Explore Scientific 9mm 100-degree eyepiece

[A McEwan]

Hi all,

I recently ordered one of these eyepieces in the Winter Sale from Optcorp in the United States. I was tempted by the reports on CN of the quality of the optics, not just the expansive field of view. I ordered it at the sale price of $299.99 which coimpared very favourably to the UK retail price of £380-odd with no sale reduction offered. So anyway, it arrived a few weeks ago and I've put it to some use in various ways since then. Here are my results.

First views were through my 90mm f6.6 triplet Apo. I observed some open clusters, notably M35 and the Pleiades. The companion cluster to M35, NGC 2158, was quite obvious and showed nice sharp star points across the massive field of view. In the 600mm focal length scope it gave 66x and 1.5 degrees. I also observed the nearly full Moon through the eyepiece and compared it to a 9mm Baader Genuine Ortho.

The clarity and detail resolved was very similar to the Ortho, but the Ortho had a slightly colder feel to the view. Also, the edge of the field of view in the ES100 is not colour-free. There is a slight amount of false colour to be seen, but in a field of view that large it is really not a problem for me. What was amazing was being able to see the whole disc of the Moon at that level of magnification! This was only improved upon when I added a 2" 2x ED Barlow to the optical train. The magnification of 132x still enabled the whole disc to be seen at once, and still with plenty of space surrounding the disc! Phenomenal!

Comfort-wise there was no blacking out and the eye relief was short but not too short. I had to swivel my eye to take in the view at the edge, but it was a comfortable thing to do.

I then used the eyepiece in the same telescope using my Baader Herschel Wedge to view the Sun in white light. The view was a little bright as my viariable polarising filter and Solar Continuum filters are both 1.25" format, but I have a slection of 2" ND filters, so added a 0.9 filter to it and that gave a very nice view with plenty of contrast. Again the limb showed a small amount of false colour, but again the useful magnification and field of view outweigh this for me.

Next up was the same white light configuration but in my Equinox 120ED. Same results. Lovely view, small amount of colour fringing at limb. Comfortable to use. I have invested in a 2" solar continuum filter for this eyepiece for the future.

Then last night I used the eyepiece for normal astronomical viewing in my Equinox 120 and a friend's 12" f4.9 Dob. The view of Saturn through the Dob was very impressive, but the real highlight came when viewing M57 in the Dob. The amount of detail was very impressive, with obvious striation in the ring nebulosity. The surroundin field of view obviously held the object in the view for a long time, making it very easy to hold and reacquire the target.

M13 in the 120mm was stunning, as was M57 again, and after a while I just stopped swapping eyepieces as it became so easy with the one degree field of view (at 100x) to find objects I was searching for, including the double double (easily split), Albireo (lovely colour tones), Saturn (again!) etc. Incidentally, when Saturn was in, or near, the middle of the field, there was no hint of the false colour mentioned previously.

So my conclusion is that this eyepiece is very very good. Exceptionalvalue for money if bought at a reduced price, and even worth considering at full price in the UK (compare it to the 8mm Ethos...). It's comfortable to use and gives very satisfying views with no particularly annoying optical aberations, apart from a small amount of false colour, near the edge, on bright objects. It's also very nicely made, quite hefty and solid and Barlows up very nicely indeed.

Ant

[david o]

Thank-you Ant,

Nice write up.

[John]

Sounds like an excellent eyepiece Ant. Thanks for posting the review. These ultra-ultra-wide eyepieces sort of "re-write the rules" a bit don't they - you can spend a whole evening enjoying both DSO's and higher resolution stuff with just a couple of eyepieces in use

[JamesM]

Thanks for the great review. Clearly these eyepieces prove that you can have the cake and eat it! Not a cheap bit of cake but it would seem extremely good value.

Thanks again Ant.

James

[Doug]

Well Ant

I've gone and done it a 9mm 100*fov on the way ,

Due to your review Thanks alot

Doug

Essex UK

[A McEwan]

Good job, Doug - You will enjoy it! Gonna buy a great big refractor to go with it?

Ant

[Doug]

Hi Ant

Don't tempted me, Just started early retirement cash in hand "DOH"

I was looking at eyepieces and thought why not, got it from OPT in the USA

good price wanted it soon the post was $73.00 but still a lot better then UK prices

was looking at Nagler T4 22mm but that would work out the same as here , so looks like Telescope house gets that one

Thanks again Ant

[pleiades]

Hi Ant

Do you own any Ethos to say how is, comparing ES100 for you?

[A McEwan]

No Ethos for me - too pricey I'm afraid, specially when the ES-100s became available as a slightly cheaper option. I shall determinedly resist any temptation to look through an Ethos.... just in case...

[pleiades]

[John]

I do have some Ethe but from all the reports I have read I'd expect the ES100's to come extremely close to matching their performance. It's just a pity that the pricing of the ES is so high in the UK - just a bit too close to the Tele Vue rivals perhaps, although there is still £90 difference between the 9 ES and the 8mm Ethos.

[Coco]

Damn it... I just ordered the 14mm ES100 after reading the CN and Astro Babes review, being that I'm using 5.9/650mm scope perhaps I should have gone for the 9mm option..

I see you still list yours ? I take it its a keeper

[coffee_prince]

Guys I am considering ordering a few of the es82, how much did you guys get stung at customs cahrges etc?

[Coco]

Guys I am considering ordering a few of the es82, how much did you guys get stung at customs cahrges etc?

Mine's been tracked all the way to..... 'waiting customs clearance'

If you choose the USPS option (cheapest) they have a contract with parcel force, always expect VAT and clearance, still its £100 cheaper than telescope house.

Once I get my 14" Dob () I'll be getting the 9mm EP.

[coffee_prince]

they way I see it, the telescopehouse prices are already heavily inflated but I agree, with charges it still offers good value. I guess its because they seem to be the sole suplier of explore scientific in the UK at the minute.

good luck on the custms, update us on how it goes!

[Coco]

they way I see it, the telescopehouse prices are already heavily inflated but I agree, with charges it still offers good value. I guess its because they seem to be the sole suplier of explore scientific in the UK at the minute.

good luck on the custms, update us on how it goes!

TH are a wholesaler too, they need to build in some profit for themselves and there dealers, if they dont get any interest from dealers they no doubt will sweep the dealers to one side and go direct, then they can reduce their prices.

As for ES the sooner the better as far as I'm concerned

[Doug]

Hi Guy

This eyepiece will not stay at that price for ever when that stock goes that will be it

get the 9mm ASAP, when I spoke to the man at OPT thats what he told me , wish we all lived near to each other , then we could try then all out

Doug

Essex

[Coco]

Well the eyepiece is in the loving possession of Her Majesty's post waiting for a £55 VAT and clearance charge.. hey ho... still saved £100+..

[Doug]

A Mc Ewan

how are you Ant hope you are enjoying the darker skies ?

I was trying to think where my journey started with eyepieces, I do beleave it was you

I can't beleave it was in May 2011 and on your recommendation I purchased the 9mm 100fov and loved it

last week I got the 20mm 100fov and this week the 14mm 100fov on order, unable to look through them dew to cloudy weather

was wondering did you ever get any more ?