Which eyepieces for Skyhawk?

[SophieT]

Hi everyone, I'm a complete newbie on here and to telescopes in general! I bought a skywatcher Skyhawk 1145p recently for my daughter (and me!). We have got to grips with the basics of the eq1 mount and the general movement of the telescope. Using the eyepieces supplied (10mm, 25mm and 2xbarlow) we've had a good look around and studied the moon. All nice so far! Now I'm looking at the best eyepieces to get... Going away to Devon in October so darker skies await! I'm a bit baffled by the eyepieces on offer. What we really want to see are DSOs and planets. After MUCH googling I'm thinking a 6mm and a 32mm (suitable with my scope) or do I get a 12mm which will double up as a 6mm with the Barlow? It's all a bit confusing! Any help would be much appreciated! Thanks! 

[RT65CB-SWL]

Hi Sophie (+ daughter) and welcome to SGL. 

Have a look at http://www.skysthelimit.org.uk/ Alan the propieter is very helpful and his prices are very reasonable/competitive that is kind to the purse/wallet and without the tears. 

The eyepieces you mention I think would be an improvement over the supplied ones, as they have had a bit of negative feedback, especially the 10mm. 

[SophieT]

Thankyou Philip! I shall check it out! 

[ronin]

Scope is a it on the "fast" side, f/4.4

When scopes get fast the eyepieces tend to be a bit of a concern, generally it means more costly ones. Doesn't it always.

See what Alan has in stock, he is good and will give a honest opinion. He told me I was mad. If neither of you wear glasses then try plossl's but at the shorter focal lengths the eye relief gets small. Usually about 2/3 of the eyepiece focal length. So a 6mm plossl means the eye will be about 4mm from the top lens and that may be uncomfortable and with glasses impossible.

Eyepieces with longer eye relief are as you will guess more expensive. Alan sells BST Starguiders and very good but £49 each - which is not bad for the performance of the eyepiece.

At f/4.4 I would use the scope for wide and medium magnification viewing, trying to get high mag out of it may be troublesome - equally I have just recalled the BST Starguider in 3.2mm format which may or may not work for the high end. That really is an option to borrow one and try. Sort of "might work, might not" and I lean towards the might not.

The supplied barlow may not be good, usually they are not. So as you say a barlow with longer focal length eyepieces may be a fair option, but I think you would need a better barlow then the supplied item. Again Alan has a few.

Buy a couple to get by with at present. Say this as in Oct (I think) is The IAS at Stoneleigh: http://www.ukastroshow.com/

Titled International Astronomy Show but web page is UKAstronomy show. Bit of an identity crisis I guess. But Coventry and Stoneleigh are close, so could be worth you making a visit. Just to see all the shiny bits that are calling out to you to buy them. Rule 1: Leave ALL credit and debit cards at home.

Big problem of eyepieces is that you need to define a budget, GSO plossls are around £30, Vixen plossl £35-40, TV plossls £70-100 (but good), BST Starguiders are £49, Altair Lightwwave £55, X-Cel LX are about £59. Without a defined budget you will soon get told that Delos are good for your future improved scopes, then Delites. The last 2 options cost more the twice the cost of the scope.

My eyepieces consist badsically of the BST set (6) and a 6mm Altair.

Difficult to suggest anything specific, simply f/4.4 is out of my experience on perfomance. As a guess, a 6mm and a 15-18mm. Not actually if me I would drop below 8mm, equally I have the 8mm BST and it works well as a nice medium/high mag option.

[SophieT]

Thankyou Ronin, we will certainly check out the Stoneleigh show, I'm not far from there! 

Budget wise, I don't have a huge budget.... I've looked at the kits with lots of lenses but too costly for me in one go, and with reading reviews I see it's a better option to get the lenses individually unless I go for a higher end set. The plossl ones keep popping up as potentials. Thanks for your advice! 

[Putaendo Patrick]

With patience you can pick up some very good EPs secondhand. For example in Kettering, someone is selling 10mm and 30mm Vixen NPL Plossls for 50 pounds (new these would be nearly 90):

http://www.astrobuysell.com/uk/propview.php?viewcon=116092

I don't know the seller, but these Vixens are very nice Plossls for the price (and a big improvement on the supplied Skywatcher 10mm).

[SophieT]

Oooh, thank you, that's a good site, I shall bookmark that! 

[billyharris72]

Overall, I think Plossls are still the best value when looking for a compromise between quality, field of view and price. In terms of eye relief they can be tight, and this can be awkward if you wear glasses, but if you don't have astigmatism (sometimes even if you have, as in my case) you can take them off and adjust the focus to suit.

32mm Plossls are great, but with your scope a 25mm is already getting you down to x20, so I'd recommend going for something shorter. Why not split the difference with your current set and go for a 17 or 18mm? The Skywatcher ones are about £20 on FLO and are pretty good (I have one well regarded eyepiece in the £100 + price bracket that does not compare well on optical quality even if the field of view and eye relief are better). A decent Barlow lens (something like a Celestron Omni, in the £30-ish price range) would probably als be a good investment.

No need to rush though. Why not spend some time and get the best from the eyepieces you have? When you identify something that you need new eyepieces for that will also give you the information you need to make the best choice.

Billy.

[SophieT]

Thankyou Billy! I did so much research on telescopes before I bought one in my price range, but never really researched eyepieces. I think an investment in a really good Barlow is a good start for me too. Thanks! 

[RT65CB-SWL]

8 hours ago, SophieT said:

Thankyou Ronin, we will certainly check out the Stoneleigh show, I'm not far from there! 

Budget wise, I don't have a huge budget.... I've looked at the kits with lots of lenses but too costly for me in one go, and with reading reviews I see it's a better option to get the lenses individually unless I go for a higher end set. The plossl ones keep popping up as potentials. Thanks for your advice! 

Hi again Sophie,

Don't bother with an eyepiece set/kit in a case. Many of 'us' prefer to purchase individual eyepieces.

[SophieT]

I might still have to buy a nice posh case to put them all in! It'll be like when I choose a chocolate from a box!  

[RT65CB-SWL]

2 hours ago, SophieT said:

I might still have to buy a nice posh case to put them all in! It'll be like when I choose a chocolate from a box!  

Use a 'posh' ice cream container - it's cheaper (and yummy)*

Seriously... Clas Ohlson do plastic tool/instrument cases (with diced foam inserts)... http://www.clasohlson.com/uk/view/content/search?N=0&Ntk=All&Ntt=tool cases&Nty=1&D=tool cases&Ntx=mode+matchpartial&Dx=mode+matchpartial&showTabs=true   ...very similar to the Peli ** range of cases and cheaper.

 

 

* the ice cream is 'yummy' not the container!

** https://peliproducts.co.uk/products/cases.html?gclid=CI6VmK6vyc4CFdIV0wodMJoCsw

[SophieT]

Great, thanks Philip! Oh dear, I'd better get finishing off the ice cream! ☺️

[Ricochet]

I know someone with a 1145p and from what I remember the Starguiders work well in it, even at f/4.4. Unfortunately, I don't know which eyepiece/barlow combinations get the most use. I do know that he has an 8-24mm zoom and your daughter might appreciate the zoom ability rather than having to fiddle about changing eyepieces. If you have a look on eBay, you should be able to find a VITE branded one for about £30.

In October you will probably find that planetary viewing is quite difficult. Venus/Mars/Saturn (south to west) will be setting in the early evening and Jupiter (east) will only just come up before sunrise so you will need very good lines of sight to the horizon in order to see them. Also, due to the altitude, you will have to look through a lot of atmosphere which will also blur the images.

That means that DSO viewing is probably going to be your most reliable option during the holiday. Optimal DSO viewing needs an exit pupil in the region of 2-3mm so you should look for an eyepiece in the 9-13mm range. I would also suggest something a bit brighter and wider, say a 4mm exit pupil so a 17-18mm eyepiece and then you keep your current 25mm as a "finder" eyepiece. As stated above, a 32mm isn't really needed in your telescope as it will give a very low magnification.

For lunar and planetary you can go down to a 0.5-1mm exit pupil (2.5-5mm eyepiece) but a 2.5mm eyepiece will result in 200X magnification, which is pushing the limits of your scope and the UK atmosphere so I wouldn't go that low. The 5mm and 3.2mm Starguiders would be good choices here because they have good eye relief and the field of view is a bit wider than that of a Plossl, which makes it easier to keep the target in view. If you do want to stick with Plossls then I would advise sticking with focal lengths over 8mm and using a 2X Barlow to get to higher magnifications or the eye relief gets a bit too small to be comfortable.

 

The equations needed to calculate the above are:

Exit Pupil = Eyepiece Focal Length / Telescope Focal Ratio (4.4)

Magnification = Telescope Focal Length (500) / Eyepiece Focal Length

[Alan64]

A 32mm(16x, and binocular-like) and a 12mm(42x) sound to be reasonable choices.  Some find a dedicated 6mm difficult to look through, with its smaller eye-lens and short eye-relief, therefore barlowing a 12mm is an excellent idea, whilst retaining the comfortable eye-relief and larger eye-lens of the 12mm.  A  simulated 6mm(83x) would allow for observing the craters on the Moon and the rings of Saturn, in addition to a host of deep-sky objects.

The 32mm would augment the finder-scope in the spotting of individual objects in the sky, then to increase the magnification for a closer look.  The 32mm would also give somewhat wide-field views of the star-fields within the Milky Way in summer, and the galaxy in Andromeda and the Pleiades in winter.

The EQ-1 can be motorised, and for automatic hands-free tracking, and in keeping any object standing still there in the eyepiece, and for as long as you'd like...

https://www.firstlightoptics.com/skywatcher-mounts/ra-economy-motor-drive-for-eq1.html