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Stu1smartcookie

At last , a clear night ! But , am I happy ?

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So , I’ve had my new scope 2 weeks and tonight the skies have cleared ... there is a bit of chill in the air and I’ve had my first experience of dew on my scope , but , I set out , in my fairly light polluted garden to try and see some deep sky stuff . I tried to find many Messier objects but I had no luck . I’ve got a 250 flex tube dob by the way . Even using an app on the phone and pointing the scope in the direction I still was disappointed. I couldn’t even get a glimpse of Andromeda as it’s hiding behind the house. Ok , I did find a few double stars which was great but not much else that I could recognise . So , what am I doing wrong here ? I think the finderscope isn’t the best so I’ve purchased a telrad .. I will hopefully use it for the first time tomorrow. My saving grace was Mars which actually is showing a bit of detail. What mag EP should I use for scanning a patch of sky ? .. I’ve mainly been using a 20mm plossl . I may even be seeing stuff without realising . Sorry for the naivety of this post , but I am a bit frustrated. Especially as I have a decent scope . I suppose going to a dark site is going to help a lot .. any advice on any of the above would be most welcome . 

Thanks in advance , 

stu 

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Have you got a pair of binoculars ? M31 should be easy to find then note the stars to hop to it and copy with your scope, should at least see the fuzzy patch of the core from a light polluted site.

Dave

Edited by Davey-T

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M13 is a great place to start. Easy to find on the Keystone of Hercules.

M57 is another to give a go, small though so add some power once you think you are in the right place.

Is the 20mm Plossl your lowest power, widest field eyepiece? It gives quite a narrow field of view, 0.83 degrees so you need an accurately aligned finder to centre objects easily.

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It is possible that you were looking at the objects, but just didn't recognize them. Remember that DSO's will always be grey fuzzy 'clouds' nothing spectacular like you see in magazines. But once you find it, it is easy to locate it again.

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I would agree with Stu that the fov your scope is giving is part of the problem. It will take time to get used to "nudging" your dob from something you know to something you are trying to find. Just how much nudging moves one fov and how far is that in relation to the distance you need to move?

Keep at it ... it will come with a little experience and once you have acquired this skill you will be able to find anything.

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Just to illustrate that point,  if you had, say, a 2” 30mm 82 degree afov eyepiece, this is the field of view you would get. Position the two stars Sulafat and Sheliak at either extreme of the fov and you can’t miss M57.

Even with your 20mm eyepiece, if you position Sheliak in the right place, M57 will appear at the far edge.

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Was clear here too - though first time back in the dome since before summer and my kit knew that. Scope needed balancing, re collimating, loosening the mirror mount as optics were pinched after last removal, spiders removing from OTA, etc.

All done, then CCD frosted over as dessicant is expired. :Sighs:

At least I managed to train the PEC on the mount...

😕

 

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Well , firstly , many thanks to all of you for the advice .. I’m going to invest in a couple of EP’s to give a wider fov . Last night I had brilliant clear skies and I saw m13 ... but not in the dob as I was using my trusty SW 102 star travel ( I still love this scope) . Of course the view was a bit fuzzy , but I was elated . Don’t tell the wife , but I’ve just bought a Williams optic z73  as I want to get into astrophography ( she does know now ... and I’m still in one piece , but it’s going to cost me a holiday somewhere lol ) I did a lot of research on small refractors before I took the plunge and I think I’ve chosen well ... especially as I will use this scope for terrestrial viewing too and it’s ultra portable .  

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The range of small WO fracs are very nice for imaging. Did you get the flattener as well ... that will make a world of difference. And don't forget your copy of this. Your journey to the dark side begins ...

 

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I'd recommend a 36 or 42mm eyepiece for 2 or more degrees of field to make hopping and locating easier.  (The contrast is poorer at such low mag, but you can still get to the right region from the star patterns.)  Don't forget to allow for the fact that everything is rotated through 180 degrees compared to charts, so turn the chart upside down.  If you use a planetarium (like Stellarium), you can invert the view over both axes to give the same view as through the EP.

Doug.

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I have a 200p dob and M13 and M57 are nice to view

Have you aligned the finderscope to be spot on?

A telrad will help MASSIVELY as it did with me, I use the telrad to position the scope roughly in the right location which takes a few seconds and then use the finderscope and match what I'm seeing against a star map\atlas and then slowly star hop using the brighter stars to where I want to be, took me a complete viewing sessions (my first, I'm new to all this as well haha) to get into the hang of things

You may not need EPs to give a wider FOV as I would consider the 9x50 Right-Angled finderscope which makes things a lot more bearable on he back and neck ! https://www.firstlightoptics.com/finders/skywatcher-9x50-right-angled-erecting-finderscope.html 

M13 you can see in the finder as a very small fuzzy blob, I usually start with a 25mm EP to center an object then put in my 15mm and then 8mm EP so zooming in on the object each time till I get the right FOV and then observe

Here is my first astro image and its of M13 which I took the other night through my mobile phone, it looks far better through the scope

Clear skies and good luck 

DSC_0041.JPG

Edited by PaulM
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Tried to run my all sky camera on the first clear night for some time only to get an entirely white image, so I have a fault.  Typical that - nice clear sky and thousands of stars visible to the naked eye plus no moon and my camera fails!!! :BangHead:

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1 hour ago, PaulM said:

I have a 200p dob and M13 and M57 are nice to view

Have you aligned the finderscope to be spot on?

A telrad will help MASSIVELY as it did with me, I use the telrad to position the scope roughly in the right location which takes a few seconds and then use the finderscope and match what I'm seeing against a star map\atlas and then slowly star hop using the brighter stars to where I want to be, took me a complete viewing sessions (my first, I'm new to all this as well haha) to get into the hang of things

You may not need EPs to give a wider FOV as I would consider the 9x50 Right-Angled finderscope which makes things a lot more bearable on he back and neck ! https://www.firstlightoptics.com/finders/skywatcher-9x50-right-angled-erecting-finderscope.html 

M13 you can see in the finder as a very small fuzzy blob, I usually start with a 25mm EP to center an object then put in my 15mm and then 8mm EP so zooming in on the object each time till I get the right FOV and then observe

Here is my first astro image and its of M13 which I took the other night through my mobile phone, it looks far better through the scope

Clear skies and good luck 

DSC_0041.JPG

Brilliant , Paul ...thanks for the advice . 

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3 minutes ago, Gina said:

nice clear sky and thousands of stars visible to the naked eye plus no moon and my camera fails!!!

So everything working within expected parameters then ...

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4 hours ago, Demonperformer said:

The range of small WO fracs are very nice for imaging. Did you get the flattener as well ... that will make a world of difference. And don't forget your copy of this. Your journey to the dark side begins ...

 

Hi , I am picking up the flattener today , hopefully ... its certainly something that i think i will need  :)

 

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2 minutes ago, Demonperformer said:

So everything working within expected parameters then ...

Precisely!!!!

Edited by Gina

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Nice clear night, no wind so thought I'd try a bit of imaging for the first time in a while.

Started everything up, found target, calibrated PHD, remembered to turn on the camera cooler :icon_rolleyes: selected the right directory to save images so have I thought of everything ?

Set it off imaging and went in for a cuppa, came out an hour later to check progress and I hadn't started autosave in Artemis Capture :BangHead:

Also forgot to turn off the RDF.

Dave

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I use a Rigel finder and a 9x50 RACI finder on my Dob.  The RACI is good for checking and tracking (esp. at high mags) on account of the large field of view, but of course it is poorer on faint objects (dim stars, fuzzies) and in terms of contrast.

The Rigel is smaller and lighter than a Telrad, and sits nice and high, making it easy to use.

Doug.

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I agree Doug, a unity gain Finder like a Telrad or Rigel, plus a RACI of some sort, ideally 9x50 work as a really good two stage system for finding. Get in the ballpark with the Rigel then you should either be able to see the object, or pin down the star field in the RACI.

For info, the charts I posted are inverted ie dob view. I find SkySafari so useful for setting the fov and limiting magnitude star visibility, that makes it very easy to match the star patterns and hop successfully from a bright star to a target.

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