Another versus for lazy nights: 80/640 vs 90/900 vs 102/640

[Sonmalul]

Hello there. 

Lurker creating account...so new here but old here :)

After much reading I decided to ask the fine eyes of sgl for their oppinion in order to buy a scope wich will make my eyes and spul happy. 

 

To spare you from reading my (oberving) life story, I'll post my question now.

I am in a bit of o dilema. Or may I say, a trilema.

I must make a choice between:

https://www.bresser.de/en/Astronomy/Messier-AR-80-640-AZ-NANO-Telescope.html

https://www.bresser.de/en/Astronomy/Telescopes/BRESSER-Messier-AR-90-900-NANO-AZ-Telescope.html

https://www.bresser.de/en/Astronomy/Telescopes/BRESSER-Messier-AR-102-600-NANO-AZ-Telescope.html

 

I know there are other options such as 90/500 or 90/1250 or 102/1350 etc but my one big problem here is the wind and it would be a shame to buy something that dances with the gusts, wouldn't it?

I have been using for many years now a what you might call a dept store frac, a .965 60/700 and a very(76/300) small dob mounted newt.  

They were primarily used for land observations (with some acrobatics for the newt), watching things 1-2 km away...as well as ships maybe 6-8  nm away. 

They were also used for short and pleasing viewing of the Moon, Venus, Saturn and the Pleiades. 

 

So my ideal scope must have a simple and pleasing to the eye AZ mount, it must be good for land observations and some jooyful rides to the Moon and back to Venus, Saturn and a bit of easy to spot stars  

I had the 80/640 and used it for a few days  

The views were better than through my scopes but it had a big problem : right before focus and (to a smaller extent) in focus, bright stars and distant bright city lights had a cone of unfocusable glare, only on the left!

(attached you will find a phone snap of the the effect on two distant, close together,red industrial lights to give you an idea)

The dealer was not much help in diagnosing the problem so I returned the scope hoping I got the (only) lemon and the next one will not be "broken" .

 

To conclude:

80/640: I was pleased with the looks l and the build of the 80/640 Al tube and it performed good for my needs with the supplied 26mm Plossl and some 12 and 6mm "shuper" GSO plossls I also bought. But it had a plastic focuser  and a ready-to-pop-out plastic tube clamp wich seemed to remind me too much of the .965

 

90/900: I fancy the 90/900 in hope of little CA but I am afraid of it dancing in the wind...and also the focuser is also plastic. 

 

102/600: I like the Hexafoc on the 102/600. Way overkill for my needs but i part of the pleasure for me is also the looks and feel of it.

Anyone with hands on experience with it?

Have read a lot...also the interferometry tests and all... Would the CA be so bad as to make my amateur Moon and Venus gazings a pain?

 

This is the one(102/600) I am most inclined to purchase.

I also feel ripped off because the 102/1000 costs exactly the same as the 102/600...

Having confessed all that I feel a stone lifted of my soul. 

 

Thank you all!

[Ricochet]

On 06/05/2020 at 08:55, Sonmalul said:

They were primarily used for land observations (with some acrobatics for the newt), watching things 1-2 km away...as well as ships maybe 6-8  nm away. 

They were also used for short and pleasing viewing of the Moon, Venus, Saturn and the Pleiades. 

Given you are mostly looking for distant terrestrial views and planetary/lunar astronomy, I would suggest that instead of any of these you look at a small Maksutov telescope. This will give you CA-free views and the smaller size will be less prone to the wind that you worry about. 

For instance Bresser offer both 90mm and 100mm options and you can also buy their nano mount separately. However, you do not have to stick to one brand. The vixen dovetail is universal so you could buy a Skywatcher Maksutov and put it on the Bresser nano mount or put one of the Bresser scopes onto a Skywatcher AZ5. 

[Sonmalul]

Thank you, R. 

I have indeed thought about a mak but I always loved the way a frac looks.

Also I am a bit turned down by their preceived (by me at least) mechanical complexity- moving a mirror in order to  acheive focus and at the same time keeping it perfectly square to another mirror  

Maybe my fear is comparable to the aversity to the injection engine felt by some die hard carburettor grease monkeys

I am verry attracted to fracs... It's just something about them that makes me happy to see them in the house. 

 

Also, if someone has ANY experience with mounting the Bresser 102/1000 on the AZ Nano, please, do chime in. 

I have been looking for this answer for months with no result. 

I used the AZ nano with the 80/640. 

The mount head is not flimsy at all!!

The weak link in the whole package is the way the legs extend (no secondary bushings inside the larger tubes) and the way they are attached to the tripod head (plastic fork style mounts). 

I think about mounting AZ nano's head to a Bosch sturdy field tripod. 

I always wanted the 102/1000 but my frugality will not let me spend on the mount as much as i spent on the tube. 

So, if I can work my magic with the 102/1000 on the Nano, it would be great, if not, I am confined to chiosing between 80/640 (again) of the 90/900.  

Doesn't anybody else think (from my blurry pic) that something was sriously off with the acope I bought?

 

Reading my post I realize I write a lot!

I will try to fix this in the future, I promise!

[heliumstar]

Don't be afraid of the Mak. It's not fragile in any way.

102/1000 will not work on Nano. More pain than gain.

What is your budget?

[Merlin66]

Yeah,

The 102/ 1000 will definitely look like a refractor

But in any wind, on a small AZ mount it will be a disaster!

I use a 102/1100 as a solar scope mounted on an HEQ5 mount, and in the wind it's a real PITA!

The Mak is a good straight forward design, minimal issues - worth reconsidering.....

[ScouseSpaceCadet]

It seems like you need a 102/1300 or 90/1250 Maksutov. Tack sharp, no chromatic abberation, works as a spotter scope, great at high magnification on planets/lunar, stable on a small alt-az mount and won't catch the wind as much as a refractor. Easy to store, comfortable viewing position and around your budget and... and... Sold yet? 😁

Edited May 9, 2020 by ScouseSpaceCadet

[Sonmalul]

Fearing I will sound like a spoiled princess, i'm gonna say that looks are also important for me. 

Fracs really have a warm spot in my heart. 

Speaking of budget...I must make some currency conversions but it is somewhere around the 300 USD/EUR/GBP mark. 

 

The choice for me has somewhat boiled down to those two: a 90/900 Bresser or a 102/600 Bresser, both on that AZ nano mount (wich I am thinking of beefing up by changing the tripod). 

My mind ping pongs between their pros and cons as follows:

90:

+ side: Decent aperture for my leisure sporadic viewing of ships, Moon and Venus/Saturn. (~6400 mm^2 area)

- side: Focuser that is not...well...as sturdy (looking) as the 102's Hexafoc. (Maaaaaybe someday I will want to attach my Canon EOS to it just for variation and fun) and the tube clamp is...well...I feared my former 80/640 will pop out of it :/

 

102:

+ side:  Hexafoc, metal interconected tube clamps, larger aperture ~8200 mm^2 area, shorter tube will resonate less in the same wind as the longer one 

- side: 100+Eur more expensive and my 2 fears: the fear that I am going to acheive enough magnification only with tiny "pinhole imagers" (i.e. 4/6mm Plossl) and the fear that the views are going to be a christmas tree of happy fringing around Venus, the moon or any ship on a lighter background...

 

I bought the 80/640 thinking it would give me best of many (small) worlds but I gave it back for the problems posted in my picture in the initial post :(

 

I would open heartedly choose the more expensive 102/600 (and admire that focuse also :) ) but I don't want to be disappointed and wish I was sensible and chise the 90/900. 

The 102/600 is 2x the price of the 80/640 :/

 

Sorry, again, for the log post. 

It' just how my mind seems to translate thoughts into letters :D

thank you all again!

[Sonmalul]

I think I forgot to mention one important thing:

I will be using Plossls, multi coated ones, and I don't intend in acheiving magnifications bigger than 100x. 

So for the 90/900 my EPs would be: 26, 17, 12

for the 102/600 would be: 26, 15, 10 or 8

 

If the 102/600 is able to provide decent views without much CA or other abberations, I am willing to spend the extra money; if not, I will buy the 90/900 in hope that its longer fl would correct those abberations and I am willing to give away the focuser for the better views. 

 

Have a great night everybody!

Edited May 9, 2020 by Sonmalul
Typo

[heliumstar]

102/600 will show CA. It bothers me personally. I have 90/900 refractor (Sky Watcher) and it is much better in that regard. 90/900 will need a better mount though. The good thing is that you can use much higher magnification with it. Saturn looks great in mine.

 

 

[Sonmalul]

9 hours ago, heliumstar said:

102/600 will show CA. It bothers me personally. I have 90/900 refractor (Sky Watcher) and it is much better in that regard. 90/900 will need a better mount though. The good thing is that you can use much higher magnification with it. Saturn looks great in mine.

 

 

Helium thank you for your opinion and experience. Much appreciated!

I am also expecting Some CA in the 600 but I hope I don't get the "light tails" I got in the 80/640. Any idea what those might have been?(my first red photo)

Also, by any chance, do you have any experience with 102/600?

CA, I can live with it as long as is does not degrade the sharpness of the focused image too much. 

But what other optical annoyances can one expect from a 102/600 and not from a 90/900?

Thank you!

[Erling G-P]

18 hours ago, Sonmalul said:

Fearing I will sound like a spoiled princess, i'm gonna say that looks are also important for me.

Are you saying THIS doesn't look good ? - I find it downright sexy! 😁

 

Edited May 10, 2020 by Erling G-P

[Sonmalul]

8 hours ago, Erling G-P said:

Are you saying THIS doesn't look good ? - I find it downright sexy! 😁

 

To continue the princess talk: neah...I need a longer one!

That's what she said anyways :P

:)))

Jokes apart it is indeed a beautiful scope, but I really want a frac (it will be used only sporadicaly) and I really want it in white...and you know...well... a Takahashi is a Bit above my paygrade :P

[Sonmalul]

The choices for me, have boiled down to those:

80/640 again (although i am quite cautious about buying it again from this (only) dealer because mine had a problem and they had another one "resealed" in stock) Maybe they got a lemon lot. 165 Eur

90/900 long fl and I think a good overall package for the money. Fear of it dancing with the winds. 230 Eur

102/600 scared of the short fl not (only) because of CA. Highest price but nice tube rings and focuser. 350 Eur

All are on AZ nano.

Please help me and spend my money so I can blame you

[ScouseSpaceCadet]

Sonmalul, if your heart is set on one of those three with CA as a concern, you only want to use it for mostly solar system and terrestrial observation from home, then the 90/900 is probably the best choice for you. I think you really knew that already.  😉

 

 

[Sonmalul]

SpaceCadet, indeed my mind is set on the 90/900. Seems you can read minds

I am also a bit put off by one consultant at a major online astronomy shop who said it IS good for my wants and needs but if my area has winds (at it does a lot) and if I can afford the 102/600, get that. 

I like it, amd I am willing to slend the extra money for peace of mind that it would not wobble.  Of what use is a nice tube if it wobbbbbles?

My only concern is if it will be able to provide enough magnifications...to use on Venus, for example...

I plan on using 26, 12.5 and 7.3 mm Skywatcher "shuper" Plossls. 

[ScouseSpaceCadet]

If you want to view planets, out of the three, the 90/900 is the best option. The others are widefield telescopes.

A 7.3mm plossl and 90/900 refractor will provide 123x magnification. Way below the telescope's recommended max limit of 180x.

 

[John]

90mm F/10 refractor will create a fair bit of force on the mount head through lever arm. The 102mm / F/6 somewhat less.

I don't know the Nano mount but it would be worth checking if it's able to cope with the longer tube.

 

[ScouseSpaceCadet]

16 minutes ago, John said:

90mm F/10 refractor will create a fair bit of force on the mount head through lever arm. The 102mm / F/6 somewhat less.

I don't know the Nano mount but it would be worth checking if it's able to cope with the longer tube.

 

The 90/900 is sold with the AZ Nano, so unless Bresser have boobed somewhat, and although not the ideal mount for the scope, it's probably fine for his purpose? 

[John]

4 hours ago, ScouseSpaceCadet said:

The 90/900 is sold with the AZ Nano, so unless Bresser have boobed somewhat, and although not the ideal mount for the scope, it's probably fine for his purpose? 

Quite a lot of scopes have been supplied on mounts that are not fully up to the job over the years I'm afraid. I've owned a few of them !

Meade put their long 5 inch and 6 inch refractors on the LXD55 mount on an aluminium tripod for example

Looked impressive but was a nightmare to use at over 100x magnification.

 

[johninderby]

The Nano mount has a 4kg capacity and the 90/900 OTA is 2.5kg with finder diag etc. so while it would hold the OTA would think vibrations could be a problem with the long tube.

The Nano mount would be fine with the 90/500 OTA though.

Edited May 12, 2020 by johninderby

[Sonmalul]

Judging a mount by its carryweight is somewhat a false advertisment. 

There can be heavy things put on a mount that create a small windsail/lever and light things (90/1200) that create a lot of pull on the mount with only a little nudge from either ends of the tube. 

I have used the AZ nano. The mount/tripod I can assure you it can hold 6-8-10kg with no problem, Vertical load!! I rested part on my weight on it for this exact purpose. Twist it and there is your wobble. The problem lies in the joints. Te nano has some flex points: the plastic fork style mounts between the legs and the flathead, the retaining lockrings for extending the legs, the legs rotating a bit...

The mount head on its own is very solid. It's all metal with some plastic clading. I wrote in a previous post that if it fits a Bosch surveyor tripod, that will be the ideal mount for me. 

Bosch Bt160

https://rthde.files.wordpress.com/2013/06/bosch-bt160_.jpg?w=630

 

Also, the 90/900, as well as the 80/640 and 90/1200 comes with a plastic elastic clamshell mount. This clamshell does not only flex but the only locking nut can be slid of the clamshell with relative ease even when tightened down. Make it too tight and the clamshell flexes and it popa out on its own :/

[Sonmalul]

After much searching online and dozens of phonecalls, it seems the fates are against me. 

The Bresser 90/900 will be available only from the 1st of of september in my country. 

The 102/600's situation is the same. 

I am now left with 80/640 and the 90/500 to choose from. Both are available at once. 

The 80 is MgFl coated and the 90 is "multi coated". 

Please help me choose something so I can enjoy a bit of this, (warm period) this year. 

I would also choose some 15 and 6 mm Plossls for those scopes...

I must confess I feel guilty. I haven't contributed with anything to this forum and all i do is ask questions. But I really want to be able to look at something this year...so thank you very much for your kind words everyone. 

[Ricochet]

46 minutes ago, Sonmalul said:

I haven't contributed with anything to this forum and all i do is ask questions

I think that asking a question is also contributing. In the future other people may have similar questions and also find this thread. 

With regards to your two choices, between an 80mm f8 and a 90mm f5.5, I think the f8 will probably give more pleasing terrestrial views and would therefore be my choice. Hopefully the issues you saw with the previous example were a one off. 

[heliumstar]

1 hour ago, Sonmalul said:

After much searching online and dozens of phonecalls, it seems the fates are against me. 

The Bresser 90/900 will be available only from the 1st of of september in my country. 

The 102/600's situation is the same. 

I am now left with 80/640 and the 90/500 to choose from. Both are available at once. 

The 80 is MgFl coated and the 90 is "multi coated". 

Please help me choose something so I can enjoy a bit of this, (warm period) this year. 

I would also choose some 15 and 6 mm Plossls for those scopes...

I must confess I feel guilty. I haven't contributed with anything to this forum and all i do is ask questions. But I really want to be able to look at something this year...so thank you very much for your kind words everyone. 

 

6mm Plossl is very uncomfortable eyepiece.

Why not get this : https://www.astrobuysell.com/uk/propview.php?view=161556

and Sky-watcher AZ5 (https://www.firstlightoptics.com/sky-watcher-az5-deluxe/sky-watcher-az5-deluxe-alt-azimuth-mount.html) mount and be done with it.

[Sonmalul]

6 hours ago, Ricochet said:

With regards to your two choices, between an 80mm f8 and a 90mm f5.5, I think the f8 will probably give more pleasing terrestrial views and would therefore be my choice. Hopefully the issues you saw with the previous example were a one off. 

Thank you very much for your time and answer. 

That is why I have in the first place chosen the f8 over the f5.5

But you see, here is where firsthand(eye) experience comes in handy. I was leaning towards the 90mm because they say it has multi coated lens vs only MgF2 on the 80mm and I thought it would make a night and day difference...hopefully. 

I will follow your advice and buy (Again) the 80/640 if you say the coatings are not that important for my usage....hoping it will be better.