25mm BST Explorer vs 26mm Meade 5000

[angusb1]

Just a quick review. We tried both eyepieces in a 6" F12 achromat and an 8" F4 newtonian. Unfortunately when the EPs were tried in my newtonian it had become uncollimated to such a degree that we couldn't make a useful comparison. With the MPCC it was bad due to the miscollimation but without it the coma was quite severe and the view at the last 25% of the field was terrible.

We tried both eyepieces in the refractor on M42 and on M45. On M42 the 26mm Meade showed nice contrast to the nebulosity and it appeared bright against a dark sky background. The 25mm BST Explorer showed a similar amount of detail to the nebulosity but the image was not as bright and we thought the contrast was not quite as good. Both of us preferred the view through the Meade.

On M45 the Meade showed quite a flat field across the view. The stars on axis were very sharp but those around the last 10% of the field were softer. The BST by comparison showed a slightly larger field of view. This surprised us as both eyepieces claim a 60 degree apparent field of view so if anything we expected the BST to show a slightly smaller FOV since it has a longer focal length. The stars on axis in the BST were as sharp as in the Meade but the stars in the outer 20% were softer, and stars that had been sharp in the Meade near to where the view became softer were noticably softer in the BST.

Although the build quality of both eyepieces was good and they both had a pleasant twistup rubber eyecup we both preferred the Meade in this respect. The BST was slightly smaller and lighter. It was frustrating that we couldn't try these in the shorter newtonian as both would have given us some nice widefield views of some of the more open clusters. I observe regularly with James who owns the refractor and Meade 26mm though so hopefully next time we can compare the EPs in my scope on some wider targets.

[John]

Thanks for those notes - very interesting. Seems to confirm that the 25mm BST is the weakest of the range. An F/12 scope is going to be pretty forgiving so if you were seeing issues with that goodness knows what you would see at F/4

Tom Trusock of the Cloudynights site did an interesting review of the Astro Tech Paradigm eyepieces which appear to be clones of the BST Explorers:

First Look: Astro-Tech Paradigm Eyepieces - CN Report

His findings seemed to indicate that the 25mm had more issues than the rest as well.

[andrew63]

Thanks for the posting an interesting review, sure it will be useful to those making a future purchase. At one time those meade were more expensive, but can now be picked up for around £50 which sounds pretty good in line with your findings. I had the 12mm BST and that was a very good eyepiece.

andrew

[Tinker1947]

Unless i hear bad things i will start to collect these one at a time....

First Light Optics - Baader Hyperion 68 degree eyepiece

[johninderby]

Curious that the BST design doesn't seem to scale well at the longer focal length. In comparison I have used most of the Celestron X-Cel LX series and the 25mm LX is just as strong a performer as the rest of the line. No drop-off in performance at all.

Also used the 25mm TMB Planetary clone , and the performance doesn't just so much fall off compared to the shorter focal lengths but plummets like a stone. Might appeal to the seagull lovers out there I suppose.

John

[John]

Unless i hear bad things i will start to collect these one at a time....

First Light Optics - Baader Hyperion 68 degree eyepiece

I'd do some research into how people find Hyperions in fast scopes. Your 250 is F/4.7 - that's a fast scope. There may be better options.

[Bart]

I'd do some research into how people find Hyperions in fast scopes. Your 250 is F/4.7 - that's a fast scope. There may be better options.

I also heard some negatives about the Hyperion in fast scopes. I changed my mind on these and went down the road of importing Explore Scientific EPs. Very good EPs indeed.

Bart

[sticks]

I just had first light with my new BST 25mm and it is stunning in my MAK 127 - stunning. Makes the Plossl EP that came with the scope look really dull and lifeless. Jupiter was well defined with the BST and the Plaedes (well parts of it at a time!) looked lovely. I think we sometimes get into nuances that a general observer isn't going to have to worry about if he is looking at the view and no two opinions are the same anyway. I have heard this EP described as "runt of the litter" based on one review in a fairly fast scope. For £41 each I love all my BSTs and this new one is a cracker.

[rwilkey]

I think it depends what scope it is used in, the Mak 127 is well capable of giving a good account of the 25mm BST I think.

[angusb1]

I just had first light with my new BST 25mm and it is stunning in my MAK 127 - stunning. Makes the Plossl EP that came with the scope look really dull and lifeless. Jupiter was well defined with the BST and the Plaedes (well parts of it at a time!) looked ilovely. I think we sometimes get into nuances that a general observer isn't going to have to worry about if he is looking at the view and no two opinions are the same anyway. I have heard this EP described as "runt of the litter" based on one review in a fairly fast scope. For £41 each I love all my BSTs and this new one is a cracker.

I'm happy with my 25mm BST too but when I put it side by side with the 26mm Meade 5000 I preferred the Meade. Not better by a huge margin, in fact a very similar EP, but definitely better. I'd like to have the opportunity to compare the rest of the BSTs against the Meade 5000s as I think the 18mm and 15mm are better than the 25mm, but I don't know anyone who has any of the Meades apart from my mate James who just has the 26mm.

I also heard some negatives about the Hyperion in fast scopes. I changed my mind on these and went down the road of importing Explore Scientific EPs. Very good EPs indeed.

Bart

I have the Explore Scientific 82 degree 11mm and its in a different league to both the BSTs and the Meade 5000 series but it costs 4 times as much as the BSTs. The equivalent in the range to the BST 25mm is the ES 24mm at £260 and for that money it should be better. Having used the ES for the first time on Thursday I'd love to get more but they are going to have to wait, and in the meantime I'll enjoy the BSTs.

[Bart]

I'm happy with my 25mm BST too but when I put it side by side with the 26mm Meade 5000 I preferred the Meade. Not better by a huge margin, in fact a very similar EP, but definitely better. I'd like to have the opportunity to compare the rest of the BSTs against the Meade 5000s as I think the 18mm and 15mm are better than the 25mm, but I don't know anyone who has any of the Meades apart from my mate James who just has the 26mm.

I have the Explore Scientific 82 degree 11mm and its in a different league to both the BSTs and the Meade 5000 series but it costs 4 times as much as the BSTs. The equivalent in the range to the BST 25mm is the ES 24mm at £260 and for that money it should be better. Having used the ES for the first time on Thursday I'd love to get more but they are going to have to wait, and in the meantime I'll enjoy the BSTs.

No, Angusb1, you're right about the BSTs and the ESs, there is a marked price difference. I was more comparing the ESs against the Hyperions based on Tinker1947's statement that he intended to collect the Hyperions for his fast scope.

I am a big fan of the BSTs and while I probably have enough EPs I still have a hankerin for another BST and the 25mm is the target which is what sparked my interest in this post.

Its a pity you didn't get a chance to test it in your fact scope because if it was favourable, I'd probably know whats on my shopping list next.......

Clear skies

[angusb1]

I'd like to try the Hyperions too but I don't know anyone who has any.

My F4 scope is collimated properly now so the next chance I get I'll try the 25mm and report back with my findings. I have the 18mm to compare it against so should be able to give a review of edge sharpness and field flatness at the least.

[rwilkey]

The Baader Hyperions do not perform well at f/4, so avoid these for fast scopes.

[angusb1]

Sorry Robin, I meant that I'll test the BST 25mm, not the Hyperion.

[rwilkey]

That should give you good results.

[up2nogood]

Hi guys,

As i'm learning as i go along! i hear this talk about slow and fast scopes!

Is my 8" dob classed as a fast scope?

And would the Meade Series 5000 be good for the 8" dob?

Cheers.

[John]

8" dobsonians usually have a focal ratio of F/6 and a focal length of 1200mm. By todays standards they are medium-to-fast I would say but not as demanding as F/5 or F/4.7 scopes. The Meade 5000 series eyepieces should work well as should the BST Explorers.

All eyepieces will in fact work with the scope of course but some start to show distorted stars in the outer parts of the field of view. This is called astigmatism and bothers some people more than others. Wide angle eyepieces tend to show astigmatism in fast scopes unless they are specially corrected not to do this but this is quite difficult to achieve from an optical point of view and therefore wide angle eyepieces that show no astigmatism in fast scopes are expensive.

[up2nogood]

Hi thanks for that.

So would a Baader Hyperion 68 degree not be as good in a 8" dob then say a Meade 5000 series

[John]

....So would a Baader Hyperion 68 degree not be as good in a 8" dob then say a Meade 5000 series

Assuming that we are talking about the Meade 5000 series plossls then I think they might be a little sharper at the edges of the field of view than the Hyperions but the Hyperions would have more comfortable eye relief (that's the distance your eye needs to be from the top lens of the eyepiece).

In practice I don't think there would be much difference between the two to be honest.

There are Meade 5000 series super wide and ultra wide angle eyepieces as well which I've not tried so I can't comment on.

If your scope was the 10" F/4.7 (ie: faster) then I'd be more cautious about the Hyperions.

Sorry I can't be more definite - eyepiece choice is quite a personal thing