ooo aparature fever...... 200p/250px/flex...

[garethmob]

well i was waiting for it to happen and it has

resently i bought a 8" OTA from here from kind earl and me and my grandfather was going to build a dob base for it as a little project, but in the last week he seriously hurt his back (moving a glass cabinate on his own when it was way too big for him ) and so its currently near enought perminantly on hold

as im terrable at building things (imagine an ikea book case... with the shelves backwards and the front being the back) iv come to the conclusion of aving a look elseware and i was thinking about the scopes i put in the title

the skywatcher 200p solid

skywatcher 200px flex auto

skywatcher 250 solid

now i could get enough money to get about 400 - 450 if i sell my PST as well as my 6/7" dob and the 8" OTA

a few questions i have if any one else has tried them on these :

there would be a few mods id make like wixy, gemrad, telrad, spottin scope ect is there enough room on the solid tube or the flex to do the above mods

also i have a synscan goto controller can i plug it into the flex?

i understand the difference between the 200 and 250 is 77% extra light but what exactly does that mean

also on the eyepeices front, would my current line up be ok the them

32mm vixen, 10mm vixen, the standereds in the startravel 102, standerds in meade etx70 and a cheap skywatcher 3x barlow

thanks in advance for any help/advice/suggestions

[jondg14]

Hi Gaz,

I'm seriously looking at the SW 300P FlexTube. My original plan was to get an 8" but aperture fever has got a hold of me too! I don't know a great deal about these scopes but my friend has a solid SW 250PX dob which produces some stunning views (Decent detail on planets and DSOs look great with a bit of magnification). I think he went for that size because any bigger and it would start to become a little tricky to transport. Although that's where the FlexTube comes in!

My dilemma is whether to go with the manual, AUTO or GOTO. I'm shying away from GOTO because I think part of what I enjoy about astronomy is hunting down an object myself!

[UTMonkey]

If you can afford Auto I would definitely recommend it, but if funds are tight you will be happy with a manual.

There is a bit of weight in these 300's....

[jondg14]

My budget right now can just about run to the AUTO but then I suppose I need to consider a light shroud and a power tank.

I may need to join the gym in order to lug a beast like that about!

[garethmob]

one of the things im seeing if i can budget are the mods i mentioned above jon

iv got a wixey (that gives u the alt setting circle) and the gemrad (gives u the az setting circle) then theres the telrad which is one of them MUST HAVE mods (iv tried the RDF, spotting scope, even the stupid celestron attempt and the day i looked through a telrad i releised i must have as it gives little rings in the FOV to help stars jump

there is a few little bits as u mentioned a light shroud and powertank (av a look in maplins for a car jumpstarter they do the same job and the maplin one even has a little transformer inside for the awkard 6v an 9v attachments:P

[jondg14]

one of the things im seeing if i can budget are the mods i mentioned above jon

iv got a wixey (that gives u the alt setting circle) and the gemrad (gives u the az setting circle) then theres the telrad which is one of them MUST HAVE mods (iv tried the RDF, spotting scope, even the stupid celestron attempt and the day i looked through a telrad i releised i must have as it gives little rings in the FOV to help stars jump

there is a few little bits as u mentioned a light shroud and powertank (av a look in maplins for a car jumpstarter they do the same job and the maplin one even has a little transformer inside for the awkard 6v an 9v attachments:P

Yeah the mods can majorly bump the price up! I agree the telrad is a must have. I've coped with the Celestron "red dot" finder so far though and it has worked reasonably well for me.

The maplins 3-in-1 jumpstarter looks just the job. I can't believe I was thinking of spending £100 on the SW power tank

I'm just considering whether I buy an Astrozap shroud or attempt to make my own. I'm thinking of a camping mat and velcro solution

[garethmob]

well Buy Foam Camping Mat - Single at Argos.co.uk - Your Online Shop for Camp beds, airbeds and camping mats. £5.99 but a little tinkering orr

£59 from a well known astro online shop

[garethmob]

any ways............... the origional question would it be better to go for a solid tube or flex at the above mentioned

the skywatcher 200p solid

skywatcher 200px flex auto

skywatcher 250 solid

i guess i could push to a 250flex next payday but is there enough room for the gemrad mods or the telrad wixey spotter scope ect

and would the auto be better for me than the manual (i know skywatcher are bringing auto dob bases soon is there any prices out on these yet? )

[spaceboy]

I will probably get cursed for this but I would steer clear of the flex dobs in favor of a solid tube. Among the usual balancing problems I hear light scatter is also an issue. While you can transport a relatively large dob easily if it is collapsible you have the primary objective of getting the best views you can out of the scope. If this is going to be compromised even in the slightest it would not be money well spent. While I often wish for a larger scope I think any bigger than my 250PX and I'm going to have travel and storage issues. A 12" solid tube is there for out of the window. Would I compromise and have a flex tube so I can have that extra light grasp ? probably not. I'm sure all who have flex dobs get great views but are they as good as a solid tube ???

[garethmob]

i can see what you mean spaceboy, the gains of the flex do they outweigh the fails of what you can lose, i know u can get cloths like the astrozap or a camping mat to put there

is there any flex people who can help as well on their experiences

[Matthew]

I bought my 300p for £450 and its worth every penny.I would have loved to have bought the goto version but as we know its very expensive.However,ive bought a iphone holder and the GoSkyWatch app has a goto which is very accurate,its also very handy to have a interactive map of the night sky whereever you point your scope.

The biggest problems ive had with stray light is when theres a full moon but the astrozap cover has cured it.At the next valleys meeting your more than welcome to have a look gareth

[garethmob]

thanks taffy_2 althrough looking through a 300p might make me wanna upgrade again lol i hate cloudy nights cloudy = ebay

[acey]

i understand the difference between the 200 and 250 is 77% extra light but what exactly does that mean

I don't know where 77% comes from; the area ratio of 10" to 8" mirrors is 100/64 = 1.5625, i.e. 56.25% more light in 10".

What it means is being able to see stars just under half a magnitude fainter (5log(10/8) = 0.48), if both telescopes are compared side by side. How faint you actually see depends on the darkness of the sky. Going from an 8" to a 10", and not doing a side-by-side comparison, you might notice little or no difference in the view, though you'd notice the extra weight.

There is no inherent disadvantage of the open tube design - if there's a problem of dewing or stray light then you just wrap up the open section with a shroud. But most people seem able to manage a solid tube 10" well enough so it's questionable whether you need to go for a flex option for that aperture.

The 12" flextube is a big, heavy scope. If your 8" seems really small to you and you feel you've exhausted its possibilities then go ahead and upgrade but be prepared to exert far more effort in moving around a 12".

I went from 8" to 12" after using the 8" for several years and certainly don't regret it. But the 8" is the kind of scope I could use for a quick peek in the back garden, the 12" isn't.

Light ratio for 12" to 8" is 144/64 = 2.25 i.e a 125% increase. Magnitude difference is 5log(12/8) = 0.88. I could certainly see that difference when I upgraded. But the weight difference is even bigger.

[Matthew]

I agree acey,i had never seen the flextube untill the day i bought it and i was very supprised lol,but the extra effort is worth it.It wont hurt to have a peek gareth

[Nathan_Pembs]

However,ive bought a iphone holder and the GoSkyWatch app has a goto which is very accurate,its also very handy to have a interactive map of the night sky whereever you point your scope.

I've recently bought the GoSkyWatch app, but haven't got the holder or the chance to use it yet.

Is it really that accurate?

[Matthew]

It gets you pretty close,ive only used it for lunar and planetry work,what i did was get jupiter in the center of my 40mm e/p and set jupiter on the goto on the app and adjusted the holder untill it was central.Im going to use it in conjunction with my telrad but its a useful thing to have

[Mark at Beaufort]

I totally agree with everything that Acey has said. I have a 250mm flextube and its great. When I first obtained it I started to get dew on the secondary mirror so I made a shroud out of neoprene. I have since modified that and bought a lightbridge shroud which with a few alterations now fits.

My viewing area is about 30 metres from the garage where I store the scope. If I come home late and the sky is clear I prefer to grab the 6" Newt or the 4" APO frac and place it on an alt/az mount.

I keep my flextube fully open so I might as well have a fixed tube and save the money on a shroud.

Mark

[astrokat]

i love my flexi i made my shroud for a 10er and i have all the mods on the scope and there is plenty of room i would be interested in your pst if you do decide to sell