself, perfect. no color aberration, the focusing image ,diffraction ring, airy disk , everything ,perfect !! )

That's great !!
Finally, I watched the half Moon.

When I watched the half moon, I understand why this telescope shows me the pattern of the planets so densely, clearly.

Please see the half Moon picture. I express the coloring of the Moon as possible exactly.

Maybe everyone feel a little red trend....

This coloring is THE GOTO 80mm standard Triplet APO's feature ....

This is very interesting to me. please remember the Moon picture by Takahashi 80mm F15 triplet type semi-apo .
( at my hope page, somewhere, it is ...) 2 Moon picture's color are much diffrent .....

Finally, I have been thinking that ( Telescopes, is difficult to have 2 factors at the same time).

1, Classic Telescope
2, High -performance ( as good as it of recent newest APO ).

I have been thinking that there will be difficulty to find such Telescope which has 2 contradicting element.

At last I could meet !

In addition to them, this telescope has the best dignity !

In other words, this GOTO kogaku standard triplet type APO 80mm F15 has 2 contradicting element. .and in addition to them,
has the best dignity !

The scope is my dream Telescoope which I have been dreaming to watch for more than 40 years long.

I have been watching GOTO kogaku 80mm doublet type ( F12.5) since I was 12 years old, so
the dream telescope was ( in fact ) at that time, right next to the scope .

This is beyond my imaginations.

I can say NOW, GOTO kogaku's telescope has the best dignity in addition to it's high performance .

This time, at last I understand that why GOTO kogaku has been called ( Noble telescope maker ) ..
To understand it , needed 40 years long in the case of me..

I appreciate the God to let me meat this telescope , giveme opportunity to watch star..........................

koji matsumoto/ 02/ August in 2019

< The publication of GOTO kogaku 's documents, I have got from GOTO kogaku 's approval ...>