Eyepiece collection for use with a 102mm f7 ED refractor.

[Grump Martian]

I have a Starfield 102mm refractor. I am considering changing some of my eyepieces to optimise my viewing with this great telescope.

My current eyepiece collection consists of the following;

ES 8.8mm, 12.5 Pentax XF, 16mm Nirvana, 22mm Nagler & 32mm Panaview.

The Nagler I will keep. The 16 mm is very good, but can go. The 32mm Panaview does a job. But can be improved upon. An Explore Scientific 30 mm and Televue 31mm Nagler eyepieces are very heavy compared to the Panaview.I feel that I should have another eyepiece with a shorter focal length than the 8.8mm that I have. But what focal lenght would be reccomended? A 5mm ?.

I would be interested to hear what eyepiece collections that other Starfield refractors users have.

[CraigT82]

With mine I’m using the following:

•StellaLyra 30mm UFF (23x, 2.95°, 4.3mm exit pupil)

•ES 14mm (51x, 1.6°, 2mm EP

•Nirvana 7mm (102x, 0.8°, 1mm EP)

•Nirvana 4mm (178x, 0.46°, 0.57mm EP)

•StellaLyra 3mm LER 55° (238x, 0.23°,  0.43mm EP)

My aim was to half the exit pupil with each jump down, with an extra one at the short end for high power lunar views.

I’m happy with this set. Are there better eyepiece out there? Yes. Am I willing to spend the extra money on them? Not really. These lot present good value for money. The Nirvanas are a little tight on eye relief but I don’t wear glasses so they’re fine for me. The 3mm LER is a little tight of FoV but it’s very easy to look through and I think the smaller field helps to focus the eye on a particular feature rather than just gazing around the field.

I do have a set of BCOs too which I consider as specialist eyepieces for specific jobs.

[apaulo]

With my starfield and 200p ota i use a full set of baader morphs 4.5mm- 17mm, explore scientific 24mmx68 and a pentax XW3.5 

[Mr Spock]

My eyepiece use with the 102mm Starfield depends on what I'm observing. So...

For double stars etc I use the 30mm StellaLyra UFF, x24 and 2.94° fov; 13mm Nirvana, x55; 7mm Nirvana, x102; 4mm Nirvana, x179. If I need to split tight doubles I add in the x2.5 Powermate.

For planets I use a x2.5 Powermate and 12.5mm ortho, x143; 9mm ortho, x198; 7mm ortho, x255.

I have lots of eyepieces but I reckon these give the best spread of magnifications and image quality for my intended targets. I like to use the x2.5 Powermate for planets as it makes using a variable polariser easy: just attach one piece to the eyepiece and the other to the Powermate, then rotate the eyepiece to get the best effect. I find a variable polariser essential for bright planets such as Venus.

If I had a choice of a single set I'd go with the 30mm UFF and a complete set of Nirvanas (which I have) and the Powermate.

[Don Pensack]

12 hours ago, Grump Martian said:

I have a Starfield 102mm refractor. I am considering changing some of my eyepieces to optimise my viewing with this great telescope.

My current eyepiece collection consists of the following;

ES 8.8mm, 12.5 Pentax XF, 16mm Nirvana, 22mm Nagler & 32mm Panaview.

The Nagler I will keep. The 16 mm is very good, but can go. The 32mm Panaview does a job. But can be improved upon. An Explore Scientific 30 mm and Televue 31mm Nagler eyepieces are very heavy compared to the Panaview.I feel that I should have another eyepiece with a shorter focal length than the 8.8mm that I have. But what focal length would be recommended? A 5mm ?.

I would be interested to hear what eyepiece collections that other Starfield refractors users have.

Looking for improvements?

At 30mm, a UFF eyepiece.  Heavier than the Panaview, but sharper to the edge and with a flatter field.

At f/7, you can use eyepieces down to 3.5mm.  Certainly a 5mm would be useful.  I use a 5mm every time I use my 102mm f/7.

But, let's look at the series.

With a 30mm as a low power (24x), your next power up can be a 14-15mm easily.  The jump to a 14mm is only 27x, to 51x.

And a great 14mm could be a 14mm Morpheus or a 14mm StellaLyra 80°.

Then to a 9-10mm, where there are a lot of choices, but the two 14mm choices would be fine.  You really don't need the 12.5mm XF.  Your 8,8mm would be fine here.

Then to a 7mm, where you can stay with the 80mm SL or something narrower if you prefer, but a 7mm is a prime Moon eyepiece, so wider is better, I think.

If you spring from the 8.8mm, though, a 6.5mm Morpheus would fit in well, too, or a 7mm, so you have choices.

Then to a 4.8-5mm  There are a lot of possibilities there.

 

The sequences for exit pupil are a little different:

30mm>>21mm>>15mm>>11mm>>8mm>>6mm>>4mm>>3mm

In the other direction: 3.5mm>>5mm>>7mm>>10mm>>13mm>>19mm>>26mm>>37mm

 

This sequence works well, too, and uses a smaller number of eyepieces in the set:

22mm>>16mm>>11mm>>8mm>>6mm>>4mm

 

And, in practice, a set with eyepieces at every 30x works fine in the 102mm:

30/60/90/120/150x, or 24mm, 12mm, 8mm, 6mm, 4.7-4.8mm

Given what you have, you could simply ditch the 16mm and add a 6mm and a 4.7-4.8mm and have a nice set.

 

No right or wrong answers.  My own set is shared with a scope that is a different f/ratio and focal length, so I have a lot more eyepieces.

But in the 4" refractor, I tend to use  22mm, then 14mm, 9mm, 6.5mm, 4.5mm, and 3.7mm.  My other eyepieces get used more in the other scope.

In practice, I often skip from the 22mm to the 9mm to get around the light pollution.

 

[Marian M]

Hi!

Below my eyepiece set for TS 102 F7 which I presume is similar. The red column eyepieces are missing today but planned for acquisition in the upcoming future.

Aside this I use the APM 2.7 ED barlow 

The wides for DSO, the narrows for Moon and planets

For binoviewer, highly recommended, the Morpheus and SLV set + 1.7 and 2.6 GPCs 

 

								1.71	1.29	0.86

Edited March 22, 2023 by Marian M

[mikeDnight]

The 5mm Pentax XW is a very nice eyepiece, and so is the 3.5mm. Both would be nice with your Starfield 102.

[Franklin]

My 4" ED is f/7.7 and I have too many eyepieces, the LVW's get used the most, though a little on the heavy side, I like the 65deg and constant good eye relief. I've got the set but mainly use 22mm, 13mm, 8mm and 5mm. The 3.5mm gets used on doubles if the sky permits.

[John]

I have 102mm F/6.5 and a 100mm F/9 refractors in the 4 inch class. Mostly I use a 1.25 inch eyepiece set as follows:

24mm Panoptic

14mm Delos

10, 7, 5 and 3.5mm Pentax XW's

4-2mm Nagler zoom

For wider angles of view with the 102mm F/6.5 I have a 31mm Nagler plus 21, 13, 8 , 6 and 4.7mm Ethos's which are used in 2 inch mode.

So two eyepiece sets, which is admittedly rather extravagant 🙄

 

 

[Paz]

I think big jumps across the longer focal lengths and small jumps at the shorter focal lengths is a useful principle and is reflected in some of the sets up mentioned already.

I have use NPLs/SLVs for light set ups and Naglers/Delos for heavier set ups and use both with my 102mm f7. But if I am taking a reduced number of eyepieces out here's how those full sets will typically get trimmed down if it is useful to illustrate.,.,.

NPL/SLV collection is 40, 30, 25, 20, 15, 10, 6, 5, 4, 2.5, these would typically get thinned down to: 25, 10, 6, 4.

Nagler/Delos collection is 31, 22, 17.3, 12, 10, 8, 6, 4.5, 3.5, these would typically be thinned down to 17.3, 8, 4.5, 3.5

[Piero]

In my 4" f7.4 I like the set: 24 Pan, 13-9-7 Nagler T6. The 3 naglers are then barlowed with the baader qturret or VIP. They offer plenty of FOV and don't affect the balance of the telescope.

Other times, I use the set: 30mm, Zeiss zoom +/- VIP Barlow. That's my 2" set for that telescope. It's largely used when I feel lazy or for observing planets and the Sun.

Edited March 23, 2023 by Piero

[bosun21]

This is my second Starfield and I use a full set of Baader Morpheus eyepieces accompanied by a 30mm SL UFF. This covers a wide range of observing although I am now looking to add a 2.5x powermate to use both in the Starfield and my 12” dobsonian for lunar and planetary work at higher magnification.

[mikeDnight]

Grab yourself a binoviewer and two pairs of good ortho's, Plossl's, or similar. They don't need to be expensive! Something in the 25mm & 16mm range or there abouts would be fine. With a 2X barlow attached to the nose piece of the binoviewer you'll get around a 4X amplification. It's a real game changer when observing the Moon and planets. 

[Franklin]

On 22/03/2023 at 21:05, John said:

So two eyepiece sets, which is admittedly rather extravagant 🙄

 

Nothing wrong with extravagant, fantastic eyepiece collection there John.

[Moonlit Knight]

I have used one of these scopes for the past 3 years. I use exclusively Explore Scientific eyepieces mostly 82 degree series. 4.7 and 6.7 cover planetary observation, which is my main interest along with white light solar, but here I switch to Baader Orthos. The drift time is perfect for me and these two have proven to be by far the best planetary eps I have owned (previously TV plossls, Radians and Naglar). I also have a 11 and 14 mm in the 82 series and a 20 and 28 mm in the 68 degree series. I find them all absolutely sharp to the edge of field and, with this scope cannot find any undesirable characteristics. Everything just works together beautifully and with this outfit (and I stress with this outfit) changing anything would be an expensive folly which is unlikely to improve my enjoyment of the views. 
 

I don’t know why ES are not as popular in the UK as they are in the states. They are often tested against TV, the difference is often tiny and like most things astronomy gear wise, very subjective.