Which 5mm EP

[bomberbaz]

EP's are such fun to research if you wear glasses, you have the extra concern above everything else of eye relief which generally speaking needs to be at least 16mm. I might be in the market for one but i need to look at options and see what others think.

I have 5 choices ranging from £200 down to just under £100. I haven't researched the prices yet properly but just been looking at the specs and getting some review information but I am in information overload here so wondered what anyone else thought.

Vixen LVW 5mm circa £200

Televue Radian 5mm circa £190

Celestron Ultima LX 5mm circa £120

Vixen NVL 5mm also around £120

Baader Hyperion around £100

All have good enough eye relief although its a little tight on the Celestron.

I would like to go for either the Vixen or Televue as both are quality and have good write ups about them, although not sure which is best or indeed if I need one.

So the question is, is it worth me shelling out for either the Vixen LVW or Radian at that price or would any of the bottom cheaper three perform well enough in a 12" DOB with Baader coma corrector?

PS. I have started a similar thread about 3.5mm EP's but its a choice of two!

[John]

I've suggested a Pentax XW for this focal length as well as the 3.5mm on under your other thread. To buy new though they exceed your budget.

The Radian's have now been dropped, apart from the 3mm I think, so that would have to be a used buy.

If you are buying new then the Vixen LVW would be my pick from your list. If buying used then the XW's should be within budget.

[Naemeth]

If it helps any, the Vixen LVs I have (same as NLVs, it's just the LVs have a hard rubber eye cup instead of a plastic one for the NLVs) perform very well at F/5. I haven't tested them against my TV plossl yet, but you would do well with them. If you get them 2nd hand, you will probably be able to get them for ~£35 (for some reason they hold hardly any of their from new value).

The Hyperions are a massive no, I haven't seen much good about them at F/5.

If you wanted, you can still get Radians from: http://www.robtics.nl/index.php?cPath=28_46_248

Go for a used Pentax XW though .

[Ben Ritchie]

5mm is a sweet spot with my AP130, as it gives a touch over 200x for planetary work and i've tried a fair few 5mm eyepieces over the years. The 5mm Pentax XW is my personal favourite, it is a terrific eyepiece with great clarity and sharpness, although used the 5mm Radian is IMO better value; it's also fairly compact and lightweight compared to the XW, which is sometimes an advantage. In my view it's not quite as good though, and some people don't like the tint. If you watch and wait the Radians turn up used for around £100 quite regularly and sometimes a bit less than that. I'd take it over anything else in your list, although I would grab a used XW in preference if budget allows and you're lucky enough to catch one for sale at a decent price.

With a 12" Dob (i'm assuming untracked?) I wouldn't go for orthoscopics or similar, although those are extremely good for planetary work if you can cope with the lack of eye relief and limited AFOV. For me neither characteristic is great in a Dob, but many would disagree with me

[E621Keith]

Do you want to buy new?If you are willing to buy secondhand, a used 5 lvw can be a good choice. The cost around £100 each. Obviously if you can afford it, you should get a 5XW.

[alan potts]

I would go for the 5mm Radian, it is an excellent eyepiece but sadly mine is wanted by someone here and that means no courier costs to UK. I believe Telescope House still have one on stock, they did have a week ago. If not I would go for something that I have had a little scope time with and that is the 5mm XW as some have suggested. I know it is a little over what you were going to spend on the zoom but I think is will be worth it in the long run.

I would think long and hard though 5mm gives you over X300 and that is a bit top end for me. I think you should be looking at a 6mm eyepiece. It is sometimes better to have an ordinary eyepiece that you can use than a fabulous one you can't !!

Alan

[Moonshane]

Hi Steve

I'd urge you to do nothing at this stage. you might find that the Nagler zoom is OK for you without specs and this would be an all round best solution. Personally, If I didn't have the zoom, I'd be looking to gain 'mental' powers (which I do use on a fairly regular basis) with a barlow or powermate.

a 2.5x Powermate might be a good buy. or if you have a 2x barlow already this would help you too. if you do have a 2x barlow bring it and use with my 8mm and 10mm Radians? this will provide an insight into the mags we are talking about.

[bomberbaz]

Hi Steve

I'd urge you to do nothing at this stage. you might find that the Nagler zoom is OK for you without specs and this would be an all round best solution. Personally, If I didn't have the zoom, I'd be looking to gain 'mental' powers (which I do use on a fairly regular basis) with a barlow or powermate.

a 2.5x Powermate might be a good buy. or if you have a 2x barlow already this would help you too. if you do have a 2x barlow bring it and use with my 8mm and 10mm Radians? this will provide an insight into the mags we are talking about.

I do have a half decent barlow mate, I am not rushing into anything though, just trying to get some ideas and options. Whqatever I do I am afraid that unless I can get a 2nd hand pentax, new isn't an option.

Thanks as always for the input, you have all given some good info that is duly noted.

Steve

[Qualia]

If I were looking for an eyepiece with decent eye-relief, great optics and field of view and significant re-sale value at 'around' £200, I'd bide my time and save for that extra needed for a TV Delos. I'd be wary of going 300x though.

[michael.h.f.wilkinson]

I do use 290x on good nights (XW7, magnificent optics), so a well-collimated, well cooled 12 should be OK at 300x on nights of really good seeing. A 6mm might be a bit more useful. I did do a comparison of Vixen LV and Radian EPs and found the former close to the latter in performance, but with a more restricted FOV (obviously). The LVW are superior to the LV in that respect. I cannot say I liked the stiff, rubber eye cups of the LV, the Radian click-stop is far better (as is the XW twist-up eye cup.

[Ben Ritchie]

I do use 290x on good nights (XW7, magnificent optics), so a well-collimated, well cooled 12 should be OK at 300x on nights of really good seeing

I agree. Provided you can afford it, a top-notch highest power eyepiece is well worth having - it will get used very rarely, but when conditions allow those nights live long in the memory. I had a 3.5mm XW for a while and Saturn at 297x under Pickering 9 seeing with the AP130 was simply stunning.

Sadly I couldn't justify keeping such an expensive eyepiece in the case for use on a couple of nights a year, but I still miss it.

[knobby]

Its just my opinion but when you are at the limits, that's were an ep needs to work hardest... So for me that's where to spend most money.

Widest and highest power.

[bomberbaz]

Its just my opinion but when you are at the limits, that's were an ep needs to work hardest... So for me that's where to spend most money.

Widest and highest power.

hit the nail on the head there knobby my son. This is exactly why I am " maybe" looking to buy a couple of quality EP's. on the occasions that conditions allow high mag viewing I dont want to be in a position of wanting at the business end of things.

If on the odd few occasions every now and then I can crank it right up and pick out detail only previously seen on images, then that for me would be reason enough to have an EP in my box.

[michael.h.f.wilkinson]

There is one severe risk when buying a few top-of-the-line EPs and combining them with more mediocre ones (or more accurately: outstanding EPs with those that are merely very, very good), and that is what I call the ratchet effect. Once you have some really good ones, the others will show up their deficiencies, and so you replace them by better ones, which might even be a touch better than the best ones you had so far. Therefore, your former best EPs start showing their deficiencies. This process iterates until you either:

1) Have all EPs perfectly balanced in terms of quality (the mythical final set-up)

2) Run out of money and/or have divorce papers shoved under your nose.

[Naemeth]

There is one severe risk when buying a few top-of-the-line EPs and combining them with more mediocre ones (or more accurately: outstanding EPs with those that are merely very, very good), and that is what I call the ratchet effect. Once you have some really good ones, the others will show up their deficiencies, and so you replace them by better ones, which might even be a touch better than the best ones you had so far. Therefore, your former best EPs start showing their deficiencies. This process iterates until you either:

1) Have all EPs perfectly balanced in terms of quality (the mythical final set-up)

2) Run out of money and/or have divorce papers shoved under your nose.

Couldn't agree more. My LVs and soon my TV plossl will mean my other eyepieces don't get used. I'm probably going to have to end up splashing out on more eyepieces...

[bomberbaz]

There is one severe risk when buying a few top-of-the-line EPs and combining them with more mediocre ones (or more accurately: outstanding EPs with those that are merely very, very good), and that is what I call the ratchet effect. Once you have some really good ones, the others will show up their deficiencies, and so you replace them by better ones, which might even be a touch better than the best ones you had so far. Therefore, your former best EPs start showing their deficiencies. This process iterates until you either:

1) Have all EPs perfectly balanced in terms of quality (the mythical final set-up)

2) Run out of money and/or have divorce papers shoved under your nose.

hahaha, yes there is this but I am sure at lower powers my existing collection is more than up to the job for now. (Thinks will I be reminded of this statement in 12 months time )

Steve

[Tiki]

For about a hundred pounds a s/h 5mm LVW would take some beating. Very good value.

[bomberbaz]

For about a hundred pounds a s/h 5mm LVW would take some beating. Very good value.

are you selling one, hehe

[cs1cjc]

The NLV 5mm is very nice if you can live with a 45* field of view. The eye relief is 20mm and the eye guard is up or down with no intermediate position and I found it did not suit me well. Like others I think 5mm is already on the short side.

[bomberbaz]

Not sure what it is but I seem to be able to hit higher magnification at pretty good quality fairly often. True its only planetary mainly but I did have M13 the other days with a 5mm and it was not to bad at all although at 8mm the contrast was slightly better. However it was in a 3/4 moon. Maybe I am missing something but higher mag doesn't seem as bad as maybe it should.

[michael.h.f.wilkinson]

Not sure what it is but I seem to be able to hit higher magnification at pretty good quality fairly often. True its only planetary mainly but I did have M13 the other days with a 5mm and it was not to bad at all although at 8mm the contrast was slightly better. However it was in a 3/4 moon. Maybe I am missing something but higher mag doesn't seem as bad as maybe it should.

Useful magnification is a very personal thing. I find I go higher than many others say is useful often. I found that after selling my 7mm ep and later my 14mm (which barlowed beautifully in the 2x TeleXtender), I missed 290x, feeling that 239x or 250x offered by the 8.5 and 8mm was insufficient. I am really glad I have a 7mm back, and I am considering getting a 5mm and 6mm (also for the faster fracs). If 300x and above work for you, go for it!

[Moonshane]

I tend to agree Michael