Getting the best from astromaster 130eq

[biggysmalls]

I have a celestron astromaster 130eq as my first scope I've had a bit off success with viewing Jupiter and Saturn in the last 4/5 months of having it. I've been looking at filters and Barlow lenses but not sure what effect these would have can anyone clear this up

[rwilkey]

I have never found colour filters very helpful on planets, but that's just my personal experience, I do use an ND96 (0.09) on the Moon as I find it rather bright sometimes, I also have a variable polariser which is really helpful sometimes. Here is a useful guide to filters: http://www.lumiconfi...-spec.php�� When considering filters, please bear in mind that there are 'visual' filters and 'CCD' filters, you should only consider visual filters for visual use. The most useful filters for seeing nebula that I have are the UHC (Ultra High Contrast) and the OIII filter, if you are into DSO's (Deep Sky Objects), the UHC being the best all rounder.

[swamp thing]

Hi

Not much of a planet observer myself but a good quality Barlow is a very good investment IMO. Good eyepieces you will swap and change throughout your observing career but a good Barlow will be in your eyepiece case for life. Go for a 2" version if possible as Barlowing the larger 2" eyepieces enables much more comfortable viewing.

I don't know much about colour filters, I do have a set and they do seem to help a bit on certain occaisions, but it normally takes me a while to work out what's doing what to help. Normally I tire of them and observe without TBH. if you are a more dedicated planetary observer you may well stick with them. Some seem to think they do nothing whilst others (myself includede) can see a slight improvement but it is very slight I might add they don't make a huge difference by any stretch of the imagination.

[Capricorn]

You will need a collimator and some additional eyepieces. Buying the scope was the start only.

Being f/5 you will have to manintain collimation of the scope in order to get a reasonable image.

I prefer single eyepieces. However a Tal barlow is always a good recommendation and perhaps an 8mm BST eyepiece. The balow will work with whatever eyepieces you have and with the BST would make an 8mm and a 4mm.

I would say that below 4mm you will have to balance off magnification and image quality more and more.

The scopes best area would be the medium magnification views of things like clusters and other messiers that have a reasonable angular size. Go identify 20-30 to look at. Trying to get 200x out of it is not going to be easy, 130x-150x OK, 100x better.

Filters, perhaps a moon filter, for when the moon is bright. Always puzzles me, we point scopes at dim distant objects then ask about putting a filter in that removes some of the light.

The above mean spending another £120

[StarryBob]

If you want to collimate the astromaster I think you will need to remove the primary mirror and put some sort of mark on the centre as for some stupid reason they don't have one.

[Lenny147]

I had to mark the primary myself with the same scope which is not as hard as it sounds, i also invested in Tal x 2 barlow and updated a couple of eps, it did make a massive difference with the views on the scope

[Ally8446]

Marking the primary is a doddle. Take out the BLACK screws and the whole unit slides out. As the mirror is 130mm across, get a piece of paper and a pencil compass. Draw a 130mm circle and very carefully cut it out. Then fold it in half then half again so that you basically have a quarter circle. Snip off a couple of mm from the point and unfold it. You'll have a perfect template. Carefully place the paper on top of the mirror and with a chisel top permanent marker put a dot in the hole, and a voila, you have centre marked your mirror. Most then get a reinforcemet sticky ring for paper folders and place that in the centre (makes it stand out more when collimating).

Clear Skies

[umadog]

Here are some links on LP filters:

http://www.cloudynights.com/item.php?item_id=63

http://www.cloudynights.com/item.php?item_id=1520

http://www.cloudynights.com/item.php?item_id=1412 [focus on AP]

To get the most out of your scope you should invest in a good collimation tool and verify the positioning of the centre spot. Your collimation will only be as good as your spot position and that will need to be very accurate at f/5. You can use the paper idea above. A possibly more accurate way is the Catseye template: http://www.catseyecollimation.com/template.html

Capricorn, the reason for filters is contrast. Yes, we want telescopes to gather as much light as possible but equally important is that the target object is as contrasty as possible. Many objects we observe aren't so much faint as they are low contrast. If a filter improves contrast at the expense of a little light loss then the object will be seen better.

[dag123]

Ditto to what Ally8446 said.

Except I used a small blob of blu-tac as I did not have a marker pen handy.

Regarding collimation, I was given a chesire ( the standard one from FLO) for Christmas, but I still find it far easier to use my trusty 35mm film case with a hole in the lid, folowed by a star test on Polaris as the final bit of my polar-aligment.

dag123