Skywatcher Startravel 102 AZ 3

[happy-kat]

There is a new combination, FLO now do the ST102 on the all new Skywatcher AZ5, it has slow mo controls and looks a better head for balancing, hopefully SGL member John will be writing a review of the mount very soon. Oh though that price is quite a bit higher than the AZ3 combo.

link here

 

[Alan White]

@happy-kat the ST102 AZ5 combo looks good, but looks to lack mounting rings, perhaps a direct fitted dovetail to the tube, mak style going on?

 

[happy-kat]

It does look like that, my ST80 has a dove tail bar fitted and that also includes 3 tripod thread holes.

[Stub Mandrel]

I'm surprised no-one has mentioned 'fringe killer' and 'semi-apo' filters which (according to user reviews) work wonders on the Startravel scopes.

Also I've seen claims that the CA reduces as you increase magnification with the S=larger ST scopes, suiting them to planetary work.

That said although I've seen some, I've never actually looked through one...

[happy-kat]

I guess sometimes i doesn't always fit a thread but chromatic aberation has been mentioned several times already on the thread.

[Stub Mandrel]

1 minute ago, happy-kat said:

Chromatic Aberation had already been mentioned 5 times on this topic.

Exactly, but I didn't see a mention of the filters that appear to control it on these scopes?

[happy-kat]

Ah you were too fast I changed my post :-) I don't use a filter on my ST80 can't say I find CA noticeable  on the Moon though it was noticeable on Jupiter but strangle not solidly I had moments on what I recall as being none but if I used the supplied 10mm is was strong.

[Mangleworsle]

I found the same with the included 10mm on my 102, but when using a Skywatcher Ultra Wide 6mm it virtually disappears, so it would seem that it's that particular eyepiece.

[cloudsweeper]

The Startravels are great 'scopes - the widefield views (especially with the smaller ones) are a strong point, although the magnifications are low and the exit pupil is large at low power.  Still good for viewing and hopping though!

I have the 120 with the advantage of a slightly bigger aperture, and it is still very easy to manage and have up and running on the AZ-4 in no time at all.  I put a Crayford DS focuser on it, making it a very pleasing package!

As for CA, I only notice it on the brightest objects, and for them you can mask off most of the aperture to remove it anyway if it is a concern.

Doug.

 

[Mangleworsle]

1 minute ago, cloudsweeper said:

The Startravels are great 'scopes - the widefield views (especially with the smaller ones) are a strong point, although the magnifications are low and the exit pupil is large at low power.  Still good for viewing and hopping though!

I have the 120 with the advantage of a slightly bigger aperture, and it is still very easy to manage and have up and running on the AZ-4 in no time at all.  I put a Crayford DS focuser on it, making it a very pleasing package!

As for CA, I only notice it on the brightest objects, and for them you can mask off most of the aperture to remove it anyway if it is a concern.

Doug.

 

I bought the Starwatcher Auto-Focus Unit and it's really transformed my focusing, (my shaky hands).  really wouldn't be without it now, and recommend it to all who's hands aren't as steady as they once where, and those who have problems focusing.

[Alan White]

I like my ST80 a lot, just the focuser that is mediocre to terrible.
As for CA, so what, grew up with it on scopes, I can ignore it and observe happily.
Very tempting at ST120 though.

[happy-kat]

I bought one of those Baader helical focuser it is small and seemed worth a try on the ST80 to give something to use for tweaking final focus.

[Stub Mandrel]

1 hour ago, Mangleworsle said:

I found the same with the included 10mm on my 102, but when using a Skywatcher Ultra Wide 6mm it virtually disappears, so it would seem that it's that particular eyepiece.

That fits with the 'increased mag=less CA' that some people report.

[Mangleworsle]

The other eyepiece I have bought is a Revelation Astro 40mm eyepiece projection unit. It is so bright viewing the moon last night it took me completely by surprise ( I really can't believe how eyepieces have come on in the past 20 years) and again no discernible CA, when I coupled it with a 2X Barlow the view was outstanding.

I would appreciate any advice on other eyepieces for the ST102. Plus I am also thinking about getting an Astro DSLR, again any comments?

Sorry about the gushing but things have just got so much better since I was last involved with Astronomy.

Jim

[happy-kat]

Eyepieces such choice but to help suggestions what is the budget per eyepiece and what focal lengths do you already have and have you read the what do I need to know about eyepieces thread. link here

Unfortunately a dslr will absolutely show the CA like a neon paint brush but post processing can help there.

[Mangleworsle]

Hi happy-kat,

I currently have the 10 & 20mm that came with the scope (ST102) plus the 2X Barlow.

I have bought a 3 & 5 Barlow.

A 6 mm Starwatcher Ultra wide, not the plantary version.

A 40 mm Relelation Astro camer a projection eyepiece

And a 12 mm illuminated graticule eyepiece for initial setting up.

Thanks

Jim

[nightfisher]

18 hours ago, Alan White said:

I like my ST80 a lot, just the focuser that is mediocre to terrible.
As for CA, so what, grew up with it on scopes, I can ignore it and observe happily.
Very tempting at ST120 though.

Alan, have you thought about the bresser 102 F5 with hexa focuser

[Alan White]

Just now, nightfisher said:

Alan, have you thought about the bresser 102 F5 with hexa focuser

I have Jules, but don't like the Bresser finder foot being non standard.

[ollypenrice]

On 12/07/2017 at 18:29, laudropb said:

I never put too much faith in the reviews in the Astro mags. Never seem to give a truely bad review. 

 

There may be an innocent explanation for that. When I wrote reviews I simply declined to review equipment which I knew from experience to be bad. Doing a review is very disruptive to one's own observatory and I simply never wanted to waste my time on stuff I didn't trust. Even so, I had a manufacturer complaining that my review of their product was luke warm and sounded grumpy. The magazine editor backed me and published with one small alteration which I was happy to accept.

More generally the slower Skywatcher achros are not expensive and have a lot to be said for them. I have the 6 inch F8 which is pretty good.

Olly

[Davey-T]

5 minutes ago, ollypenrice said:

There may be an innocent explanation for that. When I wrote reviews I simply declined to review equipment which I knew from experience to be bad. Doing a review is very disruptive to one's own observatory and I simply never wanted to waste my time on stuff I didn't trust. Even so, I had a manufacturer compla

Here's a case in point, the revues of this have been very variable, some unhappy, some raving about it.

Dave

https://www.firstlightoptics.com/vixen/vixen-vsd-100-f38-flat-field-refractor.html

[Chris]

3 hours ago, Alan White said:

I have Jules, but don't like the Bresser finder foot being non standard.

I don't know how easy it would be to attach an RDF to the carry handle? it appears to be threaded for a camera adapter. You can also swap the Bresser shoe for a Synta one I've heard.

I've owned a couple of Bresser achromats and found the optics to be very good, although mine were f/9.4 and f/13 scopes, not the 102mm f/5.9. The Hex focuser on my AR127L was very nice for a stock focuser...Skywatcher take note! 

https://www.firstlightoptics.com/bresser-telescopes/bresser-messier-ar-102s-600-refractor-ota.html

[happy-kat]

@Mangleworsle I would draw a simple spreadsheet up with the eyepieces and barlows you have including columns for magnification and exit pupil. For example you 10ml with x5 barlow gives 0.4mm exit pupil that is very small! A smaller sharper view is easier on the eye then larger softer. I would use the eyepieces you have with the different barlows to work out what magnifications you use the most and then buy an eyepiece to match what you use.

I have only one barlow 1.6x and prefer to use straight eyepieces personally.

[Mangleworsle]

Thanks Happy-Kat, going to have to revive my spread  sheet skills. I can see your reasoning so will get on with it, however not sure how to get to get exit pupil but am sure the formula will be in one of my books.

Thanks again

Jim

[cloudsweeper]

51 minutes ago, Mangleworsle said:

Thanks Happy-Kat, going to have to revive my spread  sheet skills. I can see your reasoning so will get on with it, however not sure how to get to get exit pupil but am sure the formula will be in one of my books.

Thanks again

Jim

Eyepiece focal length divided by telescope focal ratio (f-no.).

Range generally about 0.5mm to 7mm.  For decent contrast, you want about 2mm to 4mm.

You can go higher than 7mm, but that effectively wastes light (misses the pupil).

Doug.

[davyludo]

58 minutes ago, Mangleworsle said:

Thanks Happy-Kat, going to have to revive my spread  sheet skills. I can see your reasoning so will get on with it, however not sure how to get to get exit pupil but am sure the formula will be in one of my books.

Thanks again

Jim

I have to look up equations on Google ALL the time. You'd think I'd remember them after the 20th time.... 

Anyway - aperture/magnification = exit pupil.

So 100mm aperture and 100x mag gives a 1mm exit pupil.