is Travelscope 70 any good for a guiding scope ?

[Purplehayze104]

Hi All

just curious but could i use a celestron travel scope for a guide scope its got a 70mm aperture, 400mm fl, & a f5.7 trying to keep the budget down for my trip into imaging, also ordered every photon counts so looking forward to a bit of 'light' reading on me hols

[haitch]

Well if I can successfully guide with a 50mm finder and a Philips webcam in a light polluted back garden I'm sure you can get away with that.

[Stargazer33]

I have bought the Travelscope 70 for exactly that purpose. I haven't used it yet, but I intend to try any day (or should that be night!) now. I will be using an Orion Starshoot AutoGuider and PHD. All mounted on top of my C8 XLT.

HTH.

[Purplehayze104]

thanks for reply, sounds promising, got a fair bit of light pollution here too so glad it could work out ok, ive not thought of guiding with a webcam sounds like a good option

[Purplehayze104]

ive been looking into the orion starshoot guider myself to go with the travelscope for guiding purpose so be good to hear how you get one with it southerndiva357 been a reliable lil scope

[lensman57]

Hi All

just curious but could i use a celestron travel scope for a guide scope its got a 70mm aperture, 400mm fl, & a f5.7 trying to keep the budget down for my trip into imaging, also ordered every photon counts so looking forward to a bit of 'light' reading on me hols

Hi,

There is a similar thread with the same scope on the forum at the moment, my feeling is that at f5.7 it is slow for guiding unless you have a very sensitive guide camera. A 50 mm finder is about f3.7 and a lot lighter and faster and you probably already own one. The size of the aperture is almost irrelevant, you want a fast scope to guide with unless you have a scope with a very long focal length and that is another matter.

Regards,

A.G

[Purplehayze104]

thanks lensman57 appreciative comment, unfortunatley ive only got a 6 x 30 finder on my scope so an upgrade could be on the cards

[lensman57]

thanks lensman57 appreciative comment, unfortunatley ive only got a 6 x 30 finder on my scope so an upgrade could be on the cards

HI,

If you already have the 70 mm travel scope then give it a try, another way of making the 70 work for you is to purchase a 0.5X focal reducer, these are about £25.00 and fit a 1.25" nose piece, this in theory should bring the focal ratio down to F2.85 which is very fast. The only problem is wether the scope could achieve focus with the reducer in place. Good luck and keep us informed.

A.G

[haitch]

HI,

If you already have the 70 mm travel scope then give it a try, another way of making the 70 work for you is to purchase a 0.5X focal reducer, these are about £25.00 and fit a 1.25" nose piece, this in theory should bring the focal ratio down to F2.85 which is very fast. The only problem is wether the scope could achieve focus with the reducer in place. Good luck and keep us informed.

A.G

can I hear a hacksaw in the background?

[Steve Ward]

I use a Mercury 705 , 70/500 ( f 7.14 apparently ) with a Synguider and have no problems with it ...

[Purplehayze104]

I use a Mercury 705 , 70/500 ( f 7.14 apparently ) with a Synguider and have no problems with it ...

do you have much grief with the synguider as ive been curious to hear about one from someone who uses one, read some reviews but mostly bit pessamistic about it ?

[Steve Ward]

I love it ...

Consistently gets me 20 minute subs , no point me pushing it further with a DSLR , although I've tested it to 30 mins.

Easy to set up , self-calibrating , no graphs to worry about .....

[Purplehayze104]

I love it ...

Consistently gets me 20 minute subs , no point me pushing it further with a DSLR , although I've tested it to 30 mins.

Easy to set up , self-calibrating , no graphs to worry about .....

thanks for the info, that would be a handy peice of kit as ive not got use of a laptop and was thinking i may have to invest in one certainly work out cheaper than a lappy an guide cam get up

[lensman57]

thanks for the info, that would be a handy peice of kit as ive not got use of a laptop and was thinking i may have to invest in one certainly work out cheaper than a lappy an guide cam get up

Synguider is fine with an F5 scope on a dark site with average seeing conditions, or somewhere withouht the use of a laptop perhaps , the sensor is only 1/4" format therefore has a very narrow Fov. I have one, used it a couple of times and decided that it was not worth trying to be a contortionist to use one near the zenith as the screen is not rotatable. Try and focus and get the exposure right on a very small and dim orange screen while your neck is twisted upwards. A dedicated planetary - guiding camera with a laptop is a much more practical proposition. There are quite a few of these Synguiders on Astro buy and Sell for about £160.00, I guess this tells you something.

A.G

[Steve Ward]

Just stick it in a diagonal ...!!! .... ... you wouldn't look through an EP straight through when facing the zenith , doesn't mean you should dump the EP....

It works out for itself its orientation in Auto-calibrate ....

[lensman57]

Just stick it in a diagonal ...!!! .... ... you wouldn't look through an EP straight through when facing the zenith , doesn't mean you should dump the EP....

It works out for itself its orientation in Auto-calibrate ....

HI,

I am using a 50 mm finder to save weight as my set up is mobile and can not carry the weight of an ST80 and the scope and other bits and pieces. With the 50 mm finder and a diagonal Synguider can not achieve focus. I dont know how this would work with an upright finder though as anything that helps to get rid of all the wires and PHD must be a good thing.

Regards,

A.G

[Daddystu]

HI,

If you already have the 70 mm travel scope then give it a try, another way of making the 70 work for you is to purchase a 0.5X focal reducer, these are about £25.00 and fit a 1.25" nose piece, this in theory should bring the focal ratio down to F2.85 which is very fast. The only problem is wether the scope could achieve focus with the reducer in place. Good luck and keep us informed.

A.G

I use a travelscope 70 and reducer. The reducer in fact allows you to bring the image into focus. Without the reducer both the QHY5 and my webcams wont reach focus without an extension of some sort. To the OP: Yes you can successfully guide with it. To maximise the FOV you'll want the reducer and preferably a 1/2" sensor ie QHY5. Also, i'd suggest mounting it in 110mm or 125mm guidescope rings as this gives you a good bit of 'wiggle room' to find a guidestar. Don't stray too far though as the guide correction accuracy will decrease.

[ollypenrice]

F5.7 sounds OK to me for guiding. Like hundreds of others I guide with the ubiquitous ST80, F5.

I'm not a fan of the standalone guiders. Some people get good results, some don't. When you have guiding issues - and they can just appear out of the blue - you need control and you need information to see what is going wrong.

Olly

[Purplehayze104]

thanks you all for replys on this subject certainly thinking of using it now for guiding, probably with a QH5Y camera & focal reducer, (list of purchases getting longer) all be worth it in the end (fingers crossed)

[Twisted Lip]

I use a Mercury 705 , 70/500 ( f 7.14 apparently ) with a Synguider and have no problems with it ...

Steve - you have just become my hero lol. I've had one for about 6 months and really struggled to get it working, in fact I've never managed to get it to find a star. I've always assumed it was because my guidescope was rubbish and so I've just picked up a Star Watcher ST80 to try it with. Any advice welcome!

Cheers

Will