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Do You Really need an ~80mm in the Stable?

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#26 Jon Isaacs

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Posted 17 May 2020 - 10:19 AM

I'm strictly visually.  Currently I own three 80 mm Refractors:

 

- ST-80 with a 2 inch Focuser, 6 degrees with the 31 mm Nagler, 6.6 degrees with the 41 mm Panoptic. A one trick pony..

 

- AT-80 LE, 80 mm F/6, FPL-53 Doublet. 5.5 degrees with 41 mm Pan, 5.0 degrees  with 31 mm Nagler. Sharp optics, good all around.

 

- WO 80 mm F/7 Mergrez ll FD.  Narrower field that the F/6, better on the planets and doubles.

 

I also have a NP-101. It weighs 12 lbs, the 80 mm Apos are 7 lbs. That's a big difference and it means the NP-101 needs a larger, heavier mount.

 

My 80 mm Apos are handier, on my Bogen 3040, I can the whole rig outside with the racks loaded with eyepiece's with one hand.

 

They're also a better size for birding..

 

AT-72 on Bogen with eyepieces CN.jpg

 

 

Jon


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#27 bobhen

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Posted 17 May 2020 - 10:46 AM

For wide field imaging – sure.

 

“For me” for visual observing, nothing below 100 mm thank you. If I want a real wide field view under a black sky, it’s binoculars rather than the 60 to 80 mm refractors. I find planetary, lunar and deep sky observing just more satisfying in the 100 mm class.

 

Early on, I owned 2 extremely nice 80 mm refractors but sold them both. In contrast, I’ve owned a cheap Celestron/Synta 102 mm F-5 achromat for 16 years.

 

Some 100 mm apos are extremely lightweight these days

.

Bob


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#28 Echolight

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Posted 17 May 2020 - 11:33 AM

AT-80 LE, 80 mm F/6, FPL-53 Doublet. 5.5 degrees with 41 mm Pan, 5.0 degrees  with 31 mm Nagler. Sharp optics, good all around.

 

My 80 mm Apos are handier, on my Bogen 3040, I can the whole rig outside with the racks loaded with eyepiece's with one hand.

This is what I'm aiming for in a little scope.

 

Although I'll surely stop short of carbon fiber...at least to begin with.

 

And currently I only have a Velbon 607 for a grab and go mount.



#29 25585

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Posted 17 May 2020 - 12:06 PM

Review of the 80mm S-W Equinox http://scopeviews.co.uk/SWEq80ED.htm


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#30 LDW47

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Posted 17 May 2020 - 12:22 PM

I currently have 2 scopes:

 

1) a 127mm APO which can be paired with a .8 Reducer/Flattener 

2) a C8 which can be paired with a .63 Reducer 

 

Do you all find much use for something in 70mm-80mm range?  I typically image DSO's and planetary.

 

Thanks,

 

Mauricio

If you can find a decent 90mm go with it !  Clear suitable skiys !


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#31 LDW47

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Posted 17 May 2020 - 12:24 PM

Review of the 80mm S-W Equinox http://scopeviews.co.uk/SWEq80ED.htm

I love my 80 Equinox !  Clear equinox skize !


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#32 LDW47

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Posted 17 May 2020 - 12:27 PM

I never enjoyed 80mm scopes, despite trying them several times. I find even if its for grab and go, there's ample selection in the 100mm category that just makes more sense. Personally I've landed at a setup that works well for me, albeit nowhere near grab and go. I use my 50mm apo as a finder on my 152, and the whole thing is a 3 trip setup that takes about 5 minutes.

The 50mm with my maxvision 40mm 68° ep gives a fantastic wide field view, and the extra light grasp of the 152 makes a big difference in what I see for sure. I ended up here because I find if sky conditions are poor, I tend to get lazy and stay in, and when they are good, even if I start with a grab and go, I end up thinking I really should go back in for the big guns.

Its a good job most don’t follow your and a few others line, lol ! There would be a lot of disappointed astronomers ! Clear 80 skize !


Edited by LDW47, 17 May 2020 - 12:30 PM.


#33 drd715

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Posted 17 May 2020 - 01:10 PM

Keep in mind that I am not a very experienced or knowledgeable observer.  One night I had several telescopes set up and the Celestron 80mm f/11 achromat gave the most pleasing views. 60mm, 102mm, 120mm refractors, 6 inch newtonian and 8 inch SCT. All scopes were cooled down so I guess the seeing that night favored the 80MM. So the 80mm is a keeper for me.

It's because it was an F-11. A crisp sharp contrasty view. 


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#34 Jon Isaacs

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Posted 17 May 2020 - 01:22 PM

This is what I'm aiming for in a little scope.

 

Although I'll surely stop short of carbon fiber...at least to begin with.

 

And currently I only have a Velbon 607 for a grab and go mount.

 

It happens to be carbon fiber but it's no lighter than the William Optics 80 mm because it needs heavy rings to mount and avoid damaging the carbon fiber. I prefer aluminum.

 

I can't find much on the Velbon 607, hopefully it's sturdy enough for an 80mm.

 

“For me” for visual observing, nothing below 100 mm thank you. If I want a real wide field view under a black sky, it’s binoculars rather than the 60 to 80 mm refractors. I find planetary, lunar and deep sky observing just more satisfying in the 100 mm class.

 

Early on, I owned 2 extremely nice 80 mm refractors but sold them both. In contrast, I’ve owned a cheap Celestron/Synta 102 mm F-5 achromat for 16 years.

 

 

 

Binoculars have their place but have different capabilities than an 80 mm telescope.  The telescope is more versatile, more comfortable for longer inspections, accepts filters and diagonals.

 

Last night the skies overhead were about 21.4 mpsas. I had the 80 mm F/6 along plus 7x35s, 10x50s, 10.5x70s and 15x70s plusva parallelogram mount.  I had the 16 inch Dob set up as well. 

 

I used the 10x50s for star hopping help and 15x70s for brief sessions but the 80 mm F/6 probably saw an hour and a half of more dedicated observing including Venus, Jupiter, Saturn, several doubles stars along with all the deep sky, the Veil, the north American, the wonders of the summer Milky Way..

 

Interestingly, also setup and ready but unused was my NP-101. I could have chosen it, many nights I do but the difference between the 4 inch and the 80 mm at low powers is there but for what I was looking at, 80 mm is satisfying and sufficient.

 

I recently acquired an Celestron 102 mm F/5 like Bob's. I've had one before. It's a good low power scope but a one trick pony like the ST-80, it's lacks the versatility of the apo. With a 30 mm Widefield it's a stunner but for higher mags, doubles, the planets, terrestrial, birding, photography, I take the 80 mm apo.

 

It is light for a 4 inch, about the weight of a 80 mm apo, maybe a tad bit lighter.

 

Lots of choices....

 

Jon


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#35 Littlegreenman

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Posted 17 May 2020 - 01:59 PM

Over the years I've had, and sadly sold off, the scopes below:

 

Tele Vue 85, that spoiled me for false color. Small compact package. weighs some, and if you are going 2" the diagonal and eyepieces add to the weight. Very early version

 

More than a few of the common but still excellent Vixen 80mm f/11 achromat, lightweight, but longer than the TV-85. Vintage, Japan, branded Celestron or Vixen

 

The uncommon Vixen 90 f/11-ish achromat, made in Japan pre-2000

 

Vixen/Celestron 90mm fluorite, mid 1990's

 

Vixen 102mm fluorite, circa 2000, Orion by Vixen

 

One of my pet peeves are website/internet/forum post headlines:

"What is the best..."

Change "best" to "appropriate" and consider also "trade offs."

 

Things to consider:

The above differ in size & weight. Some are better grab and go than others.

I have not had an apo that is lighter than the TV-85; wish I had.

 

Price range is large. And higher price scopes somehow seem to demand pricey accessories!

I'm not anthropomorphizing too much, but my TV-85 would pout if I used an "economy" eyepiece in it.

 

The above all have acceptable to excellent optical quality; some are better at wide field than others and some are limited in wide field. I doubt I could be happy with a classic Short Tube 80, due to false color.

 

The difference between the Vixen 80 and 90 mm achromats visually was just enough better, and even closer to a 4" f/10-12 achromat that I would choose the 90mm over the 80mm. The 90mm is just that much smaller than a 4" to make difference. That makes the 80mm Vixen achromat in my mind less desirable. The problem is that Vixen 90mm achromats rarely show up for sale, have been priced high enough to make me consult the I Ching for advice, and then are sold quickly. 

The other scopes differ more such such that each one occupies a slighty different spot.

The Vixen 90mm fluorite is even rarer.

But these days are a few 90mm apo class scopes, if that fits your want.

 

So, should you get an 80mm class scope to compliment other scopes?

I would say yes, but think about how you would use it to choose one to fit that use.

Do you want ultimate grab and go, wide field, does false color or expense make a difference?


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#36 drd715

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Posted 17 May 2020 - 02:08 PM

For wide field imaging – sure.

 

“For me” for visual observing, nothing below 100 mm thank you. If I want a real wide field view under a black sky, it’s binoculars rather than the 60 to 80 mm refractors. I find planetary, lunar and deep sky observing just more satisfying in the 100 mm class.

 

Early on, I owned 2 extremely nice 80 mm refractors but sold them both. In contrast, I’ve owned a cheap Celestron/Synta 102 mm F-5 achromat for 16 years.

 

Some 100 mm apos are extremely lightweight these days

.

Bob

I would have to agree 100/102mm is about the smallest I like for visual especially as the FL gets longer. 

 

The  80mm class is a fair choice for imaging though particularly if your budget is limited. It is possible to afford an APO triplet at 80mm  - the 102 triplets are much more expensive. 

 

 

For me it is the 102ED F-11 a sweet scope with an exceptional image sharp color free and just able to grab and go on an alt/az. I  already had/have a 90mm F-7 CaFl doublet that is superior, stacked on a 152ED (it could use a better focuser though). 

 

A 102mm F-7 FPL-53 doublet would be a a fine  "one scope only" first scope refractor. 



#37 Tyson M

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Posted 17 May 2020 - 02:26 PM

The StellarMira F10 80mm apo is a rarity. It's a Long Perng doublet refractor with Lanthanum lenses, must be a great little planet killer. Around the same price as a Vixen SD81S, another desirable 80mm.    

Those are two 80mm scopes I've loved using or piqued my interest for sure.


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#38 balu01

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Posted 17 May 2020 - 02:57 PM

I think yes you do need one. Don't have one right now and miss it.

 

Problem is it is hard to find a high quality 80mm F6 scope. I wish those LOMO's were still in production.

But having a TS 80F6 which was a great scope I constantly miss the little thing. Very portable great widefield views , the only mistake I made is I should have ordered the 2.5" FTF instead of the 2" so I ended up selling it.

 

Longer ones, I don't see mush sense for having as in that case (my case) FC100DL and here the added aperture is also beneficial. I know for some a long FL 80 is great this is just my point of view.

 

I see the FSQ85 being a great alternative which I might have to give in and get one, but have not decided which other scope I would surrender to make it happen.


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#39 bobhen

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Posted 17 May 2020 - 03:01 PM

Its funny how different experiences impact each of us. So I'll expand on my earlier post. 

 

Many years ago I was out near Teton Village Wyoming and had both my 80 mm F-6.6 and 8 x 42 binoculars. I spent the vast majority of that session using the binoculars. It’s a session I remember to this day – because of the binoculars.

 

Most optical systems have advantages. 80 mm refractors have some but so do binoculars. Binoculars are the ultimate grab-and-go optics for both day and night. Two-eye viewing also has advantages and sweeping the star fields of the Milky Way under a dark sky using both eyes is captivating and immersive.

I just find the 80 mm stop “between” binoculars (with their advantages) and the 100 mm class of refractor with their better resolution and light gathering a stop that I can easily bypass.

 

1. I’ll take binoculars, with the binoculars two-eye advantage, over an 80 mm refractor for ultimate grab-and-go, low power, wide field observing,

2. I’ll take a cheap 102 mm F-5 achromat over the more expensive 80 mm apo for low power, wide field deep sky observing. That extra inch in the achromat just cannot be overcome when both scopes are used as “low power” telescopes.

3. I’ll take a 100 mm apo over an 80 mm apo for lunar planetary observing with the better resolution of the 100 mm class of apo over the 80 mm class. If portability is an issue: Takahashi produces 100 mm apos that weight 6 pounds and Borg produces a 107 mm apo that is both light and modular.

 

So for me, I just don’t see where the 80 mm apo or achromat have the advantage. I wish I did because 80 mm apos are a lot cheaper than 100 mm apos.

 

Bob


Edited by bobhen, 17 May 2020 - 03:02 PM.

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#40 areyoukiddingme

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Posted 17 May 2020 - 03:28 PM

My 80 mm on a Stellarview MV-1 and camera tripod, and my Televue 101 on a Stellarview MC-2, with extension column on an Oberwerk tripod.

 

When I leave home to observe, it's hard to not take the 80 over the 101 for obvious reasons.

 

IMG_0457.JPG


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#41 desertlens

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Posted 17 May 2020 - 04:34 PM

The OP has posed something of a vexed question. The first choice is: do you have any interest in exploring the capabilities and challenges of a small scope? If so, you'd be well served by an 80mm. I spend a lot of time around three inches and have been consistently surprised as to what can be accomplished at such apertures. Persistence is important, and some effort toward improved observing skills. If this sounds like fun to you, then 80mm is probably where you should start.


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#42 Scott in NC

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Posted 17 May 2020 - 06:55 PM

Yes!  An 80mm refractor is so versatile that I don’t ever want to be without one.  Here’s a pic from yesterday while I was doing H-alpha solar observing with my Stellarvue Nighthawk, rigged up with a Lunt 60mm H-alpha etalon and B1200 blocking filter.

 

A6A878B8-EE29-41EF-ABF3-380C3FA73573.jpeg


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#43 Jon Isaacs

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Posted 17 May 2020 - 07:19 PM

Its funny how different experiences impact each of us. So I'll expand on my earlier post. 

 

Many years ago I was out near Teton Village Wyoming and had both my 80 mm F-6.6 and 8 x 42 binoculars. I spent the vast majority of that session using the binoculars. It’s a session I remember to this day – because of the binoculars.

 

Most optical systems have advantages. 80 mm refractors have some but so do binoculars. Binoculars are the ultimate grab-and-go optics for both day and night. Two-eye viewing also has advantages and sweeping the star fields of the Milky Way under a dark sky using both eyes is captivating and immersive.

I just find the 80 mm stop “between” binoculars (with their advantages) and the 100 mm class of refractor with their better resolution and light gathering a stop that I can easily bypass.

 

1. I’ll take binoculars, with the binoculars two-eye advantage, over an 80 mm refractor for ultimate grab-and-go, low power, wide field observing,

2. I’ll take a cheap 102 mm F-5 achromat over the more expensive 80 mm apo for low power, wide field deep sky observing. That extra inch in the achromat just cannot be overcome when both scopes are used as “low power” telescopes.

3. I’ll take a 100 mm apo over an 80 mm apo for lunar planetary observing with the better resolution of the 100 mm class of apo over the 80 mm class. If portability is an issue: Takahashi produces 100 mm apos that weight 6 pounds and Borg produces a 107 mm apo that is both light and modular.

 

So for me, I just don’t see where the 80 mm apo or achromat have the advantage. I wish I did because 80 mm apos are a lot cheaper than 100 mm apos.

 

Bob

 

So, if you have a 4 inch APO that weighs 6 pounds and a 4 inch F/5 achromat for the low powers, that still doesn't provide a good, handy scope for terrestrial viewing at anything more than binocular magnifications.  

 

The 4 inch Achro is very soft and the 4 inch APO, too bulky.

 

Last night, the view of the Veil, of the North American, of the nebulosity of summer Milky way, way better than any of the binos I had.. filters.

 

It's a question of balance.  If I were traveling to the dark skies of the Navajo reservation and had to choose between an 80 mm apo and my 4 inch F/5, it would be the 80 mm, it's just so much more versatile.  

 

As it is, I take my NP-101, the focal length of an 80 mm apo with the performance of a top notch 4 inch APO.

 

It weighs 12 pounds and costs $4000 brand new and even so, an 80 mm apo is remarkably close at the eyepiece.

 

It's the difference between an 8 inch and a 10 inch, much more the same than different.

 

Jon


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#44 Littlegreenman

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Posted 17 May 2020 - 10:21 PM

My 80 mm on a Stellarview MV-1 and camera tripod, and my Televue 101 on a Stellarview MC-2, with extension column on an Oberwerk tripod.

 

When I leave home to observe, it's hard to not take the 80 over the 101 for obvious reasons.

 

attachicon.gifIMG_0457.JPG

Between the Telescopes and the Monitor Audio speaker I don't know what I would choose.


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#45 areyoukiddingme

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Posted 17 May 2020 - 10:27 PM

Between the Telescopes and the Monitor Audio speaker I don't know what I would choose.

No contest. I see more in the 80mm than the Monitor Audio speaker.



#46 Wildetelescope

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Posted 17 May 2020 - 10:35 PM

I'm strictly visually.  Currently I own three 80 mm Refractors:

 

- ST-80 with a 2 inch Focuser, 6 degrees with the 31 mm Nagler, 6.6 degrees with the 41 mm Panoptic. A one trick pony..

 

- AT-80 LE, 80 mm F/6, FPL-53 Doublet. 5.5 degrees with 41 mm Pan, 5.0 degrees  with 31 mm Nagler. Sharp optics, good all around.

 

- WO 80 mm F/7 Mergrez ll FD.  Narrower field that the F/6, better on the planets and doubles.

 

I also have a NP-101. It weighs 12 lbs, the 80 mm Apos are 7 lbs. That's a big difference and it means the NP-101 needs a larger, heavier mount.

 

My 80 mm Apos are handier, on my Bogen 3040, I can the whole rig outside with the racks loaded with eyepiece's with one hand.

 

They're also a better size for birding..

 

 

 

 

Jon

Love the eyepiece rack design!!!!

 

jmd


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#47 desertlens

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Posted 17 May 2020 - 11:44 PM

... much more the same than different.

 

This comment from Jon is the best characterization I've seen of the actual effect of stepping down in aperture.



#48 Illinois

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Posted 18 May 2020 - 06:30 AM

I have SW150 ED refractor and 16 inch dobsonian. I have Orion 80ED for about 10 years and I keep it! 80ED is perfect for grab and go, get up early morning and the sky is clear then I grab my 80ED to look at stars. Nice to take it for travels. 80ED is great for low power. Veal Nebula, large open clusters and many faint DSO in milky way!
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#49 Jon Isaacs

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Posted 18 May 2020 - 06:42 AM

Love the eyepiece rack design!!!!

 

jmd

 

Me too.

 

They're right there at my fingertips, they're easily organized, no mixing up my type 6 Naglers,  nearly horizontal so they're less likely to dew up, and very secure..

 

5651502-Bogen eyepiece rack CN.jpg

 

Jon


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#50 bobhen

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Posted 18 May 2020 - 07:08 AM

So, if you have a 4 inch APO that weighs 6 pounds and a 4 inch F/5 achromat for the low powers, that still doesn't provide a good, handy scope for terrestrial viewing at anything more than binocular magnifications.  

 

The 4 inch Achro is very soft and the 4 inch APO, too bulky.

 

Last night, the view of the Veil, of the North American, of the nebulosity of summer Milky way, way better than any of the binos I had.. filters.

 

It's a question of balance.  If I were traveling to the dark skies of the Navajo reservation and had to choose between an 80 mm apo and my 4 inch F/5, it would be the 80 mm, it's just so much more versatile.  

 

As it is, I take my NP-101, the focal length of an 80 mm apo with the performance of a top notch 4 inch APO.

 

It weighs 12 pounds and costs $4000 brand new and even so, an 80 mm apo is remarkably close at the eyepiece.

 

It's the difference between an 8 inch and a 10 inch, much more the same than different.

 

Jon

The 4” F-5 is absolutely fine for daytime use because you use it a lowish powers and you can stop it down to 60 to 80 mm, which improves CA and is plenty of aperture for daytime use. You can't increase an 80mm to 102mm for nighttime observing.

 

If you want a lightweight “apo” for daytime use, "along with nighttime observing", then a Borg 107 is a fine choice. The Borg will be more portable than an 80 mm because it’s light and designed to be modular for travel and will bring significantly more (27 mm more) aperture to nighttime observing.

 

Your view of the Veil might have been better in the 80 mm than in binoculars but it would have been “even better” in the 4” F-5 achromat. If you are going to the trouble of setting up a tripod and mount then why use the 80 mm for deep sky observing when you have a 102 mm?

 

Once one sets-up a tripod and mount then the Borg 107 or Tak 100 is the better choice both day and night and even the 4” achromat becomes the better choice for deep sky observing. And of course, if one chooses not to use a tripod and mount then binoculars are the choice both day and night.

 

Once you set up a mount there are alternatives to 80 mm that just bring more to the party “without” a portability penalty. And binoculars still retain the “no mount” ultimate grab-and-go advantage. Some people have even filtered their binoculars. And some have purchased image stabilized, ED binoculars that are impressive under a dark sky. Nowhere does an 80 mm have the advantage over the alternitives.

 

Having owned a superb Celestron 80 mm F-8.8 Fluorite apo and a TV Genesis and a excellent LZOS 105 mm F-6.2 apo triplet, saying that an 80 mm apo is “remarkably close” to a 100 mm apo is not my experience.

 

I think the popularity (if it is indeed popular) of the 80 mm size is mostly due to its lower price and not due to any actual performance or portability advantage, as there are better alternatives. It’s just that those alternatives can be more costly.

 

Bob


Edited by bobhen, 18 May 2020 - 07:20 AM.



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