Focusing on Celestron NexStar 6SE

[bgd]

Hi everyone! 

I'm pretty new to this hobby and I'd like to ask the experts before I freak out. So I just got this scope as a Christmas gift and I really love it, but I'm a bit concerned of having a mechanical issue. I'm having a really hard time bringing an object into focus regardless if it's a tree or the moon. I get to the point where it's almost clear but still blurry enough to make it unpleasant to watch  . As much as I try to rotate the focusing knob as slow as possible I can't get a perfect focus. So far I have only the stock eyepiece (24mm) and diagonal and I know that it's not the best glass but I wasn't expecting such a bad experience... What should I check? Is there any "calibration" type of a thing that I have to do and I'm not aware of?   Any idea is much appreciated!

Thank you!!!

[baggywrinkle]

I had the 6SE and I did find that its a lot of turns to get focus. I now have thje 9.25SCT and it is the same when first setting up, or when changing to a DSLR.

If you do a daylight check then you need an object at a good distance away otherwise too close and it is difficult to focus. The supplied ep I found to be OK.

The Moon should not be a problem. Are you getting dewed up? SCT are known as dew magnets...I bought both a dew sheild and heater strap for mine.

The 6E is normally a very good performer.

[wheresthetorch?]

Hi bgd.

As you say 'unpleasant to watch' this suggests the image might be moving around as though you are looking at it underwater? If so, are you using the scope indoors and looking through a window? If so, thermal currents will make the image move around and drift in and out of focus.

If you get the moon in view while outside you should be able to reach crisp focus while slowly turning the focuser, but you may have to turn it a lot.

And as already stated, check the objective lens and your eyepiece for dew.

Let us know how you get on.

[Vox45]

You may have dew on the corrector plate (the glass on top of the scope) you should be able to see the mirror at the bottom of the scope through that glass

A dew shield is a must (you can make one or buy one) and you may want to let your scope cool down by putting it outside 1 hour before observing

[Grotemobile]

I have got a CPC 800 & this is a must.

http://www.firstlightoptics.com/dew-prevention/astrozap-flexi-heat-dew-shields.html

http://www.firstlightoptics.com/astronomy-cables-leads-accessories/hitecastro-single-channel-dual-port-dew-controller.html

Something I would not be with out.

Steve

[bgd]

First of all I would like to say tank you all! I didn't expect so much help! 

I had the 6SE and I did find that its a lot of turns to get focus. I now have thje 9.25SCT and it is the same when first setting up, or when changing to a DSLR.

If you do a daylight check then you need an object at a good distance away otherwise too close and it is difficult to focus. The supplied ep I found to be OK.

The Moon should not be a problem. Are you getting dewed up? SCT are known as dew magnets...I bought both a dew sheild and heater strap for mine.

The 6E is normally a very good performer.

I'm not complaining / worrying about the number of turns to get an object in focus, the issue is getting the object in perfect focus.

Hi bgd.

As you say 'unpleasant to watch' this suggests the image might be moving around as though you are looking at it underwater? If so, are you using the scope indoors and looking through a window? If so, thermal currents will make the image move around and drift in and out of focus.

If you get the moon in view while outside you should be able to reach crisp focus while slowly turning the focuser, but you may have to turn it a lot.

And as already stated, check the objective lens and your eyepiece for dew.

Let us know how you get on.

 As wheresthetorch? is saying above, and I believe he knows exactly what I'm talking about, the problem might be because of the thermal currents because yes I was indoors, the windows was open but right under it I have a super hot radiator.

You may have dew on the corrector plate (the glass on top of the scope) you should be able to see the mirror at the bottom of the scope through that glass

A dew shield is a must (you can make one or buy one) and you may want to let your scope cool down by putting it outside 1 hour before observing

I'm going to take it outside, wait long enough to adjust the temperature and I'll get back with an update.

I have got a CPC 800 & this is a must.

http://www.firstlightoptics.com/dew-prevention/astrozap-flexi-heat-dew-shields.html

http://www.firstlightoptics.com/astronomy-cables-leads-accessories/hitecastro-single-channel-dual-port-dew-controller.html

Something I would not be with out.

Steve

That's pretty interesting, I didn't even know that something like that exists! Thank you!

Unfortunately I didn't record anything to show you what it looks like but I fond to videos on youtube:

This is the first video https://www.youtube.com/watch?v=6uKf5lJvKVQ and that's what I was expecting to see but what I really get it's something like this: https://www.youtube.com/watch?v=2kA48frrxgA , notice how the image is not clear and how blurry it gets once it gets closer to the edges?

I'm going to jump off topic just a bit: In the idea of backing up my first steps into astronomy and having something to play with while I learn, I was thinking to get Baader Planetarium Hyperion 8-24mm Click Stop Zoom - Mark III and after that I'll probably get Celestron X-Cel LX 3x Barlow Lens or the 2x one, so I believe that this setup will cover enough situations and will last me a while. Any thoughts? 

[Peter Drew]

Yes, my thoughts are forget the 3X Barlow this would give far too high a magnification with the zoom eyepiece. The 2X Barlow would still push the telescope to the limit. 

[YKSE]

About the zoom, I agree with Peter, a barlow will be just be waste of money in your scope,  unless you're planing to 6.3x focal reducer, then a barlow makes better sense.

As to focus issue, I'd suggest that you put the scope away from radiator when doing daytime test. The focus travel in SCT is very long, you need to rack ii all the way slowly in one direction, if good focus is achieved, then backwards towards the other direction. Aslo, focus position for daytime targets (much more closer than infinity) can be very far from position for sky objects.

[bgd]

Yes, my thoughts are forget the 3X Barlow this would give far too high a magnification with the zoom eyepiece. The 2X Barlow would still push the telescope to the limit. 

About the zoom, I agree with Peter, a barlow will be just be waste of money in your scope,  unless you're planing to 6.3x focal reducer, then a barlow makes better sense.

As to focus issue, I'd suggest that you put the scope away from radiator when doing daytime test. The focus travel in SCT is very long, you need to rack ii all the way slowly in one direction, if good focus is achieved, then backwards towards the other direction. Aslo, focus position for daytime targets (much more closer than infinity) can be very far from position for sky objects.

Should I get the 2x instead or 3x + Celestron f/6.3 Reducer Corrector? Which of the following would be a better choice?

zoom eyepiece 8-24 + 2x barlow 

zoom eyepiece 8-24 + 3x barlow + Celestron f/6.3 Reducer Corrector ---> not sure it it's true but would this combination give me more light and acceptable magnification but lower image quality while the previous combination higher image quality but not so much light?

Related to the focus, I just created an image in Photoshop which would be similar (probably the edges are not that blurry) to what I'm experiencing. So I'm going to repeat myself that I'm not having trouble finding the object, I'm having issues getting the object in perfect crisp focus.

On the left is what I see while on the right is what actually it should be but I will give it a try tonight (if it's not cloudy) outdoor as wheresthetorch? suggested

[wheresthetorch?]

Hi bgd. Yes, the radiator will definitely be causing you problems. I confidently predict much better views when you get outside (and freeze like the rest of us!!).

[baggywrinkle]

2x barlow as a max, the 8-24 Baader lens is quite good, its feiled of view is dependant on the setting. I have one and use it a lot on all three of my scopes.

 Not so good for afocal imaging.

A good thing about a zoom is it tells you what the max mag you can get given the seeing conditions that evening, then you can swop over to a higher quality lens if you have one. It also means less kit to carry.

[bomberbaz]

hi there, I am not acquainted with the viewing conditions of where you are in NY but I would seek local advice before you go shelling out on a barlow. The zoom at 8mm gives you x188 so should be more than enough for now, just hang back until you get a feel or local advice would be my approach.

[YKSE]

Should I get the 2x instead or 3x + Celestron f/6.3 Reducer Corrector? Which of the following would be a better choice?

zoom eyepiece 8-24 + 2x barlow 

zoom eyepiece 8-24 + 3x barlow + Celestron f/6.3 Reducer Corrector ---> not sure it it's true but would this combination give me more light and acceptable magnification but lower image quality while the previous combination higher image quality but not so much light?

I'm not quite sure of your combinations, I'd say either

1. Zoom eyepeice 8-24 only.

or

2. zoom eyepiece 8-24 + Celestron F/6.3 Reducer + 2x barlow

The 3x barlow is a no-no to me.

[bgd]

Hi bgd. Yes, the radiator will definitely be causing you problems. I confidently predict much better views when you get outside (and freeze like the rest of us!!).

I'll give it a try tonight!

2x barlow as a max, the 8-24 Baader lens is quite good, its feiled of view is dependant on the setting. I have one and use it a lot on all three of my scopes.

 Not so good for afocal imaging.

A good thing about a zoom is it tells you what the max mag you can get given the seeing conditions that evening, then you can swop over to a higher quality lens if you have one. It also means less kit to carry.

I'll pass by B&H today and get the 2x 

Thank you for your recommendation!

hi there, I am not acquainted with the viewing conditions of where you are in NY but I would seek local advice before you go shelling out on a barlow. The zoom at 8mm gives you x188 so should be more than enough for now, just hang back until you get a feel or local advice would be my approach.

Viewing conditions in NYC just stinks... so much light pollution I'll get the Celestron X-Cel 2x which is not that expensive and I'll give it a try tonight with my stock 25mm

I'm not quite sure of your combinations, I'd say either

1. Zoom eyepeice 8-24 only.

or

2. zoom eyepiece 8-24 + Celestron F/6.3 Reducer + 2x barlow

The 3x barlow is a no-no to me.

I'll start my collection with the second setup and after I learn more, I'll get some other glasses. 

Thank you everyone for your help! I'll probably go out tonight and freeze a bit in the meantime Happy New Year! 

[bgd]

As I said, I'm coming back with the results [emoji3] Yay! I'm so happy! [emoji106] Just took a picture with my phone.

See below:

[wheresthetorch?]

Great news!!!

[nightfisher]

Nothing wrong with that image at all, glad you are getting better results

[bgd]

Great news!!!

[YKSE]

Glad that you get the focus issue sorted out.

The Baader zoom will cover most of your working range. With the f/6.3 reducer, you might need to add a 30/32 mm plossl to give you max field of view and bigger exit pupil(~5mm), for viewing extended objects.

[tich]

I love my C6 & I've just recently brought a Nexstar mount for it so I can used it to observe while I'm imaging at the dark site or when I'm at star parties. I still need to get a dew heater for it at some point as they do attract dew even when a shield is fitted when the seeing conditions are poor.