Eyepieces

[daz]

Hi guys

I promised I would keep the equipment questions to the relevant section.....

OK, I have my little 'scope which came with 3 eyepieces but are unbranded apart from a 'H' in front of the focal length on top of the eyepiece itself. I assume therefore, that these are a cheap 'n' cheerful type.

I also have a Plossl 6mm from Celestron, but it is difficult to any clear image from this, but I don't know if this is down to the focusser, collimation, or my skills in using!

So, onto the questions (at last, I hear you mumble!).

Are plossl pieces where I should be aiming?

Would a 30 / 25 / 20 mm be a good place to start?

And is it worth buying a laser collimator? I have seen them on eBay at around 20 quid???

Thanks people!

Darren

[russ]

Hi Darren,

Oh we like equipment questions......just fire away.

To answer your first few questions in reverse order:

And is it worth buying a laser collimator? I have seen them on eBay at around 20 quid???

No real need to. You can get perfect collimation using a film cannister with a hole drilled in it. But i personally wouldn't be without my laser collimator. Still need to do a good collimation the old way first but then use the laser to fine tune the collimation each time you go out. I bought the one off Ebay for £20 and it works well.

So, onto the questions (at last, I hear you mumble!).

Are plossl pieces where I should be aiming?

Would a 30 / 25 / 20 mm be a good place to start?

What do you think your budget will be? Only there's two destinct grades of plossls available.

There's the standard plossl - Celestron (your 6mm will be one), Meade, Orion and Antares all market a range of them. These are reasonable eyepieces and certainly better than the standard items (Huygens) that came with the scope. The best priced ones are from Scope'n'skies, who have an Ebay shop, and are badged as Antares. Get them for about £12 each on Ebay.

Then there's the high quality Plossls - again marketed by the same firms but they are a couple of notches above the standard plossls and well worth the extra money. Their product names are Celestron Ultima, Orion Ultrascopic, Antares Elite and Parks Gold. All are the same eyepiece with a different badge and are manufactured in Japan not China.

Again the best deal by far is from Scope'n'skies with the Antares Elite Plossl at £45 each. A big jump over the standard plossl but well worth it.

I also have a Plossl 6mm from Celestron, but it is difficult to any clear image from this, but I don't know if this is down to the focusser, collimation, or my skills in using!

Could well be collimation. The 6mm plossl should provide a good image, not ultra sharp but still reasonable.

How many times have you used the 6mm? It could have been just a poor sky or whatever you were looking at was poorly placed in the sky, ie very low down.

I would check the collimation though. Are you okay with this or would you like some links to some good tutorials?

OK, I have my little 'scope which came with 3 eyepieces but are unbranded apart from a 'H' in front of the focal length on top of the eyepiece itself. I assume therefore, that these are a cheap 'n' cheerful type.

Yep you're right they are cheap'n'cheerful. Standard fare for a lot of scopes. H stands for Huygens, probably spelt that wrong. Very basic design. Low power views will be okay but a modest eyepiece upgrade will give a marked improvement in image.

This is the Ebay dealer and shop i kept going on about.

http://www.scopesnskies.com/

They offer some great prices and excellent service. You can get their things slightly cheap in one of their Ebay auctions but if you can't be doing with that, the website prices are pretty good.

Hope that helps for now

Regards

Russ

[Rob]

Good advice there Russ, nothing I can really add to that. Here is a simple, but effective collimation tool.. very similar to what I use!.

http://www.shop-com.co.uk/amos/cc/main/catalog/pcd/7836308/ccsyn/261

You should be able to find it somewhere in the UK.

Rob

[daz]

Wow! Many thanks for all this. Glad to see my reading and research wasn't too far out. Have seen SnS on eBay, but of course, wasn't sure about quality, etc. I shall definitely take a browse through their site.

I do indeed have one of the Celestron collimators, what I don't have is the instructions! So, if you have any links to instructions I would be forever grateful!

Thanks again

Darren

[OXO]

http://www.astronomics.com/main/category.asp/catalog_name/Astronomics/category_name/KAQ832AUVKUW8GJ8KP4D1U7175/Page/1

Click on the above link then goto the link that reads below..

Celestron Firstscope 114 model #31048/31049/31050/31052, 4.5" Newtonian telescopes instruction manual

There is instructions on how to use your collimator it's the same with most reflector's of your size.

James

[Ant]

I feel that I have to defend the Parks Gold Ep's. They are in a similar league to Teleview IMO.

I owned a full set a few years ago, and they were as good under most conditions to the Naglers...

With regard to the EP's I think that a 30, 25 and 20mm are a little too close together. I think that I would go for a 25 and a 10mm... and then a 2 x shorty barlow.

Regards

Ant

[russ]

Ant's right about the Parks Gold, which also applies to the other three, they are superb eyepieces. Always been considered something of a bargain in the eyepiece world. Especially because their performance is so close to the premium brands.

Up to now choosing between the Parks, Celestron, Orion and Antares has been down to purely which name you prefer seeing stamped on the side of the eyepiece as the price difference between brands was only £5-10.

But at the moment, thanks to Scope'n'skies, the Antares is way cheaper. Almost half the price in fact. So it would be pointless paying £80 for the Parks, Orion or Celestron when you can have the identical Antares for £45. Unless you really want to spend £35 for that name on the side.

Bottomline, these eyepieces are worth every penny. They were a bargain at £70 but at £45 :shock:

Best spread of eyepiece sizes IMHO is 5mm, 10mm, 20mm and 30mm. With a good quality Apo barlow thrown in for good measure. As Ant said, the Orion Shorty Plus is about the value one on the market.

Regards

Russ

[daz]

Thanks all very much - plenty to give my flexi-friend a good workout

With a good quality Apo barlow thrown in for good measure.

Russ: I know APO stands for apochromatic, but just what does it mean ?

DJ

[Ant]

there are generally three types of lens configerations...

APO - very expensive three element lens systems that hardly suffer from chromatic abberations, even at short focal lengths

Semi APO - example Skywatcher ED80/102 These are better corrected tha the achro.

Achro - these use two elements and suffer from chromatic aberation (different wavelengths of light reach a slightly different focus point) and the most common end result is a blue halo around bright stars...

It's a lot easier (cheaper) to make a good, well corrected, achro refractor the longer the focal ratio. So a good 6" F10 is cheaper to make than a 6" F/5.

You can process out chromatic abberations to a degree with photoshop.

See http://p2.forumforfree.com/m27-bagged-vt163-backyardastrono.html for a really nice image that suffers from CA and then scroll down to see what can be done with PS.

Hope this helps.

Ant

[GazOC]

It's a lot easier (cheaper) to make a good, well corrected, achro refractor the longer the focal ratio. So a good 6" F10 is cheaper to make than a 6" F/5.

It's also worth noting that the aperture/focal ratio relationship is not fixed.

ie. 6" f5 will show a lot more false colour than a 4" f5.

Gaz

[russ]

Hi Darren,

I thought I would recap on what would be best before you get confused.

Laser collimator - no real need for one of these. Your Celestron collimator will be fine.

Eyepieces - worth spending the extra here. But no need to spend silly sums on Naglers and Pentax XL's.

You'll proably be happy with the cheaper (£15-25) plossl eyepieces for now but worth forking out for those more pricey (£45+) models.

Barlow - invaluable item, but get a good one. The Orion 2x Shorty Plus, Celestron Ultima 2x or Antares Elite 2x are all 3 element apo (one element is a rare exotic glass) design. The barlow instintly doubles your eyepiece collection and is a must for webcam imaging of the solar system. Hence why it's so important to get a good one. The Orion for instance is only £50, so we're not talking huge sums here.

As with the eyepieces, all the barlows i mentioned are identical. Straight off the same production line in Japan.

You can get an idea of users opinions of all this kit on Excelsis:

http://www.excelsis.com/1.0/catalog.php?categoryid=6&PHPSESSID=01d3c05e2b254e12a8adf488dc0ccc4a

Cloudynights used to be good for reviews but IMHO they gone down hill big time of late and only concentrate on high end kit. You can check out their reviews here:

http://www.cloudynights.com/

Regards

Russ

[daz]

Again, humble thanks to you all.

I think I have enough info to get me looking in the right direction

eyepieces - looking........my talents are wasted... :joker:

[GazOC]

Hi,

If and when you decide to buy try to ask around to see if the EP's you want are avaliable under a different brand. There are a lot of low/mid range lines that are identical except of the company markings.

For example, Orion sell (through SCSAstro in the UK) some good, cheap EP's called the "Ultrawides" they cost around £65 (last time I looked) in the UK branded as Orion but you can pick them up for just over £20 (inc p&p to the UK) unbranded from the USA.

There are lots of EP's in that sort of price range that are the same, 9 times out of 10 if a low/mid range EP has the same spec as another then it will be identical and you are paying either for the name or for the promise of improved QC, which if the seller has a good "returns" policy is redundant anyway-you just do your own QC.

Gaz

[OXO]

Dont forget there are some Bargains to be picked up secondhand too(Thanks Gaz ).

James

[GazOC]

Dont forget there are some Bargains to be picked up secondhand too(Thanks Gaz ).

James

..takes a bow...