Halouri lunare si o mica luneta olandeza

In seara zilei de Joi 6 Februarie 2020 am observat vizual si fotografic haloul lunar de mai jos.
Pentru poze am folosit camera compacta Coolpix S3300 pe trepied foto bricolat.

Halou lunar 6 Februarie 2020

Halou lunar 6 Februarie a.c.

In seara zilei de Sambata 7 Martie a.c., m-a sunat prietenul meu Armand sa ma anunte ca cerul este dominat de un halou lunar intens.
Am luat imediat ''sapuniera'' mea Coolpix S3300 si am observat, vizual si fotografic, acest halou lunar care a fost foarte persistent ,durata lui depasind trei ore.

Halou lunar 7 Martie 2020

Halou lunar 7 Martie a.c.

Halou lunar 7 Martie

Cu decenii in urma, pe vremea lui Ceausescu, doar rareori de gaseau binocluri de vanzare - de pilda 8x30mm, rusesti  iar costul lor era prohibitiv (cam cat un salariu sau mai mare).
Am incercat atunci sa confectionez un binoclu galilean, folosind o pereche de lentile plan-convexe ca obiective si cu doua lentile divergente echiconcave drept oculare.Lentilele divergente proveneau dintr-un binoclu jucarie.
Grosismentul binoclului urma sa fie foarte redus ,undeva pe la 2.5x.
Am avansat binisor cu proiectul, colegii mei de servici confectionand pe strung tuburile principale pentru obiective si cele culisante, pentru oculare.
Urma acum asamblarea celor doua tuburi principale si pentru aceasta a trebuit sa duc la servici unul din subansamble pentru a fi gaurit pe masina de gaurit in coordonate.
Dupa asamblare provizorie,colimare,testare si  trasare, urma gaurirea celui de al doilea tub si apoi trebuia sa fac asamblarea finala.
Din pacate, cineva (vreun nemernic care oricum nu a putut sa faca mare lucru cu ele), a sustras intr-o noapte lentilele unuia din subansamble ,aflat in sertarul biroului meu .Astfel proiectul, ramas fara lentile, a capotat.

Cu timpul, subansamblul ramas fara lentile a fost facut cadou amicului Csillag iar pe cel ramas intreg l-am folosit ,rar, drept ''luneta olandeza''.
O ''luneta olandeza'' este o luneta galileana cu grosismentul mai mic decat grosismentul echipupilar.

Luneta olandeza  cu puterea de marire de 2,5x

De curand insa mi-a venit ideea de a imbunatati aceasta luneta care ,din cauza obiectivului simplet , trebuia diafragmata la apertura de 20mm pentru ca aberatia cromatica sa fie (cat de cat ) suportabila.
Am schimbat asadar obiectivul simplet de 60mm diametru (vizibil in fotografia urmatoare in stanga sus,langa diafragma de 20mm) cu un obiectiv dublet acromat (stanga, mijloc), provenit dintr-un binoclu si avand parametrii de baza : D liber = 50mm , F= 190mm.
Ocularul a ramasa acelasi ,avand f= -50mm (dreapta,mijloc).

De la obiectivul de binoclu am refolosit celula metalica (stanga ,jos) dar aceasta are diametrul mai mic decat interiorul corpului lunetei.
Am compensat diferenta dintre acesti doi diametrii cu un inel confectionat dintr-un segment de tub de carton ,vopsit negru mat dupa ajustare (inelul se vede in fotografie gata montat pe celula obiectivului de binoclu).

Luneta olandeza 3,8x

Luneta olandeza 3,8x50mm

Sa calculam grosismentul lunetei olandeze astfel obtinute:

G  = focala obiectiv/focala ocular = 190/ 50 = 3,8x

O caracteristica a lunetelor olandeze este dependenta campului lor vizual de diametrele obiectivelor.
Cu cat diametrul obiectivului este mai mare, cu atat campul este mai mare.
Aceasta inseamna ca diametrul obiectivului este mult mai mare decat cel cerut de grosismentul echipupilar.
Verificat prin observarea obiectelor ceresti, campul acestei lunete olandeze este de 3.5 grade, imaginea sa este clara, contrastul este bun, cu o buna saturatie a culorilor.
Iata un mic instrument utilizabil, confectionat din parti disparate care zaceau uitate prin unghere.
Dar oare se poate vedea ''ceva'' cu un asemenea instrument minimal ?

Image stabilizer for binoculars ala Alan MacRoberts

I'm an amateur astronomer since I know about.

I got my first binoculars  only  in the summer of 1999 at Methuselah's age of 45.

This was a  10x50mm Tasco binocular of doubtful quality which  shortly after was replaced by a 7x50mm  Fujinon Mariner binocular of excellent quality .

Since then I always had at least a pair of binoculars.

For the amateur astronomer who begins to observe the sky with the naked eyes , binoculars are great tools because they extends in a great way the innate vision.

You just take your binoculars  to a corner away from artificial lighting. 
The simple gesture of rising your binoculars up to the starry sky, seems to be a sign of recognition, or a  very powerful secret password entered in the  ancient mechanism of the world.
Suddenly the cover of the daily cellar disappear and the panorama of the Universe  unfolds before your eyes.
You feel the heavenly scent of Queen of Night flowers, you hear in your ears the distant barking of dogs , but your look has already

took you over there. At the same time you here  and beyond .

But  the  mobility of  binoculars is followed by their largest, maybe the only, disadvantage: shaking images induced by the weakness of our body.

By 2007 or 2008, I found on the site of  ''Sky&Telescope'' magazine an article which presents the solution found by  Alan M. MacRoberts to stabilize the binoculars.

His ''image stabilization device'' is simple and inexpensive, is made of wood and some screws and by using hand tools within everyone's reach.

You find the entire article at the link below :

http://www.skyandtelescope.com/astronomy-equipment/image-stabilize-your-binoculars/

I become interested and started thinking about the little project of building such a device.

The first amateur convinced by this  idea was my friend Csillag Attila from Arad, whose version of a stabilization device is shown below.

MacRoberts image stabilizer with a ''Sakura'' 9x60mm binocular, built by Csillag Attila in Arad

Soon ,Serban ,a student in Deva , built a device that belongs to this category, even if it failed to ensure all degrees of freedom of the  MacRoberts's  image stabilizing device.

Image stabilizer built by Serban ,student in Deva

Dan Vasiliu in Bucharest made a collapsible version of the  MacRoberts device, using components from a discarded tripod . Dan's collapsible version  is very suitable

for  amateur astronomers living in big cities and who have to travel a distance to their

place of observation.

Moreover,''the  shoulder mount for binoculars'' of Dan Vasiliu is part of a kit called

''the  minimum setup for observations''  which includes: binoculars, shoulder mount, a

compass, a star map and a flashlight with red light.

Shoulder mount for binoculars, built by Dan Vasiliu, Bucharest

Dan Vasiliu testing his shoulder mount for binoculars

''Minimum  Setup for Observations'' according to Dan Vasiliu: binoculars, shoulder mount collapsed, compass, star map and flashlight with the red light

A beautiful version of the MacRoberts device was made by Dan  Nicolcioiu aka

ZENDOW. 

The MacRoberts device nicknamed Li-zooka, built by ZENDOW  in Targu-Jiu, wearing his Revue 10x50mm binoculars

Tavi Blagoi aka Erwin is my friend and felow member  on www.astronomy.ro’’ forum and on ''60mmtelescopeclub'' Yahoo group.

Next day I posted this article ,Tavi let me know about his version of a MacRoberts image stabilizer made of Aluminium profiles.The counterweight is a piece of door frame filled with sand.

Tavi's device have shoulder cushions and is a work under development,in the future he intend to add a swivel.

Aluminium image stabilizer built by  Erwin / Tavi in Timisoara

10x50mm binocular on Tavi's Aluminium device ,notice the shoulder cushions

Sand filled counterweight of Tavi's device

Below I present some pictures of my MacRoberts  image stabilizer ,nicknamed Bizooka ,on which I can mount three of my binoculars.

Myself, my MacRoberts image stabilizer holding the 7x50mm Fujinon Mariner binocular

My  10x50mm  Baigish binocular mounted on the device

Details of the Fujinon Mariner 7x50mm binocular  on the ''Bizooka'' device

Overal Imperial dimensions  of the frame of my device are: 1.6’’x 9’’x 42’’.

Sides are made of laminated plywood  12.7 mm / ½ ‘’ thick and the two spacers at the ends are made 30x40mm or 1.2 ‘’ x 1.6’’ solid wood.

Pivot plate of solid wood has dimensions of :30x150x205mm or 1.2’’x 6’’x8’’.

The arm supporting the  binoculars is 3mm/ 0.8’’  thick , made of a sandwich of two layers of 1.5mm /  1/16 ‘’ steel sheet.

The hole for the 1/4 inch screw holding the binoculars to the steel arm at their hinge, is  located at a heigh of 225mm or 9 ‘’ from the bottom of the frame.

The handle of the swive plate is made of 12.7 mm or ½ ‘’ plywood.

Here are the results of the  testing of my ''Bizooka''/MacRoberts  device  on May 13, 2011:

,, Last night until from 23:30 to 1:00 I  tested the functionality of my MacRoberts image stabilizing device.

On average each binocular was used approx. half an hour.I observed in the same order, with each pair of binoculars , star fields of Gemini, Leo,Virgo, Ursa Major, Coma Berenice but also the Moon,Saturn, Lyra , Cygnus and Scorpio, Libra and Serpens  Caput.

Of the  Deep-Sky objects  I observed Mel111 , M13, M92, M57 and Stock1.

The order of using the binoculars was: Fujinon Mariner 7x50mm,  Sakura 9x60mm and  Baighish 10x50mm.

The device performed well with all three binoculars.The Sakura 9x60mm binocular is just the weight limit for objects near the horizon,  probably I have to add a few hefty screws  to the counterweight to compensate for this configuration / situation.

After more than an hour and a half of varied observations  with  binoculars mounted on the device, I returned to normal observation with handheld instruments: horror!

It is as if you swap the first class armchair on a high speed ''Intercity'' train for a ride on the buffers of the same train.

Great surprise, and actually a double one,  came from observing the double stars .

Last year, when I managed to resolve in binoculars the double stars 16 - 17 Dragon and   Nu Dragon , Zeta Lyrae, 61 Cygni or Albireo,I had to sit on a chair, and, excepting the first two mentioned stars of Draco, all the rest of stars had to be near the  meridian.

During this testing of my  MacRoberts device, although Lyra and Cygnus were at 30-50 degrees altitude, all the stars like Zeta Lyrae,61 Cyg or Beta Cyg have been resolved in all binoculars. Wider  stars like Alcor-Mizar, Epsilon Lyrae or Zubenelgenubi in Libra are too easy to be split to be added here. ''

If you access the original article by Alan MacRoberts on the ''SkyandTelescope'' site and you take the time to read the comments, you will find my comment in which I proposed the nick-name of  "bizooka''  for this device.

The equation is:           Binocular+ Bazooka =Bizooka

I 'm sure  after you build such a device, you will join me saying: '' Thank you Alan MacRoberts'' !

                                                  BIZOOKA FOR EVER!

Mircea

Optimizarea telescopului meu newtonian 76mm F/9 -Revamping of my Three Inch F/9 Newtonian Reflector

Telescopul meu reflector tip Newton D=76mm F=700mm,dupa modernizare.
Acesta a fost initial un telescop ''Optus'' comercializat(si de) reteaua Lidl.
Inafara de optica din sticla si suportul din plastic al cautatorului,toate celelalte elemente ale tubului optic sunt confectionate din metal.
Am testat telescopul pe obiecte ceresti .Am vazut ca rezolva Porrima in Virgo  ,Epsilon 1-2 in Lyra si Alula Australis /Xi in Ursa Mare  si mi-a prezentat patru sau cinci benzi pe Jupiter ,Syrtis Major si calota polara a lui Marte.
Acest telescop e un supravietuitor!
My three inch F/9 Newtonian reflector ,after revamping.
This was initially an ''Optus'' telescop sold (also by) Lidl .
Excepting the glass optics and the plastic finder support ,all other components are made of metal.
I have tested the telescope on heavenly bodies and I find out it resolved double stars like Porrima in Virgo ,Epsilon 1-2 in Lyra and Alula Australis /Xi Ursae Majoris and it showed four or five belts on Jupiter ,Syrtis Major and the Polar Cap on Mars.
This telescope is a survivor!

Telescopul a avut ocularul cu axa orizontala.Am rotit portocularul cu 45 grade pentru pozitia recomandata de Herschel.
De fapt am rotit cu 45 de grade axele orizontale care se aseaza in lagarele furcii.
The telescope had the ocular in horizontal direction.I rotated the focuser with 45 degree to to position recommended by Herschel.
Actually I rotated with 45 degree the horizontal trunions sitting in the fork.

In constructia originala , tubul culisant al portocularului intra in fasciculul de lumina al oglinzii principale.
Initially ,the draw tube of the focuser was obstructing the light of the primary mirror.

Am rezolvat aceasta obstructionare suparatoare taind  tubul culisant al portocularului imediat la capatul dinspre oglinda secundara a cremalierei .
I solved this annoying obstruction by cutting the draw tube of the focuser right at the end of the rack next to the secondary mirror.

Detaliu al trepiedului din lemn ,de constructie proprie.Bratele de rigidizare sunt tot din lemn si sunt prinse in suruburi normale , suruburi cu carlig iar capul unui surub cu ochi joaca rolul de inel de asamblare.
Detail of the DIY wooden tripod.The spreader arms are made of wood and assambled through normal screws , hook-screws while the head of an eyelet-screw is holding all together.

Bucsa de nailon care forma ajustaj cu axa verticala a furcii nu mai exista.Am confectionat la un atelier de strungarie aceasta bucsa metalica ce formeaza ajustaj cu joc mic cu axul furcii.In acelasi timp ,prin diametrul sau ,bucsa va permite folosirea pe acelasi trepied a unui alt reflector mic si a unui lunete super RFT de 60mm F/4.
The nylon bushing fitting the vertical shaft of the fork there is no more.A machining shop made this steel bushing matching the fork shaft.When deciding the diameter of the bushing, I had the choice to make the tripod available to be used by another small reflector and of a 60mm F/4 super RFT refractor.

Trepiedul de constructie proprie nu mai este colapsabil decat pe directie radiala dar pe aceasta directie se poate inchide complet.

The DIY wooden tripod is  only radially collapsible but by this direction it can be fully closed.

Portocularul ,desi de dimensiuni normale , a fost prevazut de catre proiectant cu o bucsa care permitea folosirea ocularelor de 24,5 mm.Acea bucsa a fost inlocuita cu o bucsa de aluminiu care permite folosirea ocularelor pe standard de 1.25''.
Ocularul din imagine este un ocular militar de tip Kellner cu focala de 40mm ,primit de la prietenul meu Silviu aka ''zoth''.La o marire de 17,5x ,ocularul cuprinde intreg roiul deschis al Pleiadelor M45 iar imaginea stelelor este foarte frumoasa ,punctiforma peste intregul camp vizual de doua grade.
Even if the focuser is of normal size ,it was provided by design with a cap allowing the use of 0.965'' oculars.
The original cap was replaced  with an Aluminium cap allowing the use of 1.25'' oculars.
The ocular in this picture is a 40mm Kellnerian provided by my friend Silviu aka ''zoth''.At a magnification of 17.5 x ,it embrace the full open cluster of M45 or Pleiades ,while the images of the stars are pin pointed all across two degree  visual field.