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Big apperture (80-100mm) binoculars performance? Terrestrial viewing (1 Viewer)

Rui_Caratão

Well-known member
Big aperture binoculars like the APM 100 ED semi-Apo, Garrett 100mm, General HI-T 100mm seem to be highly regarded by Astro entusiasts as a great value for Money and capable of good views, however most topics on Cloudynights are always from an Astro point of view, their terrestrial view performance is mentioned briefly as good but without a reference standart with known spotting scopes most of us dont really get what kind of views are they able.
Can those ED Semi-Apo big eyes deliver the same performance (brightness, Contrast, Sharpness) as the new 82mm class chinese ED Glass (Razor HD, ZR 82Prime HD, etc.) or even be better ?
Since I use my optics also indoors taking advantage from my window panoramic view, I would like to take the benefit of my 2 eyes resolution instead of one and just had a relaxing moments scanning the fields and mudflats.
Their use on stationary viewpoints like raptor counts, bird hides etc. is also to consider, and I can see their pros when you have to use them for more than 6hours straight!

Kowa Higlander PROMINAR is probably a good standart, and although I have never looked trough one, it is probably safe to assume that they perform like any other Kowa scope maybe even better than the known Tsn823, the later is probably more comparable with Docter Aspectem 80/500ED, wich I have already tried, but both to costly for my wallet...
 
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Rui, i was in the same situation, from what they tell me on cloudy nights, none of these semi apo performs well up the 40x, some people even say 30x ... if this ok for you, they are fine. Also, they need good eyepieces. However well means no equal to a true ED.

With a 120 ed scope or a C6 with binowiever you can get a extraorinary perform, but missing the low mags range. You can fix this in someway with an aditional binos ...

Third option, buy two 80 to 100 ED straight scopes and made a binoscope, both of best worlds. Is expensive than the semi apos binos, but far away of the docter or the kowas. For example you can buy two on the second hand market, or one of them. I think for 1500 euros you can get it.
 
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Cosme said:
Rui, i was in the same situation, from what they tell me on cloudy nights, none of these semi apo performs well up the 40x, some people even say 30x ... if this ok for you, they are fine. Also, they need good eyepieces. However well means no equal to a true ED.

You probably read the same threads that I did, and you get the same idea. Still, they are very inconclusive, since I see no terrestrial viewing optic reference to be compared to.

The only photos available around the web are taken with an Iphone at 63x trough APM 100, they seem usable showing probably more CA than the current 1000euros class spotters, but dificult to have sure...
http://www.cloudynights.com/ubbthreads/attachments/6348731-photo 1.JPG
http://www.cloudynights.com/ubbthreads/attachments/6348738-photo 2.JPG

Cosme said:
With a 120 ed scope or a C6 with binowiever you can get a extraorinary perform, but missing the low mags range. You can fix this in someway with an aditional binos ...

Portability and 40x to 70x magnification is what I am after, I really dont want to go the astro telescope way.... binoviewers were my first thought but I heard they can be dificult to achieve focus on my angled 82mm spotting scope.
 
Cosme said:
Third option, buy two 80 to 100 ED straight scopes and made a binoscope, both of best worlds. Is expensive than the semi apos binos, but far away of the docter or the kowas. For example you can buy two on the second hand market, or one of them. I think for 1500 euros you can get it.

Its an option to consider, and the results probably depend on wich combo you choose, however the Docter Aspectem 80/500ED with the 20-50x vario zoom that I tried was very good

Docter Review on Binomania ...
http://www.binomania.it/wordpress/?p=262
 
Rui, the sywatcher 120ed and binoviewers is not more expensive than a semi apos ... a C6 is the same. Both for 40x to 70x are much better than both binoscope and semi apo binos. To me is the way to go. I ask by mp in cloudynights to five apm owners and they told me 30x 40x is the limit

120 binoviewers are like 85 binos, not 60 like many people think, and keeping the resolution of a 120 glass! is half of the price of the docter, with interchangeable eyepieces option, the docter are always fixed
 
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Picture using an Orion 100ED refractor from 2.8 miles [4506 meters] away, I know this is not a binocular, just thought you would like to see. Prime focus on a not super clear day.
 

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Terrestrial view trough an ED refractor is great Cosme, but 120mm is a hudge piece of equipment and no way I would carry it to raptor watching points or birding hides. I could go for a small apperture (80 or 90máx) and fast ED refractor, but maybe the image get to dim to use with binoviewers, and they would still be a chunky piece of equipment to carry around.
I love the big binoculars idea, straight binoscope mounts or EMS spotting scopes by the way , they are compact, easy to carry around, fast to assemble on the field and with a costum made waterproof carrying case I would be confident to use them outdoors, Portugal weather is like California so I guess it would be fine.
TS advertises this 100 APO (most probably semi-Apo) http://www.teleskop-express.de/shop...m-APO---45--angled---for-1-25--eyepieces.html to be spray waterproof and nitrogen filled but online reviews are hard to get.....


Thanks Steve, dont know wich magnification you use but thats a very good photo for a 4.5 km distance, do you get a close performance with your celestron 80ED refractor? In good viewing days even spotting scopes can show good results, but refractors are certainly better. In attach a handheld photo with an 85mm spotter...
 

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Terrestrial view trough an ED refractor is great Cosme, but 120mm is a hudge piece of equipment and no way I would carry it to raptor watching points or birding hides.

Rui, then forget about the big binos too! they weight twice the refractor with binoviewers!

The TS: same as the APM, Oberwerk, Garrett etc ... they are not APO ... 40x as much
 
Terrestrial view trough an ED refractor is great Cosme, but 120mm is a hudge piece of equipment and no way I would carry it to raptor watching points or birding hides. I could go for a small apperture (80 or 90máx) and fast ED refractor, but maybe the image get to dim to use with binoviewers, and they would still be a chunky piece of equipment to carry around.
I love the big binoculars idea, straight binoscope mounts or EMS spotting scopes by the way , they are compact, easy to carry around, fast to assemble on the field and with a costum made waterproof carrying case I would be confident to use them outdoors, Portugal weather is like California so I guess it would be fine.
TS advertises this 100 APO (most probably semi-Apo) http://www.teleskop-express.de/shop...m-APO---45--angled---for-1-25--eyepieces.html to be spray waterproof and nitrogen filled but online reviews are hard to get.....


Thanks Steve, dont know wich magnification you use but thats a very good photo for a 4.5 km distance, do you get a close performance with your celestron 80ED refractor? In good viewing days even spotting scopes can show good results, but refractors are certainly better. In attach a handheld photo with an 85mm spotter...

Hi Rui,
Thanks! That scope focal length is 900mm and I was using a Pentax K100 D Super 6 MP camera Prime Focus, using the telescope as the lens for the Pentax. I think the crop factor for this Pentax camera is 1.53. So I think the focal length is 1377mm for this 100ED telescope using that camera[I think]. I have a picture of the same area I took with the 80ED. I will try to find it. Looking through an eyepiece is usually a lot better. I found the 80ED picture.

Rui, I would say your picture is very good considering handheld and the distance.
 

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Cosme, weight is not much diferent if I dont go for Oberwerks, but size is!! any refractor setup is very long even if you go for fast refractor, you can spare a few inches using a 90º diagonal but I really want to use 45º since its better for long periods of terrestrial view. All Miyauchi clones seem quite handy to me .... http://i3.photobucket.com/albums/y96/PATOPGUN/Mvc-095s.jpg

Altough I havent tried the semi-apos, the only way to go above 50x without CA is going for the Kowa HG Prominar the Docters or the new APM Apo, but the Higlanders have also the non-fluorite version, they certainly are superbly collimated but how much diference exists between them and the other achromats? If the semi-apos havent collimation issues I am sure they are capable of mid range mags, only sacrificing CA.
 
Thanks David, that would be awesome! If I went to Aveiro I defenetly pay you a visit ;)
I know you have lots of CR viewing info on your web, but there is nothing like experiencing it.
 
Rui, like i said i was in the same situation, and here are my conclusions:

The best: Binoscope with two scopes. Depend of the scopes is more or less expensive. Is also the lighter combo. I said the best beacuse you can get low mags too.

The beasts: C6 or 120 ED binoviewers ... forget about wide FOV... this is a 80x instrument.

The under 1300 euros non ED binoculars:

The chinese semi-apo: heavy as hell, dissapointed beyond 40x

The vixen BT81: 4 kgs, not to carry with them all day long, but having a good breakfast and some rest, you can even take it to some places ... and i think even with 80mm they are better than the chinese semi apos ... however, even the best achromatic scopes beyond 40x begin to show CA

So, Kowas and docters aside, live with 40x max or 80x min, or buy to ED scopes and pair them. Some people has done, so it perfectly possible.

http://forum.snipershide.com/s4-sni...where-buy-big-eyes-double-spotting-scope.html

There was a member forum too who made one with two nikons, let find the thread and i post it
 
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Cosme said:
Rui, like i said i was in the same situation, and here are my conclusions:

Wich one did you choose Cosme?
I didnt want to loose the lower mags, so the binoscope with two scopes is the option that I like most plus you can get in most cases gas filled and waterproof combo like that straight Nikon fieldscope ED.

I can imagine on 2hand market very good options without CA:
Kowa TSN4, 824
Leica APO televid77
Nikon fieldscope 78ED or 82ED2
Zeiss (old) 85 T*FL or 65
Swarovski Habitch ST80HD

or non APO or HD models, sacrificing CA beyond 40x but not resolution. In fact resolution is probably my biggest doubt between this kind of combo and semi-apo binoculars, they certainly share more or less the visible CA, but they probably resolve less per barrel...is out there any thread discussing their measured resolution?

Leica televid 65 or 77
Kowa Tsn1, 2
Swarovski Habitch ST80
Pentax 65 or 80ED (probably better placed in this group)

I can imagine a few more options, but I guess that their usage will be refrained by the availability of holding brackets and minimum IPD. Is there anyone selling this universal and adjustable brackets or they have to be costum made for each diferent combo?
 
Wich one did you choose Cosme?

By now, none ... o:D

I can imagine a few more options, but I guess that their usage will be refrained by the availability of holding brackets and minimum IPD. Is there anyone selling this universal and adjustable brackets or they have to be costum made for each diferent combo?

No idea, but i dont think its gonna be much expensive to order one custom made or even selfmade, buying the rings in astro stores
 
Rui; I keep searching for solutions to the big mags with two eyes ... i share this with you:

My 5" C5 SCT, after subtracting for central obstruction, is the equivalent of an 81mm bincular. So the best possible widest field I can get, even with a higher quality 26mmCA binoviewer/0.8x opnose, is by using my 26mm Meade/60° eyepiece with a 27.3mm field stop. This gives equivalent to 44x81 with 1.4° TFOV. Using the lower quality 20mmCA binoviewer/1.25x (no OCS) the best I can get is 64x81 with a 0.8° TFOV. In both cases I can use a longer focal length eyepiece for slightly lower power, but cannot get any wider FOV.

The new Celestron C6 SCT with diagonal would operate about f/11. With binovewer and the Denkmeier 0.8x optical nose it would have a focal length near 1320mm. With a 30mm eyepiece you could get a lowest power of 44x. Since Denkmeier has a CA (clear aperture) of 26mm, you would be able to get a widest FOV of about 1.2° in this 6" scope. After subtracting the light loss for the central obstruction (50mm dia), the C6 would give a maximum widest field equivalent of a 100mm binocular at 1.2° at 44x. You could lower the power by using a 32mm or 40mm eyepiece, but you cannot get a wider FOV.

Source (and the whole thread) :

http://www.cloudynights.com/ubbarch...=collapsed&sb=5&o=all&fpart=1&vc=1&PHPSESSID=

So: In a C6 you can get for example, a 100 mm binoculars, and over 70x using 82 afov eyepieces without waste any fov, or stay on those 44x with the same FOV, but 44x at the end, however 60 afov is still very good ...

In the C5, you can get 44x with more FOV (1.4) but losing apperture (80 mm binoculars) so if you want to reach those 70 is at cost of less exit pupil.

Even if you pick the C6, it weights 3.7 kgs, plus half a kilo of the binoviewers, but is still very good, is the same you find in a 100mm binoscope. Happens the same with the C5 compared with 80 mm binoscope, wich are both the equivalents with binoviewers. Only in a Vixen Bt81, wich is not ED, you find similar weight.

I made a estimated calculation: The C6 OTA is selled for 600 euros, 500 euros the Denk BV, and two eyepieces, lets says 400 euros both ... the combo is 1500 ... The C5 combo is about 1200. Now compare with two straight scopes of the same apperture and its up to you if it worth or not :t:

pd: I hope David can tell us if its all correct in the C5 case, since he has tried BV on it, because one part of the equation can screw all; they are using mirrors, us prism, have no idea if prism can works the focusers measures, the reducers, the BV ...



:t:
 
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Hi Cosme, thanks for sharing the info you collected :t: . You are probably right, you get better views and spend less choosing the C6 or C5 with binoviewers and 60 Afov 44x lower end mag is still very acceptable ;)
 
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