Aperture Fever!

[jetstream]

3 hours ago, Ledge1962 said:

I started with a 4", then went to a 10" SCT and now a 14" Dob. I have a good area in New Zealand that doesn't suffer from light pollution, and have a good view of the sky so I do not need to move them, so housing them gave me the freedom to go to whatever size I could afford. I have looked at 16" but the change from 14 to 16 is not worth it, so a 22" will probably be next.  If I had gone straight to a 22, it would have been a lot cheaper and then I could have started saving for the 36".  Aperture fever is very contagious. 

Great point.

In my own aperture fever I had the idea of a 1 magnitude gain minimum between scopes. The jump from 90mm to 250 mm was huge, from 250mm to 381mm large and from 381mm to 609mm- well we'll see.

To the OP- many DSO respond to increasing their size in the EP while maintaining high eye illumination- something that fastish F ratios at longer FL's give (large scopes). This is important IMHO.

[maw lod qan]

I hope soon to upgrade. I would love a C14 SC, but right now, of have you hit the lotto. 

So my plan is probably going to a 12" dob, with me grinding the mirror for the experience. Then later jumping up again to an 18 or 20.

But, all that changes if the  2 tickets I'll buy to tonight hit.

[Stu]

26 minutes ago, maw lod qan said:

But, all that changes if the  2 tickets I'll buy to tonight hit.

Enjoy grinding your mirror ????

[kirkster501]

Of course a bigger scope is "better" all other things being equal. But never forget, the best scope is the one you can easily use.  How many times have we heard that????  A cliche but it's so true.

Some beginners, especially ones who have the financial means, get excited about big scopes but then get disillusioned at the size and weight of them.  Sadly, seen that so often, and they get fed up and quit.  Have they seen the size of a 16" Dob?  Even a 12" one????  Or a C14 and the mount needed for it?  A CPC 1100 - fab scope - is a big beast to handle and store if you have never seen one in the flesh.  

The best telescope is the one that *you* can set up and use easily, on a sustained basis.

[Mr niall]

6 hours ago, kirkster501 said:

 But never forget, the best scope is the one you can easily use.  How many times have we heard that????  A cliche but it's so true.

Picked up my new (to me) 300p on Saturday - managed to have an hour on it last night. Its so big that we can't physically find somewhere in the living room to put it where its not in the way.

Additionally its so heavy, my wife had to help me lift it to take it outside, and then bring it back in later on. All things considered, she's not happy with me....

Great scope though, bagged M51 almost immediately, only taken me two years.

And in the wise words of Marge Simpson... "Well, I guess as long as you're happy, then nothing else matters!" ?

Edited April 30, 2019 by Mr niall

[kirkster501]

7 minutes ago, Mr niall said:

Picked up my new (to me) 300p on Saturday - managed to have an hour on it last night. Its so big that we can't physically find somewhere in the living room to put it where its not in the way.

Additionally its so heavy, my wife had to help me lift it to take it outside, and then bring it back in later on. All things considered, she's not happy with me....

 

Indeed.  They are huge, much bigger than many expect them to be.  Difference between the 200 and 300 is huge.

[Mr niall]

7 minutes ago, kirkster501 said:

Indeed.  They are huge, much bigger than many expect them to be.  Difference between the 200 and 300 is huge.

Yes but based on last nights experience I'll soon be sleeping in the living room with it every night anyway so will have lots more time to enjoy it.

Every cloud....

[Paul73]

Maybe a little Dob kennel in the garden??

You could get an even bigger scope then....

[wesdon1]

Wow, i didn't expect so many comments! Very very much appreciated! It's patently obvious, after reading through all the comments, that i am even more of a "Newbie" than i originally thought! haha I've learned a lot from every single comment, and i very much appreciate all the knowledge shared with me. I would just like to add, i didn't mean to Demean 5.1 inches of aperture on a Newtonian, or any other type of Instrument for that matter. I was just trying to express (in my own very inexperienced, Naive way) the "Relative Size" of my Telescope, in comparison to what's available! Please Please forgive me if i offended anyone in any way whatsoever! I'm learning fast what matters, and hopefully one day it will be me giving advice to some other "Newbie" who has "Aperture Fever" ( Or "Mount Fever" or any other "Fever" for that matter! haha) To finish, Thanks again for all comments and advice, it really helps people like myself move forward in this amazing hobby/Passion! Now will someone PLEASE TURN OFF THE STREET LIGHTS WHERE I LIVE!?? haha

[kirkster501]

As SPM used to say, and I repeat it again, a 3" refractor like the ED80 or a Dob 200.  Cheap, cheerful and fantastic scopes, both of them.

I love my Helios Apollo bins for visual.

[ollypenrice]

15 minutes ago, wesdon1 said:

Wow, i didn't expect so many comments! Very very much appreciated! It's patently obvious, after reading through all the comments, that i am even more of a "Newbie" than i originally thought! haha I've learned a lot from every single comment, and i very much appreciate all the knowledge shared with me. I would just like to add, i didn't mean to Demean 5.1 inches of aperture on a Newtonian, or any other type of Instrument for that matter. I was just trying to express (in my own very inexperienced, Naive way) the "Relative Size" of my Telescope, in comparison to what's available! Please Please forgive me if i offended anyone in any way whatsoever! I'm learning fast what matters, and hopefully one day it will be me giving advice to some other "Newbie" who has "Aperture Fever" ( Or "Mount Fever" or any other "Fever" for that matter! haha) To finish, Thanks again for all comments and advice, it really helps people like myself move forward in this amazing hobby/Passion! Now will someone PLEASE TURN OFF THE STREET LIGHTS WHERE I LIVE!?? haha

What a great post and, no, you didn't demean anybody. What you opened up was the question of what you can see in what telescope and that is a highly intelligent question which cannot easily be answered. The one answer we can confidently give is that no one telescope is best for everything. Since most people in this madhouse like buying telescopes you've hit the good news!!! 

lly

[wesdon1]

12 minutes ago, kirkster501 said:

As SPM used to say, and I repeat it again, a 3" refractor like the ED80 or a Dob 200.  Cheap, cheerful and fantastic scopes, both of them.

I love my Helios Apollo bins for visual.

Thanks Kirkster501, i've learned a lot from all the very helpful/educational comments to my Topic/Question! The late SPM was fascinating to listen to on TV, so anything he says, i consider it incontrovertible fact! lol I'm thinking, after reading the many comments, that i should get a 70-90mm Refracter, and a 200mm Newt on a dob mount. (much more for your money, i'm learning! lol) Then i will drastically improve my EP collection, to get maximum benefit from said instruments.

[wesdon1]

6 minutes ago, ollypenrice said:

What a great post and, no, you didn't demean anybody. What you opened up was the question of what you can see in what telescope and that is a highly intelligent question which cannot easily be answered. The one answer we can confidently give is that no one telescope is best for everything. Since most people in this madhouse like buying telescopes you've hit the good news!!! 

lly

Thank you so much for your kind comments. Very much appreciated! I'm learning at frantic pace, and enjoying every minute and moment of it!

[ollypenrice]

1 minute ago, wesdon1 said:

Thanks Kirkster501, i've learned a lot from all the very helpful/educational comments to my Topic/Question! The late SPM was fascinating to listen to on TV, so anything he says, i consider it incontrovertible fact! lol I'm thinking, after reading the many comments, that i should get a 70-90mm Refracter, and a 200mm Newt on a dob mount. (much more for your money, i'm learning! lol) Then i will drastically improve my EP collection, to get maximum benefit from said instruments.

Although I'm in the happy position of ofsetting the insane cost of premium kit against my business, the truth is that I could easily live with just four eyepieces for all our scopes and, for any one scope, I could live with just three or even two. Give me a really good eyepiece and all I want to do is settle down and look through it till I can start to see what's there. This takes time but it's time well spent.

Olly

[newbie alert]

On 29/04/2019 at 09:34, Timebandit said:

 

 

Bigger is not always better with the faint fuzzy hunting.

A smaller aperture under truly Dark Sky's will out perform a larger aperture in a light polluted area.

The 8 inch Newt I have at a dark site will best my 14" Dob at a light effected area on the faint fuzzy .

Best of all I can have the smaller newt in the car and going in a couple of minutes. The larger Dob takes Sooo much more time and effort to move. And you have the same problems at the dark site and at packing up time. 

A truly Dark site can really make the most of a smaller aperture .

 

 

 

While I understand what you're saying, portability is a major factor.. however..take a big dob to a dark site and wow...I'm not really a visual guy either but wow.. 

This 16 inch was very portable 

[saac]

On 25/04/2019 at 19:40, ollypenrice said:

You can go bigger and bigger and bigger for as long as you like but this comes at a price. Your focal length also goes up and so your field of view comes down. Very soon you can forget the Pleiades. They won't fit. M31? You'll only see small fragments but, yes, you'll see them well.

Don't make the mistake of assuming the moon and planets will be best seen in a very big scope. I ran a 20 inch Dob here for about 14 years but it was F4.1 and didn't give anything like as good a planetary image as our TEC140 Apo or 14 inch Meade SCT. On the Veil it was fantastic (you could move it along and trace the filaments) but on the Rosette it simply didn't have the field of view. Don't forget all those targets which are best in binoculars...

The man who has seen everything will need a bigger scope to see new things. But in this scope he may no longer be able to see things he could see before... I think that's my key point.

Olly

 

One of the best posts I've read about the pros/cons of increased aperture.  If only it was as simple as just getting a bigger mirror. 

Jim  

 

[L8-Nite]

On ‎24‎/‎04‎/‎2019 at 10:17, wesdon1 said:

I'm just throwing this one out there. At what point do you stop seeking more and more Aperture? ………………………………………………...

For me, it was when I realized it wasn't about the size of aperture, but about having a manageable scope with premium quality optics.

Your views are only going to be as good as the weakest link in your optical train. 

[ollypenrice]

8 hours ago, L8-Nite said:

For me, it was when I realized it wasn't about the size of aperture, but about having a manageable scope with premium quality optics.

Your views are only going to be as good as the weakest link in your optical train. 

'It ain't what you see, it's the way that you see it.' There's a lot in this... That's why folks will pay so much for apochromatic refractors.

Olly

[andrew s]

I think for imaging/visual  there is a definate sweat spot or small region. It is bounded by a number of factors.

Less than 300mm due to the change in the effect of seeing as the " seeing cells" get resolved.

S/N ratio scales as diameter not area 

Weight/portability goes as size^2 or size^3 depending on type

Cost goes as diameter^x where x is 3 or more.

This leads to the normal range of scopes we see used by SGL members.

Regards Andrew 

 

Edited May 3, 2019 by andrew s

[Timebandit]

10 hours ago, newbie alert said:

While I understand what you're saying, portability is a major factor.. however..take a big dob to a dark site and wow...I'm not really a visual guy either but wow.. 

This 16 inch was very portable 

 

 

Very portable ?

 

The breakdown time of the scope,  needing a reasonable size vehicle to fit everything in without damaging anything(even with a truss). Setting up time when your at site,  re collimation of the scope at the site. Then the same when packing away and when set up at home again. I would not say 16" very portable.

 

I have tried a 14" at a dark site and a 8" at dark site. On a like for like dark site ,yes bigger is better(all things being equal). But as I said not always. The 8" in a dark site area with easily out do a 14" in a light polluted area. So bigger is not always better.

For people who do not have access to these big scopes or budget for ,or transport. Then you can really get the best out of a smaller scope by getting to a true dark site, where it will punch above its weight when compared to a big scope being used in a light polluted area.

I have no axe to grind as I have a larger and smaller scope. But Dark Sky's are where it is at(with faint fussies). And if you are working and have limited time in the evenings then you do need a quick get up and go set up. The 8" is just such a good all rounder for this type of task.

 

 

 

[kirkster501]

10 hours ago, newbie alert said:

While I understand what you're saying, portability is a major factor.. however..take a big dob to a dark site and wow...I'm not really a visual guy either but wow.. 

This 16 inch was very portable 

Doesn't look much like the UK with those palm trees in the background dude  . Did you get that in your Easyjet baggage allowance? 

[niallk]

1 hour ago, Timebandit said:

Very portable ?

 

The breakdown time of the scope,  needing a reasonable size vehicle to fit everything in without damaging anything(even with a truss). Setting up time when your at site,  re collimation of the scope at the site. Then the same when packing away and when set up at home again. I would not say 16" very portable.

For sure, judging portability is subjective.

I can only comment on my two scopes, but I got my 15" explicitly for portability.  If I go to a dark site, I really want to make the most of it.  I've travelled once with my 10".  The 15" breaks down simply, fully captive parts, nothing fiddly.  The mirror box is a bit heavy, but I don't carry it too far, and it came with wheelbarrow handles.  Moving it is a doddle at a star party.  I've wheeled it up a rutted path, and into a field - nice big soft pneumatic tires absorbing the uneven terrain.

Takes just a few min to assemble/ disassemble at the end of the night (3-4min), and about 1 min to collimate in the dark.  I learned how to do it - it's just something to face into and conquer if owning a Newtonian of pretty much any size, and now I actually enjoy collimation because I get to play with a laser in the dark.  It's now really no big deal at all... I don't even label the trusses - random each time: no fuss. My scope has easy to adjust knobs for both mirrors - no fiddly Allen keys (my 10" is not so pleasant to collimate, but the secondary thankfully rarely needs touching up!  The Astrosystems secondary holder in my 15" is a user friendly design)

YouTube is great - you can look up videos of putting together a scope, and judge a design's suitability for your needs.

The 'old school' but simple and well thought out Kriege type design of which there are many variants is quite elegant imho 

Edited May 3, 2019 by niallk

[andrew s]

Once you are seeing limited, and not doing lucky imaging by eye or device, then all aperture brings is extra photons and possibly a bad back. Improved S/N let's you go deeper if sky brightness allows, or image with shorter exposures and/or higher cadance.

It all depends on what you want to observe and how you want to do it. Spectroscopy,  my thing, is photon limited so I have a 400mm ODK but it takes two people and a ramp to get it on the mount! ?

You pays your money and takes your choice.

Regards Andrew 

[F15Rules]

On 25/04/2019 at 19:20, Stu said:

Much depends how often you want to observe and what sort of astronomy really interests you. Big dobs tend to excel at the fainter deep sky objects and benefit from the darkest skies you can find. That means observing at new moon only and making the commitment to get to those dark sites, often many hours drive away.

I wouldn't choose an 20" dob as an ideal planetary scope. They are more likely to require excellent seeing conditions to get the best high power views from, and those dont happen very often. There are other, smaller scopes which will more reliably give you good planetary views. Ultimately a large scope has better resolution, but you can end up waiting quite a while to make the most of that resolution when the seeing steadies.

Personally, I prefer to get out more often and for shorter sessions, otherwise I feel too removed from the hobby. As you will see from another recent post of mine, I enjoy a challenge in what ever scope I'm using, even my 65mm Newt

I owned a 16" Sumerian Dob for a while, which I enjoyed a few wonderful sessions with, but given that I have a dodgy back, found that I didnt use it as much as I had hoped, even though it was a compact truss design. Lifting a 16" mirror box into the car boot didn't really work for me.

The solution I have now is one which I believe I will stick with. It is a 14" 'dob in a box' from Sumerian with a very nice John Nichol mirror in it. In many ways it is quite compromised, not as stiff as the larger designs, but it suits me just fine. I can carry it with one hand very easily and it does not strain my back at all. It is very easy to get away to dark sites and I will use it often in future.

Everything is a compromise and it takes time and experience to work out where your preferences lie.

Sorry about the random order of the images.

...And I never was any good at Meccano when I was a lad. 

Too much like the "MFI or Ikea" of scopes for me, I will stick to "Delivered fully assembled"!?

Dave

[Saganite]

12" OO VX is the cure for aperture fever in my case, top quality ,easily portable, and the perfect complement to my pair of refractors.