Okay, so I sold a 12" dob I bought off IIS some 12-18 months ago to keep in a caravan at my dark site. I'd originally wanted an 8" as it was the biggest I knew would comfortably fit through my caravan door (which is pretty narrow) but got offered a 12" at a good price. Let's just say that the base of that dob was larger in every dimension than the doorway! With some contortionist skills it could fit through safely but it was far from comfortable.
I've had it under the skies on three occasions and attempted views on two of those; all three times beaten by the elements. My entire property is clay so it holds water pretty well. First night the secondary dewed over while I was waiting for the primary to cool and I was doing some low powered observing.
Second attempt I capped the dob and left the fans running for a few hours and later found that the primary and secondary had a light amount of dew from the moisture being sucked up from the ground level. Third attempt had a nice breeze which staved off the dew but terrible seeing which limited me to some nice lower power views but the planets (which I wanted to do) were like looking up from the ocean floor.
I'd originally wanted a no fuss telescope to leave up there but between the dew issues and the utter pain of getting the dob from inside the caravan to outside I'm reevaluating my options.
I can go back to getting an 8" F/6 dob like my original idea OR leaving my HEQ5 up there as well and getting a C8 or a SW180. I'm largely not interesting in trying to chase down faint fuzzies but more interested in star clusters, luna and planetary.
Apart from tracking, is there going to be much that a SW180 or C8 is going to give over a stock SW 8" F/6?
Choose the right scope to suit what you want to observe.
I would suggest for a dark site the subjects of interest are DSO’s - nebulae and galaxies not possible in the city. Alternatively if in the city, it’s mainly lunar planetary and bright clusters (mak or SCT).
Having had all of these scopes at one time or another I can say the SW180 and C8 will show DSOs better than some might think but they can never match the wide fields of an f/6 newtonian of the same aperture. OTOH if magnification is your game, the SW180 should do better than others at high power on the planets, but the mak and SCt require a mount that tracks - so it’s really your call.
The dob is as simple as it gets. If you go with an SCT or the mak, you’ll have to assemble tripod, level the head carefully, mount, put scope on top, lug out a battery, connect the wires and handset, align with the pole etc before ready to observe. It takes me 39 minutes and that’s assuming I get it all right first try.
What’s more if you think dew is bad with a newtonian its much worse with an SCT. First mistake is attempting to cool the scope as far as you have done - which is why it dewed over.
Personal experience:
1. the SW180 is that it wont dew over so quickly as an SCT (lots of thermal mass in the thick corrector - which is a good thing).
2. Both SCT and mak should be insulated to stop them cooling - this very effective kills the internal tube current from the central baffle, and keeping them warm prevents them dewing over. Both will benefit significantly from a dewcap. Last resort - if the dew over - is a heater strap inside the insulation around the OTA, and a battery to power it.
You need to focus on the real problem which seems to be managing storage of the scope.
May I suggest that you leave the base outside under a cover and just put the ota in the van..the issues of dew can be sorted just as easily.
Alex
Choose the right scope to suit what you want to observe.
I would suggest for a dark site the subjects of interest are DSO’s - nebulae and galaxies not possible in the city. Alternatively if in the city, it’s mainly lunar planetary and bright clusters (mak or SCT).
Having had all of these scopes at one time or another I can say the SW180 and C8 will show DSOs better than some might think but they can never match the wide fields of an f/6 newtonian of the same aperture. OTOH if magnification is your game, the SW180 should do better than others at high power on the planets, but the mak and SCt require a mount that tracks - so it’s really your call.
The dob is as simple as it gets. If you go with an SCT or the mak, you’ll have to assemble tripod, level the head carefully, mount, put scope on top, lug out a battery, connect the wires and handset, align with the pole etc before ready to observe. It takes me 39 minutes and that’s assuming I get it all right first try.
What’s more if you think dew is bad with a newtonian its much worse with an SCT. First mistake is attempting to cool the scope as far as you have done - which is why it dewed over.
Personal experience:
1. the SW180 is that it wont dew over so quickly as an SCT (lots of thermal mass in the thick corrector - which is a good thing).
2. Both SCT and mak should be insulated to stop them cooling - this very effective kills the internal tube current from the central baffle, and keeping them warm prevents them dewing over. Both will benefit significantly from a dewcap. Last resort - if the dew over - is a heater strap inside the insulation around the OTA, and a battery to power it.
A cass of some description would ride on the HEQ5 which is a pre-SynScan but tracks well. I can eyeball PA to within a degree or so which is enough for observing with occasional recentering so mount setup is a minute or so.
One of my other considerations is exit pupil. I can binoviewing up to about 3mm but for mono viewing I like to keep below 2.5mm otherwise astigmatism becomes distracting on star clusters. Basically, my young eyes suck
95% of my trips to Heathcote are for AP but doing some visual between checking on everything keeps me happy. An 8” F/6 is easy to use no fuss visual and as you mention, dew on the corrector can be a pain. My first telescope was a 10” LX200 which I usually used on concrete to help stave the dew.
For DSOs they’re all the same aperture. For others the 8” dob is push to and has a much smaller CO and is optically simpler. The C8 and SW180 help with tracking and are binoviewer friendly but I’d probably do mono more often on these occasions anyway.
Quote:
Originally Posted by xelasnave
You need to focus on the real problem which seems to be managing storage of the scope.
May I suggest that you leave the base outside under a cover and just put the ota in the van..the issues of dew can be sorted just as easily.
Alex
If I was up there more often I’d consider it. Some months I’m up there a few times but other times months can pass. Largely depends on the weather and work
Hi, Atmos. I guess you could go with the 8" dob (and leave there) and on those nights you want planetary (with tracking) take your heq5 which should be fine if balanced ok. I get excellent planetary views with my 8" Parks. Cheers Richard
Hi Colin,
Perhaps you should buy yourself a Travel Newt so you can keep it in one of those tiny caravan cupboards, whip it out and observe mount free! http://www.kasai-trading.jp/zingaroe.html
I have a C8 and a 100mm refractor. The c8 is very light, more compact and much easier to carry out using the weight bar as handle, even when assembled with OAG and camera. Particularly when you take off any useless weight and finderscope and stick with a telrad.
The crisp wide field view through the refractor, is worth the effort , although it is like holding an overgrown baby and probably needs a handle. I have not owned any other scopes but I can see the attraction of a new fast Newtonian if the weight is manageable. I would like one of those for AP but they also look quite long and heavy.
How about a GSO 6” f6 newt on a HEQ5
It’s light , cheap ( $300 ) portable, a snack to collimate and provides great all round views and imaging of Clusters , nebulas , planets and moon
I think you have seen some my imaging work over the past 18 months with my 6” . Visually it is superb !!
My 2 cents .....
A cass of some description would ride on the HEQ5 which is a pre-SynScan but tracks well. I can eyeball PA to within a degree or so which is enough for observing with occasional recentering so mount setup is a minute or so.
One of my other considerations is exit pupil. I can binoviewing up to about 3mm but for mono viewing I like to keep below 2.5mm otherwise astigmatism becomes distracting on star clusters. Basically, my young eyes suck
95% of my trips to Heathcote are for AP but doing some visual between checking on everything keeps me happy. An 8” F/6 is easy to use no fuss visual and as you mention, dew on the corrector can be a pain. My first telescope was a 10” LX200 which I usually used on concrete to help stave the dew.
For DSOs they’re all the same aperture. For others the 8” dob is push to and has a much smaller CO and is optically simpler. The C8 and SW180 help with tracking and are binoviewer friendly but I’d probably do mono more often on these occasions anyway.
If I was up there more often I’d consider it. Some months I’m up there a few times but other times months can pass. Largely depends on the weather and work
I understand.
But if you are not there everything can be under threat.
I have learnt we only own what we can control..absense surrenders ownership.
Anyways maybe place land mines around the mount base that i suggest be kept outside...When imaging with time to observe I use 80mm binos which I prefer over everything else...3d effect etc..your photos are the close up..but cruising with big binos is hard to beat when imaging.
One of the most useful scopes I have is this, even used for birding and terrestrial with the Baader zoom eyepiece, and is perfect on my Gitzo tripod when camping
you mentioned astigmatism - I have the same, can't see a thing without my glasses. Maybe that's why I have just never enjoyed the views through any of my newts and ended up selling them. For me, I just can't beat the views through an ED refractor. On a home made alt az mount and manual setting circles, I can find anything quickly and it's fast to setup and take down. The 100mm generic ED is a pretty darn good scope for most things and I've always been surprised at what it can show when compared side by side with a larger reflector (except for resolution in clusters). For under 1K you could pick up a s/h ED80 for low power cluster and general viewing and something like a 127 Mak for the planets/double stars. Better still, a nice triplet 100mm.....but as you say, $$$ !
Hi, Atmos. I guess you could go with the 8" dob (and leave there) and on those nights you want planetary (with tracking) take your heq5 which should be fine if balanced ok. I get excellent planetary views with my 8" Parks. Cheers Richard
As long as the 8" dob moves smoothly it is possible with a bit of practice to hand track at 200x but it is definitely easier with the HEQ5 tracking.
Quote:
Originally Posted by AstroApprentice
Hi Colin,
Perhaps you should buy yourself a Travel Newt so you can keep it in one of those tiny caravan cupboards, whip it out and observe mount free! http://www.kasai-trading.jp/zingaroe.html
Pretty awesome but given I feel like I need extra stability with 10x50 binos I think this would absolutely do my head in
Quote:
Originally Posted by Sunfish
I have a C8 and a 100mm refractor. The c8 is very light, more compact and much easier to carry out using the weight bar as handle, even when assembled with OAG and camera. Particularly when you take off any useless weight and finderscope and stick with a telrad.
The crisp wide field view through the refractor, is worth the effort , although it is like holding an overgrown baby and probably needs a handle. I have not owned any other scopes but I can see the attraction of a new fast Newtonian if the weight is manageable. I would like one of those for AP but they also look quite long and heavy.
I do have a 100mm refractor and it does give exceptional views but it isn't something I'd want to leave up there. Maybe I just need to pack more into the car!
Quote:
Originally Posted by LewisM
Buy an Astroscan Portaball.
No, seriously
I haven't been able to find an Astroscan one but Mag1 is still making them with Zambuto mirrors. I've heard about them being talked about as stuff of legends with the views but also had mixed reviews in regards to hand tracking at high powers due to moving on 3 axis. Being 8" they're also not quite as expensive as I'd first expected.
I like the theory (TS have some "better" options) but I wouldn't touch Orion Optics with a barge pole
I'd probably also use an AZ-EQ6 for this so the EP doesn't go up and down on different sides of meridian hehe
Quote:
Originally Posted by xelasnave
I understand.
But if you are not there everything can be under threat.
I have learnt we only own what we can control..absense surrenders ownership.
Anyways maybe place land mines around the mount base that i suggest be kept outside...When imaging with time to observe I use 80mm binos which I prefer over everything else...3d effect etc..your photos are the close up..but cruising with big binos is hard to beat when imaging.
Alex
I'm currently sitting out with 10x50 binos and enjoy checking ou the Milky Way this time of year. Cannot go 250x on Jupiter with them though
Quote:
Originally Posted by Ukastronomer
Surely there is nothing more convenient, and time efficient than a refractor on an altaz mount
One of the most useful scopes I have is this, even used for birding and terrestrial with the Baader zoom eyepiece, and is perfect on my Gitzo tripod when camping
Smaller refractors are nice for wide field views but they do lack the aperture to well resolve globular clusters (my main visual telescope is a 4" refractor). Same as with the binos, you cannot push the magnification.
Quote:
Originally Posted by Hoges
you mentioned astigmatism - I have the same, can't see a thing without my glasses. Maybe that's why I have just never enjoyed the views through any of my newts and ended up selling them. For me, I just can't beat the views through an ED refractor. On a home made alt az mount and manual setting circles, I can find anything quickly and it's fast to setup and take down. The 100mm generic ED is a pretty darn good scope for most things and I've always been surprised at what it can show when compared side by side with a larger reflector (except for resolution in clusters). For under 1K you could pick up a s/h ED80 for low power cluster and general viewing and something like a 127 Mak for the planets/double stars. Better still, a nice triplet 100mm.....but as you say, $$$ !
I'm approaching -1 in my eyes astigmatism wise so while not horrendous (I observe without glasses just fine as long as the exit pupil is below 2.5mm) I'd guess that what you were running into is the difference between the focal ratio of an ED refractor and F/4-F/5 newt. if I use a 25mm eye piece in my 10" F/10 I am working at 2.5mm exit pupil which is my limit. In a 10" F/5 it's 5mm and I know I'll get double vision on planets and the sky will be full of the not good kinds of diamonds.
