Newbie with (probably) a simple question regarding eyepieces...

[goonergaz]

Hi to one and all

This looks like a great place, I've been looking around for a few days now and I've joined up in hope of some answers for a complete newbie to get the best from his cheap setup...

I recently aquired a Meade DS2080 GOTO from a guy at work. Having looked around these telescopes are probably a fair starting point for someone like me who has kids and wants to look at the moon and a few planets without fear of the kids breaking my £100s worth of kit!

Anyway, I was getting a little down trying to set the thing up when I thought 'WTH' I'll see what that bright spot is and physically pointed the scope about right and used the motor to fine-tune in on...JUPITER! Wow, what a sight, from dispair to delight in just seconds...I could just about make out 4 moons - then I remember I had a 9mm eyepiece and OMG I could see the gass 'rings' and everything...I was stunned.

So, long story short (too late!) - I'm trying to find a reasonable eyepiece to get even closer to the action. Initially I was looking to get a 2x barlow, and looking here it seemed a TAL was the ideal solution. However, reading further someone mentioned that rather than a barlow it would (probably) be better to just get a half-decent 6mm eyepiece - in particular the TMB being mentioned as a good solution.

So, ready to buy and I create an account here and read the fantastic 'everything you need to know about eyepieces' and after some calculation it seems my scope (f/10) can only cope with a 7.5mm eyepiece

I'm basically after advice and clarity, if I were to buy a 6mm TMB would it be usable with my scope? Also, what sort of 'gain' would I get over my stock 9mm? I'm in the 'middle man' budget (as you can probably bet) - I already spent ~£100 on the 2080 so another £35 on an eyepiece is quite a chunk - but by the same token I'm happy to spend on a half-decent eyepiece as I could keep it if/when I upgrade my 2080.

Any help/advice is greatly appreciated, please go easy on me as I'll probably have little idea what you're talking about being so green

Thanks in advance

[ScubaMike]

Hi GoonerGaz.

Your DS2080 has an 80mm aperture (just over 3") and a FL of 800mm

A rough rule of thumb regularly quoted here is that you should use a maximum magnification of approx 50x per inch of aperture (subject to seeing conditions limitations).

Therefore, you should be looking at keeping the magnification to around 150x.

800mm FL used with a 6mm eyepiece would give you approx 133x mag,

the 7.5mm EP would yield approx 105x, which may be more useable.

(PS, your 9mm is giving just under 90x)

If you really wanted to push it, a 5mm would give 160x, but it would depend on the stability of your mount, and the conditions you were viewing in.

[ScubaMike]

PS. I have only been "into" this hobby for a few months. You'll be amazed how quickly you pick things up - just keep reading the forums and gather opinions.

[goonergaz]

Hi GoonerGaz.

Your DS2080 has an 80mm aperture (just over 3") and a FL of 800mm

A rough rule of thumb regularly quoted here is that you should use a maximum magnification of approx 50x per inch of aperture (subject to seeing conditions limitations).

Therefore, you should be looking at keeping the magnification to around 150x.

800mm FL used with a 6mm eyepiece would give you approx 133x mag,

the 7.5mm EP would yield approx 105x, which may be more useable.

(PS, your 9mm is giving just under 90x)

If you really wanted to push it, a 5mm would give 160x, but it would depend on the stability of your mount, and the conditions you were viewing in.

Many thanks ScubaMike

So, in reality a 2x barlow would have been too much power? Good job FLO were out of stock!!

Regarding picking stuff up, yeah - I knew nothing a couple of days and my knowledge seems to double every day...oh wait :)

[rwilkey]

Hi Goonergaz, the Meade DS2080 is a great starter scope with GOTO etc, my wife has the DS2090 and it is very good, they also make a 102mm now, which is also very good: eBay - The UK's Online Marketplace EP's are difficult shout as there are so many choices out there, I find the BST Explorers work well in the DS2090, they make one in the 5mm fl and the 8mm. 5mm might be pushing it a bit though, bear in mind also that your tripod is not the steadiest out there, so you would need excellent seeing conditions for high power. BST Explorers from: 1.25" Eyepieces

[Hairycamel]

Hi there. I had a TMB II 6mm eyepiece in my ETX125 scope and I had fantastic detailed views of the moon with it.......

[rwilkey]

I have heard only good reports about the TMB II Planetary's, but have not tried one as yet. Well respected on this forum, might be a small balance issue on the DS2080 as it is quite a light tube, are they very heavy? They look a bit chunky, which is why I went for the BST Explorers

[goonergaz]

Hi Goonergaz, the Meade DS2080 is a great starter scope with GOTO etc, my wife has the DS2090 and it is very good, they also make a 102mm now, which is also very good: eBay - The UK's Online Marketplace EP's are difficult shout as there are so many choices out there, I find the BST Explorers work well in the DS2090, they make one in the 5mm fl and the 8mm. 5mm might be pushing it a bit though, bear in mind also that your tripod is not the steadiest out there, so you would need excellent seeing conditions for high power. BST Explorers from: 1.25" Eyepieces

Hi rwilkey, that scope does look like the ideal next step - I'm sure at some point I'll upgrade as there's nothing like a night under the stars . Thanks for your suggesting the BSTs, unfortunately as you've said - I think 5mm is too much and 8mm not enough...I really want to make the magnification worth it, and it seems 6mm is the ideal for my scope.

[goonergaz]

Hi there. I had a TMB II 6mm eyepiece in my ETX125 scope and I had fantastic detailed views of the moon with it.......

thanks, that looks like a nice scope - if I read the advice right your max should be 250x and the most powerful eyepiece you should use is a 5mm? (254x)

Nice to see if I'm understanding things right

[goonergaz]

I have heard only good reports about the TMB II Planetary's, but have not tried one as yet. Well respected on this forum, might be a small balance issue on the DS2080 as it is quite a light tube, are they very heavy? They look a bit chunky, which is why I went for the BST Explorers

balance issue? in what way? it's not heavy (not that I would know what a heavy tube is)

looks like meade do a 6.4mm EP - giving me 124x think I'll still go with a TMB II at the moment, seems a good 'long term' investment

[rwilkey]

I think an ep around 6mm would be the best shot, which suggests the TMB's, at least you can lock the tube so balance may only be a temporary issue. In upgrading I would think of something more on the lines of the SW Evostar First Light Optics - Skywatcher Evostar 102 (EQ3-2) or larger aperture if you are sticking with refractors and have the budget, as telescopes like these are upgradable parts wise. But enjoy the DS2080, it is a cracking scope if my wife's DS2090 is anything to go by. Sorry, the tube is not heavy, I meant ep's can sometimes be heavy, I have certainly found this on some occasions, mind you, my Porta II mount does not have a locking mechanism so balance is more critical, but I find my wife's scope a little on the light side.

[goonergaz]

hhmmm, these guys let you try the EPs first - I could go for a 5mm & 6mm - that way if 5mm works I get a better result...anyone used them before?

1.25" Eyepieces

[rwilkey]

I haven't taken the 'try them option' but have to say you get great service from Alan, great communications, he's also letting me field test a new line soon.