Evostar 120 Vs Explorer 150PL

[spaceboy]

I have heard from a friend, sinus ops often leave you worse than you were in the 1st place. Hope this isn't the case for you.

[brianb]

I have heard from a friend

Bad news spreads fast. All operations have a failure rate but they're pretty low ... Really it's not helpful to spread this sort of third party information on public forums. If people started to believe the "X ops leave you worse off" stories they hear, the surgeons would be out of business and more patients would be sufferring for longer ... and probably paying a fortune for quack "cures" with no hope of working.

[Wurzil]

dont worry im not scared

According to the disclaimer thing i had to sign when i agreed to the operation i could: go blind, get meningitis, get a disfigured nose, pain and headaches, oh and death if the anaesthetic goes wrong. I guess if all that happens i wont be too worried about still having a blocked up nose!!!

[Kef9]

What is it about a refractor ?

Its because they are portable, give unobstructed views, can be used in the daytime and dont take hours to cool down.

They are just cooler to own. I see clear skies, I pick it up on the mount and take it through some doors into my back garden, let it cool down for a few minutes and off you go.

I want to go to dark sky site or take it with me on holiday. Both the telscope and mount will fit on my parcel shelf leaving the rest of the car boot free to use as I wish. Got a family of 5 going on a holiday and need to fit all the luggage in the boot AND take your telescope? No problem, i have done it using a vauxhall astra hatchback.

Lastly regarding aperture. I got my Startravel for a very good price. 6" of aperture which is nice for DSO's in a nice compact package. What more do you want? (apart from an 8" frac !).

For planets I have my C100ED which shows no false colour whatsover and provides great contrasty views.

What more can I say. I might get a dob one day but they are massive and to me seem to involve lots of messing around (collimation) which I cant be bothered with to be honest. By the time the thing has cooled down the clouds might have come in.

Have I persuaded you yet?

Just waiting for the dob crowd to make a passionate defence (maybe?)

[spaceboy]

The talks are on the table with Santa's little helper!! TBH It's not looking good at the mo as I can't find a good one going 2nd with in reasonable driving distance so may have to buy new before the VAT increase. I did originally have it in the budget for new but I couldn't resist a little green and black No. 13

[brianb]

Its because they are portable, give unobstructed views, can be used in the daytime and dont take hours to cool down.

All of which are true with a Newtonian of similar aperture. Large refractors take ages to cool ...

... Go look at the images produced by world class planetary specialists. Now look at the instrumentation they're using. Without exception, SCTs and Newtonians in the 11"+ aperture category. Fact, you need aperture to get resolution.

[Moonshane]

All of which are true with a Newtonian of similar aperture. Large refractors take ages to cool ...

... Go look at the images produced by world class planetary specialists. Now look at the instrumentation they're using. Without exception, SCTs and Newtonians in the 11"+ aperture category. Fact, you need aperture to get resolution.

nerny nerny ner ner.

as much as I love fracs, I sold mine and went to dobs mainly for the purity of the images and resolution as well as ease of use (although OK fracs easier on EQ mount agreed). I don't find collimation fiddly at all and letting them cool is just part of the set up time really. while mine are cooling I use my double fracs to have a peer round - some people call them binoculars

[spaceboy]

Hi Everyone

I'm pretty sure what the outcome of this one will be but I'm getting irritated at my urge for a refractor. The way I'm seeing it is there will always be the debate Lens Vs Mirror so I figured if I have both then there would be no debate (for me anyway).

Thanks

SPACEBOY

I some how knew it was always going to be a hard question to have answered. The idea of no mirror to get dusted up appeals and as there is only a lens to cool is appealing also but talk of colour when I have only had a reflectors clean view on the sky may become an issue. As I said before if fracs were that bad why would people still buy them??? I am open to the idea of the 150PL for the same intended purpose but pictures can be deceiving and the OTA is probably HUGE

BTW Shane if I could I would have your OO's any day of the week. I have OO envy for your set up but I always knew I would have a limited budget so I was never going to have anything that out standing. I was amazed I managed to get a fairly good EP collection from my limited supply of £££'s

[Kef9]

All of which are true with a Newtonian of similar aperture. Large refractors take ages to cool ...

... Go look at the images produced by world class planetary specialists. Now look at the instrumentation they're using. Without exception, SCTs and Newtonians in the 11"+ aperture category. Fact, you need aperture to get resolution.

No it isn't.

1. A newtonian of similar aperture will never beat an ED frac in any category so what would be the point?

2. A standard newtonian cannot give unobstructed views due to the central obstruction = Loss of contrast.

3. A newtonian is not really suited to daytime use. How often have you used yours for this purpose?

4. In general there is no messing around with a frac. No collimation. Nothing. Yes some triplets do take a while to cool but doublets don't. Its alot better than a newtonian where you have to have fans whirring to cool things down.

Yes you do need aperture to get resolution. I have never diputed that but with aperture comes less portability. No sain person would prefer a newtonian over an ED frac with the same aperture unless they were skint. Dark skies mean alot more than aperture. Can you get there?

nerny nerny ner ner back at ya Shane!

[brianb]

if fracs were that bad why would people still buy them?

Small ED / apo fracs are great for wide field low power visual work and small scale imaging. There are advantages for serious solar observers who prefer to use Herschel wedges to solar film (there is maybe a 10% improvement in contrast). You can't do this with a reflector because of the heat concentration round the secondary mirror. Incidentally you can't use a Petzval frac or a barlow lens in this mode for the same reason. But solar film works well with a Newt, Mak or SC ... provided you use full aperture rather than an offset mask, unless your scope is big enough to allow at least 4" offset.

The central obstruction argument is simply wrong ... the contrast loss is about the same as that caused by the diagonal you'll almost certainly use with a frac, but not with a Newt.

You need to be working at f/8 or slower to get reasonable colour correction with even a triplet APO at 6" aperture. Now a 6" f/8 frac tube is the same length as a 6" f/8 Newt tube (actually a bit longer because the focuser hangs off the end instead of poking out the side) and the 3 lenses weigh more than the mirror.

Have you ever used a premium grade Newt?

[Kef9]

I personally thing CA is a bit overatted. Yes it is annoying but I dont have a problem with it in my F5 achro. If you get 6" premium apo then you don't need to be above F8 either to get rid of false colour. I'm sure if you rang Astrophyics or TEC they would disagree with your statement since they sell these instruments with FL's lower than F8.

To say that the contrast loss is the same as a diagonal is a bit OTT in my opinion. Okay then you must get double the contrast loss because you are using 2 mirrors and then further contrast loss because of the central obstruction of your dob.

Yes I have used a premium newt, it was Moonshanes 12" OO in fact and it was very impressive. There is no doubt about that. Yes you do obviously see more stars and gain greater resolution but the sheer size of a 12" dob is alot to consider. Like I have said before I may get one someday but for now I am definitely in the frac crowd. Everyone has their own tastes at the end of the day.

[spaceboy]

Yes you do obviously see more stars and gain greater resolution but the sheer size of a 12" dob is alot to consider. Like I have said before I may get one someday but for now I am definitely in the frac crowd. Everyone has their own tastes at the end of the day.

I think I'm going to go with the frac I will then be able to argue with myself in the mirror to which is the better. I'm not going in to it blindly as it's only 4.75" so I has no misconceptions to what I'm going to see. I assume??? (fingers crossed) it will not be no worse than the 127 Skymax ??? other than some false colour but I can't be dealing with a MAK 2hr cool downs and dew magnet objective lens.

[russ]

All of which are true with a Newtonian of similar aperture. Large refractors take ages to cool ...

... Go look at the images produced by world class planetary specialists. Now look at the instrumentation they're using. Without exception, SCTs and Newtonians in the 11"+ aperture category. Fact, you need aperture to get resolution.

That's very true for imaging. But imaging and visuals are two very different things. When you look at what scopes the top planetary sketchers are using, it's not 11"+ class scopes but 8" class scopes.

Having owned an ED100 and Celestron C8 side by side, i can say with confidence that i had more good nights with the ED100 than i did with the C8. I was able to make the most of clear spells or short sessions that the SCT couldn't hope to be ready in time for.

As for newts, i love em as well. The 150 doesn't need that long to cool. It's not heavy, it's not chore and performs brilliantly. And it's cheap enough to own without breaking the bank. I would take the 150PL over the Evo 120 without a doubt.

[Moonshane]

I think this all just proves that there are lots of different scopes that suit different people and in the end (in my view anyway) the 'best' scope is one you feel comfortable using and that gives you the best visuals for the money you have.

ultimately, it's usually the sky that wrecks it for us all!

personally, I find dobs more comfy to use than fracs. I also consider carrying the 12" out less trouble than setting up my old 120mm frac on a mount and tripod.

In all honesty though I do to some extent miss the tight star points across the whole wide view that the frac gave me - the advantages of that though a low compared with what the dob gives me in terms of added stars.

vive la difference! as they say in Greece.

[nightfisher]

good luck with the op spaceboy, have a look at the lunar imaging thread for my post "second attempt" it was done with my evo star 120 but could be better as im still learning the witchcraft that is imaging;) the 2 pics might give you a clue as to a frac

[GrantEb]

Almost like, do you prefer slim, or not so slim chicks?

Guess you won't really know until you've tried both.

But on a more serious note, this is a very informative thread.

[spaceboy]

I find dobs more comfy to use than fracs. I also consider carrying the 12" out less trouble than setting up my old 120mm frac on a mount and tripod.

QUOTE]

Your not wrong there!!!! Tripods are a pain in the A** but once done it makes life so much easier and I have a tracking motor for that extra bit of laziness. The biggest pain for me is the counter weights but I should only need to use 1 x 5.1kg weight with the Evostar 120 ??

[Moonshane]

depends on the accessories. I found it better with two weights in truth when using it 'fully loaded'

see post #10 here http://stargazerslounge.com/equipment-discussion/106456-eq-alt-azimuth-giro.html

[John]

Alt-azimuth mounts can be fun with refractors

[Moonshane]

agreed John - I definitely preferred mine in alt-az mode and if I went the frac route again I'd be getting a Giro III or similar.

[spaceboy]

good luck with the op spaceboy, have a look at the lunar imaging thread for my post "second attempt" it was done with my evo star 120 but could be better as im still learning the witchcraft that is imaging;) the 2 pics might give you a clue as to a frac

Thanks Nightfisher. It's been found that I have a torn cartilage. Only took 2 years of complaining about knee pain for the Dr's to finally do some thing about it. Now saying it's probably been to long to repair but have to do an endoscopy to check if any thing else can be done.

In your thread the 1st picture was greenish coloured, is that false colour ? I thought it was only apparent on the limb ? Like the second picture BTW.

Is that a Konus John??

[John]

....Is that a Konus John??

Yep - same optics as the Skywatcher / Celestron 150mm F/8's. Distinctive paint job .......

[spaceboy]

Yep - same optics as the Skywatcher / Celestron 150mm F/8's. Distinctive paint job .......

I thought Konus were Japanese ? I have some Konus colour filters which are made in Japan.

[nightfisher]

first pic was just not a good one, but not false colour, just an amateur making a hash of it:D

[russ]

Alt-azimuth mounts can be fun with refractors

AltAz is the way to go for me. Whether that be a dob or a frac/newt on a AZ4. So easy, so quick to setup and i've not missed the drives once in 18months. Do have a driven mount too, i never bother with it.

I like all scopes but some are easier to live with. The frac or 150 newt on the AZ4 is my most used setup. I can lift out with one hand and the eyepiece case in the other hand. A one trip setup done in 15seconds.