Eye Pieces!!!!!

[rusty]

Hi All

Thanks for all your kind advice to date, but i seek even more!!!

I have decided to buy a 10 inch Dob and am now considering eye pieces. I am thinking of purchasing 4 or 5 quality eye pieces that will allow me good coverage of the entire night sky.

I would be interested to hear your thoughts on what sizes and types of eye pieces I should include in my collection (and perhaps brands as well???).

Thanks again.

[iceman]

What is your budget?

For premium eyepieces, 4 or 5 of them will cost you quite a lot! Much more than the scope itself.

[Starkler]

If buying quality eyepieces, you can get away with three and a barlow.

If you can afford it, buy the Pentax XW's that dave47tuc is selling, they dont come much better than those.

[davidpretorius]

15months on for me and I am only using two eyepieces - a 5mm vixen and a 30mm super wide from andrews comm.

I intend to have a:
4mm tmb to go with the 5mm vixen for planetary

10mm Pentax

24mm panoptic or 22mm LVW

Don't rush, work out what you are going to look at the most ie planets or wide views and then save and get then one at a time.

I reckon anyay!

[ausastronomer]

Hmmmmmmmmmmmmmmm, "they don't come much better" !!!!!!

Geoff you and I both know, they are the best :)

CS-John B

[wavelandscott]

rusty,

Good luck with the new scope...and a fine choice it is. Many of the Dob scopes come "packaged" with an eyepiece or two...

I would strongly encourage you to use the eyepieces that come with the scope a few times before making any decision on buying new eyepeices...many of the scopes come with "decent" eyepieces that should get you off and running in this hobby.

Get some viewing time under your belt with your new scope before buying new eyepeices...figure out what you like/don't like about what you have.

Also take advantage of other astro folks in your area...go to a few veiwing nights look through some other people's eyepieces in your scope...most folks are happy to let you have a try...In my opinion then and only then is it time to go shopping for new eyepeices.

My biggest reason for recommending a "go slow" approach is that there are many many good quality eyepeices available in a variety of price ranges...it is easy enough to go right to the Pentax/Televue (and others) "top shelf" stuff but you may find that the slight difference in the view between top end and good quality is not a big enough difference to justify the larger difference in price.

Once you decide what you want to spend (budget)...many people can offer many many options to match your budget and interests.

In the meantime read as much as you can and use your gear and other people's gear to gain some veiwing experiences...

When you are ready, I'd recommend reading the article on Televue's website about eyepiece selection (3 eyepieces and a barlow can do you for a long time)...

Like all things "consumer" oriented it is easy to spend a lot of money on things that you won't use very much but "others" have claimed are must haves so you rush out and buy...catch your breath, learn to use what you have (are getting) and then decide to upgrade or not...choose well and your eyepeices can last a lifetime!

Good Luck!

[OneOfOne]

I won't add my totally unbiased opinion.

[janoskiss]

Rusty, if you have cash to burn:
XW 30mm for wide TFOV
and for getting down, in this order:
XW 10mm (the DSO eyepiece for your scope)
XW 7mm (the other DSO EP ;))
Denkmeier 14, 21mm (based on John B's recommendation)
Add a carefully selected barlow for higher powers on planets (or get more EPs <7mm ;)).

But some other good choices are Nagler, Panoptic, LVW, Penax XF, Hyperion, Stratus, Radian, Burgess planetary, TV Plossl, Antares Elite Plossl, UO HD ortho, UO classic ortho, depending on budget/personal preferences.

[Dujon]

Hello, Rusty.

I don't think you can go past wavelandscott's advice (assuming you're a newcomer to the game). I purchased the Bintel 10" Newtonian, which came with a 26mm (Kellner, I think) plus two plossls (15mm and 9mm). Since I am interested in planetary viewing - when available - I purchased a 2x Tele Vue Barlow second hand from a member of this site.

In view of the fact that I'm still learning (and the blasted clouds refuse to go away when I have time available to use the 'scope) I reckon that they'll do me for the time being.

Good luck with your ponderings.

[rmcpb]

Rusty,

Sit on your wallet for a while, you have spent enough money for the time being and use the scope as it comes BEFORE starting the slippery slope of buying accessories.

As for your next purchases, you may be better off with a chesire eyepiece (collimation will be very important in your scope), a Telrad, a viewing chair, red torch, planisphere, magazines, star atlases, etc, etc.

Note I did not mention filters or eyepieces in that list, they come later after you have spent quite a bit of time hugging your dob and getting to know it and your observing interests. Then start buyiing one thing at a time and you will make wise and useful purchases. Otherwise you will be in the Buy and Sell section trying to flog off all those must haves that you found you never used.

Make haste slowly.

[janoskiss]

must say I agree that it is good advice to wait and use the EPs you have - as long as you have a fairly comprehensive usable set and they are not junk EPs. What do you have?

[rusty]

Hi Janoskiss

I already have two Meade eyepieces, a 9mm and a 25mm that came with the 70mm Meade refractor I have. I think I will get the Dob through Bintel which according to their website and Dujon above means I will get a 26 or 32 mm FMC Kellner and 9 and 15 mm GSO Plossls. That's a good start I guess!

Cheers

[wavelandscott]

rusty,

The GSO plossl eyepieces will be okay to get started with (that's what I started with too the Bintel scope and eyepieces). Those 5 eyepieces should give you a good range of magnification and a good comparison to use when looking through other people's eyepieces.

Sounds like you will be off to a good start!

Clear Skies...

[Dujon]

YES!

Some form of collimation tool is essential, Rusty. If your budget will stand the strain then buy it with the 'scope. Even if you can't strike a deal on price at least you'll save additional freight charges.

I purchased a laser unit with my 'scope but have found it too sloppy in the focuser. Since then I have acquired a 'Cheshire' design which seems to fit properly and does a pretty good job (even though I've not had a proper chance to fully evaluate it)

[rusty]

Hey Dujon

Thanks for the tip. I read your thread about collimation. I would be interested to hear how your Chesire works out for you.

Cheers

[CoombellKid]

bummer he's selling the ones I already got :rolleyes:


If ya go XW's then swap the 20mm for a 20mm t5 ;)

regards,CS sunny days

Rob

[janoskiss]

rusty, the GSO Plossls will be fine. I recommend you swap RKE for a 30mm Superview or a 32mm GSO Plossl, and grab a 2x barlow to give you higher powers.

[Dujon]

Well, it was rmcpb who brought up the subject, I was merely reinforcing the comment and urging you, if you can, to purchase one at the same time as your 'scope.

The Cheshire unit I purchased seems to be better than the original laser, but I've only had one short viewing after using it. As a matter of interest, I used the Cheshire and then checked with the laser unit. The laser unit indicated that I was out in my adjustments - but the slightest touch on the laser housing (for example turning it off/on) caused the 'red dot' on the primary mirror to move anywhere between the mirror centre mark and two-thirds of the way to the mirror's edge.

I'm sure that not all laser collimation tools are like this, otherwise others would have mentioned it.

[Lee]

I really found little enjoyment out of observing initially with my Dob, mainly because of low quality eyepieces - A few Series 500 from Andrews (rubbish).... the best thing I did was get a couple of good EP's.... I only use 1 or 2 in an observing session usually - widefield 20 or 32mm plossl, and a 10mm Pentax XW for closer views. I often just use the 20mm plossl alone for DSO viewing.... absolutely beautiful EP..... this is with the 8" Dob BTW.....

[rmcpb]

What Lee has said is very true and we are not arguing the need to get some good eyepieces, just that initially collimation will be more important and a bit of time to work out which eyepieces to get so you don't waste your money.

[OneOfOne]

Funny you should mention this, I was concerned with the "slop" with my laser when it was put into the focuser and so machined a piece of aluminium down to make a "snug" fit for it, basically a "tight 1 1/4 to 2 adaptor" (this took an amazing amount of work because the only scrap I had lying around was 80mm diameter, that's 30mm of turning...and another story, anyone want a bucket of swarf?). I tried it at the weekend and was able to get the return spot to drop right down inside where it came from! (It is a Bintel deluxe with the target). I then dropped in the Cheshire only to find that it was out. After pondering what could have gone wrong I measured my new adaptor. It appears the central hole is not concentric with the centre of the adaptor by about 0.04mm...quite enough to show up in the collimation. I should point out my lathe was originally used in the ammunitions factory in 1945! In hindsight I should have rotated the whole adaptor rather than just the laser, this would have immediately shown the problem.

I have since measured the other 2 adaptors I have and found the one that came with the scope to be out by almost 0.06mm and the other, which came with the GSO focuser, to be out by a tad over 0.01...actually if I jiggle the vernier, I can make it close to zero all round. The remaining issue still remains with the slop, which is very hard to get rid of.

This weekend I will try again using the GSO adaptor and orient the tube so the laser points directly down rather than to the side where gravity will cause it to "drop".

The moral of the story? Try to get as snug a fit as possible for the laser and try to check concentricity if you are using an adaptor. Previously I used the GSO adaptor to align the mirror and then checked it with the Cheshire to find it was spot on, and took about 10 minutes to do (first time).

I would be interested to hear if others agree with my theory or have other points to add. Lasers are great, but as I found, they can cause you to get the optics "perfectly out!"

[CoombellKid]

I had the same problem...

The problem with laser collimaters is they assume that your focuser and how
the laser sits in the focuser, and is central and square to the optical train. If
your focuser is not aligned to the optical train, then like me you'll get problems
with a laser. I brought a laser collimater when I brought my scope could never
get it to work well, I ended up making a collimation cap and put the laser away.
When I got the Chesire, I could imediately see where the errors were. Although
it didn't tell my focuser was out of alignment I found that out another way. After
I aligned everything with the Chesire, the laser interestingly enough was almost
bang on.

regards, CS

Rob