32mm or 38mm panaview?

[Del Boy]

I need one more eyepeice to complete my range and since I prefer DSOs it will probably be the piece that I use most. I'm trying to way up the differences between the 32 and 38mm panaview.

I hear the 38mm is quite bulky but I'd like to know what the difference in exit pupil would be between these two as I have no idea how to work that out!

I'm using a Skywatcher 300p which is a 12"

F4.9 scope. Any help or comparisons between these two would be greatly appreciated.

[Astro_Baby]

My own experience was the 38mm had a better 'wow' factor than any of the others in the Panaview range.  Technically when mated to my 200/F5 it would produce an overlarge exit pupil and, according to theory, would result in a darkening of the central area of view.

In practice I never saw any problems with it, perhaps my eyeballs open wider than other peoples but I cant say.

I found the views with the 38 pleasing and for some very diffuse objects like large clusters found it really excellent - the pleiades were amazing with it I always thought.

It does suffer from poor edge correction at F5 although I cant say it ever really bothered me as it always seems to only occur at the last few mil of the lens.  Some people cant stand edge issues with lenses but I never found it distracting in the least.

It was one of the most comfortable eyepieces I have ever used but the size of its eyecup is so large than some people find it awkward.  Much will depend on the size/shape of your face I think.

If it works for you its a great eyepiece, it may not technically rank up there with Televue or Pentax, but it was none the less a really nice bit of glass and I do regret having sold mine off some time ago.  Its a veritable bucket full of stars if you can get on with it and it always seemed to provide a porthole in space experience in a way that few other eyepieces do (the Nagler 31 excepted).  The 100' eyepieces produce a much wider field but I never found them so comfortable and with the feeling of depth  that the Panaview 38 produced.

I would seriously suggest you try before you buy because from reading other experiences I think its a bit of a 'marmite' eyepiece that you either love or hate.

[Del Boy]

Thank you for your response. I don't really have an opportunity to try either which is why I was hunting for peoples opinion but like you say I guess it's down to your own personal preference. I'm just gonna have to take a shot in the dark and choose one over the other and hope it works well!

[avtaram]

Totally agree with Astro_Baby.

I have the Panaview 38mm and it does really give me the Wow factor when using it in my 12" Dob.

For me this eyepiece is a keeper.

Avtar

[Saganite]

Hi Delboy,

I had the 32mm and it was a really lovely eyepiece not least because of its construction and the way that

the eyecup rotated up to give supreme comfort. It was not sharp though across the entire view  but not so much

that I could not use it and enjoy doing so. I used it for over a year but then bought a Televue 32mm plossl, not such 

a wide field of view as the Skywatcher but it has become my No 1 eyepiece and a keeper.

Whichever size you choose you will not be disappointed. Good luck

[Del Boy]

Thanks guys. I think I've settled on the 38. Here's to open skies! =]

[Del Boy]

Actually one last thing. If I was to go for the televue 32mm, does the fact that I would have to use the 2" to 1.25" covertor make any difference?

[rwilkey]

Hi Delboy, my thoughts are that with fast scopes they are a bit soft at the edges, but on axis - incredible!  I chose the 32mm as the exit pupil is better in my scopes, also with the 38mm you have the danger that the 'spider' will be visable at such low power; I have a friend with a SW 200P who had that problem with the 38mm.  Personally I love the 32mm PanaView and can live with its small weakness in fast scopes.

[rwilkey]

Actually one last thing. If I was to go for the televue 32mm, does the fact that I would have to use the 2" to 1.25" covertor make any difference?

Hi Delboy, no, not at all, just means you can use 2" filters with 1.25" ep's (thinking practicalities).  The TV 32mm plossl is also a stunning piece of engineering and the 'safe' option.

[great_bear]

Note that the Sky-Watcher ED range (e.g. ED40) is sharper off-axis than the PanaViews

[great_bear]

My own experience was the 38mm had a better 'wow' factor than any of the others in the Panaview range.  Technically when mated to my 200/F5 it would produce an overlarge exit pupil and, according to theory, would result in a darkening of the central area of view.

Yes, this is one of those pervasive myths in astronomy.

There is no darkening in Newtonians due to low magnification: If you sat behind someone wearing a hat in a cinema (e.g. a central obstruction) you would instinctively move your head to one side and forget about it. The same thing happens with a scope. You wouldn't deliberately position your eye behind the shadow of the central obstruction, you would move slightly to one side so a segment of the illuminated ring enters your eye instead.

[Astro_Baby]

As I say GB I never saw any problems, some people say they can see the spider vanes and central obstruction when using the 38mm but I never saw any problems with mine at all and it was used an awful lot as well.

[John]

I've only seen the central obstruction "shadow" when using an 8" SCT with a 50mm eyepiece to view the Moon against a twighlight sky. It can't have been due to the exit pupil size as that was a mere 5mm.

I have seen washed out looking DSO's and paler background sky when using eyepiece / scope combinations that generated an oversize exit pupil though. With my F/5.3 even the 31mm Nagler is less efficient than the 21mm Ethos on all but the darkest of nights in this respect. On that basis I'd recommend the 32mm over the 38mm to the original poster for use with an F/4.9 scope.

To answer the question on working out the exit pupil, you divide the eyepiece focal length by the focal ratio of the scope so the 32mm delivers a 6.53mm exit pupil and the 38mm 7.76mm.

[bingevader]

I sometimes dream that it would be nice to upgrade to an 82° 32mm EP, but they're prohibitively expensive for me.

Robin, I thought you had the ES 30mm 82° EP, does it take second place to the Panaview then!?

I have the 32mm Panaview, it is a little soft towards the edges, but I too, can live with it.

For the money, it's a rather splendid performer and I can only echo Astrobaby's comments, although on the shorter FL eye piece.

[russ.will]

I had the 32mm Panaview in my 200p F5 and had a very enjoyable time with it. A nice big eye lens, plenty of eye relief and a great twist up eye cup, all contribute toward an EP that is easy and pleasant to use and probably good enough to keep most people with F5, or above, scopes happy for a long time - Of course, that's not how it works with EPs, even if you think you are happy..... Now, I don't know if it was just down to the sheer extra illumination of my 300p FlexTube making it more noticeable, but the view seemed to go from only 5-10% being a bit ugly, to about 20% and I really didn't like it anymore.

Back then, options for upgrading were a little different and I ended up with an ES82 30mm, which still rates as one of the est EPs I've ever looked through and certainly one of the very best I've owned. Sure, with vastly reduced astigmatism, the coma of the scope was clearer, but that's not the fault of the EP and I deeply regret selling it. However, that will seem like a massive jump from where you are and there are a few more options available these days that straddle the gulf in quality and price.

At this point, I'll bang my familiar drum and say have a look at the Maxvision 28mm SWA, because with the Euro on it's knees, that price is £80. I bought mine when the Euro was stronger, it was closer to £100 and I'd still be recommending it at that price.

Basically, the MVs are de-badged Meade Series 5000 SWAs and in those colours, some of the SWAs were oft talked about in the same breath as Televue Panoptics. Obviously not by Panoptic owners, who'll never admit something can rival a Televue! <Ducks for cover!>

Indeed, there have been feint mutterings among the S5000 owners that the MVs were in some way, not quite subject to the same QC as the Meade badged examples. Some may suggest that people might say that if they had a £216 EP (the RRP of the 28mm SWA in the UK) and overnight it's residuals were slashed, but I couldn't possibly say.

No matter, it's that rare case of a much more expensive design for peanuts and in my (by now ES 305 Dob) it was a cracker. Very sharp and as well corrected as you're going to get without spending A LOT more. It's certainly a cut (or two) above the Panaviews. the only problem it really introduces is that to improve on it and even then, not by much, it's than a jump to £300+.

Before you ask (if you checked) I also had the 34mm and that was nice, but didn't offer a much wider FOV, whilst it did deliver lighter skies and was a balancing nightmare as it's 60% heavier. The 28mm stayed on the right side of those equations.

Russell

[triton1]

+1 for the 28mm mv,great ep and at a great price.

[great_bear]

I'd still recommend considering the Sky-Watcher ED range over the Sky-Watcher PanaView range

[Ags]

According to my understanding an over-large exit pupil affects the whole field not just the center and is not related to the central obstruction coming into focus. Exit pupil refers to the diameter of the parallel beam of light that leaves the eyepice representing a point in the image, such as a star. If the exit pupil is bigger than your eye pupil, some of the light cannot enter your eye and the whole image (every point on the image) becomes darker.

The light loss due to excess exit pupil effectively stops the scope down. For example, if your eye pupil is 5mm, a 8 inch f4 scope with a 10mm exit pupil would be stopped down to a 4 inch f8 scope with a 5mm exit pupil. Obviously the EP will seem to perform better at f8 than at the nominal f4. This may explain why the 38mm is preferred to the 32mm in fast scopes.

To calculate exit pupil, divide EP focal length by scope F ratio.

[great_bear]

Sorry, but your understanding is (partially) wrong.

The image does not get darker, it merely stops getting brighter - as the exit pupil is now iris-dependent. Note that - at that point - it is physically impossible for any scope - at that magnification - to provide you with a brighter image. That's why it's embarrassing when people use the phrase "wasted light" to describe this scenario. The light is no more "wasted" than the light falling around you during everyday life.

The only meaningful comment that can be made about the situation is that you're getting no improvement over a smaller-aperture scope at that point - i.e. a smaller scope could suffice if you were only using such a low magnification. Chances are however, that one would be using a range of magnifications, so the point is typically moot.

[Ags]

Yes, I was a bit confusing. Diffuse objects stop getting brighter (and carry on getting smaller). But stars start getting fainter.

[Fish]

Ooooo this is getting technical .... If it looks good, it jolly well is good :-) My 38mm panaview has been fantastic in every scope I have used it in , great value for money. It is my most used eyepiece ....

[russ.will]

Have you got anything F5 or shorter?

Russell

[nicks90]

i own both the 32mm and 38mm panaview and the 38 is by far my favourite. I use them both in my 12" f4.9 dob.

Issues? yes, plenty.

The 38mm is so low powered that you will suffer from a grey sky unless you live somewhere dark. I got around that by fitting a baader neodymium filter (which is use on all my 2" eps when at home and also on my camera lens) and it really made a massive difference to contrast and darkening the skies. I actually use the 38mm ep as my 'finder' once I'm in the general vacinity using my RDF. The field of view with this whopper means i can almost get Sulafat and Sheliak in Lyra in the same FOV. Makes stumbling across faint fuzzies and framing things like the leo triplets really easy. Its is a HEAVY ep. No other way to describe it, its big and heavy so be prepared to velcro on a weight or two at the bottom to maintain the dobs balance. Towards the edges - 20% - you do start getting comet tails. I dont know if this is coma or astigmatism, I;ve never really understood which looks like what, but it isnt that distracting. But overall I love this ep. I dont get blackouts or dark spots and find it very easy to use and it really is beautiful to get the whole of the plieades in the fov using a 12" dob. I swear that under dark skies merope and alcyone have a 'fuzziness' about them!

The 32mm I find suffers badly from 'fishbowl effect' at the very edge and I find this properly distracting. So much so, that I never use it for sweeping the sky or searching for objects. I would rather spend the time putting the 38mm in and out to get the objects centred and then swap back to the 32. But once on target, objects are lovely when in the centre. Obviously the sky is darker being slightly higher powered and I use this for single fuzzies and tighter clusters where they will fit in the FOV, but the leo triplet or bodes dont look as good to me in this ep as its all a bit tight and the galaxies are on the edge so start to go a bit mushy. Its a lovely ep for globs as well, really clear and tight. but like the 38mm, the outer 20% goes comet like and then warps into fishbowl effect.

would i buy the 32mm again?

no. I'd rather save up a few more pounds and get the maxvision. But i doubt i will ever sell my 38mm.

[bingevader]

Funny how people's eyes and experiences with eyepieces vary!

I've never had any fish bowl effect with the 32mm.

Yes it's soft around the edges, but nothing else.

Do you mean the 28mm MV?

[nicks90]

nope, definately fishbowl effect in the 32mm panaview.

dont get me wrong, its a nice ep and i like using it on objects that fit correctly framed in the fov - i just dont find it pleasant to sweep the cosmos with.

edited to add:

I had a chance to use both these eps in a big SCT and with its slow F ratio, these eps were unbelievable! They really were almost perfect (to my untrained eye) and everything right up to the edge was simply breathtakingly crisp and clear. No fishbowl effect in the 32mm either. Maybe that one just struggles a bit under F5.