τι ειναι τουτο κομη?

[nio22]

εχθες εβαλα στο bresser skylux σταυρονημα (spikes)και μου εβγαλε κατι σαν κομη (δειτε στην φωτο)

δεν ξερω τι μπορει να φταει.

παντως δεν το βλεπω μονο με την χρηση φωτο το βλεπω και απο το προσοφθαλμιο!!!help

[OPTOPHILE]

OUT OF COLLIMATION......

[nio22]

και τι πρεπει να κανω?

[Bi2L]

Ευθυγραμμιση.... και δεν εισαι ο μονος...

[OPTOPHILE]

COLLIMATION

[nio22]

ναι το καταλαβα! αλλα σε διοπτρικο πως γινεται? να βγαλω τους φακους απο

μπροστα και μετα να τους ξαναβαλω να βγαλω τον εστιαστη και να τον ξαβαλω παλι το ιδιο θα εναι αφου ολα ειναι φιχ.δεν ξερω!!!

[babgia]

Για το συγκεκριμένο δεν γνωρίζω, αλλά τα Bresser που έχω αν αφαιρέσεις το κάλημα δρόσου φαίνοντε τρεία ζευγάρια βίδες για ευθυγράμιση του φακού (πρωτεύοντος) η μία είναι για την ρύθμιση & η άλλη ασφαλίζει την θέση του φακού.

[geonik]

Το αστερι που φαίνεται στην φωτογραφία είναι απο το κέντρο του πεδίου ?

Αν όχι πρέπει να βγάλεις μια φωτογραφία με ένα αστέρι στο κέντρο του πεδίου...

[babgia]

Δεύτερο μήνυμα το ίδιο.

[nio22]

ειναι στο κεντρο του πεδιου στο crop τα εκανα λιγο μουτι

παντως μου το κανει σε ολο το πεδιο!!

[roryt]

Στα διοπτρικα η ευθυγραμμιση εχει να κανει με το αν το οπτικο καναλι ειναι ευθυγραμισμενο με το κεντρο του φακου. Συνήθως οφειλεται στον εστιαστη και τοτε ειναι σχετικά ευκολο να διορθωθει. Υπαρχει μια διαδικασια (ευκολοτερη απο αυτην του κατοπτρικου) οπου προσπαθεις να ευθυγραμισεις το εστιαστή με το φακο , δες ας πούμε εδω ή εδώ ή εδώ αν και μπορεις να βρεις πολλές αναφορες στο Ιντερνετ

[OPTOPHILE]

First remove the focuser and housing. The draw tube will be loose and adjusting the allen screws only adjust the tube down and alignment could be worse. Get that caliper again and measure the hole to the scope tube. Is it round? Is the draw tube centered? If not there are two ramps cast in the holder with pads on them. You can build up the pads or what I did was to slightly bend the casting blocks where the pads are glued. A screw driver with a little pressure in the hollow opening will make them a few thousands taller then use the top Allen screw to adjust the remaining play. Add a touch of lithium or molly grease to the pads and upper tension block where the Allen screws are put back together.

 

Now the tricky part. Remove the lens cell and measure the end of tube to see if it is square. Mark the high spot with felt pen. Got to love those felt pens LOL. Now mark the outer lens with a dot and the cell. Remove the ring and remove the outer glass lens. Mark the second lens and cell.

 

Measure the seat where the lens sets is it square. Without going in detail use tiny slivers of black carbon paper or wax paper to get everything square and adjust according to where you put your marks on tube and cell. This might take a few tries to get it dead on but the results are worth it because a lens assembly that is off just a tad will produce poor performance at high powers where at low powers you won"t even notice it.

 

Now another problem with Synta refractors (China made) is some are suffering from astigmatism. Not much can be done because it is in the figure of the glass. My unit had a problem with astigmatism at high powers on stars, however I noticed most planets were great. Here is how to check this problem. Using high power within the scopes ability, say 200x 4" 250x 4.5" 300x 5" etc. focus on a bright star. Not too bright but bright and look for a elongation of image just before or after focus. If it stretches then jumps to a pinpoint you have astigmatism.

 

My scope had it on one side of focus only. Did I fix it? Well did I HaHa. Yes I got rid of 90% of it. How you say. Take your outer lens ring off and remove the lens leave the second negative lens in place and mark it. Turn the outer lens 180-degrees and put it back. Start star testing. Is it worse or better? Move lens 2-4 degrees with

suction cup only. Loosen ring so you can turn and leave out rubber ring or gasket. Now lightly snug ring each time to hold glass firm. Star test better or worse? Keep doing this small rotation on the outer lens and if you are lucky you will find the flaw is a combination of both lenses as in my case.

 

When you got the best you can get hold the lens down while you tighten the ring with the gasket or rubber ring. In my case down. You are done This might not fix the problem depending on the nature of the aberration Astigmatism For me it helped allot not perfect but much better..

 

This can be done in house during the day with a bright sun. Get a small shiny ball bearing and mount it on a stick with super glue. Set it up about 60-100 feet outside in the sun from in the house with an open window or door. You can do some very accurate star testing. Actually I prefer to use this over a real star test because the seeing is perfect on a nice day at 100 feet. Also it helps to use a dark green filter to make all adjustments as the filter kills the flare and hollows which make precise dialing in a task. My 120 skywatcher is pretty darn good for a achromat and a light yellow filter say #8 or #12 depending on how much color you have works fine and if you got some bucks get a chromacor or mv1 or other corrector. I heard they work very good but kinda pricey.

 

 

If after the collimation with a cheshire and laser you have the same image, then the "coma" picture is sign of objective de-centering. So you have to send the scope to the factory for repair.

 

 

NEVER TOUCH THE OBJECTIVE ELEMENTS ALONE THE ELEMENTS HAVE SPECIFIC DISTANCE BETWEEN THEM AND SPECIFIC ROTATION!! !!!!!!!!!!!!

 

 

!!![