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Yes, I modified my Docter Aspectem to make the best 20x80 money can buy…

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#1 Mad Matt

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Posted 14 June 2018 - 09:17 AM

Yes, call me crazy... I have modified my Aspectem Vario and replaced the zoom eyepieces with TeleVue 24mm Panoptics making them an excellent fixed magnification 20.8x80.

 

IMG 6330
IMG 6332

 

Probably the first question you are wondering is why?

 

Well, after the novelty of the Vario it wore off, the small FoV and lack of eye relief starting to distract from my enjoyment. I thought about selling it a few times but sharpness and clarity of the views it provided simply did not let me take that step.

 

What I felt I needed was a 20x80 (or 20x100) with at least a 3° FoV to compliment my 40x80 UWA. Of course it needed to be able to hold its own against the UWA which, as you can imagine, is not an easy task. I looked at the current offerings and, although many are quite good, they simply did not hold up to the standard set by the Aspectem. This is not surprising considering they cost 4 times the most expensive 20x100 currently available.

 

Looking at the construction of the Aspectem I realised that the original eyepieces could easily be removed, revealing the M52x1 thread used to mount them. The focal plane is actually about 16mm above that thread so I thought there might be a chance that a standard telescope eyepiece could be adapted to work with them. The journey started with finding an eyepiece that harmonised well with the objectives and would come into focus given the physical space available. As many know, the vast majority of wide angle, well corrected eyepieces have field correctors in front of the focal plane. These unfortunately would not work due to the prism construction and eyepiece in-focus requirements. Looking at the design and specifications of almost every 24-26mm eyepiece out there, It turned out that, in theory, two eyepieces could meet my quality expectations and FoV requirements while providing for a technically feasible implementation: the Televue 24mm Panoptic and Explorer Scientific 68° 24mm.

 

The second problem was figuring out how to focus. Most 1.25” helicoid focusers made for telescopes are too long for this purpose and 2” focusers are two wide. For almost a year I pondered ways of making my own helicoid using 3D printing but could not come up with a suitable solution. Then one day I stumbled upon an M42 15-26 Helicoid camera lens adapter used for macro photography... It occurred to me that with a little modification, they might be the solution I was looking for.

 

I then tested the ES 68° 24mm and, although on-axis sharpness was quite good, edge sharpness was only average… I think it is obvious that this project was not about being average crazy.gif ... So I ordered a pair of 24mm Panoptics to test. My first views with the prototype where very encouraging. Excellent center sharpness and edge correction. 

 

The rest was a matter of building an adapter/focuser that allows 24mm Panoptics to be used in place of the original eyepieces. What I came up with is an M52x1(F) —> M42x1(M) adapter, the helicoid focuser mentioned above, and some 3D printed parts to make it all work together.  Unfortunately I did not realize that I forgot to to take pictures of the individual parts until everything was assembled… Mia culpa.

 

Luckily, I do have the 3D CAD renderings which actually give a better understanding of the parts and how they interact. As you can see, the construction is actually pretty simple. The black components are pre-made and the red, yellow and blue components are what I had printed (Shapeways). 

 

Aspectem Panoptic Adapter V51
 
I also had to make new prism covers as the originals did not fit around the M52 adapter.
 
Aspectem Prism Cover V10

 

The focusers are non-rotating so the winged eyecups actually stay in the position they are.

 

I should note that neither the binocular, nor the eyepieces needed to be modified, other then removing the original eyepieces. It takes about 2 minutes to switch back to the original eyepieces and about 15 minutes to remove the Panoptics from the helicoid adapter (They have to be gently heated).

 

In my opinion, the result is indeed “the best 20x80 money can buy”… Ok, its actually a 20.8x80 and the claim might be a little steep but until someone shows me something better, I’ll stand by it flowerred.gif grin.gif

 

Center sharpness is excellent and stars remain pinpoints of light to the edge of the FoV. Upon deliberate and close inspection of Lyra, I could see it starts to a develop slight spikes in the outer 10% but still maintained a stellar core. Maybe not quite as good as my Swarovski EL but I would still consider them “sharp to the edge”. Transmission is excellent, actually better then with the original eyepieces due to fewer glass/air surfaces. Color rendition is on the cooler side in comparison to original Vario eyepieces which I find to be very warm. Of course being Panoptics, these are not orthoscopic. When viewing the roofs of distant houses, slight pincushion distortion is noticeable. It is actually slightly less then the distortion present in the Vario eyepieces and I don’t find it uncomfortable or distractive.  

 

The only negative point I can find is a very slight vignetting that makes the field stop a little fuzzy. The FoV checks out to be little over 3.1° using Navi and Achrid in Cassiopeia. Their separation according to SkySafari is 3.1° and both are simultaneously visible at the field stop. This is actually slightly better then what calculations based on the field stop diameter says it should be (3.08°). The noticeable vignetting starts literally right at the field stop. I suspect that if I where to reduce the field stop from 27mm to 26.8mm it would probably not be noticeable at all.

 

And now one last bit for bonus points… I can also use UHC filters with these grin.gif

 

IMG 6334

 

Unfortunately due to the weather lately I have not been able to get these under some dark skies. The forecast for the next 10 days does not look promising so I will post my observing impressions once the weather gods decide to have mercy on me. blush.gif smile.gif


Edited by Mad Matt, 14 June 2018 - 10:11 AM.

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#2 edwincjones

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Posted 14 June 2018 - 09:29 AM

you have more courage (and skill) than I have

I considered buying the Vario
then I could counter all those negative zoom binoculars posts,
but the short ER discouraged me.

edj

Edited by edwincjones, 14 June 2018 - 09:35 AM.

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#3 Mr. Bill

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Posted 14 June 2018 - 10:09 AM

I agree with edj....you got bigger cajones then me...and better machining skills.

 

bow.gif


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#4 Mad Matt

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Posted 14 June 2018 - 11:04 AM

I agree with edj....you got bigger cajones then me...and better machining skills.

 

bow.gif

 

Thanks guys, but really no machining was involved. I prefer letting machines do the work for me. I simply threw something together CAD and sent it off to the printer. Once it arrives I just glue it to the precision machined stuff I get off ebay. Yup, I am lazy grin.gif


Edited by Mad Matt, 14 June 2018 - 11:16 AM.


#5 KennyJ

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Posted 14 June 2018 - 01:25 PM

Congratulations Matt on a very creative, interesting and successful project!

 

Kenny


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#6 RLoret

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Posted 14 June 2018 - 03:17 PM

Very, very impressive work!


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#7 Pinac

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Posted 14 June 2018 - 03:59 PM

Congratulations!

Great project, great execution, great result!!

Whether or not you really created „the best 20.8x80 money can buy“ is not even that relevant .... you created the ONLY one! smile.gif


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#8 Gyna

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Posted 15 June 2018 - 06:34 AM

I have no words. My sincere admiration for you great great work! Enjoy your new... DocVue Panoctem!

 

Marco


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#9 denis0007dl

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Posted 15 June 2018 - 01:08 PM

Amazing project Matt! like-button.jpg


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#10 Foss

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Posted 15 June 2018 - 05:23 PM

Thanks guys, but really no machining was involved. I prefer letting machines do the work for me. I simply threw something together CAD and sent it off to the printer. Once it arrives I just glue it to the precision machined stuff I get off ebay. Yup, I am lazy grin.gif

Lazy in a binocular genius sort of way. CAD to commercial 3D printer to product is light years ahead of anything I could do...notwithstanding the rubber eyecups from China I ordered on eBay. WTG Matt!


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#11 ullomat

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Posted 16 June 2018 - 02:32 AM

Matt,

 

I am really looking forward to look at and through it. Next change may be BTM or the "Darfschein".

 

Great project!

 

But I've to admit that I miss the Vario a little bit. I really liked to zoom in and use the higher magnifications. smile.gif

 

cs,

Uli


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#12 Mad Matt

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Posted 16 June 2018 - 02:43 AM

Matt,

I am really looking forward to look at and through it. Next change may be BTM or the "Darfschein".

Great project!

But I've to admit that I miss the Vario a little bit. I really liked to zoom in and use the higher magnifications. smile.gif

cs,
Uli

Thanks Uli! I will be sure bring the Vario eyepieces and we can switch it back just for you 😁

The ability to zoom is nice but I found that I would set it to 30x or 40x and just leave it there. That is kind of a silly thing to do when you have the UWA which are much more enjoyable at that magnification 😳😁

What I was missing was a wider FoV for the big stuff like NGC7000, Andromeda and the dark bands of the MW

I can’t wait to hear your impressions when you have a chance to look through them 😊

Edited by Mad Matt, 16 June 2018 - 03:22 AM.

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#13 edwincjones

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Posted 16 June 2018 - 04:41 AM

Thanks Uli! I will be sure bring the Vario eyepieces and we can switch it back just for you
..............
I can’t wait to hear your impressions when you have a chance to look through them



Max,

On behalf of the US CN members, I would like to invite you, and the binos, to a star party over here sometime.
WSP, TSP, GCSP, Stellafane, your choice

edj

Edited by edwincjones, 16 June 2018 - 04:45 AM.

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#14 Mad Matt

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Posted 16 June 2018 - 05:14 AM

Max,

On behalf of the US CN members, I would like to invite you, and the binos, to a star party over here sometime.
WSP, TSP, GCSP, Stellafane, your choice

edj


That would be an honor Sir! Stellafane is actually on my bucket list 😁

#15 edwincjones

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Posted 16 June 2018 - 09:07 AM

About 10+ years ago we did have a mini CN big binocular star party at Okie-Tex.
-I had my 100mm Miyauchis
-another CN member had his 20x120 Nikons
-a CN member has several 70mm fujis
-someone had his homemade, and very nice, 5" binoculars
- others?

edj
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#16 lit

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Posted 16 June 2018 - 12:24 PM

hi there MM

 

can u see the belts of Jupiter through these now


Edited by lit, 16 June 2018 - 12:25 PM.


#17 Mad Matt

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Posted 16 June 2018 - 12:59 PM

hi there MM

 

can u see the belts of Jupiter through these now

I don't know... I wish I could see Jupiter at all bangbang.gif ... At the moment I can only comment on its ability to resolve terrestrial clouds... which it does very well lol.gif



#18 lit

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Posted 16 June 2018 - 01:01 PM

I don't know... I wish I could see Jupiter at all bangbang.gif ... At the moment I can only comment on its ability to resolve terrestrial clouds... which it does very well lol.gif

l remember Giessen had a lot of clouds and could be cloudy long time

 

l hear ya...



#19 Mad Matt

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Posted 16 June 2018 - 06:59 PM

hi there MM

can u see the belts of Jupiter through these now

I was able to catch a few holes in the clouds. I could not see any bands on Jupiter. The problem is primarily my eyes. At about 3.5mm EP, I have a slight astigmatism that becomes apparent on very bright objects. The bands are easy with my 40x80UWA, I have also seen the GRS in the UWA.

I also caught Saturn for about 2 minutes. The gap between the planet and rings was easy to see. Mars was simply a small, bright red ball. Pretty much what to expect from 20x tongue2.gif flowerred.gif 

I did have nice views of M51, M101, M13, M92, M57 and the North American and Pelican nebula (just barely with UHC filters and because I know what to look for). I thought that was not bad considering that it never gets completely dark this time of year (50°N Latitude) and the Milky Way was not even visible with the naked eye last night. The 3.8mm EP is a good compromise for the light polluted skies I have to deal with. It also confirmed my experience with the Vario at 20x, that extended objects with low surface brightness such as M101 are easier to see then with my 40x80 UWA.I felt that, for the sky conditions, the extended objects where slightly brighter then the Vario at 20x.

 

M101 was directly visible and for a brief moment, I thought I noticed a little detail.

M51 I could see its companion but could not observe it long enough to tickle out details.

M57 was definitely a ring.

M13 a grainy snowball and at times while letting my eye scan around, I though there was a darker lane running roughly vertically on the left (west) side (I think this is an effect of the low magnification in combination with a formation brighter stars on that side).

M92 was a compact fuzzy ball.

 

While scanning around the MW in Cygnus, the edge sharpness was wonderful. The experience is very simular to scanning with my SV 8.5x42 EL where my eyes are the limiting factor for edge sharpness, not the instrument. This provides a simular "window to space" feeling I love so much with my UWA and EL's and that I only get when I am looking up directly at the object with straight through binoculars.

 

Now I really can’t wait to get these under a very dark skies grin.gif


Edited by Mad Matt, 17 June 2018 - 06:18 AM.

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#20 C.Hay

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Posted 17 June 2018 - 07:13 AM

Dear Matt,

I stand in awe of your courage, confidence and capability.

Wishing delightful views ahead,

Christopher



#21 RickyD85

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Posted 17 June 2018 - 11:55 AM

Great job, they look fantastic.

Could you not have started with a cheaper bino though?!

#22 Mad Matt

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Posted 17 June 2018 - 12:26 PM

Great job, they look fantastic.

Could you not have started with a cheaper bino though?!


Yes, tried that already... the results where ok but not what I wanted.

I could have simply purchased an APM 20x80 which is a great binocular. That would have cost about as much as the two panoptic eyepieces. I simply wanted better, and as you know, quality has its price.

#23 RickyD85

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Posted 17 June 2018 - 12:29 PM

Well hats off to you then.

It seems you were chasing perfection, and that it has paid off! Hope you're enjoying your hard work!

Kudos for making them exactly how YOU wanted.

Edited by RickyD85, 17 June 2018 - 12:33 PM.

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#24 ThomasM

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Posted 17 June 2018 - 03:54 PM

Yes, call me crazy... I have modified my Aspectem Vario and replaced the zoom eyepieces with TeleVue 24mm Panoptics making them an excellent fixed magnification 20.8x80.

 

 
 

 

Probably the first question you are wondering is why?

 

Well, after the novelty of the Vario it wore off, the small FoV and lack of eye relief starting to distract from my enjoyment. I thought about selling it a few times but sharpness and clarity of the views it provided simply did not let me take that step.

 

What I felt I needed was a 20x80 (or 20x100) with at least a 3° FoV to compliment my 40x80 UWA. Of course it needed to be able to hold its own against the UWA which, as you can imagine, is not an easy task. I looked at the current offerings and, although many are quite good, they simply did not hold up to the standard set by the Aspectem. This is not surprising considering they cost 4 times the most expensive 20x100 currently available.

 

Most used equipment: APM 100mm 45° APO, Docter Aspectem-UWA 40x80, Docter Aspectem-Panoptic 21x80, Fujinon 16x70 FMT-SX2, Lunt/APM 10x50, Swarovski 8.5x42 EL, Vintage Zeiss 8x30, DIY parallelogram mount.

 

Very nice construction and especially just making CAD drawings to send the pieces needed to printing.

 

What puzzles me, such fixed 21x80 binocular is nice for terrestial view but for astronomical use 45 or 90 degree view is much more comfortable. You own already an APM 100 mm binocular 45 degree  telescope which gives with 24 mm Panoptic 23x magnification. Why do you need a 21x80 binocular for viewing the night sky?


Edited by ThomasM, 17 June 2018 - 04:11 PM.

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#25 Mad Matt

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Posted 17 June 2018 - 11:19 PM

Very nice construction and especially just making CAD drawings to send the pieces needed to printing.

What puzzles me, such fixed 21x80 binocular is nice for terrestial view but for astronomical use 45 or 90 degree view is much more comfortable. You own already an APM 100 mm binocular 45 degree telescope which gives with 24 mm Panoptic 23x magnification. Why do you need a 21x80 binocular for viewing the night sky?

That is indeed a valid question. The answer is actually simple... I am probably one of the few people who actually prefer using a parallelogram mount over a normal 45° or 90° telescope. I find it a much more relaxing and rewarding experience.

 

The edge sharpness of the Aspectem-Panoptic combination is also a little better then with the APM-Panoptic combination. Also, but not quite as important, the 21x80 provide a 3.1° FoV whereas the 45° APM's "only" provide a 2.8° FoV. Granted, the difference of  0.3° is not much, but for the really large stuff such as Andromeda I feel it makes a difference.

 

I still use my 45° APMs for “working it” under dark skies, pushing my limits and discovering new objects. On the other hand, both the Aspectem are for laying back and enjoying the view. Currently I tend to do more of the latter. smile.gif


Edited by Mad Matt, 18 June 2018 - 03:17 AM.

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