Upgrading an Orion ST80 guiding 'scope, or start all over again?

[choochoo_baloo]

(I have read similar threads about this, but nothing quite answers my question, so I feel it warrants starting a new thread )

I am a relative newcomer to astrophotography, and have been fiddling about with my Orion Short tube 80 achromatic guide scope. Whilst using the PHD 2 drift align tool, I noticed very obvious 'traingular' type stars whilst focusing on very bright ones e.g. Vega, and generally medicoce resolving of a star field. Don't get me wrong, I fully expected this with a cheap achromatic refractor.

Therefore I'm now assuming this is going to inhibit guiding my performance going forward. Therefore as an upgrade I see two possibilities:

1. Replace the stock focuser on the Short tube 80, to get that rigidity and fine control. Though the FLO advertsided ones run into £100s.....

2. Buy a whole new guide scope system. This makes me wonder whether to save up for a doublte ED - i.e. really going for the resolving ability - like this bad boy: http://www.teleskop-express.de/shop/product_info.php/language/en/info/p1151_TS-INED-70mm-f-6-Refraktor-Reiseapo---Carbon-Tubus---2--Crayford-Auszug.html, or the smaller/popular Altair achromatic 60 mm finder with the focuser upgrade.

 

Any advice gratefully received.

[Davey-T]

It should be fine for guiding, PHD isn't too fussy about the star shape, there is a video on Astronomy Shed on how to fettle the focuser.

I have an Altair 60mm with helical focuser and the focuser is crap, I ended up locking it fully in and adjusting the guide camera using a parfocal ring.

Dave

[choochoo_baloo]

8 minutes ago, Davey-T said:

...there is a video on Astronomy Shed on how to fettle the focuser.

Please can you link the video - knowing me I may well end up watching the wrong one!

[Thalestris24]

9 minutes ago, Davey-T said:

It should be fine for guiding, PHD isn't too fussy about the star shape, there is a video on Astronomy Shed on how to fettle the focuser.

I have an Altair 60mm with helical focuser and the focuser is crap, I ended up locking it fully in and adjusting the guide camera using a parfocal ring.

Dave

Hi

Is that one of the 'guidescopes' AA say you shouldn't use as a guidescope?

Louise

[steppenwolf]

46 minutes ago, Davey-T said:

I have an Altair 60mm with helical focuser and the focuser is crap, I ended up locking it fully in and adjusting the guide camera using a parfocal ring.

I did the same with mine!

The ST 80 is fine as a guide scope and furthermore, focus for guiding is not critical - in fact there is an advantage to having the guide star slightly out of focus as it is easier for the guide software to find the centroid. More critical is clamping the focuser down tight and leaving it that way once focus is achieved to minimise ant chances of differential focus. To help make the original focuser more 'solid' bearing in mind that you won't be changing its focus position that often, wash up a 2 litre plastic bottle of milk and cut the plastic into strips and use these to shim the draw tube - works a treat!

[Davey-T]

1 hour ago, choochoo_baloo said:

Please can you link the video - knowing me I may well end up watching the wrong one!

http://www.astronomyshed.co.uk/forum/viewtopic.php?f=19&t=4258

Dave

[Dave In Vermont]

The ST80's are capable of excellent AP - as well as great fun visually. And many of us pamper and love 'em enough to say "To heck with the price!" and buy these for them:

 

 

Congratulations on your purchase! You'll see what I mean.

Dave

 

 

[SonnyE]

Oh, I am sure you will have to get the TS 70. You won't rest until you do.

I have to wonder why you feel the need, but it isn't my problem...

[Alien_Photons]

The triangular stars are pinched optics. There is a ring on the top off the lens cell back this off a bit it only needs to be a bit more than finger tight.

Its great for guiding, wide field visual and travel. Put a badder neo in it and you will get a good look at the planets too.