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JohnnyNewBoy

Question about image seen

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Hi everyone I am new to this community also to everything about space and telescopes , recently I bought a Bresser 60/700 , few minutes ago I watched some star I guess at W 270* don't know the angle...I used a H12.5mm also a H20mm I want you guys to tell me how do I know when I focus to much ? For example lets say the focus wheel its fully retracted I see the start small like some human cell when I begin to turn the wheel to focus more after 5-6 cm the star begin to be very small and bright after that when I continue to turn the wheel to fully extended focus the star begin to be bigger so big that I can only see that star in full view, the edges of star are sharp not blurry...What exactly should I see when I look at a very bright star on the sky ?

Thanks and sorry if I did not express my self very well, my english isn't my native language and i'm not familiar with telescopes terminology.

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Yes. All stars, no matter how bright or how large, are points. So as HK says, when at its smallest you are focussed. 

A great technique to assure perfect focus is to adjust the focuser until you think you’re perfect then keep going just a little more, go past focus the other way so to speak. Then go back the way you came.

Because your star image gets larger when you go past focus in either direction this helps to confirm you’re all tickety boo by helping you judge where the ‘middle’ is. 

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I should also add that once you’re focused on your star of choice, everything else is then in focus - stars, galaxies, the moon, planets etc. 

Everything, from the moon, to the farthest deep sky objects are essentially at ‘infinity’ as far as optical systems are concerned and therefore effectively at equal focus distance. 

This also means that your focus point with any given eyepiece is always at approximately the same position.

This will vary from eyepiece to eyepiece though unless your eyepieces are parfocal which means they’ll all focus at the same position.

Minor adjustments are only needed to compensate for slippage/slop in the focuser mechanism and ‘breathing’ due to temperature fluctuations. 

Edited by johnfosteruk
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Yeah I remember there was point when the start was super small and very bright i could bearly see it and after I pass that stage the star begin to be very large but not blurry...maybe I need some other eye scopes from what i'v read lens with H on them are poor..Thanks.

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15 minutes ago, JohnnyNewBoy said:

I remember there was point when the start was super small and very bright

This is when the star is in focus

15 minutes ago, JohnnyNewBoy said:

after I pass that stage the star begin to be very large but not blurry

At this point you are not seeing the star, but are using the star light to view the inside of your telescope. 

There is not a lot to gain by viewing a single star, you want to be looking for doubles and clusters of stars. 

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2 hours ago, Ricochet said:

you want to be looking for doubles and clusters of stars. 

And nebulae, and galaxies, and planets etc ?

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An in focus star just looks like a point of light - very much as though you are viewing it without a telescope.  If it evolves into a solid fairly focussed miniature disc, or a disc with a a circle around it - then it is no longer a start and you have found a planet - try to the two brightest objects above the horizon in the south and round towards the SW just after it starts to get dark (assuming you are in the Northern hemisphere - the left one might be Mars and the right one might be Saturn ? find

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On 04/10/2018 at 14:42, JohnnyNewBoy said:

This is my day two since I got the telescope and I'v learn so much, thanks to you guys...Clear sky to all.

When you have a bright star focused to a tight, tiny point all the smaller stars will be easier to see Try pointing the scope in the direction of the constellations Perseus, Cassiopiea or Cygnus, they are in the Milky Way and you should be able to find patches that are relatively rich in tiny stars. If you can find an 'open cluster' you will be truly impressed. Also try spotting Saturn or Mars just above the Horizon in eth south.

The free program Stellarium will help you find you way around (there's a phone app version as well).

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