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New Member, new kit, some thoughts, but no idea!


Guest MikePMC
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Guest MikePMC

Hi everyone, I just thought I'd introduce myself as a new member and try and get some help if possible. I found this site on a link from one of the optics shops on the net whilst trying to figure out what I need to buy in addition to what I already have but I'm a little confused to be honest!

Originally, I bought a £5 "national geographic" telescope for my daughter as a stocking filler at Christmas. She spent so much time using it and reading about stars and planets, I decided to invest in something worthwhile. It's probably best I list what we have, some of the concerns I have and then what we'd like to do with the kit.

What we have.

I bought some secondhand kit on ebay from someone that was upgrading. It consists of:-

Celestron NexStar 130SLT with motorised GOTO tripod

Achro 2 x Barlow lens

Celestron 25mm lens

Celestron 9mm lens

Celestron T adapter 1.25"

Revelation 42mm Camera adapter for Canon (has a screw in piece that fits into T-adapter).

My concerns.

Everything seems to be woring well, the motor and the GOTO I got to work but had trouble getting it to align at first and when I did get it to align, it often went off alighment within minutes. Is this normal or just me?

We got to see Jupiter as well as it's moons earlier in the year and it was quite a moment. Using the 2 x barlow and the 9mm lens gave best results for magnification but I felt it was a little bit blurry. I've since read it might be the quality of the 9mm lens and also read about collimation and wonder if this is correct as the telescope has been transported a lot. Not sure how to check it never mind rectify if it is wrong.

What we'd like to do.

Well, she really just wants to look at the stars, planets, moon etc. She has just turned 9 so her concentration time is limited but Jupiter, Saturn, the moon etc seem to take her interest most. Is there much point in increasing the magnification or is the 25mm and 9mm acceptable with the barlow lens? She is doing a project in school about space so some photos would be good. We have a Nikon D40 DSLR but obviously the Canon adapter is useless but not sure what I need to buy to get it to fit. Is it just the Nikon ring adapter? Will this screw onto the T adapter or the screw in part that seems to be part of the 42mm Revelation camera adapter? Is there a need for a focusing adapter or similar? I have no idea here despite having a good read.

I've attached a picture of the camera adapter, the "screw in" piece and the T-adapter so you know what I'm babbling on about.

The tripod seems a little shaky sometimes as well, is this normal or do I need to tighten anything up or adjust it?

If anyone can offer any help.

Many thanks,

Mike

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Firstly welcome to the forum!

That's a lot of questions. Ones that I will let the more experienced members answer as I am fairly new to this myself (Dec 2011).

However I do know that when it comes to astrophotography (aka The Dark Side) it is not as simple as attach, point and shoot. Scope collimation (as you mentioned) is critical and so is focus for which you would ideally need a Bhatinov mask. Also in order to track the object you're wanting to photograph an equatorial (as opposed to alt/az) mount is required.

That is where I will end my contribution as I am primarily a visual observer and an inexperienced one at that. So I am sure in no time our more experienced members will be along go offer more helpful guidance/advice.

Welcome to EMS :)

Felix

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Hi Mike and first off let me welcome you to EMS. :)

I am not into astrophotography myself, I am purley a visual astronomer, so I will leave the photo side of things to the experts.

The scope you have is a good begginers scope, don't get me wrong, there is better out there, but there is also worse, much worse. What you have for now will keep you and your daughter going for a while yet!

First off, with regards to the eye peices, yeah stock ep's are not great but they will do to start you off if on a budget.

For £35-£45 an ep, the BST explorer range are a good start, much better quality than stock ep's without breaking the bank!

With regards to barlows and the ep's that you do have, a barlow will double the magnification (if a 2x barlow) so your 25mm ep with a barlow will be a 12.5mm, your 9mm with a barlow will be 4.5mm. Having checked your scope's stats, it is a F5, with a focal length of 650, so your 25mm ep will give you 26X magnification, (barlowed = 52x mag) and the 9mm ep will give you 72x magnification (barlowed =144x mag).

I would say for your scope, the 9mm barlowed will be pushing the limits of what you can see clearly, Jupiter for example you said looks blury, this will be down to atmospheric conditions and the limits of your scope, Jupiter will look better the higher in the sky it is, so you may want to wait a few months and try again.

The mount being a bit wobbly, thats the trouble with cheaper scopes, the more you pay for amount, the better quality it will be. Adding extra weight to the scope (a dslr camera for example) will only add to the wobble.

With regards to the collimation side of things, from the sound of it, collimating it will not hurt, if it has been transported around a lot and never collimated, chances are the mirrors will be out of allignment. For collimation tutorials, your best bet would be to look at astro babys guide to collimation found here...... http://www.astro-baby.com/collimation/astro%20babys%20collimation%20guide.htm

is a good place to start.

As for the goto, really need to see it to offer any good advice, have you put the date in correctly, have you put the time and your cooridinates in correctly and have you aligned to at least two stars correctly, all can affect the tracking of the scope.

Hope the above helps, I`m sure a astrophotographer will be along shortly to assist with the photo side of things.

If you are still stuck, let us know and we will see if we can meet up somewhere to have a look at your scope.

Regards,

Darren.

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If using for DSLR photography, you may need to use a barlow with a T-adapter.

Without it, you wont get infinity focus

Better still , use the celestron T-adapter/2x barlow (its all in one)

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Hi and welcome to EMS.

Even though your scope is at the budget end as far as scopes go it is still capable of good images, of the moon, planets and deep space galaxies and nebulas. In regards to your blurred images this could be down to collimation, and if so you will need a laser collimator or a cheshire sight tube. It could also be that 9mm barlowed is to much power for your scope, or even the mount itself giving off vibrations or wobbles.

What I'm trying to say is keep using the scope and learn with it, and if you are still keen, then upgrade to something better, but come here and ask for advice before you do.

You will be able to take quick photo's of bright objects such as the moon, but astrophotography of deep space stuff is out of the question until you convert to an EQ mount.

Best advice is to read, read and read some more, there is alot of advice in this forum.

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Best advice is to read, read and read some more, there is alot of advice in this forum.

And then ask us a load of questions! ;)

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yes start off slowly to learn and then really the most important thing is a good mount, polar alignment and a lot of advice from these guys.

I have only just started too and would have given up if not for how helpful this lot are. Def an EQ mount though.

I am sure one of the experts will give you a full and proper answer when they come on line

Welcome aboard

Sheila

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Hi Mike, welcome to EMS. :-)

I too am very new to the hobby, I caught the bug from my as good as husband Wayne and the lovely people on this forum. :-)

I can't really help any more with your questions, I still look at "pretty things" with Bob the Dob lol.

It's surprising what info you absorb by just reading posts, talking to other people and using your scope. :-)

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Yes the mount is key to it all in my opinion, does not matter what scope you have if it flapping around in the wind ;)

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Guest MikePMC

Thanks for the help so far. I've spent a few hours with the scope this evening getting the collimation right (or what I think is right)?? It took three attempts and some heart stopping moments when one of the primary mirror adjusters came away from the mirror! I managed to get it back in and I was surprised by how far out it was, assuming I've done it right and it is now aligned up correct. Of course it's possible it was not as bad as I thought and I've made it worse but I won't know that until I get to test it. Not that its going to be possible to test it tonight now its raining.

Mike

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To test the collimation - first get a bright star in the eyepiece to the best focus you can achieve. Then defocus it slightly by turning the focus knob inwards - you should see some bright airy circles. These should be perfectly concentric. Now come back to the focus point and defocus slightly outwards (ie the opposite direction of focus tube movement). Again the bright airy circles should be concentric.

If the circles aren't perfectly concentric in both directions of defocus then the collimation will want to be checked over. :)

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Hi Mike, a warm welcome to EMS.

I suspect that it drifting out of view is down to poor alignment . Once you have it set up even some where near, it should be good enough to keep stuff in the eyepiece for a while.

Iam not sure how the handsets work on those, but check the date format, on a Meade I had, it was in the American style.

You probably need to stick your co-ordinates in as well, these can be obtained from Google Earth, put the cursor where you observe from and the co-ordinates are at the bottom of the picture.

To be honest, I found the easiest way to get the Meade to work, was to find Polaris in a low power eye piece, tilt the tube down, and level it with a spirit level. Then start the alignment procedure. The instructions were pants.

If you get stuck, just shout up.

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Guest MikePMC

What did you use to align the mirrors Mike?

I used an old cap with the drilled hole. It would be interesting to try with a laser alignment tool to see how close I have got though. I keep peering out the window to see if there is enough gap in the cloud to test it. I've looked a the moon for a few minutes and it looks clear but really need to wait for some clear skys to test on a star as advised.

Mike

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