10" dobsonian suggested eyepieces

[Norfolk star gazer]

I read the forums after I posted and saw the threads you mentioned.

It does appear that I have the same problem as others and the protective cap is very tight and it must have loosened the rubber when I took it off.

Good to know that super glue works. Did think about doing that but was worried that it might perish the rubber, or knowing my luck stick my eye to the eye piece

Hoping to try it out tonight..

[JamesF]

The 250PX is quite unkind to lower-end eyepieces in my experience.  The fast focal ratio really seems to show up problems that aren't visible in slightly slower OTAs.  I have a long focal length plossl that I've almost always used as a "finder" eyepiece in most OTAs, but in my 10" I found it barely usable.  I'd suggest looking for used good quality eyepieces and just picking them up when they're offered for sale.

Tele Vue plossl's come up occasionally at reasonable prices and Naglers in the 13mm to 5mm range don't seem that uncommon if you're prepared to go up to £160-ish.  They can be the sort of eyepiece that you keep forever and do tend to hold their value fairly well should you decide to sell.  It's taken me several years, but I've picked up a nice range this way by having a bit of a "wish list" and picking things up when they turn up.

I'd expect ES eyepieces to work fairly well too, but not many people seem to be parting with them.  Perhaps that's a good sign

Orthoscopics work nicely and aren't generally too expensive, but the field of view is quite small and the shorter focal lengths aren't for anyone who isn't prepared to glue their eyeball to the top of the eyepiece.

It does seem pretty much impossible not to improve on the kit eyepieces though.

James

[Norfolk star gazer]

Well I had a brief time out before the clouds came over and kept swapping the un branded 10mm stock EP that came with the scope with the Celestron 9mm and had a look at Jupiter and can honestly say that I didn't see much of a difference. Maybe my stock 10mm was a good make, but I was expecting more from the £60 Celestron.

Jupiter was a little bigger with the 9mm, a little bit sharper and the bands were a bit clearer. I might have been expecting a bigger difference (considering the price) but I can honestly say that it wasn't a massive one It might not have been a good night to view and need to do a bit more, but maybe I should have gone for a 7 or 8.

[Norfolk star gazer]

Due the 9mm having the faulty eyepiece, the shop offered me a replacement, refund or credit note. As I wasn't over impressed with the 9mm one, I swapped it for a 7mm. Hoping to get out tonight (weather permitting) if only to see how Jupiter looks through it.

Will try and stay up late for Saturn!

[Norfolk star gazer]

Managed to get out tonight for an hour or so and tried the new 7mm Celestron x-cel EP.

I was impressed with the sharpness when looking at Jupiter and could make out the bands clearly and even the little black dot.

Also tried a basic 4mm, but couldn't focus clearly enough. I'm guessing that the Scope can't cope.

Maybe I will try a 6 or 5 at some point. Didn't manage to see Saturn as the clouds appeared just about the time i could have seen it.

[John]

300x is just too much for Jupiter most of the time even with a top flight eyepiece and perfect collimation. The seeing conditions are the limiting factor. I find 180-220x the most I can use on the planet with my 12" dob the majority of the time, if I want a crisp, contrasty view.

The 7mm X-Cel LX eyepiece would be giving you 171x which will show Jovian details very nicely with a 10" scope.

[Dave In Vermont]

Agreed with above. More magnification will serve to give a blurry view/image where the contrast is what's desired. To be able to discern the finer details of the object, not the size. Learning to eek out the finer details requires practice with such tricks as averted-vision - looking slightly to one side.

Clear & Sharp Skies,

Dave

[Norfolk star gazer]

300x is just too much for Jupiter most of the time even with a top flight eyepiece and perfect collimation. The seeing conditions are the limiting factor. I find 180-220x the most I can use on the planet with my 12" dob the majority of the time, if I want a crisp, contrasty view.

The 7mm X-Cel LX eyepiece would be giving you 171x which will show Jovian details very nicely with a 10" scope.

I've only had my scope for week, so still getting used to the magnification thing and lots of other stuff to learn as well.

I assume that a 6mm would fall into the 180-220 range, but a 5mm would be to much?

Does the same logic of the 180-220 also apply to say Saturn?

[Norfolk star gazer]

Agreed with above. More magnification will serve to give a blurry view/image where the contrast is what's desired. To be able to discern the finer details of the object, not the size. Learning to eek out the finer details requires practice with such tricks as averted-vision - looking slightly to one side.

Clear & Sharp Skies,

Dave

I have tried the averted vision trick and it takes a bit of getting used to as I do wear glasses but don't feel comfortable wearing them when using the scope. Tend to have a bit of eye strain at the end of a session, so must be trying to hard!

I'm happy with what I've seen so far and things can only get better.

[jetstream]

Setting the scope out to cool down is a must for planetary and so is collimation. How do you collimate? A half decent zoom like the Baader MK3 might be an asset to you- it will show coma (as others do) and possibly a bit of astigmatism but the zoom advantage can be a big one. The zoom can be had with the Baader barlow that will give nice high mag and smooth it out a bit.

[Norfolk star gazer]

I have a laser collimator and it was slightly off when I first set it up, but was spot on Friday and was a lot easier to do than I thought.

Will have to get into the habit of doing it more often ( as I am constantly moving it in and out of the garage). I do try to get it out to cool down prior to using it, but the last few days it's been a case of getting it out between showers, so don't want to get caught out with the rain. The garage is cold, does that mean I don't have to get it out for very long first?

Will look at the Baader MK 3 and Barlow. I do have an assortment of basic EPs as well as the Celestron one and a 2x Barlow and will see what works best (when I get a good nights weather). Keeping missing this chance to see Saturn! It just came into view last night and the clouds rolled in.

To be honest, the Celestron 7mm performs very well, but even a basic 8mm gives me a good view?

Jason

[jetstream]

You have some very nice equipment Jason and if the garage is close to the outside temp the mirror will equalize faster-good thinking. To get the best planetary/lunar views collimation should be spot on - with certain steps taken.

Do you use the laser unbarlowed? The collimation subject can cause much debate.... one generally accepted method is to use a Cheshire tool. This will center the secondary under the focuser and accurately point it at the primary. It then allows you to adjust the primary itself. Before or if people start a bunch of pro's and cons on this subject just do yourself a favor and buy one, FLO has them and will help you. Apologies for being blunt  at f4.7 you need collimation to be accurate to get those fantastic planetary views your scope is capable of.

Your scope will not only show you the bands of Jupiter but detail in and off of the bands, the polar caps with striations, white ovals etc. A zoom allows you to "catch" the seeing more often than with fixed fl EP's. The Cheshire trumps the zoom handily in terms of need though....

Best Regards

Gerry

[Norfolk star gazer]

I use the laser collimator un barlowed. The guy in the shop recommended the Cheshire at about £45, but said that for an inexperienced user, the cheaper laser one would be easier.

When I collimated it last Friday, the primary mirror looked spot on the centre, but the secondary mirror was a couple of millimetres off to the right, but I'm not sure if was how the collimator was sitting in the focuser as although it was tight, there still seemed to be a bit of movement, which considering how minute the scope can be out, it should be unmovable. I will collimate it again this week (if the clouds allow me out)

It only took a minor adjustment on the primary and both were then spot on. I can see that it can easily go off, so will make it best practice to collimate each time I'm planning on using it.

I haven't had the best seeing conditions yet by a long shot, so am confident that the views can only get better and it sounds like I made the right choice. I find that Jupiter is very bright and I have to strain my eyes to see it clearly, so have ordered an adjustable polarising filter and hopefully that will cut down the glare.

Thanks for the advice, it was all very useful

[Space Beagle]

I must admit I never used the X Cel LX's on my 250px (f4.7 Flextube one), but they seemed to work fine (for me) on my 200p (f5).

I do still have a Baader Zoom mind you and it is still very useful on the 250px, so, I would recommed one of these too, when funds allow!

I'm sure that collimation will soon become second nature to you!

Enjoy you new kit!

Doc

[Norfolk star gazer]

I've had the scope for under 2 weeks now and even with the bad weather, I've managed to see Venus, Jupiter & Saturn.

I find that the best EP to use so far has been the 7mm Celestron X-Cel.

I couldn't see any seperation of the rings, but not sure if that's because it was to close to a very bright moon or if I need a higher magnification EP.

I have tried a basic 4mm, but the magnification was too much (300x) and was wondering if my scope could cope with a 6mm or even a 5mm ?

[John]

The rings of Saturn are clear at around 25x with a tiny scope or even a finder. They should be completely obvious with a 10" scope at any power at all. Are you sure it was Saturn ?

[Norfolk star gazer]

It was Saturn, unless I've discovered a new planet with rings

The rings were clear and sharp, but I couldn't make out any detail etc.

It was around 11.30pm and the moon was very close and bright and there were some clouds around, so not the best conditions.

The planet I've discovered was very bright and a polarising filter would probably have helped and I've got one today.

I might get a chance to use it tonight. If the clouds go away.

It's all perfectly collimated and ready for action!

[John]

Sorry I misunderstood you earlier post then - congratulations on Saturn !

Like a number of these well known features, the Cassini Division does not always jump right out at you, especially if the conditions are not too steady. The C or Crepe Ring can be hard to spot as well and the Encke Division has eluded folks with very large scopes and great skies all too often !.

[Qualia]

Although Saturn is extremely pretty, in terms of deatil I find it quite frigid, especially if comparing it to Jupiter. With reasonable skies, good aperture and optics you should be able to make out a number of subtle belts across the planet itself, the three ring system - A, B & C and hopefully the Cassini Division. With the 10" all this is easy to see, but to be honest, with the 4" achro, I've only ever had a fleeting hint of the Cassini Division at best. Needless to say, the Encke Division continues to elude me, but I will try again this year.

[Norfolk star gazer]

I'm viewing Saturn through a 10" skywatcher and using a Celestron X-cel 7mm EP.

I'm happy with what I've seen so far in poor conditions, so look forward to better nights

[Norfolk star gazer]

I'm wondering if a 6mm TMB will perform better

[Mr Spock]

I have a 6mm TMB and used to have a 250mm Skywatcher. The TMB worked fine for planets.

[Norfolk star gazer]

I have a 6mm TMB and used to have a 250mm Skywatcher. The TMB worked fine for planets.

Thanks. Will look into getting one. In your experience with a 259px, what was the highest magnification you used on planets. Am considering a 5mm, but not sure if the scope can cooe

[Norfolk star gazer]

Cope. Not cooe

[Mr Spock]

I had a 4mm NLV. I didn't get to use it often but it did give me my best ever view of Mars. My scope was on an EQ6 though and tracking a dob with a 50° eyepiece at x300 wouldn't be easy.