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11mm Delite - lots of scatter and ghosting

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#1 CrazyPanda

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Posted 28 February 2017 - 05:49 PM

So, a while back I purchased an 11mm Delite to fill a magnification gap in my collection. I bought it primarily for observing the planets and Jupiter. My initial first light impressions were positive, but until this morning I've, not really been able to give it a fair test on the planets due to seeing conditions and terrible mirror shift.

 

Prior to this morning, I noticed that every time I observed jupiter, there was a lot of scatter - and what seemed like an obvious ghost reflection from my eyeball. I chalked it up turbulent seeing and my diagonal being meh, and didn't worry about it that much since there wasn't enough detail to really do a planetary comparison with.

 

Well this morning I had good seeing and a brand new Feather Touch crayford to resolve fine focusing issues, so I decided to take it for another spin and do a comparison with other eyepieces in my collection. 

On axis, it is very sharp, but I observed a tremendous glow around the planet + a ghost glow which I think is reflection from my eye. When I placed Jupiter just outside the field of view, the whole field lit up with a very obvious glow. Thinking it was my 2" diagonal, I switched it out for my stock 1.25" diagonal that came with the scope. The cheaper diagonal definitely made things worse, so I figured maybe my 2" diagonal wasn't so swift either. 

To eliminate the diagonal as a source of scatter, I placed the eyepiece directly in the back of the scope with no diagonal and repeated the tests. Same problem as in the 2" diagonal, meaning the source was the eyepiece.

 

For comparison, I did the same tests with my 12mm Nagler Type II, new 17mm ES 92, and 20mm Plossl + Barlow. 

 

None of those showed nearly as much scatter as the 11mm, and none showed any sort of eyeball reflection ghosting (or whatever it was I was seeing). 

 

The overall sharpness and contrast with the barlow + plossl was definitely worse than the Delite alone, but the 12mm Nagler Type II had noticeably better contrast, and the 17mm ES 92 also had better contrast and sharpness (though being lower power, not surprised the sharpness was better).

 

Here's a simulation of what the view looked like in the 11mm Delite. The offset glowing ball seemed to move when my eye/head moved, but was also somewhat dependent on where Jupiter was in the field (which is also to be expected I suppose).

 

This is a simulation of what it looked like with jupiter in the field:

 

jupiter11mmDelite.jpg

 

 

And just outside of the field:

 

jupiter11mmDelite_2.jpg

 

Based on this mornings observations, I'd have to say the 11mm is a dud for planetary viewing. Will be doing more tests as the skies permit, but a bit disappointed with it for the time being.


Edited by CrazyPanda, 28 February 2017 - 05:56 PM.


#2 alex_d

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Posted 28 February 2017 - 06:02 PM

Wow, im just about to buy one of these for a 4" refractor  with a 600mm focal length, never heard of trouble like this before, what kind of scope do you have?



#3 junomike

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Posted 28 February 2017 - 06:17 PM

popcorn.gif

 

Mike


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#4 Peter Besenbruch

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Posted 28 February 2017 - 06:56 PM

On axis, it is very sharp, but I observed a tremendous glow around the planet + a ghost glow which I think is reflection from my eye. When I placed Jupiter just outside the field of view, the whole field lit up with a very obvious glow. Thinking it was my 2" diagonal, I switched it out for my stock 1.25" diagonal that came with the scope. The cheaper diagonal definitely made things worse, so I figured maybe my 2" diagonal wasn't so swift either. 

To eliminate the diagonal as a source of scatter, I placed the eyepiece directly in the back of the scope with no diagonal and repeated the tests. Same problem as in the 2" diagonal, meaning the source was the eyepiece.

 

For comparison, I did the same tests with my 12mm Nagler Type II, new 17mm ES 92, and 20mm Plossl + Barlow. 

 

None of those showed nearly as much scatter as the 11mm, and none showed any sort of eyeball reflection ghosting (or whatever it was I was seeing). 

 

...Here's a simulation of what the view looked like in the 11mm Delite. The offset glowing ball seemed to move when my eye/head moved, but was also somewhat dependent on where Jupiter was in the field (which is also to be expected I suppose)....

Based on this mornings observations, I'd have to say the 11mm is a dud for planetary viewing. Will be doing more tests as the skies permit, but a bit disappointed with it for the time being.

If I lived in a cold climate I would say that looks exactly like condensation, or micro-ice crystals. Clean optics help retard condensation some. If it's not that, you really did get a dud.


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#5 rogeriomagellan

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Posted 28 February 2017 - 07:21 PM

Hi.

 

Just out of curiosity, did you get a brand new DeLite eyepiece?



#6 bmurphy495

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Posted 28 February 2017 - 08:23 PM

I have an 11mm & 18mm DeLite and have not noticed this. Now I'm kinda nervous. 

 

B



#7 MortonH

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Posted 28 February 2017 - 08:59 PM

My 11mm DeLite is optically excellent and has none of these issues.  Agree with post #4 that it looks like condensation.


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#8 CrazyPanda

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Posted 28 February 2017 - 09:07 PM

Wow, im just about to buy one of these for a 4" refractor  with a 600mm focal length, never heard of trouble like this before, what kind of scope do you have?

8" LX90 (older version - non ACF)

 

 

Hi.

 

Just out of curiosity, did you get a brand new DeLite eyepiece?

Yep, ordered it from Amazon. Fulfilled by Adorama. I got it Feb 8th, so I think I can still RMA it, which I may do.

 

 

My 11mm DeLite is optically excellent and has none of these issues.  Agree with post #4 that it looks like condensation.

Definitely not condensation, the glass is perfectly clear when I look through it, and no condensation on or inside of the optical tube.

 

 

Playing with it some more right now and just pointing it at a lamp, I noticed that the position of the sliding eye guard makes a huge difference in how sharp the edge of the field is. If the eye guard is all the way down, the field stop is razor sharp. If the eye guard is raised, the field stop is a complete blur. I use it in the raised position to help with eye positioning, so this could explain why there's significant glow at the edge of the field when Jupiter is positioned just outside the edge.

 

I'd have to test it with the eyeguard at its lowest position to see if that affects the image at all. 

 

It still seems odd to me that the field stop loses focus as you adjust the eye guard. 


Edited by CrazyPanda, 28 February 2017 - 09:29 PM.


#9 MortonH

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Posted 28 February 2017 - 09:20 PM

If you can definitely rule out other factors there must be something wrong with your particular DeLite.  I'm glad you still have the option to return and replace it.

 

For anyone else considering one this performance is not normal.


Edited by MortonH, 28 February 2017 - 09:22 PM.

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#10 GUS.K

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Posted 28 February 2017 - 10:17 PM

I've got the 11mm and also had a second one for Bino viewing, and both worked beautifully, no issues with mine.


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#11 Jim Nelson

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Posted 28 February 2017 - 10:31 PM

 

Playing with it some more right now and just pointing it at a lamp, I noticed that the position of the sliding eye guard makes a huge difference in how sharp the edge of the field is. If the eye guard is all the way down, the field stop is razor sharp. If the eye guard is raised, the field stop is a complete blur. I use it in the raised position to help with eye positioning, so this could explain why there's significant glow at the edge of the field when Jupiter is positioned just outside the edge.

 

I'd have to test it with the eyeguard at its lowest position to see if that affects the image at all. 

 

It still seems odd to me that the field stop loses focus as you adjust the eye guard. 

 

I can't imagine any way that the eye guard could do anything to the optics at all, it sounds like you're just forced to be too far away from the eye lens to see the field properly. With my 13mm if I extend the eyeguard all the way, the "field stop" seems fuzzy, but if I press my eye in I can see it's actually sharp, and I was just too far away from the eye lens.

 

Use an intermediate position, not fully extended.


Edited by Jim Nelson, 28 February 2017 - 10:33 PM.

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#12 jeffmac

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Posted 28 February 2017 - 11:59 PM


Since you use the eyecup in the up position, it sounds like moisture condensation. I have a 15mm DeLite and if I use it in the up position and bury my eye in the eyecup to block out peripheral light for extended periods of time, condensation forms on the eye lens and things don't look quite right. Not sure if this is your particular problem but try it out with the eyecup down and see if it makes a difference.
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#13 Ernest_SPB

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Posted 01 March 2017 - 12:27 AM

> ...what seemed like an obvious ghost reflection from my eyeball...

 

Such a reflection easy to separate - it is quite mobile (following eyeball movements)...


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#14 jeremiah2229

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Posted 01 March 2017 - 12:27 AM


This is a simulation of what it looked like with jupiter in the field:

 

attachicon.gifjupiter11mmDelite.jpg

 

 

And just outside of the field:

 

attachicon.gifjupiter11mmDelite_2.jpg

 

 

This is not ghosting nor scatter. With both of these you will pick up a secondary image(s) from another piece(s) of glass in the eyepiece and I haven't seen this in a long, long time. Coatings are pretty stable now and edges are usually darkened.

 

This can be as others have said due to condensation even though you cannot see it on the glass, just takes a wee amount to act as another piece of glass. (the halo)

 

It can also be what I call the Jupiter Effect (the halo)  where the eye and brain are trying to agree on what you are seeing. It's akin to crater illusion but with a bright target like Jupiter as the magnification increases the eye position must be maintained and some eyepieces are more critical than others with respect to eye placement. Just look away from the eyepiece and when you return the halo will disappear, the eye/brain need to get back in synch.

 

My purely uneducated diagnosis for what it's worth.  :)

 

 

Peace...



#15 CrazyPanda

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Posted 01 March 2017 - 01:10 AM

Since you use the eyecup in the up position, it sounds like moisture condensation. I have a 15mm DeLite and if I use it in the up position and bury my eye in the eyecup to block out peripheral light for extended periods of time, condensation forms on the eye lens and things don't look quite right. Not sure if this is your particular problem but try it out with the eyecup down and see if it makes a difference.

It's definitely not moisture condensation. I use the eyecup down, but the eyeguard mostly up and rest my eyebrow against the guard. This places my eye quite far from the glass, and allows air to flow between them. I bury my eye a lot closer to my 12mm Nagler and 19mm Panoptic, and those don't have this issue (to the same degree anyway). Moreover if I turn on my head lamp and move my head back quickly, the glass is perfectly clean. There is categorically *NOT* condensation or fog on the lens. 

 

 

 


This is a simulation of what it looked like with jupiter in the field:

 

attachicon.gifjupiter11mmDelite.jpg

 

 

And just outside of the field:

 

attachicon.gifjupiter11mmDelite_2.jpg

 

 

This is not ghosting nor scatter. With both of these you will pick up a secondary image(s) from another piece(s) of glass in the eyepiece and I haven't seen this in a long, long time. Coatings are pretty stable now and edges are usually darkened.

 

This can be as others have said due to condensation even though you cannot see it on the glass, just takes a wee amount to act as another piece of glass. (the halo)

 

It can also be what I call the Jupiter Effect (the halo)  where the eye and brain are trying to agree on what you are seeing. It's akin to crater illusion but with a bright target like Jupiter as the magnification increases the eye position must be maintained and some eyepieces are more critical than others with respect to eye placement. Just look away from the eyepiece and when you return the halo will disappear, the eye/brain need to get back in synch.

 

My purely uneducated diagnosis for what it's worth.  smile.gif

 

 

Peace...

 

I disagree. The glow leaking into the field when Jupiter is out of field, and that same glow around Jupiter when in field, is exactly what scatter is. It's present in the other eyepieces I tested, but nowhere near the degree that it is in the 11mm DeLite. The brighter, smaller halo is *something*. I don't know the source, all I know is that it's not present in my 12mm Nagler, 17mm ES 92, plossls, or any other eyepiece I own. If it is present, it's so subtle I haven't even noticed or been distracted by it. My DeLite is literally the first time I've ever noticed this in any eyepiece. It's as distracting as I've depicted in the image above. 


Edited by CrazyPanda, 01 March 2017 - 01:21 AM.


#16 starcam

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Posted 01 March 2017 - 03:55 AM

Maybe a coatings issue. If it was scatter, I would think it would be equal distance around jupiter.

Not jupiter in the 5 o'clock position, just an observation.



#17 Riccardo_italy

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Posted 01 March 2017 - 04:21 AM

Simply replace it.....



#18 Lt 26

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Posted 01 March 2017 - 07:37 AM

Replace it with what, another? This is not the first report of Delite ghosting. I was wanting a 5mm for a high power moon eyepiece but other reviews of light scatter ended that.

Dereck

#19 ewave

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Posted 01 March 2017 - 08:13 AM

I have nothing but good things to say about my 11mm Delite and the same goes for all Televue EPs I have or had in my case. 

I suggest you return it if you are not satisfied.  There were times I saw ghosting/flaring when observing Jupiter (yes with TV EPs),

but as others have already pointed out, it was due to dewing/condensation

and the problem went away after the EP (or scope in some cases) was more or less dry.

 

Clear skies



#20 slack

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Posted 01 March 2017 - 09:01 AM

I have nothing but good things to say about my 11mm Delite and the same goes for all Televue EPs I have or had in my case. 

I suggest you return it if you are not satisfied.  There were times I saw ghosting/flaring when observing Jupiter (yes with TV EPs),

but as others have already pointed out, it was due to dewing/condensation

and the problem went away after the EP (or scope in some cases) was more or less dry.

 

Clear skies

Tele Vue makes very good eyepieces. But I would never go so far as to assert that I had nothing but good things to say about all of them; even without comparisons to specific other makes/examples, it only takes reasonable objectivity to find fault with certain models or inconsistency (albeit, perhaps, less than with less costly makes) with some models. Of course, I don't know what TV EPs you've had in your case. ;)



#21 ewave

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Posted 01 March 2017 - 09:18 AM

 

I have nothing but good things to say about my 11mm Delite and the same goes for all Televue EPs I have or had in my case. 

I suggest you return it if you are not satisfied.  There were times I saw ghosting/flaring when observing Jupiter (yes with TV EPs),

but as others have already pointed out, it was due to dewing/condensation

and the problem went away after the EP (or scope in some cases) was more or less dry.

 

Clear skies

Tele Vue makes very good eyepieces. But I would never go so far as to assert that I had nothing but good things to say about all of them; even without comparisons to specific other makes/examples, it only takes reasonable objectivity to find fault with certain models or inconsistency (albeit, perhaps, less than with less costly makes) with some models. Of course, I don't know what TV EPs you've had in your case. wink.gif

 

Of course I speak from my own experiences and stand by my comments.  I'm sure there are plenty of fine EP makers out there.

Previous TV EPs I have experienced include the 11mm plossl, 11mm & 18.2mm Delite, 24 Pan, 8mm, 10mm, 12mm, 14mm, 17.3 Delos, 31 Nagler.


Edited by ewave, 01 March 2017 - 09:19 AM.


#22 ewave

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Posted 01 March 2017 - 09:20 AM

 

 

I have nothing but good things to say about my 11mm Delite and the same goes for all Televue EPs I have or had in my case. 

I suggest you return it if you are not satisfied.  There were times I saw ghosting/flaring when observing Jupiter (yes with TV EPs),

but as others have already pointed out, it was due to dewing/condensation

and the problem went away after the EP (or scope in some cases) was more or less dry.

 

Clear skies

Tele Vue makes very good eyepieces. But I would never go so far as to assert that I had nothing but good things to say about all of them; even without comparisons to specific other makes/examples, it only takes reasonable objectivity to find fault with certain models or inconsistency (albeit, perhaps, less than with less costly makes) with some models. Of course, I don't know what TV EPs you've had in your case. wink.gif

 

Of course I speak from my own experiences and stand by my comments.  I'm sure there are plenty of fine EP makers out there.

Previous TV EPs I have experienced include the 11mm plossl, 7mm, 11mm & 18.2mm Delite, 24 Pan, 8mm, 10mm, 12mm, 14mm, 17.3 Delos, and 31 Nagler.

 



#23 Jim Nelson

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Posted 01 March 2017 - 09:22 AM

Is my understanding correct that this all the result of a single session of observing? If so, then it's premature to say anything, particularly to insist 100% that it couldn't have been condensation somewhere (which I still think is the safest bet, actually, although I know you don't).

 

If instead this is consistently showing every time, then it's a quality control issue. None of my Delites perform anything like this.

 

The 'ghost' does look like an eyeball reflection (if the ghost moved with your eye position), but that may be a simple fix of not holding your eye so far away from the lens (I don't think anyone should be viewing from the maximum-out position, not unless you're a fan of pressing your eyeball firmly into the eyecup.)


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#24 CrazyPanda

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Posted 01 March 2017 - 09:33 AM

No, this is something I've noticed over several observing sessions, but only one observing session where seeing was good enough to warrant critical observation with the eyepiece and where the contrast issues from these aberrations impaired my ability to see features that I could distinguish in other eyepieces.

 

The glow around jupiter + "ghost reflection" or whatever the hell it is was immediately apparent to me at first light when I first got the eyepiece, and every subsequent night I did planetary observation. I only started caring about it/worrying about it when I got my first clean look at Jupiter yesterday morning.

 

For all other cases, the EP seemed to be fine. Moon looks fine, and there's something about the contrast it shows in the Orion Nebula that is incredible (maybe just a function of its exit pupil though!). But for bright point objects like Jupiter, there's definitely something off about it.

 

It could very well be it's not even a production run issue, but simply something inherently characteristic about the EP in my particular telescope (or even my eyeball geometry).

 

I'll be returning it and replacing it with another from a different retailer just to possibly help isolate any potential production run issues. I'm hoping it's not something inherent with its optical characteristics with respect to my telescope. If I have the same issue with the replacement, I'll do the same comparison in my Celestron refractor and see if that clears up the issues. 


Edited by CrazyPanda, 01 March 2017 - 09:38 AM.


#25 Jon Isaacs

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Posted 01 March 2017 - 10:18 AM

If I have the same issue with the replacement, I'll do the same comparison in my Celestron refractor and see if that clears up the issues.

 

When I see something unexpected in an eyepiece,  I will try in in other telescopes as well as try similar eyepieces in the telescope to try to isolate the issue. Sometimes it the eyepiece,  sometimes it's the scope and sometimes it's the particular combination..  

 

I also would investigate the diagonal because some diagonals have their own issues.  I see many of the Asian dielectric diagonals have a glossy black finish that can potentially reflect off axis light into the field of view. 

 

Before sending it back,  I would check these things to further identify the problem. 

 

I will say it does seem like a cleanliness issue,  an eyepiece can look clean and clear but the sign that it needs cleaning is that there's scatter on bright images.  

 

Jon


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