Sorting out which eyepieces

[TSRobot]

I thought I'd make a table so I can easily see exit pupils and magnification for different eyepieces in my setups. I have a C8se and a Antares 6.3 reducer for it. I have a lovely Revelation f6 achro too. My current eyepieces are a 32mm SW plossl, 20 SW plossl and Mk3 Hyperion zoom. I've read good reviews of the BST stargazers and as I use both my OTAs at the same time on a Skytee2 I'm sometimes a bit short of eyepieces. From my table I can see that I will get best benefit from a 25, 18 and 12 BST. Does anyone think that the 15mm BST would help much? All the figures on my table come from the online FOV calc. The B stands for Barlow x2. Thanks.

[Louis D]

I'd choose either 12mm and 18mm or 15mm alone to avoid too much overlap.  All three would be of little use.

[wookie1965]

The 15mm is regarded as a fine eyepiece in fact it was the top pick of the Sky at night magazine a few years back. 

[Charic]

I have them all, not only that, I use them all. 

No matter what the target, one of them will produce the goods, if the conditions above me allow?

The 3.2mm is  probably limited  in its use for many folk, though I use mine on the Moon. The 5mm would 'match' your scopes f/5  ratio providing the highest power for the design of your f/5 200p. The 10mm would be next. but alas, they don't exist, so a 12mm would be a good option. Its why I have a 6mm WO/SPL to match my focal ratio, Starguiders don't come in 6mm 

 

*****OOOPS !!******** Just realised, I've somehow referred to wookie1965's focal ratio? I'll leave the text as is.

With regards your own f/ratio's f/6 - f/10, I'd still use the theory based on high power matching the focal ratio, then twice the ratio, then f/ratio x entry pupil of your own eye. This will provide three eyepieces, High, Med and wide. Anything else and in-between will be a bonus.

I often read that an eyepiece of twice the focal ratio allows the telescope to work optimally, if correctly setup and  seeing conditions allow,  so  maybe folk should base  their first eyepiece on the one that is twice the focal ratio?
How much either side of this is down to the end user.

[TSRobot]

Thank you BUT, i just found a 14mm and 24mm ES Maxvision 68 degree 1.25 on astrobuysell for £95 the pair and bought em. Might need the 18mm BST to fit in the middle, but i'll wait and see. The FOV calc makes these decisions possible. It's great.

[Charic]

You could return the BST if its not good enough, you won't know until you  buy and try!
Its great to have the help and guidance from others, but at the end of the day, its your own eyes and your setup that matters.

I've been down the Tele Vue route with their Delos range, and for me, their no better that my Starguiders?  but that's my own personal preference, on my f/6 scope.
I expected far more for the price I paid, even second hand, and if I had not tried them, I'd probably still be longing for one to trial?

On a much faster scope, the Delos may warrant my attention again, as there are some benefits with their design, but now favouring a smaller fov, I might examine their De-Lites next time round? though I had looked into the future ( sorry gamblers - can't help ?) with the potential for a scope upgrade, but for now,  the scope remains, and the Starguiders shine through.

[YKSE]

You don't need buy any eyepieces, your current 32mm plössl and baader zoom covers ALL your need for your scopes. Better to put your money in buying gas for travelling to a dark site, it'll help you much more.

[Piero]

3 hours ago, TSRobot said:

I thought I'd make a table so I can easily see exit pupils and magnification for different eyepieces in my setups. I have a C8se and a Antares 6.3 reducer for it. I have a lovely Revelation f6 achro too. My current eyepieces are a 32mm SW plossl, 20 SW plossl and Mk3 Hyperion zoom. I've read good reviews of the BST stargazers and as I use both my OTAs at the same time on a Skytee2 I'm sometimes a bit short of eyepieces. From my table I can see that I will get best benefit from a 25, 18 and 12 BST. Does anyone think that the 15mm BST would help much? All the figures on my table come from the online FOV calc. The B stands for Barlow x2. Thanks.

 

Unless you hate technology, this can really help you: https://docs.google.com/spreadsheets/d/1KtV9Hl0XRQ-IGLiCjxIGSzss-b9TJ_j8ssk0lhh5UpI/edit#gid=1401763877   

Of course, you can download it (instructions inside), so that you can add your equipment. This spreadsheet will compute for your the exit pupil, magnification and many other parameters, automatically.

 

+1 to what Yong (YKSE) said above. 

[rockystar]

2 hours ago, TSRobot said:

Thank you BUT, i just found a 14mm and 24mm ES Maxvision 68 degree 1.25 on astrobuysell for £95 the pair and bought em. Might need the 18mm BST to fit in the middle, but i'll wait and see. The FOV calc makes these decisions possible. It's great.

I've got a 14 & 24 mm ep and don't find any need for anything in between - you've got different spec scopes tough, so, as they say, your mileage may vary 

[Paul73]

Good purchase. Wait until the eyepieces arrive before doing anything else. You may well find that the 14mm is a 16mm. The MaxVision 68° range didn't have a 14mm. The 16mm was a damn fine eyepiece for the money. If that is the case, you won't need anything between the 24mm and 16mm. My current main case lineup is:

24, 17.3, 12, 10, 8, 6 and 5.

Paul

[Louis D]

6 hours ago, YKSE said:

You don't need buy any eyepieces, your current 32mm plössl and baader zoom covers ALL your need for your scopes. Better to put your money in buying gas for travelling to a dark site, it'll help you much more.

The OP stated he runs with two OTAs at once and tends to run out of eyepiece options for both when used at the same time.

[Louis D]

7 hours ago, TSRobot said:

Thank you BUT, i just found a 14mm and 24mm ES Maxvision 68 degree 1.25 on astrobuysell for £95 the pair and bought em. Might need the 18mm BST to fit in the middle, but i'll wait and see. The FOV calc makes these decisions possible. It's great.

Found the ad.  The 14mm is clearly a 16mm as Paul73 suggested.  That's a heck of a deal considering the ES-68 versions of these two would set you back much more and yet have less eye relief.  You can always decloak them if you find them too large or are losing too much eye relief to the extendable eye guard.  You can't even find the 24mm ES-68 anywhere in stock in the states.

[YKSE]

4 hours ago, Louis D said:

The OP stated he runs with two OTAs at once and tends to run out of eyepiece options for both when used at the same time.

I'm not quite following your logic, I've run two scopes from time to time (both in solar and night time), I have only able to look through one scope at any moment

[Louis D]

19 hours ago, TSRobot said:

My current eyepieces are a 32mm SW plossl, 20 SW plossl and Mk3 Hyperion zoom.

 

6 hours ago, YKSE said:

I'm not quite following your logic, I've run two scopes from time to time (both in solar and night time), I have only able to look through one scope at any moment

Okay, I suppose if you like moving eyepieces from one scope to another, that's your prerogative.  I'm with the OP that I'd rather not have to do that.  It sort of defeats the convenience of having two scopes setup at the same time and pointing at the same object.  In an alt-az mount, you're likely to move the aim slightly during the swap.

If the OP has the Mk3 Hyperion zoom in the achromat to get up to some decent magnification levels (20x to 60x), then the highest power he can go in the SCT is 102x with the 20 SW plossl.  That's not bad, but it leaves a lot of magnification on the floor.  With a 12mm, he could get up to 169x which is quite an improvement on many objects.

If he puts the zoom in the SCT, he gets 85x to 254x which is great, but then he's stuck with 15x or 24x in the achro which limits it to finder scope duty.  I'm not say that's bad, but how often does anyone look at the same object at both 24x and 85x, best case?

[YKSE]

1 hour ago, Louis D said:

If he puts the zoom in the SCT, he gets 85x to 254x which is great, but then he's stuck with 15x or 24x in the achro which limits it to finder scope duty.  I'm not say that's bad, but how often does anyone look at the same object at both 24x and 85x, best case?

My understanding is that C8 and 80mm f6 are complementary to each other, not competing each other, this means they're used for their strength, C8 for small DSO, like most galaxies, Globular Cluster, small PNs, while 80mm for wide field views like large nebula, large open cluster, etc. So I've never used them at same object.

 

1 hour ago, Louis D said:

In an alt-az mount, you're likely to move the aim slightly during the swap.

Isn't it another argument for a good zoom instead of many fix-focal EPs so that you do as little swap as possible?

[Louis D]

48 minutes ago, YKSE said:

Isn't it another argument for a good zoom instead of many fix-focal EPs so that you do as little swap as possible?

Certainly, though the OP didn't seem inclined to shell out for a second quality zoom.

1 hour ago, YKSE said:

My understanding is that C8 and 80mm f6 are complementary to each other, not competing each other, this means they're used for their strength, C8 for small DSO, like most galaxies, Globular Cluster, small PNs, while 80mm for wide field views like large nebula, large open cluster, etc. So I've never used them at same object.

 

22 hours ago, TSRobot said:

as I use both my OTAs at the same time on a Skytee2 I'm sometimes a bit short of eyepieces.

While you might not use both at the same time on the same object, the OP implies otherwise.  I'm just assuming both scopes on the same object and the OP is trying to avoid swapping eyepieces and to have a better range of powers available for both at the same time.  Indeed, two quality zooms would be ideal.

[John]

21 hours ago, TSRobot said:

Thank you BUT, i just found a 14mm and 24mm ES Maxvision 68 degree 1.25 on astrobuysell for £95 the pair and bought em. Might need the 18mm BST to fit in the middle, but i'll wait and see. The FOV calc makes these decisions possible. It's great.

Isn't that the 16mm Maxvision ?

I didn't think they did a 14mm in that range

Edit: Ignore this - I can see that it's already been raised and dealt with.

 

[TSRobot]

Hi, the eyepieces arrived this morning safe and sound. Maxvision 16mm and 24mm as advised and not a 14mm as advertised, but this is of no consequence. In daylight both eyepieces are perfect and i look forward to a break in the clouds one night soon. They both give much wider views than i have previously experienced in my 80mm f6 achro which is very pleasing. Haven't tried them in my c8se yet.

You just can't beat buying 2nd hand. Almost all my kit is second hand and i have never been disappointed. 

[Louis D]

3 hours ago, TSRobot said:

You just can't beat buying 2nd hand. Almost all my kit is second hand and i have never been disappointed. 

I only buy new when it's an item I really want that just doesn't come up used very often, like the ES-92 line.  I also took advantage of the weak GBP to cross import a 14mm Morpheus for way less new than they were going for used here in the states.  I've also been tempted to try out the BST Starguiders for kicks because with FLO's discounts on all 7, they're cheaper than buying used ones here.  I could then resell them for basically no loss if I didn't want to keep them.

[Special K]

That table is a really good idea for working in the field. I don't have many ep's but often forget what the FOV and exit pupil are between my 2 scopes. Think I will craft one up too. Thanks for the idea!

[TSRobot]

Hi. Finally a clear sky here in Cov. The Maxvision 24 has turned out to be stunning and sharp over 95%. The 16mm is the same. The 24mm gave me my best Richfield experience yet albeit in Coventry LP.