Wide F.O.V. EP

[bomberbaz]

Hello all.

Since I have bought a 12" dob, I have found a gap in my EP sets. I need a wide angle view for things such as pleiades, andromeda and other large sky objects to compliment the larger aperture.

I have checked out a lot of options before coming to this at 32mm: http://www.scopesnsk...cheyepiece.html

I have seen many comments on here about how lower focal length EP's are much more forgiving and that the difference between lower and more expensive models is not as noticeable. I looked at other products such as this one from Baader at 31mm http://www.firstligh...n-aspheric.html , but is it worth paying all that much extra when at this magnification?

They both give a very similar TFOV at the quoted sizes at circa 1.5 degrees. I know the Baader wil probably hold it value better but in all fairnes, with the big difference in price does it really matter that much?

Your thoughts and comments will be most welcome

Baz

[DOBBY]

Hi Baz... at £79 for the panaview & £139 for the Baarder... is the view in the Baarder twice as good ? I would say no...is the view better..probably yes

but the panaview will still give great views in your 'scope & is a true 2" eyepiece...the baarder is 1.25" with a 2" add on adapter.

I own panaviews ...But, have used the baarder.

[rory]

baz, i dont hear good things regarding panaviews with fast scopes. they seem to best below f/6 going by reviews and comments,although some find they work for them.

theres an "40mm aero" on the classifieds, is 40mm to much ?

[Mr Q]

For these wide angle EPs, I would think the sharpness across the whole FOV would be the big advantage of an expensive one vs a cheaper one. So is there any way of describing this quality accurately in ads?

[Sarah]

I thought the Baader was a 2" eyepiece with a 1.25" adapter for scopes that only accept 1.25" eyepieces? The Baader was good as a 2" eyepiece in the right scope. However I would say that in the 12" dob it was not sharp across the whole field of view.

I agree with Mr Q.

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For these wide angle EPs, I would think the sharpness across the whole FOV would be the big advantage of an expensive one vs a cheaper one. So is there any way of describing this quality accurately in ads?

[bomberbaz]

theres an "40mm aero" on the classifieds, is 40mm to much ?

Yeah I think so. When I was looking for a wide angle EP's Iloked at the Baader and Panaviews at 35/36mm and the exit pupil is going up to 7.2/7.3 so I think thats also going to be too much.

I already have two Baader Planetarium EP in 1.25" 13 & 10mm and they are a quality piece of kit.

Hi Baz... at £79 for the panaview & £139 for the Baarder... is the view in the Baarder twice as good ? I would say no...is the view better..probably yes but

The real "but" is will shelling out the extra £60 for the Baader be worth it at this magnification, I really don't know but most of me says no.

baz, i dont hear good things regarding panaviews with fast scopes. they seem to best below f/6 going by reviews and comments

Correct me if I am wrong but isn't this usually in the lower sized EP's?

As you can maybe tell, I am leaning towards the Panaview but I don't want to charge ahead with getting some feedback & views.

Baz

[michael.h.f.wilkinson]

There is an Aero 30mm. That is a clone of the TMB Paragon 30. I had the 40mm TMB Paragon, which was excellent in my F/6 scope (though the exit pupil was a bit wide). I hear they are much better than Panaviews in fast scopes, and yet much more affordable than the 82 deg crowd (have you considered getting a 28mm Nirvana?)

[bomberbaz]

There is an Aero 30mm. That is a clone of the TMB Paragon 30. I had the 40mm TMB Paragon, which was excellent in my F/6 scope (though the exit pupil was a bit wide). I hear they are much better than Panaviews in fast scopes, and yet much more affordable than the 82 deg crowd (have you considered getting a 28mm Nirvana?)

If this is the one you mean michael http://www.harrisontelescopes.co.uk/acatalog/SkyWatcher_Nirvana_UWA_28mm_Eyepiece_2_.html then no, thats far too expensive.

I had also looked at the aero but they are more expensive and the higher magnifiacation coupled with the slightly lower FOV reduces the actual TFOV and so it wasn't hitting the spot

Baz

[michael.h.f.wilkinson]

You might get a slightly lower FOV with a 30mm Aero, but it will show much more sky without distortion. Besides, the Paragon (Aero) design is near orthoscopic. Pincushion distortion shown by many super-wide EPs can mean the stated apparent FOV is smaller than the true field of view times the magnification. The field stop diameter is the real measure of what can be seen in the sky. Finally, stars in the outer bits of the Panaview FOV tend towards seagull shapes, and the Areo has better light transmission. There is a comparison here

http://stargazerslou...-panaview-32mm/

Paragon clones are also sold by TS (also a 35mm), maybe a bit cheaper than Aeros?

http://www.teleskop-...--Gro-feld.html

the only other option is hunting for second hand ultra-wides, but even second hand they are expensive.

[Dellis]

I have a 12" dob and a 32mm Panaview which I'm very happy with. I doesn't give perfect views to the edge but for me that isn't the end of the world and I liked the 32mm so much that I bought a 38mm which I use a secondary finder after getting thereabouts with the Telrad and I also have a 26mm. All three are excellent value for money and coupled with the dob have given me a great deal of pleasure.

Dave

Edit: my dob is F5

[Ajohn]

I think a lot depends on the F ratio of your scope. You might like to look at the moonfish groups range. They give honest opinions of their own eyepieces and their prices are pretty good. As they point out though there are increasing problems below F6.

Nagler designs are supposed to be better at faster F ratios but pass. Never tried one. Konig designs should be too. At F6 good quality true Plossl's should be ok. That's where they came in - Texereau and his standard F6 telescope. He used Clave of course but his suggested limit of F6 is eyepiece/coma based.

Sacrilege but I wouldn't be too concerned about using an eyepiece that produces too large an exit pupil as long as it's not too extreme. On the other hand I have had fun just browsing around with a 75 maybe 100mm 1 1/4 eyepiece on a C8 which produce an exit pupil way way bigger than my eye can accept in one go. I can look around the view effectively by moving my eye around. That came from IR Poyser. I. pretty sure I requested 75mm. Long time ago.

John

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[michael.h.f.wilkinson]

It is not a case of large exit pupil not giving a good image (although the secondary obstruction may become a pain), it is a case of losing light. If your pupil dilates to 7mm and the exit pupil is 10mm, a 10" scope becomes effectively a 7" scope, or your 12" scope becomes an 8.4" scope. You are losing nearly a full magnitude. The same ratios hold for 5mm pupil and 7mm exit pupil.

[bomberbaz]

You might get a slightly lower FOV with a 30mm Aero, but it will show much more sky without distortion. Besides, the Paragon (Aero) design is near orthoscopic. Pincushion distortion shown by many super-wide EPs can mean the stated apparent FOV is smaller than the true field of view times the magnification. The field stop diameter is the real measure of what can be seen in the sky. Finally, stars in the outer bits of the Panaview FOV tend towards seagull shapes, and the Areo has better light transmission. There is a comparison here

http://stargazerslou...-panaview-32mm/

Paragon clones are also sold by TS (also a 35mm), maybe a bit cheaper than Aeros?

http://www.teleskop-...--Gro-feld.html

the only other option is hunting for second hand ultra-wides, but even second hand they are expensive.

Interesting and food for thought there michael, rethink in progress.

Regarding the TS EP http://www.teleskop-express.de/shop/product_info.php/language/en/info/p956_TS-WA32-ERFLE-Weitwinkel-Okular---32mm---2----70--Gesichtsfeld.html this actually ticks all the boxes but cant find a review on them. Can you tell me anymore about them from experience please?

Baz

[Ajohn]

I agree Michael. I originally bought it with my 1st decent telescope to aid finding and centring things but found I used it for more than that. The low magnification seems to effectively increase contrast particularly in terms of an inky black background.

When considering this sort of thing the exit pupil is where it should all start really as that sets the minimum magnification that can be used. Then comes the question of just how large some ones pupil can get much of which depends on the conditions where some one observes or the use of hoods etc. The point I was making really is that say some one aimed at a 6mm exit pupil but in practice conditions or there eyes mean that this can not be achieved it might still be a better option than say what should be a relatively safe option of a 4mm exit pupil.

John

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[michael.h.f.wilkinson]

Interesting and food for thought there michael, rethink in progress.

Regarding the TS EP http://www.teleskop-...sichtsfeld.html this actually ticks all the boxes but cant find a review on them. Can you tell me anymore about them from experience please?

Baz

This is an Erfle design (5 element 3 groups, typically), which is a slightly older wide angle design. I have a 22mm Erfle in my finder scope (which is F/5) and it is certainly OK as a finder EP, but does show some seagulls towards the edge. I doubt whether the 32 Erfle will be better than the Panaview 32 (also 5 elements).

[bomberbaz]

This is an Erfle design (5 element 3 groups, typically), which is a slightly older wide angle design. I have a 22mm Erfle in my finder scope (which is F/5) and it is certainly OK as a finder EP, but does show some seagulls towards the edge. I doubt whether the 32 Erfle will be better than the Panaview 32 (also 5 elements).

Sorry Michael you are leaving me slightly confused. (dont worry, it isn't hard to do) You seemed to be steering me towards the TSWA32 as a possible alternaitve for me to explore and now you tell me its probably no better than a Panaview, slightly confused.

On another note, the Moonfish group EP mentioned by Ajohn http://www.moonfishgroup.com/catalog/product_reviews_info.php?products_id=50&reviews_id=124 does look very nice indeed and gives a slightly larger view at 50x and larger AFOV, worth thinking about for sure.

Alwys the thing, start out thinking about one thing and then end up thinking about half a dozen

Baz

[Ajohn]

You might care to read the reviews on the moonfish 30mm wide field I mentioned. A little more expensive but people have been perfectly happy with it on faster scopes. I own one actually. The only comment I would make when used on a 11in F4.2 dob is wondering if I really did want that wide a field of view. Not a scope I made much use of, hardly at all, because it needed a rather dark site to be fully effective I did wonder if a straight 2in TeleVue plossl would also be ok. I have compared those with early true plossl's from Vixen, very low eye relief by modern standards and the Teleview's do match up. How well they will work down in the F4's is debatable but they are aimed at faster scopes.

John

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[Moonshane]

My view on wider field, lower power eyepieces is thus (based on my main DSO scope of 1840mm focal length f4.5 with paracorr):

• I want the whole field to be good
  
• I want the sky background to be dark and not badly affected by the LP I suffer with
  
• I want an exit pupil of around 6mm max
  
• I want a large aperture scope
  
• this aperture usually = less field of view
  
• there are few objects that extend more than 1 degree so I want at least this as a TFOV
  
• I accept that the Pleiades, the Beehive and areas like Orion's Belt will look better in the finder than the scope and that one galaxy (M31) will not fit in my eyepiece fully
  

Based on all of the criteria above, I decided on a 26mm Nagler as the ideal eyepiece which gives me 71x and 1.15 TFOV and exit pupil of 5.78mm. This is more than adequate other than for a vew few objects as mentioned. I can see the cores of M31, M110 and M32 in the same field of view and the double cluster fits easily. As with all things it's about compromise but do consider some of the above points and their relevance to your own preferences.

I previously had a 12" f5.3 dob and this worked very well with a 35mm Panoptic. These can be bought used for not much more than the price of the Aspheric new and might be an option although in my opinion it's pushing the exit pupil a bit. Not an easy decision. If I were you I'd hang on a bit and try a few in your scope maybe at SGL8 and see how you go. I bet there will be someone with all the options at that event.

if you want one now, buying used has the advantage that if you don't get on with something it can be sold again at little or no loss.

[michael.h.f.wilkinson]

Sorry Michael you are leaving me slightly confused. (dont worry, it isn't hard to do) You seemed to be steering me towards the TSWA32 as a possible alternaitve for me to explore and now you tell me its probably no better than a Panaview, slightly confused.

On another note, the Moonfish group EP mentioned by Ajohn http://www.moonfishg...&reviews_id=124 does look very nice indeed and gives a slightly larger view at 50x and larger AFOV, worth thinking about for sure.

Alwys the thing, start out thinking about one thing and then end up thinking about half a dozen

Baz

Sorry for the confusion: I meant the 30 and 35 mm TS Paragons, which are cheaper than the (equivalent) Aeros

[bomberbaz]

Thanks for the help guys, the moonfish 30mm/80 degree FOV EP ticks a lot of your boxes then shane. According to the Xcel planner for SGL, the exit pupil is exactly 6 on my scope, the TFOV is 1.6 at a mag of 50.

I get what you meant about the finder scope, Pleiades looked awesome through your finder last night, I was most impressed.

Anyway, I have found a Moonfish on ABS which is for sale at only £70. That is a bargain and I have placed my interest. I could look around forever and many people have differing experiences and as such, differing views of whats best but after reading all you chaps have said, I hope, no think I hae made the right choice.

Many thnaks

Baz

[Moonshane]

I think that will be a great buy. I have never used one but they get good reviews generally. the eye relief is also nice for you at 22mm. the good thing as I said is that buying used, you really risk little as most look after their kit, and you can sell at little or no loss.

[Spec-Chum]

Thanks for the help guys, the moonfish 30mm/80 degree FOV EP ticks a lot of your boxes then shane. According to the Xcel planner for SGL, the exit pupil is exactly 6 on my scope, the TFOV is 1.6 at a mag of 50.

I get what you meant about the finder scope, Pleiades looked awesome through your finder last night, I was most impressed.

Anyway, I have found a Moonfish on ABS which is for sale at only £70. That is a bargain and I have placed my interest. I could look around forever and many people have differing experiences and as such, differing views of whats best but after reading all you chaps have said, I hope, no think I hae made the right choice.

Many thnaks

Baz

Wow, £70, don't pay that lol

Skies the Limit have them for £59, they're not on their ebay site but email Alan...

(I know I have one lol)

Edit: They're on his actual site here: http://www.skysthelimit.org.uk/2%20inch%20telescope%20eyepieces.html

[8kids]

I wouldn't bother with the Panaviews in a fast scope, I picked up the 26mm very cheaply but its not very good in my scope. I even tried the coma corrector (picked up cheaply) with it and although it improvoves the view it's still not brilliant. Now the views with the nirvana are very good, sharp crisp views, not all the way to the edge of field but not that far off.

I'm on the lookout for a secondhand uwa eyepiece, 28mm or 30mm, have you thought about buying used? You can pick up a real bargain if your not in a hurry.

[rory]

ive picked up a 30mm aero . this is my first 2" e/p and even though i know its not big compared to some of the grenades i see around this forum,it still takes you by suprise when youve not seen one in the flesh. i cant wait to get a chance to use it. should give me x40 mag, 1.7 tfov. and 5mm exit pupil. its not a ultra wide field at 68* but i think it'll do me fine.

that moonfish under £60 seems a good buy.

[Spec-Chum]

that moonfish under £60 seems a good buy.

They are mate, I sold my 25mm BST after I got mine. I rate it that highly.

Granted it's not sharp to the edge but it's much sharper than it should be for the price and it definitely shows more pin sharp area of sky than the 60 degree BST.

I stand by my review and my challenge for anyone to find better for the price.