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bomberbaz

budget telescope (frac) for AV

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Hello all.

I am considering getting a lower costing frac for AV and then slapping it on a AZ goto mount. The scope I was thinking of was this http://www.amazon.co.uk/Bresser-telescope-Messier-AR-127S-635/dp/B0029VL9N0/ref=sr_1_27?ie=UTF8&qid=1434309609&sr=8-27&keywords=bresser+messier+telescopealthough I am open to suggestions. Thing that attracts me to this are FL OF 635 giving me a decent fov (approx 0.47, or 0.64 with just a .75 reducer), aperture 5" for decent light gathering and I can still strap it on a decent AZ mount such as the Nexstar mount http://www.365astronomy.com/Celestron-NexStar-SE-6-8-Mount-and-Tripod.html

Any thoughts would be welcome but I think that I am heading this way.

Oh I don't really know about fracs that well, although I am happy to get a fringe killer rather than shell out more for a higher range version frac. Some of them look beautiful and scary at the same time.

Steve

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Steve, i dont think that scope/mount combo would work, i recently sold the same mount unused to to the limits of what ota`s it would take

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How do you mean Jules, was it overloaded and if so, what was you putting on  it please (ota & weight).

BTW there are 2 versions of this mounts, the Nexstar 4,5 version and the 6,8 version.

Steve

Edited by bomberbaz

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I think the problem will be finding an alt-azimuth mount sufficiently *heavy duty* for a refractor of that size. Whereas the mount you cite is probably fine (indeed is used for!) for shorter OTAs - like an SCT, a 5" short tube 'frac you propose has a significant *inertia* in a longer OTA to overcome each time the motor starts. Plus it is not clear the focusser of a balanced setup would clear the mount as the telescope approaches the zenith. :)

Aside: I had "great hopes" for the Mk.I Ioptron minitower alt-azimuth mount... but the small motor burned out, even with a (within the load limits) MAK150 aboard. The Mk.II version is supposedly more robust. Sadly, with a larger scope, you are probably limited to a EQ mount. However...

I will be using the (hopefully repaired) Ioptron with my new (just purchased!) Altair Astro ED 66mm f/6. It only weighs a couple of kilos! Sure, I lose a factor or 10x light (2.5 mag) wrt to the 8" f/4 Newt, but I am already able to get good images of larger open clusters which tend to be brighter. I can also recover light by focal reducing the f/6 400mm, which looks quite tolerant (coma free) with a 0.5x Atik.  

To show that it is possible to (video) image with SMALLER apertures here

is the sort of stacked image (warts and all!) I get, with no real practice... :p

M27:

post-539-0-74275700-1434339512.jpg

M71:

post-539-0-77846000-1434339575.jpg

The PURPOSE here is not to show the faintest objects, but rather to place

(larger) objects into context with background. The field is about ONE deg?

There are still quite a lot of faintish "milky way" stars in the background,

which I can "process up"? And if I get a Lodestar or Watec 910XH, I can

recover another factor of 4x in light...  ;)

Sadly no scope is going to be a do-all device. I appreciate the constraints

of a limited budget! I still need an 8" f/4 Newt, MAK150 and now the new

66mm ED to cover all the image scales I need... For really wide stuff, I

use couple of my late Dad's old (70's manual) SLR lenses. :)

Edited by Macavity

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To explain, the scope you link to is to long, this is what i found with the 130p ds on this mount (SE8) there will always be a danger of sending it to a target and it jamming the ota focuser into the base of the mount, i have reverted back to an EQ5 with dual axis motors and really like it

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Thanks guys, got it.

Guess if I go the way I am thinking of then its a EQ 5 then, not that its that big a faff but i just prefer az.

Ok time to ponder again, no rush anyway.

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Thanks guys, got it.

Guess if I go the way I am thinking of then its a EQ 5 then, not that its that big a faff but i just prefer az.

Ok time to ponder again, no rush anyway.

Steve, have you considered the AZ EQ6?  I have never got to grips with Polar Alignment and always use Alt Az but having the AZ EQ6 I do have the option should I ever need it.  

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nice mount but to pricey, i think even 2nd hand it will be more than I am willing to pay. A EQ5 pro would just meet the weight carrying capacity i think i will need although the heq5 would be better. Like i said, no rush although i agree with you shirva, the ota is nice.

What does anybody think to this as a scope to get along with until I can afford to upgrade at a later date if i wants to :  http://www.opticstar.com/Run/Astronomy/Astro-Telescopes-Opticstar.asp?p=0_10_1_1_225 At F6.6 i think CA would be manageable and at 102mm aperture I still think views would be reasonable. 

Just a thought

Steve
 

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One thing interests me - A comparison between a small (lowish cost) fast [ED doublet] semi-APO

and a typical (slightly larger) fast Achromat. But, I guess I am now in a position to do that myself.

If I conclude anything, I'll let you know (Apologies for over-excitement. Rare I get a new scope)! :p

A thought... My ultimate choice Altair Astro  Lightwave 66 was dictated partly by a desire to use it

mounted atop my MAK150. I sense this will be perilously close to the HEQ5 weight limit though. :o 

If I was looking for a stand-alone scope, despite the above, I might consider a tad greater aperture

for a wide-field [Video Astronomy] refractor. After all, every scrap of available light helps us... :) 

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Sit tight for a doublet..you will be much happier. .ca wise

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One thing interests me - A comparison between a small (lowish cost) fast [ED doublet] semi-APO

and a typical (slightly larger) fast Achromat. But, I guess I am now in a position to do that myself.

If I conclude anything, I'll let you know (Apologies for over-excitement. Rare I get a new scope)! :p

A thought... My ultimate choice Altair Astro  Lightwave 66 was dictated partly by a desire to use it

mounted atop my MAK150. I sense this will be perilously close to the HEQ5 weight limit though. :o

If I was looking for a stand-alone scope, despite the above, I might consider a tad greater aperture

for a wide-field [Video Astronomy] refractor. After all, every scrap of available light helps us... :)

Be interested to read the results once they are in Chris. I will hold fire for now until; they are in and also as something else has given me food for thought.

One thing I haven't tried yet is an aperture mask on the existing 300p. Doesn't help the FOV but it may cure the exposure issue which has been annoying me and would certainly be a lot cheaper and less messing. Still more faffin though. 

Still kinda leaning towards a frac though

Damn this hobby can be so much fun whilst still being so flipping frustrating  :rolleyes:  :smiley:

Edited by bomberbaz

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Hi Steve,

Have you looked at the Lunt ED line of scopes? I have the 70mm, works well with the Lodestar for wide field viewing/imaging. They also make a 80mm, 102mm at very reasonable prices.

Stick one on an AVX mount and you are ready too go!

Richard

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Hi Steve,

Have you looked at the Lunt ED line of scopes? I have the 70mm, works well with the Lodestar for wide field viewing/imaging. They also make a 80mm, 102mm at very reasonable prices.

Stick one on an AVX mount and you are ready too go!

Richard

Thanks Richard, good option there although Lunts are kinda thin on the ground in the UK.

That said, I have still been thinking about this a bit still with the, "there is no rush" statement ringing in my mind and then though about this; http://www.opticstar.com/Run/Astronomy/Astro-Telescopes-Opticstar.asp?p=0_10_1_1_235as an OTA. 127mm gives me bags of aperture at the right focal length, a quadruplet should be well corrected at F4.9  and going off the specs and off what extra I would be putting on it weight wise which isn't a lot, an EQ5 would be sufficient to deal with the weight.

OTA would probs be a new purchase as I have never seen one for sale and cant find one in archives. The EQ5 however should come up at some point 2nd hand.

So yeah, leaning towards this at the moment.

Steve

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Indeed it does stash but the opticstar version is a F4.9 quad lens version whereas the bresser version does not state the lens number but I assume its two and as such will not be as well corrected.

Steve

note, sent an email to find out

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A couple of things come too light since starting this post and gives good reason for not rushing into things. I found some old images of the ring neb taken with same set up as i have now that had no expisure issues, so its user problem not equipment. The opticstar quad would still suffer some ca although how bad is hard to say, probs not as bad as the bresser of similar design but it would have a nice flat field due to 2nd set of corrector lens. I have no idea what i am going to do now regarding a frac, if indeed anything so its on the backburner until i have exhausted experimenting with the current setup.

Steve

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