Which BST to go for Next?

[dick_dangerous]

Hi All,

I've got another tranche of spare cash and I'm eyeing up a new BST EP to add to my collection of one 8mm EP. What's puzzling me is which focal length to go for next.

Currently, aside from the 8mm, I have two lots of SW stock 25mm and 10mm EPs, the barlow that came with the ST80, a 1.25'' moon filter and a 1.25'' UHC filter (I'm only in the market for 1.25'' EPs right now). This would mostly be for my SW 150P, with a 1200mm focal length.

I'd like to get something in between the 25mm and the 8mm, but am unsure whether to go for 12mm (x100) or 15mm (x80). I'm mostly looking for something to enhance my views of globular clusters and galaxies.

Any advice greatly appreciated!

Thanks,

DD

[AlexB67]

Hi,

Personally I would go with the 15mm, now there may be situations where you my prefer one over the other, but to start with. If I got the scope right it is the 1200 focal length Dob the 15mm will give an exit pupil close to 2mm, this is  very useful thing as a general workhorse I find. 

I have the 15mm, not the 12mm, I it is a very nice eyepiece.

If you don't mind me saying by means of suggestion, if you can tolerate  the slightly tighter eyerelief I would also consider having a look at the 16mm Maxvision, it is pretty much the same price and gives an extra 8 degrees and an exit pupil just over 2mm. From what I can see having put my 20 and 28mm Maxvision for some months now, and the 8mm, 15mm, 25mm for almost a year,  the latter are a tad sharper optics over the BSTs with great transmission too and colour neutrality If that matters to you. 

No doubt there will be some other contenders to think about other have experience with, all I can say is about those 2 makes, given that I own them. 

Good luck in the picking

[alan potts]

I think Alex's suggestion of the 16mm Max Vision is a very good one. It is a little tight on ER so they say but I had the Meade 16mm SWA which was 140 quid eyepiece BTW and I didn't think the ER was bad. These MaxVisions are by all accounts the same as the Meade SWA, being from a cancelled order when they had money peoblems, now they are just badged different.

If on the otherhand you want to stick for BST i would go 15mm as a gap filler. You asked about globulars, Myself I believe these are at their best with power from X120-150, this will depend a little on size of scope though.

Alan.

[AlexB67]

The eye relief is a plenty if you don't wear glasses I find with the 20mm. With glasses I would say it is just on the limit with the 20mm, it is fine to use, but you are right up against if you want to see all the field stop in my case, if it had a tiny bit more it would be better perhaps depending on your glasses, nose shape and all that. It is workable for me with glasses, but once I settle into observing the glasses come off anyway.  The 16 mm has shorter eyerelief so I believe it will not be suitable if you do need to wear glasses all the time.

All the BSTs starguiders, even if the published eye relief figures appear on the short side, given the build and twist cup design, I find them to have plenty eye relief and are very comfortable to use with or without glasses, adjust the twist cup to suit. BSTs are very forgiving on eye placement too I find.

[dick_dangerous]

I'm thinking of sticking with the BSTs because they're parfocals - I intend to "complete" a collection with a replacement 25mm and a 5mm in the future. Plus I love my 8mm EP. Will check out the MaxVisions though, so thanks for the tip!

DD

[Chris]

I've got a set of BST's and the 16, 24, & 28mm ES Maxvisions. The BST's are very good value for money for how the perform but the Maxvisions are superb! Unbelievably good performers for how much they cost. If I was you and if you don't need glasses for observing I would pick up a 16mm Maxvision whilst they are hot, you can always complete your set of BST's has and when they appear on the second hand market but you won't see that many Maxvisions for sale second hand at second hand prices. If you are set on a BST next on the other hand I would go for the 12mm out the bunch

All the Best

Chris

[AlexB67]

I may recall this incorrectly. I've not done so in a while and could be wrong about this, but the MV focus point was close to the BSTs, when I say close I mean a lot closer to when I change to an ortho, which is a long way away from my Radians or any eyepiece for that matter and the pentaxes in turn I have.  

I end up tweaking them anyway since the focuser in the 10 inch moves quit easily when not locked. Again I could be wrong but the parfocal BSTs are almost parfocal and some not at all, like the 25 versus the 8mm, but can't be certain of this without trying. I've not tested it in a while, but I think they required a tweak with some.

Personally I've never been that fussed about parfocal eyepieces mind you so take my comment with extreme caution about how close they are to the MVs in focus point.   

[Paul73]

+1 for the 16mm MaxVision. A different league to the BST in my view. This is my Globular eyepiece of choice!!!

The re focussing only really becomes an issue when you get to the shorter eyepieces.

But, if you get on with the BST's. And, for the money, they are great. And, there is something satisfying about having a matching set....

All that you wanted was a simple "15mm will see you right!"

Paul

[AlexB67]

All that you wanted was a simple "15mm will see you right!"

Paul

Paul, I'll take full blame for that one

Still I was also hooked on  BST for a while to begin with, but it is only when you start  trying other eyepieces and the differences do become apparent and the grass can be bit greener elsewhere.

I feel the MVs are always worth a mention given the steal of a price tag. As good as the BSTs are in this price range, I just get the impression the MVs are so hard to beat at that price. I should add I can only go by my own experiences not having tested them against a myriad of other options that could be out there.  The 12mm BST down to 5mm and the MVs in the longer focal lengths would make a fine collection for very little money and give a lot of bang if you want that sort of 60 degree and higher FOV 

Of course if you are happy with 40 - 50  degrees and short eyerelief, I can open another whole can of worms I'll not get started on in terms of extra options

I'll get my coat now shall I ?

[ronin]

Of the 12mm or the 15mm I would say the 15mm is the better option.

At 80x you will get just under 1 degree view.

Stay on line and get the complete set, they look good altoghether and you will not regret it.

I have one and a half sets of them so far. :rolleyes:

They are much happier as a complete set, they have friends around them to talk with, get less stressed and generally work better. :grin:

[YKSE]

Paul, I'll take full blame for that one

I feel the MVs are always worth a mention given the steal of a price tag. As good as the BSTs are in this price range, I just get the impression the MVs are so hard to beat at that price.

I cann't agree more on this. BSTs are excellent for their value when introduced, and for some years thereafter, still good the for value, but not as much as before, since the MV serie have these steal price, and Baader Classic Orthos introduced last year. MV16 is very good, BCO 18mm is better than MV16 with better ER.

[dick_dangerous]

Paul, I'll take full blame for that one

Oh no, it's completely my fault. If you canvas opinion on the internet you always get a whole host of options - it's a good thing! I'd have never bought the 150P if I hadn't asked for upgrade advice on here!

DD