BSTs

[Dom1961]

*8mm not 6mm and will 150x be enough for saturn?and jupiter? In decent detail?

[alro]

Dom,

im not experienced enough to recommend sizes, however i do use all of mine, i just change them until i find best view of what im looking at, no very scientific, but it works fantastic for me.

I have read somewhere on here that x150 is good for jupiter.

do you intend using a barlow? If you are the 25 would give 12.5.

to be honest i hardly use barlow but when i have the quality has not been weakened.

Al

[ghostdance]

Buy the Max Vision 24mm 68°. Better than the BST for only marginally more money.

Paul

I can't comment on the BST comparison, but the MV 24/68 is a little (er, not so little! ) cracker - very impressed the couple of times I've used it (new arrival). Looking forward to viewing more through it.

[russ.will]

8, 12 and something around 25mm. I've had various 18-20mm EPs and they always end up getting bypassed as I jump from 24 to 12-14mm. I dunno why and plenty of people would feel like their arm had been cut off without something at that focal length, but not me.

Russell

[Roysten]

I've just got a 5mm BST, was choosing the 5mm and 8mm. I get very sharp views through it but through a 2x Barlow the view isn't quite as good. Barlowed it's pushing the max magnification of my scope, only worthwhile with perfect seeing.

I got mine from Astro365 for £49, though then had to pay £3.60 pp so watch out there where funds are limited, almost removes the difference for the 7mm X-CEL I was pondering too!

[SpaceWalker]

Okay so I've just worked out the magnifications, and now im thinking of a 6mm,12mm and 18mm, any opinions?

IMO,  the 25mm, 12mm,  8mm and 6mm (e.g. 12mm+2x Barlow) will give the optimal magnification spread for f/5.9 Dob, a lineup that covers most what you need.  For high magnifications you need an extra eyepiece, e.g. the 5mm BST Explorer. Or get the 9mm Celestron X-Cel LX instead of the 8mm BST, so the 2x Barlowed X-Cel LX will give you 267x under very good seeing conditions. But the 5mm (240x) would be preferable since it'll be used more frequently.

*8mm not 6mm and will 150x be enough for saturn?and jupiter? In decent detail?

No, you need for planetary at least 180x-200x or a little bit more for a full enjoyment and decent details, IMO   .  The 6mm (or 12mm+2x Barlow) will provide this magnification. But the good seeing conditions, good collimation of your scope and enough cooling time (30-60 min) go first. 

I usually observe Jupiter at 185x-250x, Saturn at 200x-250x. I don't observe Jupiter and Saturn when the atmosphere doesn't support more than 150x, because they are too small at that magnification, IMO  .

The 8mm BST  Explorer probably is good itself, but 2x Barlowed will give you 300x  what is too much for most observing conditions.

[ronin]

Planets can be magnified but do not need to be.

Best I have seen Jupiter was at very low magnification as in around 40x, suggest you look at 80x if the scope will deliver it without trouble.

Best I viewed Saturn was 125x - Tal and an 8mm eyepiece. So I would suggest that you initially look at magnifications similar, 80x to 125x, again assuming the scope has no problems. 150P f/5 ?? so 650mm.

With planets like Jupiter and Saturn you likely need a bit less magnification so that the image remains sharp. If it loses definition then Jupiters bands are less distinct and the rings on Saturn suffer, if you want to see the Cassini division you need a good image, one where the image loses definition will not show it.

[Xiionn]

Love Jupiter at around 100x. The moons are what makes Jupiter for me

[Stu]

Planets can be magnified but do not need to be.

Best I have seen Jupiter was at very low magnification as in around 40x, suggest you look at 80x if the scope will deliver it without trouble.

Best I viewed Saturn was 125x - Tal and an 8mm eyepiece. So I would suggest that you initially look at magnifications similar, 80x to 125x, again assuming the scope has no problems. 150P f/5 ?? so 650mm.

With planets like Jupiter and Saturn you likely need a bit less magnification so that the image remains sharp. If it loses definition then Jupiters bands are less distinct and the rings on Saturn suffer, if you want to see the Cassini division you need a good image, one where the image loses definition will not show it.

With a well set up 8" scope ie well collimated and cooled, planets should take a decent amount of magnification, and need it to get good detail.

I agree you should not over do it, but x180 on Jupiter is well worth using, and Saturn can take more when it is well positioned (not at the moment). Mars at opposition can take x250 in good conditions, and needs it to show the best detail.

The best I have seen Jupiter was probably at over x200 under very good conditions. The detail visible in the GRS and belts is wonderful, plus clearly observing noon and shadow transits is amazing to watch.

Don't just look quickly and be disappointed, spend time at the eyepiece and you will catch those moments of clear seeing when the view becomes pin sharp and the detail comes through, well worth it.

Stu

[spaceboy]

Here was my findings http://stargazerslounge.com/topic/128026-finally-on-the-bst-firm/ in an 8" f/5 scope.

They are one of the best budget eyepieces out there for sure. While my experiences lead me to search for another alternative it is worth mentioning that the shorter focal length BST's performed very well given a fast scope can bring out the worst in all but the best of eyepieces. Coma is always going to be an issue in faster scopes but I think the Skyliner 200P with it's slightly slower f/6 optics should be a good match for the BST's and be forgiving of even the 25mm. 

I will point out though that I have recently added the 5,8,12 & 15mm starguiders back to my collection as I have found them by far to be the most comfortable and best performing eyepiece (for their cost) in Ha and WL solar observing.

[Dom1961]

So now im thinking of getting 5mm,8mm,12mm,25mm opinions? Or shall I swap the 5mm for a different brand like a celestron exel?

[alro]

If you use a x2 barlow 25mm would give you 12.5mm , close to your 12.

then again 18 will give 9!

i find these eps very comfortable.

if you do go for 4 of these i strongly recommend you contact dealer first for best price!

Al

[Dom1961]

I thought barlows reduced image quality?

[Stu]

I thought barlows reduced image quality?

It totally depends on the Barlow. Cheap ones do, high quality ones don't.

I would stick to eyepieces for the moment

[alro]

They may do, i have x2 barlow and on the few occasions i have used with my bst starguiders i have not really noticed any quality degrade.

i dont usually use the barlow unless i want to get high magnification on moon, to see if i can justify getting 5mm. So far i can.

Al

[Dom1961]

I'll be buying them one every two months due to pocket money, so I won't be buying all at once

[Dom1961]

Ahh right okay, thanks for the advice

[Xiionn]

Revelation 2.5x Barlow is well respected, i have one and the detail loss isn't noticeable to my eye, and i have very good eyesight! Its also not expensive, so worth a look after you have sorted out your other EP's

[Dom1961]

Ahh right okay, I'll take a look some time, are the revelation ones the ones which you can screw a bit of so it acts a a 0.5x as well?

[Xiionn]

I have no idea, i haven't even thought to try! Just ordered a 5mm BST though!

[alro]

Im tempted to get 5mm for my bst herd!,

i realise there may not be many occasions to use but i like to get right into the moon!

i have barlowed by 8mm and my meade 6.4,

maybe to much at 3.2!!

al

[djpaul]

I have the following BST's which i use with my SW 120ed refractor

25mm,15mm, 8mm, 5mm, 3.2mm

All of them are fantastic and the eye relief is very good on all focal lengths

Other than that i have a few TeleVue Plossl's 

I don't feel i really need anything else

Paul

[Xiionn]

3.2...wow, whats that like? I had not considered going that far on my 150.

[Dom1961]

How often do you use your 5?

[spaceboy]

If you decide on a barlow it  is worth taking into account the effects it will have on the eye relief. Not so much an issue on the shorter focal lengths but you may start to notice it in the 18 & 25mm.