Eyepiece for planetary observing

[davekelley]

To be concise, what is better, a series 5000 plossl or a bst starguider, for planets, bright globs and double stars in a 127mak?  I'm thinking of  between 9-12mm max as my skies are generally poor and I've rarely been able to go much higher than 150x, or even go that high.  Alternatively are there any better suggestions.  I'm interested in comfortable fov and eye relief, I'm not using tracking.

Thanks everybody

Dave

[Kev M]

Orthoscopics I would have thought ?

 

[Tiny Clanger]

6 minutes ago, davekelley said:

To be concise, what is better, a series 5000 plossl or a bst starguider, for planets, bright globs and double stars in a 127mak?  I'm thinking of  between 9-12mm max as my skies are generally poor and I've rarely been able to go much higher than 150x, or even go that high.  Alternatively are there any better suggestions.  I'm interested in comfortable fov and eye relief, I'm not using tracking.

Thanks everybody

Dave

I use an 8mm BST starguider when the conditions allow it (which is fairly often) in my 127 mak (on a  manuall AZ5 mount) , it gives 187.5x mag, which is useful, and the 60 degree field keeps those fast moving targets in view for a reasonable time. The image is sharp, and I find the eye relief good, but I'm not a spectacle wearer . The twist up solid eye guards are nice, and offer a degree of protection against accidentally touching the glass. I'm very happy with the 8mm.

When the seeing is a bit iffy for the 8mm , I use a 12mm BST, which is also very nice, and gives 125x . For the odd times when the seeing permits me to rack the mag. up to 250x , I've a 6mm Baader ortho  I didn't go for the 5mm BST because I reckoned the exit pupil on a 5mm would be small enough to allow the floaters in my eye to become intrusive. and they do show even with the 6mm when looking at the Moon. The ortho is tiny, doesn't have brilliant eye relief and combines high mag with a tiny field of view , which isn't always helpful. I have a TMB clone 6mm (there are many versions, mine came from Alan at Sky's the Limit) which is easier on eye relief .

Heather

 

[ScouseSpaceCadet]

If you want comfortable eye relief and a wider fov then the BST beats the Series 5000 plossl hand down. No contest.

There are other budget alternatives though. I particularly like my Altair Lightwave 9mm.

 

Edited September 24, 2021 by ScouseSpaceCadet

[davekelley]

9 minutes ago, Tiny Clanger said:

I use an 8mm BST starguider when the conditions allow it (which is fairly often) in my 127 mak (on a  manuall AZ5 mount) , it gives 187.5x mag, which is useful, and the 60 degree field keeps those fast moving targets in view for a reasonable time. The image is sharp, and I find the eye relief good, but I'm not a spectacle wearer . The twist up solid eye guards are nice, and offer a degree of protection against accidentally touching the glass. I'm very happy with the 8mm.

When the seeing is a bit iffy for the 8mm , I use a 12mm BST, which is also very nice, and gives 125x . For the odd times when the seeing permits me to rack the mag. up to 250x , I've a 6mm Baader ortho  I didn't go for the 5mm BST because I reckoned the exit pupil on a 5mm would be small enough to allow the floaters in my eye to become intrusive. and they do show even with the 6mm when looking at the Moon. The ortho is tiny, doesn't have brilliant eye relief and combines high mag with a tiny field of view , which isn't always helpful. I have a TMB clone 6mm (there are many versions, mine came from Alan at Sky's the Limit) which is easier on eye relief .

Heather

 

Thank you.  I'm stuck between a super plossl and a starguider and can't decide.  I know I love a plossl and the BST's seem to good to be true at £49!  

 

[davekelley]

3 minutes ago, ScouseSpaceCadet said:

If you want comfortable eye relief and a wider fov then the BST beats the Series 5000 plossl hand down. No contest.

Thank you very much!  I heard the series 5000 has 60 deg and "comfortable" eye relief?

I think I'll go with bst. 

[ScouseSpaceCadet]

1 minute ago, davekelley said:

Thank you very much!  I heard the series 5000 has 60 deg and "comfortable" eye relief?

I think I'll go with bst. 

See my edit. The Altair is very good. Better than the 8mm BST I own imho. Just a bit less fov at 55°.

[Tiny Clanger]

6 minutes ago, davekelley said:

Thank you.  I'm stuck between a super plossl and a starguider and can't decide.  I know I love a plossl and the BST's seem to good to be true at £49!  

 

Shh, don't tell them, they might put the price up !

[Dark Vader]

My go to for planets currently is the BST 15mm with the BHZ matching 2.25x Barlow.

That BST 15mm is very nice for the money.

 

[SuburbanMak]

I'm a big fan of the Baader Classic Orthos - especially the 18mm & 10mm.    Crystal clear, high contrast old-school Zeiss Abbe design at £49 each  

[Laurieast]

BST 5mm ED Starguider. 

But keep it quiet 🤫

[russ]

I was very pleased with my BST (I had the original Astro Tech Paradigm) but since discovered there are slightly better eyepieces for slightly more. Another nod to the Altair Lightwave 9mm (and all the clones). The Vixen SLV 9mm beats them all in my opinion. Razor sharp and so comfortable. Just ortho field of view as the draw back.

[Zermelo]

The shorter BST Starguiders are very sharp for the money, and are good all-round EPs. If the seeing is very good then I use the 5mm in my Skymax to give 300x, but usually that's too much. The BST 8mm is more comfortable and performs well, though I've see a little light scatter that hides any very nearby moons (I'm assuming that's from the EP and not my diagonal, which is a prism).

When I was out most recently I tried out the KSON 16.8mm ortho that I picked up from eBay a while back, and was impressed with its sharpness and contrast. But it wasn't enough mag for the planets, so I ordered a 10mm BCO a couple of hours ago.

[JeremyS]

1 hour ago, Zermelo said:

The shorter BST Starguiders are very sharp for the money, and are good all-round EPs. If the seeing is very good then I use the 5mm in my Skymax to give 300x, but usually that's too much. The BST 8mm is more comfortable and performs well, though I've see a little light scatter that hides any very nearby moons (I'm assuming that's from the EP and not my diagonal, which is a prism).

When I was out most recently I tried out the KSON 16.8mm ortho that I picked up from eBay a while back, and was impressed with its sharpness and contrast. But it wasn't enough mag for the planets, so I ordered a 10mm BCO a couple of hours ago.

Indeed, I was pretty impressed by my BST 8mm too. Amazing value!

[Zermelo]

3 hours ago, Tiny Clanger said:

Shh, don't tell them, they might put the price up !

One of the real mysteries for me is that all the enthusiasm on this forum hasn't pushed the price up into three figures 😂

[Tiny Clanger]

2 minutes ago, Zermelo said:

One of the real mysteries for me is that all the enthusiasm on this forum hasn't pushed the price up into three figures 😂

Shh, really ! 🙂

3 figures would be a bit of a stretch though ...

OP was interested in eye relief, so here's a PDF with the stats for the Baader classic orthos

https://agenaastro.com/media/documents/Baader-Specs-Orthoscopic-Eyepieces.pdf

I can't with a quick search track down a similar datasheet for the BSTs, but the FLO pages for each focal length gives the eye relief, eg the 8mm has 16mm of eye relief

https://www.firstlightoptics.com/bst-starguider/bst-starguider-60-8mm-ed-eyepiece.html

[Tiny Clanger]

3 hours ago, russ said:

I was very pleased with my BST (I had the original Astro Tech Paradigm) but since discovered there are slightly better eyepieces for slightly more.

Rule 2 of telescope owning: There is always something slightly better for more money  (rule 1 is 'Clouds accompany each and every purchase' , obviously) .

[dave34]

+1 for the BST's , great all round EP's in my opinion, and they dont break the bank.

[IB20]

I have all the BST range, the 10mm Baader classic ortho is miles better than them all for planetary observing.

[Zermelo]

5 minutes ago, Tiny Clanger said:

the FLO pages for each focal length gives the eye relief, eg the 8mm has 16mm of eye relief

The manufacturer's figures may be slightly optimistic (though that's not just so of the BSTs). I saw a table somewhere (probably posted by LouisD) that had most of the Starguiderss at around 12mm effective relief. But that's still good compared with shorter plossls or orthos.

[John]

While they share the orthoscopic characteristics of a relatively narrow apparent field of view and eye relief which is at best 80% of the focal length, the Baader Classic Ortho 10mm and 18mm eyepieces are really excellent performers, way above their purchase price.

That said, I spent some time comparing the 8mm BST Starguider with my 8mm Tele Vue Ethos in my 12 inch F/5.2 dobsonian a while back and found very little difference in terms of optical performance. The Ethos just provided it over an additional 40 degrees of field of view.

In terms of light scatter control (which can be important for planetary observing) the Baader Classic Ortho would be (as it should be) slightly better than the more optically complex BST Starguider. They will also have slightly higher light transmission.

There are some good options for around £50 apiece these days

 

Edited September 24, 2021 by John

[Pixies]

Putting in the lower focal length orthos always feels like the astronomy equivalent of rolling ones' sleeves up! 

[russ]

1 hour ago, Tiny Clanger said:

Rule 2 of telescope owning: There is always something slightly better for more money  (rule 1 is 'Clouds accompany each and every purchase' , obviously) .

We need those slightly better things to give us something to research and read about on the 350 cloudy nights of the year.