Jump to content

Stargazers Lounge Uses Cookies

Like most websites, SGL uses cookies in order to deliver a secure, personalised service, to provide social media functions and to analyse our traffic. Continued use of SGL indicates your acceptance of our cookie policy.

sgl_imaging_challenge_banner_christmas_presents.thumb.jpg.587637e0d01baf4b6d21b73610610bbb.jpg

Prador

BST Explorer 3.2mm

Recommended Posts

Back in the mists of time, as most will recall, BST Explorers were rebranded to Starguider. Not sure of the reason behind this change but I'm wondering if the 3.2mm was released pre or post name change. I lack the 3.2mm but would like, if possible, to source an Explorer branded one. Having one Starguider in the case would seriously mess with my chi 😂

Share this post


Link to post
Share on other sites

They were not available when I started, nor was the elusive 6mm that I so desire ( the 6 is still not manufactured, only  'guru John' has one, imaged only!!!!!!!! 😉 )
It's my assumption therefore, that they came after the Explorer which was name changed due to  copyright laws, so possibly unlikely to come under the Explorer brand, but don't let that stop you, as you could erase/cover the branding.
It was an option for me to buy another 12mm and simply fit a Barlow cell and call it my 6mm Starguider, labeled of course.

 

IMG_0178.JPG

IMG_0179.JPG

 

On my manual scope the 3.2mm is ok for/on the Moon, being  that the target is so large and bright, but not really tried the 3.2mm  with much else to be honest, so  maybe I'll have a better look this season, what with my less light polluted garden, but those fclouds are driving me nuts, just as they were last season?

Edited by Charic
  • Thanks 1

Share this post


Link to post
Share on other sites

Might have to man up and get the Starguider. It will probably go beyond useful magnification and exit pupil on a 250mm newt but for less than £50 it's low risk. I didn't know once upon a time they came in 6mm flavour. Thank you for the info though. I've left with more knowledge than I started so win for me 😀

Share this post


Link to post
Share on other sites
8 minutes ago, Prador said:

I didn't know once upon a time they came in 6mm flavour.

Thats my point, they didn't............It's my desire to owning one, even pleading with retailers to 'provide me one', matching the focal ratio of my scope,  and completing for me what is a very useful and extremely great value for money eyepiece collection based around an f/6 scope. 

The only  reason I have the William Optics 6mm, is due to the fact I can't buy a 6mm Starguider.

 

Share this post


Link to post
Share on other sites

I believe the 3.2mm was a later addition to the range, ie: after the branding was changed from Explorer to Starguider.

I've never seen a 6mm in this range which is a slight pity because it's a very useful "goldilocks" focal length in many scopes. I can see why Charic decided that he wanted one even though it meant going for a different design :smiley:

 

Share this post


Link to post
Share on other sites

Given that the focal length is determined by the separation of the negative and positive lens groups I wonder if it might be possible to make a 6mm by taking a 5mm and finding some way to move the negative lens group up the nosepiece.

Share this post


Link to post
Share on other sites
3 hours ago, Ricochet said:

Given that the focal length is determined by the separation of the negative and positive lens groups I wonder if it might be possible to make a 6mm by taking a 5mm and finding some way to move the negative lens group up the nosepiece.

Or, perhaps more realistically, add a spacer to the 8mm as with the Hyperions and their tuning rings.

Share this post


Link to post
Share on other sites
5 hours ago, Louis D said:

Or, perhaps more realistically, add a spacer to the 8mm as with the Hyperions and their tuning rings.

That was my initial thought, but I don't know how much space would have to be added and a male-female spacer is going to have a minimum distance. Looking at the 18mm I've got the nose appears to be partially threaded from both top and bottom, with the lens cell inserted from the top, so possibly it could be unscrewed to reduce the focal length a little. What I haven't checked is how much extra thread is available in the 5mm (or if the lens cell really will unscrew).

Share this post


Link to post
Share on other sites
12 hours ago, Ricochet said:

make a 6mm by taking a 5mm and finding some way to move the negative lens group up the nosepiece.

 

8 hours ago, Louis D said:

Or, perhaps more realistically, add a spacer to the 8mm as with the Hyperions and their tuning rings.

I can just simply 2x Barlow the 12mm providing me 200x. One other option was to add my Skywatcher deluxe Barlow lens (cell only ) and screw that permanently to a second 12mm? I'd have my 6mm yes!  Well not really, as the cell alone would  only Barlow by a factor of something like 1.6, so I'd end up with a 12mm EP providing 160x  power, not quite the intention.  

First opportunity I get ( doesn't  look possible this weekend - weather is bad ) I'll  re-compare my  William Optics 6mm SPL with the Barlowed 12mm BST, and I think the combination with Meade's #140 Barlow may leave the SPL behind.
Won't know until I try. If the test comes good, maybe another 'set of three' will head to the classifieds?

Share this post


Link to post
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now

  • Recently Browsing   0 members

    No registered users viewing this page.

×

Important Information

By using this site, you agree to our Terms of Use.