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Old 19-09-2020, 12:54 AM
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hubble2140 is offline
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Posts: 40
mirror circles and cleaning my scope :)

hi everyone! i have the esprit 120 from sky watcher and i have 2 question!

1) Some glue (i guess...) has dried on my telescope and I want to clean it. the problem is that the glue is very close to the dew shield (and very close to the mirror...). i used wet wipe (with soap and water), and tried to clean all the glue! but i have a question. is the wet wipe with the soap and the water can enter through the dew shield into the mirror and harm the optics there? like you see in the image (the image that shows the telescope itself and not the mirror), the dirt is very close to the dew shield and also to the mirror, so i clean this area with a wet wipe, and also enter the edge of the wet wipe under the dew shied, because its very thin and maybe clean better the dirt... (i also tried to detach the shield but i didnt succeed...)

2) the attached images show some circles on my mirror at the edge of the mirror. what are these circles??? :undecided: :undecided:

thank you very very much!!!!!
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Old 19-09-2020, 12:07 PM
Saturnine (Jeff)
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Location: Wollongong
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Ummm, that is an Refractor Apo objective lens not a mirror belonging to a reflector telescope. From the images you've posted the redish coloured circles ( dots ) seem to be in different positions in each photo. Maybe they are some sort of reflection but as the circles are all in a consistent pattern of 3 it would seem that they are something induced by the lens cell design and show up as the lens is angled differently to the camera.
I don't have that particular brand and size telescope so hopefully someone who does can offer more enlightenment as to the nature of the reflections. The red colour is probably caused by the anti reflection coatings on the lens.
When you actually look through the scope or image with it , does anything show up on the images or actually appear in the field of view.
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Old 19-09-2020, 01:11 PM
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The red circles are plugs covering the collimation screws. Do not touch them. Meant to be there.

Clean the grease streak carefully with a wet wipe. This was likely caused by extending the dew shield with the securing screw either not released or left too tight during extension.
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Old 19-09-2020, 05:50 PM
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hubble2140 is offline
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Saturnine - thank you very much! well, i dont see any particular issue in the image...

LewisM - ohh! that is a weird place to put them but i think they are behind the lens, so i cant touch them... sometimes i clean my lens and im covering all the lens, so sometimes i clean these area too! (the area of the circles)
and about the cleaning, yeah, i clean really carefully , and i believe that the telescope is ok! thank you very very much!!!!!!!!!
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