Looking for a suitable telescope for a mobile setup

You should define breaking the bank…

But I would definitely recommand a refractor around 70mm like the Askar FRA400 at $1200 or SQA70 at $1600

https://www.sharpstar-optics.com/Products_1/34.html

https://www.sharpstar-optics.com/Products_1/SQA70.html

They are both easy to carry in a backpack, even on a plane…

Askar SQA 55 is a very portable scope and compact and comes with a hard case. At f/4.8 it has a wide angle view and doubles as a telephoto lens as well

A versatile OSC like ASI 533 MC pro is a good match for this scope

Both are quite light on the wallet as well

OAG has some issues with wide field refractors and small sensor like IMX 533 especially if you are using filters.Pls check some videos available on You Tube for feedback from some experts

My comment was specifically towards using OAG on Askar SQA55. Because of its compact nature and focal length of 264 mm, I was strongly recommended not to go for OAG as the FOV for the prism is small and sometimes it is difficult to find Guide stars

Agree with ASI 533 MC part. There is no issue at all and mine works beautifully also.

I like refractors myself. For a lot of reasons. But when starting out ~15 years ago now, I decided I like DSO Nebula specifically. And a fellow suggested a refractor, and a smaller one. The difference then was my 80mm was $1000. The next step up was a 100mm at $2500.

So I began with an 80mm triplet. Of everything I began with only two things still are working today, the original 80mm triplet, and the little 50mm guide scope.

I tried for two months with 2 different OAG’s. But neither one would work with my telescope. A vendor told me at the time OAG are meant for reflectors like SCT’s or the like. So I returned my last OAG and got a guide scope for my guide camera I had purchased. The result was immediate, my guiding turned on like a lightbulb. Been there, done that, still use a Guide Scope and Camera today even with my 130mm Triplet refractor. (Check out the price) And the 80mm, it lives with the last 3 grandkids for visual Astronomy. They love it!

I think my next telescope (if ever) will be a Petzval. But right now, they are just beginning to lose their ridiculous prices. But that is what I would be looking for.

The practical difference between my picturds with the 80 and the 130 is FOV. I like the closer, tighter FOV my 130 gives me. I did ~9.5 years with my 80mm before upgrading to the 130.

As vendors go, the Astro Tech line offers a lot at a reasonable price.

SonnyE · Jan 20, 2026, 03:44 PM

I tried for two months with 2 different OAG’s. But neither one would work with my telescope. A vendor told me at the time OAG are meant for reflectors like SCT’s or the like. So I returned my last OAG and got a guide scope for my guide camera I had purchased. The result was immediate, my guiding turned on like a lightbulb. Been there, done that, still use a Guide Scope and Camera today even with my 130mm Triplet refractor. (Check out the price) And the 80mm, it lives with the last 3 grandkids for visual Astronomy. They love it!

A bit off topic, but how did they not work? The vendor who told you that they are meant for reflectors or SCT’s are wrong, or perhaps you misunderstood - as OAG’s are definetly necessary/very useful with those kinds of telescopes to avoid flexure. They will absolutely work well with refractors though, I’ve been using them for years.

OAG’s are quite simple really but often made out to be complicated. You need a couple of things right though:

1. Get a mini camera, not a puck.
Some pucks will work but you’re making it a lot harder on yourself as the sensor often needs to be closer than the puck-shape allows. Larger sensors and prisms will be beneficial as they give a larger field of view for your guide camera.

2. Sensor distance needs to match that of your main camera.
Bring your main camera into focus roughly match the distance to your guide camera sensor, then do fine tuning with a helicoid. If you perform autofocus both cameras will be in focus. Also, doing this in daytime can be beneficial - though I don't find that it matters much.

Jan Erik Vallestad · Jan 20, 2026, 04:20 PM

SonnyE · Jan 20, 2026, 03:44 PM

I tried for two months with 2 different OAG’s. But neither one would work with my telescope. A vendor told me at the time OAG are meant for reflectors like SCT’s or the like. So I returned my last OAG and got a guide scope for my guide camera I had purchased. The result was immediate, my guiding turned on like a lightbulb. Been there, done that, still use a Guide Scope and Camera today even with my 130mm Triplet refractor. (Check out the price) And the 80mm, it lives with the last 3 grandkids for visual Astronomy. They love it!

A bit off topic, but how did they not work? The vendor who told you that they are meant for reflectors or SCT’s are wrong, or perhaps you misunderstood - as OAG’s are definetly necessary/very useful with those kinds of telescopes to avoid flexure. They will absolutely work well with refractors though, I’ve been using them for years.

OAG’s are quite simple really but often made out to be complicated. You need a couple of things right though:

1. Get a mini camera, not a puck.
Some pucks will work but you’re making it a lot harder on yourself as the sensor often needs to be closer than the puck-shape allows. Larger sensors and prisms will be beneficial as they give a larger field of view for your guide camera.

2. Sensor distance needs to match that of your main camera.
Bring your main camera into focus roughly match the distance to your guide camera sensor, then do fine tuning with a helicoid. If you perform autofocus both cameras will be in focus. Also, doing this in daytime can be beneficial - though I don't find that it matters much.

15 years ago that was exactly what the rep told me. And I wasn’t buying cheap OAG’s either.

Going to a guide scope did give me instant guiding success. And the only changes I’ve made was to replace my original guide camera with a ASI290MM Mini. Then, because it worked so good, I upgraded my guide scope to a 60mm, from my original 50mm. Which was huge at the time.

Not to mention my guide scope isn’t plagued with filter changes. And if you ever saw my setup you’d see there is no room for flexure in it. But hey, enjoy your OAG. I enjoy not having the problems and short comings of them.

bigCatAstro · Jan 20, 2026, 04:26 PM

Jan Erik Vallestad · Jan 20, 2026 at 12:07 PM

Personally I wouldn’t have chosen the doublet over a SV555 or perhaps one of the upcoming new versions. SV545 or SV535 if you want to go really wide.

Totally agree and I personally know since I used to image with the SV503 80 ED and it suffers from pretty bad chromatic aberration. The SV550 80APO is what I’m using now and it’s a world of difference. My last three images were taken with the SV550 80APO.

That is why doublets are passe for imaging. Good when they were all that was available, but surpassed by Triplets, and now Quads. I’ve used triplets all along, because I don’t want to pay the whorehouse price they charge for the Quads.

Jan Erik Vallestad · Jan 20, 2026, 04:08 PM

Aloke Palsikar · Jan 20, 2026, 03:13 PM

My comment was specifically towards using OAG on Askar SQA55. Because of its compact nature and focal length of 264 mm, I was strongly recommended not to go for OAG as the FOV for the prism is small and sometimes it is difficult to find Guide stars

Agree with ASI 533 MC part. There is no issue at all and mine works beautifully also.

You would not struggle to get guide stars with a 264mm FL scope, quite the opposite as you get a larger field of view in the first place. With long focal lengths (though often a necessity) it can become an issue however because you have a smaller field of view, and a prism with limited size. The prisms have various sizes but either would work on short focal lengths.

I have a SQA55 and even if now I use a smaller guiding scope on top, at first I used the SQA55 with a cheap Omegon OAG I had for years and probably never used before.

I was using a camera with an IMX585 sensor and it was better to rotate the OAG so that the prism was perpendicular to the long side of the sensor to improve illumination, maybe because this OAG is fairly long.

In PHD2 the stars were strangely oblong but I was able to guide no problem, so I can confirm you can use the SQA55 with an OAG!

I have to say that now, with a guide scope (TS 50mm F3.6, nothing special), I can guide ~0.15” better than with the OAG (as reported by PHD2) on my A5MN, but not sure this reflects much on the subs quality as the field of view is so wide and the resolution is ~1.5 arcsec/pixel anyway.

Said that, the quality of the SQA55 optics is outstanding, flat field and small pinpoint stars to the edge of the sensor (the biggest one I use is an IMX571). The only minor gripe is the autofocus motor setup that is a bit complicated compared to a scope with a normal focus knob, but I strongly recommend the little silver beauty!