Explore Scientific experience?

[Orange Haze]

Morning All

I posted a few weeks back on my intent to add a televue to my meagre eyepiece collection, however the taxman seemed to have different ideas on how I should spend my money this month. So while a televue may come into play on my birthday (one can hope), I am now looking at alternatives and was hoping for views on the Explore Scientific range. Seems I can get two ES's for the price of one TV.

Would like to chase down some DSO's while cranking up the views of the planets, typical want my cake and eat it observer.

I was looking at the 4.7mm and the 34mm, giving me options at both ends of the scale. I have a vixen 15mm to cope with the mid range. Would these be effective in a fast scope like mine (f4.7) and do you guys rate their overall performance and worth.

On one last point, they do seem a fair bit pricier here in the UK. Is it worth dabbling with an importer to get a better price and does anyone know a reliable one?

Thanks again All.

[RikM]

I have a 28mm 68º ES that I use as my lowest power EP in my Skyliner 250PX. I bought it from Optical Systems in Germany for a around £130 last year. It works really well in the f/4.7 but now I have a couple of years observing experience I can see the difference between the ES and TV or Pentax. I am not at all disappointed in the ES EP. I don't use this low power very often, so couldn't justify spending x3 more on a Pentax. If I dropped and killed it, I would get another to replace it rather than changing to something else.

[Scooot]

Hi Lee, How important is eye relief, this was my experience.

http://stargazerslounge.com/topic/192296-es-20mm-100-first-day-light/

[crashtestdummy]

I would go for the 30mm 82° as your widefield and I would t go as low as the 4.7mm as conditions are rare when it would be usuable.personally I would go with the 6.7 for high power.I've used both of these in a similar scope,the 30mm I still use in my 16" 4.5 and it's a great eyepiece.heavy though!!

[John]

I've only used 2 ES items - I owned their 2" 20mm 100 degree eyepiece for a while and I was loaned one of their 1.25" Focal Extender's by another SGL member to try out. I found both really excellent quality items in both build and optical terms and this is said as a lifelong Tele Vue enthusiast.

That said I'd not pay the prices that are charged in the UK for ES products - it's a real shame that ES won't allow UK dealers to come close to matching the USA pricing or even those some European vendors charge

[Orange Haze]

Thanks all for your comments so far, as usual very helpful.

Re eye relief, as I do not wear glasses when observing, eye relief is not a big issue for me, at least I hope it won't be.

I did wonder if the 4.7mm was a little optimistic given our skies. I will do a price up of the 6.7 and the 30 using the German site as a guage.

Don't think I appreciate the weight of these pieces until I read some of your comments. Have you found the need to use a counterweight at the bottom of the OTA with any of them?

I know spending money to upgrade as almost an obligation in this hobby, with every choice studied and researched to the nth degree, but to me that is part of the fun with this hobby, so thanks for your opinions and ideas!

[crashtestdummy]

When I used the 30mm in my 300p dob I had to add a kg of counterweight to the bottom go the tube.with my 16" and the paracorr I have to add 4kg!!!it's worth it though!!

[Paul73]

Lee

If you are looking for eyepieces for your Dob, you can't go wrong with the MV 68° range (search on Max Vision Explore Scientific).

The image is clear as a bell, dynamic and the build quality is splendid. They make my BST look very ordinary. I haven't tried the 34 or 40mm, But would be a bit carefull with the exit pupil size which is getting a bit big. Might be worth looking at 100° eyepieces to get those wide field views (I have no experience of these but suspect that quality will come at a price - but you will be saving a fortune if you buy the 1 1/4 inch MV's for the mid range).

I get by Ok with the 28mm 2" which is chunky, but ther are a few balance niggles at very low altitudes (the 34 is heavier again - There are several threads about effective easy fixes to Dob balancing issues).

I'm busy being confused at the other end at the moment. I need the same, or better, quality as I have in the 16 to 28mm range but in the 6 to 10mm range. I'm in no hurry at the moment the BST is holding the fort for now.

Paul

[mashedpotatomountain]

Morning All

I posted a few weeks back on my intent to add a televue to my meagre eyepiece collection, however the taxman seemed to have different ideas on how I should spend my money this month. So while a televue may come into play on my birthday (one can hope), I am now looking at alternatives and was hoping for views on the Explore Scientific range. Seems I can get two ES's for the price of one TV.

Would like to chase down some DSO's while cranking up the views of the planets, typical want my cake and eat it observer.

I was looking at the 4.7mm and the 34mm, giving me options at both ends of the scale. I have a vixen 15mm to cope with the mid range. Would these be effective in a fast scope like mine (f4.7) and do you guys rate their overall performance and worth.

On one last point, they do seem a fair bit pricier here in the UK. Is it worth dabbling with an importer to get a better price and does anyone know a reliable one?

Thanks again All.

hi lee

i ordered some ES last night actually, a couple of the 82º ones (8.8mm & 14mm) - and i ended up buying from optical-systems.com in the end.

would have liked to buy from UK but the price was a fair bit more...shame. (fingers crossed their service will be good, they have a couple of decent reviews on here anyway.)

what persuaded me to buy ES was this great review. i'm sure you've seen it already but if not you might find it useful.

hope that helps

rich

[RikM]

Hi, have you had any experience with this EP, the maxvision 68 deg Ocular? http://www.explorescientific.co.uk/en/Eyepieces/Maxvision-68-Okular-28mm.html

hubble

None at all I am afraid. I expect they are optically identical but I don't like the ergonomics of the Meade/MV.

I have also used an ES30mm 82° and that was very good as well. I actually didn't have any balance issues but I keep the alt adjusters fairly tight anyway. I prefer the slightly smaller field and lower exit pupil of the 28mm in my light polluted sky. That's the only reason I didn't go for the 30mm.

[AlexB67]

I have the maxvision version of that eyepiece, the 28mm. It is big and wide at the top as Rick says, it may not be for everyone on the ergonomics front, that said I have no problem at all with it, but big wide nose owners may find it a tad uncomfortable  .  For the price I think it is excellent for 90 pounds including shipping in the f4.7 Dob, it is quite bit cheaper than the ES, some say optically the same except for the casing and the coatings and the purging perhaps,  I don't know exactly where the differences are. 

I don't think I would push the issue for the ES to go over that 100 pounds seeing it was an Xmas present from the missus anyway.  I think she wanted that bit more FOV more than I did, but I am not complaining :0) 

[RikM]

Blessed are the big-noses

[AlexB67]

Emmerson Fittipaldi. If you anyone  has nasal equipment like this, MV is not a good choice :0)

[John]

I found that I had to turn my face sideways on to view through the Nirvana 28mm. My nose is a little larger than the average I guess and the Nirvana / UWAN 28mm does have a massively wide eye cup (face cup more like !). You get used to the technique after a short while but it seems a little odd at the outset. ES and Tele Vue seem to have adopted more conventional slightly conical eyepiece tops with simple soft rubber eye cups and on the whole I prefer that design from an ergonomic point of view.

[Orange Haze]

Brilliant, thanks again all. The mention of noses made me chuckle as my hooter is a bit more roman than petite, but I think I can cope. I suppose what has been said above affirms my research in that these pieces aren't too far off the televues in terms of quality but quite far off in terms of price.

The review you included in your post Rich was most welcome. Thanks.

One last thing I'd ask is do these eyepieces hold their value ok. I know televue pieces seem to hold very well, but does that translate to these more mid range ones? I still aim to hold a TV eyepiece or two one day....

[AlexB67]

There one positive I can say about the MV design, I find for myself anyway due to the big flat surface. Once the eyecup is adjusted to your liking it is next to impossible to get any form of blackouts with it when I rest against, I find it pretty much impossible to push inside the optimal eyerelief zone it seems.  So not all bad, MVs are very easy on the eye I find, though the 20mm is on the limit anyway for anyone with glasses, but without glasses and adjusting it I find the same. 

While I prefer the pentax design or BST I own, the XL it is very picky and needs very precise placement and twist cup adjustment. It is very easy to get inside or outside the optimal eyerelief zone where you get issues compared to my other eyepieces. I am used to that now and never have a problem, but not an eyepiece for beginners or share at a star party to try and get instant results suspect. I think with the XWs this is a much less or no problem at all from what I read. In fact the seller of the XL told me it was one of the reasons he upgraded from the 10.5 XL  to the 10mm XW.   If anyone sold an old XL 7mm second hand though I would grab in it in a nano second, but XLs don't seemed to be sold  second hand at all. I think I was lucky with that one, or at least that is how I feel about that purchase for less than half the price of a new XW  . 

[Orange Haze]

Cheers Alex. I think there are compromises to be made with any equipment you buy, especially eyepieces. Except my Rigel quickfinder of course which I am slightly in love with.

While I am getting more familiar with the terminology used in astronomy, there is the odd moment when I read something and thing "what the deuce"??

An example of this is 'exit pupil'. Can someone enlighten me?

[AlexB67]

This is a very good intro to a lot of the stuff  that is useful to know, rather than me writing a lengthy post it is all summarised nicely in that article.

http://www.rocketmime.com/astronomy/Telescope/telescope_eqn.html

[RikM]

Exit pupil is the diameter of the bundle of light that comes out of the eyepiece (it's actually the image of the objective lens or primary mirror formed by the eyepiece). You can calculate it by dividing the focal length of the eyepiece by the F-ratio of the telescope. Put simply, the larger the exit pupil the brighter the image appears up to the point that the exit pupil diameter is larger than the diameter of your pupil, then some of the light spills over. It is generally best to avoid exit pupils over 7mm or under 0.5mm.

Since the whole image gets brighter with higher exit pupils, the background sky gets brighter along with your target object. This may not be a problem from a very dark site, but with typical suburban light pollution, it can give the effect of 'washing out' the view of your object. Local light pollution may also mean that your eye will struggle to dark adapt and may not even dilate as fully as from a dark site. By selecting an eyepiece / telescope combo to give a slightly smaller than maximum exit pupil, you darken the view a little bit and this gives the effect of increasing the contrast of you object against the background sky. Theoretically / mathematically there may not actually be more contrast, but I certainly get a much better viewing experience with the slightly darker background sky.

[crashtestdummy]

I'm gutted that I won't be able to use my 30mm es 82 when I start using the 22" F3.6 as it's a massive exit pupil

[AlexB67]

Tad over 8mm, perhaps not a complete crisis ? You will not gather al the light, at 22 inches it is not as if you'll be short of that. I suppose it is how the eye takes to it and notice anything with the secondary causing issues in the view. I would not sell it before trying personally. Perhaps not all doom and gloom.

[bingevader]

@CTD, I'm finding it hard to share your pain!   If you had said:

I'm gutted that I won't be able to use my 30mm es 82 when I start using the 2" bog roll and stick back plastic Finfinity as it's massively poop 

I might have shed a tear!

22", nice. 

[AlexB67]

Another thought, if you had a paracorr or  something that pushes the magnification factor by 1.1 or whatever it is, the exit pupil would be smaller still.   At f3.6 it would be a must anyway.

[crashtestdummy]

Yeah I'm buying a featherlite SIPS system to replace my moonlite and paracorr 2 just because when combined they stick out miles and I don't want 2kg+ hanging on the focuser.with the SIPS the paracorr is inside so it's just the eyepiece weight on the focuser.

Bingevader-I get your point

[John]

I'm gutted that I won't be able to use my 30mm es 82 when I start using the 22" F3.6 as it's a massive exit pupil

I guess thats where the ES 20mm / 100 would come in handy. Most of the true field but with a usable 5.5mm exit pupil.