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Focusing help please


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Hi, thank goodness lunchtime is here I've been chewing this over all morning in my head and still don't know what I'm doing wrong.

I've had my scope a couple of weeks and so far and have been familiarising myself with the scope using only the moon. I've had some great views and managed to magnify and focus in on individual craters - everything seemed so easy and then.....

Last night, first clear skies for about a week so I thought I'd have a blast at a cople of Messier (103 and 36) and Nebula (Horsehead). I selected the required objects from the Nexremote and the scope slewed round and pointed to the suggested area in the sky but when I looked through the EP I saw nothing. Right I thought, remove x2 Barlow and use the 32mm Celstron EP. Could see the night sky through the EP but that was about it. Tried with higher magnification EP and went through the full range of focus and could still see nothing. What am I doing wrong :p

Initially I started with my x2 Barlow and a 15mm EP which did not work so I went right back, removed the x2 Barlow and inserted a low mag (32mm) EP. With the 32mm EP I cannot see the actual object I am searching for and when I then increase mag by inserting my 9mm EP I cannot get the scope to focus on anything despite going through the full range of the focuser.

A lot a help required please for thius newbie as I'm sure you'll all appreciate how frustrated I was at about 0030hrs this morning stood outside with my red head torch bobbing about and muttering obscenities quielty so as not to awaken the neigbours :(

When I select an object and the scope slews round am I right to use the 32mm EP to try and centre the object prior to increasing the mag with a lower mm EP? Is there a trick to focusing because I think I must of gone through the full focus range several times last night and in the end could not remember how many turns I'd done and completely lost my sanity :D

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my guess is that there is something wrong with your alignment routine and that you are not hitting the target also I am not sure you would be able to pick out the horsehead nebula except from a dark site its very small and faint, but its unlikely to be focussing thats the problem. It maybe dew on your corrector plate do you have a dewshield on it?

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As Rowan46 has said, you will not be able to see the Horsehead nebula s it is very dim indeed and only really responds well to imaging unless you have a huge aperture telescope and exceptional skies.

You should always start off with a wide field (long focal length, high mm number) and centre it in the eyepiece. When you have located your quarry choose a shorter focal length eyepiece (if necessary) to view the chosen object correctly.

Just to check that all is well with your telescope (and I am sure it is as you have been viewing the Moon OK), try a less challenging object. Slew to a bright star like Betelgeuse or Rigel in Orion, get the star centred in your eyepiece and get the best focus that you can. Now slew to M42 which is still well placed in the south earlier in the evening. You know you have the focus nailed so you should be able to locate M42 easily as it is bright.

If Betelgeuse or Rigel do not appear in your eyepiece then I would suggest that you carefully check that you are setting up and aligning your system correctly.

Good luck tonight!

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Rowan & Steppenwolf

Thanks very much for the advice, I'll try focusing on Rigel and then slewing to M42 tonight.

I currently don't have a dewshield fitted but don't think I'm getting condensation because I've been checking. Also put scope out minimum 1.5hrs before using so it has chance to reach atmospheric temperature. Maybe a trip to Milletts is required just in case, get myself a camping mat.

Trust me to choose a nebula that is you need a dark site to view :D suppose it's all a good learning curve for us newbies.

Thanks again guys, much appreciated. I'll let you know how I get on.

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Thanks Bunnygod, I've got Stellarium downloaded and keeping seeing references to "Turn Left at Orion" so that will be purchased this weekend.

Roll on tonight :D I'm going to keep things simple, check my alignment and setup and not get too ambitious. Hopefully that'll get me back on track!

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