BST Explorer 5 mm or 25 mm ?

[Bart]

Hello All,

I have an 8 mm BST and I love it., I might be returning an EP and haven't decided what to replace it with.

I have 8, 11, 14 good EPs and cheapish 20, 24 and 32 mm

Should I get the 25 mm BST for lowish wide-ish viewing or the 5 mm giving 250 mag when seeing permits.

Anyone use a 5 mm BST in a 10 " fl 1250 mm or is this too fast for this EP.

Thanks for any input or comment.

Bart

[LMC]

I'm not familiar with the BST brand, but in my experience a 5mm EP is rarely very useful on a Newt.

As a (former) high-power addict, the number of times I was able to use a 5mm EP in anything other than my 80mm f6 refractor, was pretty minimal.

Unless you have some sort of tracking ability, you (well I) spend the whole night chasing some elusive Lunar feature that keeps whizzing out of the wobbly view.

Even DSO's don't stand still long enough.

You already have a good. sound range of eyepieces in the high/mid range, to which you could add a decent barlow when conditions permit.

IIWY, I'd get, as you suggest, something of around 25mm - 32mm.

I think you'll really enjoy the wider field of view and get far more use from them.

Just a thought!

Peter

[rwilkey]

A 32mm plossl is a good ep to have in your collection, although the 25mm BST is also good, but the 32mm gives that slightly wider view, I would recommend the 32mm PanaView as your scope will have the dual 2" focuser. Great sharp views and it will get more use than a high power ep.

[pritc]

I have the 5mm & 25mm BST eyepieces

Great eyepieces.

I have to be honest,I used the 25mm about 10x more than the 5mm.....

But since I got a SW 32mm PanaView ,my 25mm BST takes a back seat.......

Wayne

[Bart]

thanks folks

I forgot to add I have a 32 mm 2" EP that came with the scope , its ok visually and has 70 degree FOV.

I was going to get the 5 mm to get x250 for those rare nights when conditions allow, just wondered if the BST could give that good a view with my scope given good seeing. I realise the use would be infrequent.

My ES 11mm barlowed gives me good planetary views at x 227 , the 5 mm would just be for those special nights.

Thanks again for input

Barry

[pritc]

thanks folks

I forgot to add I have a 32 mm 2" EP that came with the scope , its ok visually and has 70 degree FOV.

I was going to get the 5 mm to get x250 for those rare nights when conditions allow, just wondered if the BST could give that good a view with my scope given good seeing. I realise the use would be infrequent.

My ES 11mm barlowed gives me good planetary views at x 227 , the 5 mm would just be for those special nights.

Thanks again for input

Barry

Noticed you have a 'TMB Type II 6 mm' eyepiece in your Sig.

Is it no good??

Wayne

[cotterless45]

The only 2 Bsts that I've found excelled at f5 in a 250mm Dob are the 25 and the 12mm. The 12mm gives a sharp across the field view of galaxies, clusters etc.

I've tried the 5mm Bst, but I think that it's too much for the scope to handle . Had better views with a 6mm SP. The Meade 12.4mm 4000 EP is good.

From my old notebooks, I found a snippet advising that 7mm was just about the limit for a 250mm f5 setup.

[Bart]

Noticed you have a 'TMB Type II 6 mm' eyepiece in your Sig.

Is it no good??

Well, I didn't get any joy with it. That's the EP I'm returning.

I found a snippet advising that 7mm was just about the limit for a 250mm f5 setup

Wayne

Don't know about that. I barlowed my 11mm Explore Scientific to effectively give me 5.5mm and I got a fantastic view of Jupiter at x 227. GRS was nice, clear and crisp. I just hoped the BST might give me that little bit extra.

Bart

[Catweazel]

Does anyone have any views on which would be better on my Evostar 120 f8.3 refractor Celestron Xcel LX 7mm or BST 8mm? Probably a daft question but am trying to choose between them! Thanks CW

[Catweazel]

Does anyone have any views on which would be better on my Evostar 120 f8.3 refractor Celestron Xcel LX 7mm or BST 8mm? Probably a daft question but am trying to choose between them! Thanks CW

Never mind, the BST just got relisted at 'skies the limit', so I bought that one. Cue loads of people saying "get the Celestron"

[Daniel-K]

i lent my friend the 8MM and the veiw in the eyepiece was mind blowingly good if i rember the 5mm was to powerful and the 25mm gave stunning veiws of open clusters.

ps nice scope

[Catweazel]

i lent my friend the 8MM and the veiw in the eyepiece was mind blowingly good if i rember the 5mm was to powerful and the 25mm gave stunning veiws of open clusters.

ps nice scope

Thanks for that. What scope does your friend have? I was thinking about getting a 5mm BST if I like the 8mm. The cheap 10mm Skywatcher that came with the scope seems to work ok when barlowed with the Tal x2 (i.e at 5mm) Jupiter looks a bit 'swimmy' but cloud bands are discernable and moons look more spherical that I expected. 5mm gives me 200x on my scope. Do you think it may be too powerful? Thanks

[rwilkey]

Hi CW, I think the 5mm will work well with your scope on nights of good seeing, we have had a few good nights recently. Let us know how you get on with the BST, I read that they have a new name on them, 'Starguider' apparently, but still the exact same eyepiece.

[spaceboy]

http://stargazerslounge.com/members-equipment-gallery/167482-finally-bst-firm.html

[rwilkey]

Hi Spaceboy, thanks for the link, which really sums up the BST Explorer, great in f/7-f/9 in my view.

[Catweazel]

Hi CW, I think the 5mm will work well with your scope on nights of good seeing, we have had a few good nights recently. Let us know how you get on with the BST, I read that they have a new name on them, 'Starguider' apparently, but still the exact same eyepiece.

Thanks Robin, I will certainly post my findings with the 8mm. I spoke to Alan and he did mention that they said Starguider on them, but as I don't have a 'set' I'm not bothered about that; my eyepieces are a bit of a 'pick & mix'. If I like the 8mm I will get the 5mm too I expect. Will keep you posted! CW

[Catweazel]

Just to update, the eyepiece turned up today and it has BST Explorer written on it. I tried it out earlier on Jupiter but the seeing was not great tonight and it was quite windy here. I used my GSO 32mm to look at moon and then zoomed in with BST 8mm, which was a good combination as both gave nice sharp views; contrast was very good with BST. Will try out on Jupiter and a double star or two another night. CW

[Caldwell 14]

I am about to buy a 25mm, 18mm, 12mm and an 8mm BST's for my TAL 100RS, they should just about cover things. The only questions is do I get the 15mm or the 12mm...or even do I get the 5mm instead of those two, the 25 ,18 and 8mm are a given, perhaps a 5mm might get not get used too often

[todd8137]

Does anyone have any views on which would be better on my Evostar 120 f8.3 refractor Celestron Xcel LX 7mm or BST 8mm? Probably a daft question but am trying to choose between them! Thanks CW

7mm x-cel lx i had a 8mm on loan from Alan a side by side test the x-cel beat it hands down the filed curvature and bloated stars were unreal with the bst the x cel mega no curvature or bloated stars letting Jupiter drift by in the eps the bst was 20% out of focus on the xcel none at all get the x-cel lx

[Catweazel]

7mm x-cel lx i had a 8mm on loan from Alan a side by side test the x-cel beat it hands down the filed curvature and bloated stars were unreal with the bst the x cel mega no curvature or bloated stars letting Jupiter drift by in the eps the bst was 20% out of focus on the xcel none at all get the x-cel lx

Thanks Todd, have just got the BST however. First attempt at Jupiter not great, as mentioned above, will have to have another go in better conditions before I pass judgement. The xcel is another £30 over the BST, so should be better really. Also, I would say that my scope (f8.3) should be more forgiving on the BST than your f5, but we shall see

[rwilkey]

Catweazel, the BST's should perform perfectly in your f/8.03, no problem.

[Catweazel]

Catweazel, the BST's should perform perfectly in your f/8.03, no problem.

Thanks Robin. As I mentioned in another thread, on first light with BST, it seemed to show a halo type bright disc over the image of Jupiter?, this made it difficult to see any detail. I thought it might be because seeing was bad with cold and wind also taking its toll, but I did notice that this effect wasn't there with the cheapo SW 10mm? Will have to test it again to confirm

[rwilkey]

I have an f/9 and have not experienced this problem, just shows how differently they perform sometimes, I often use mine for double stars and they are great for these, but I will check Jupiter again next time I am out.

[spaceboy]

The xcel is another £30 over the BST, so should be better really.

That's what I've been thinking. Dared I mention it but the Xcel-lx seems to be getting itself a following often being compared to the BST's but I have to question how a set of BST's 5, 8, 12 15, 18 & 25mm £246 can be compared to a similar set of Xcel-LX 5,7,9,12,18,25 £414. At a £168 difference I would certainly hope they were better. As I have said before budget eyepieces are budget for a reason and if they were anything other wise everyone would have them. The BST's offer superb value for money and actually offer a great deal more than similarly priced alternatives. I'm sure the Xcel-lx is a good value eyepiece in it's price range but I think it would be better compared to WO SPL's, Vixen NVL's or the like than a £41 BST. I'm not saying that people shouldn't consider paying a bit more for an EP merely saying that some of the cheaper alternatives can fill the gaps nicely in an EP case. When a pea sized planets sits in the center of view what dose it matter if the outer 20% isn't up to scratch? as long as there is a sharp, contrasted planet sat in the other 80%. The BST's at 60' AFOV offer way more than is necessary to view planets. I happily sat for hrs staring through BGO's with only 40'. Just my 2p worth.

[spaceboy]

Thanks Robin. As I mentioned in another thread, on first light with BST, it seemed to show a halo type bright disc over the image of Jupiter?, this made it difficult to see any detail. I thought it might be because seeing was bad with cold and wind also taking its toll, but I did notice that this effect wasn't there with the cheapo SW 10mm? Will have to test it again to confirm

I had a similar experience with a 6mm Radian and TMB clone on Jupiter. I think it is a large eye lens out in the cold with a warm eye pushed up against it. I likened it to looking through a steamed up window at a light source. I put it down to this as it did not do it all the time, only now and again and I have never noticed it with the smaller eye lens on plossls.