The surest way to improve any telescope’s performance is to get it out under a darker sky. Living in suburban Massachusetts I’d have to drive significant distances to get to skies much darker than the one available from my red zone backyard. The darkest skies I regularly encounter are on family trips to rural areas.
Of course trying to fit a telescope into a car already packed with the whole family and all the associated cargo can be a challenge. Thus begins the search for a more portable telescope or travelscope. To my thinking a travelscope can be any telescope setup that prioritizes volume and/or weight over other concerns such as aperture or mount stability. Every one has their own circumstances and priorities and so travelscopes can look quite different from observer to observer.
As I mentioned in the general review of the AWB OneSky Telescope, my intent when buying the OneSky was to use it primarily as a travelscope. The OneSky appealed to me for its packed aperture to volume ratio and ease of setup.
The OneSky’s collapsible tube packs 5″ of aperture into a 16″ long package and the helical focuser has a very low profile. A Celestron C5 provides similar aperture in even less volume and weight but the OneSky has the advantage of going over 1º wider with a 32mm Plossl.
There are custom built travel Dobsonians that provide 8″ of aperture in a package not much bigger than the OneSky. These are impressive designs but they prioritize aperture over ease of setup, which is not what I am looking for right now. Compared to a solid tube reflector the OneSky requires maybe an extra 10 seconds to extend the OTA. Perfect.
The scope seems to maintain collimation relatively well over several sessions. When a collimation touch up is required the scope’s length makes it extremely easy as I can look through the collimation eyepiece and simultaneously reach the adjustment screws for the primary mirror cell located on the back of the OTA.
A simple travel eyepiece set of consisting of a 32mm Plossl, 8-24mm zoom, and 2.25x Barlow covers the scope’s capabilities pretty well with a max TFOV of 2.5º at 20x and high power of 180x. “Pleiades to planets” as they say. They do say that don’t they?
The OneSky’s provided base is too bulky for me to travel with so a mount that packs smaller is needed. The telescope’s standard Vixen-style dovetail allows it to be used on a variety of astronomical mounts without modification. I use it on a Bogen 3011 tripod with a UA DwarfStar head. The mount weighs 6lbs and collapses to 28.5″ long.
I find the DwarfStar to work well with the scope and when it is balanced the movement is very smooth. I think a sturdier tripod would be more beneficial then a beefier head for this setup but for travel use my preferences tend toward keeping it small and light. Viewing at 180x isn’t bad in terms of vibration and adding suppression pads when not on grass makes a big difference.
Additional Enhancements and Modifications
Since buying the OneSky I’ve made several modifications to customize the scope and enhance its performance for the way I use it. The biggest improvement has been the addition of a shroud constructed of 1/32″ Kydex plastic to protect the previously exposed secondary mirror from the contrast robbing effects of stray light and dew.
Before adding the shroud I had more than one observing session cut short by dew and sometimes would find myself trying to position my body between the secondary and a nearby light source. The OneSky’s design makes it simple to add a light / dew shield that slides into the OTA as the scope collapses giving the protection of a solid tube reflector telescope with the portability of a collapsible truss design.
I also added a Synta-style finder base to allow the use of a RACI finder along with the included red dot finder. The addition of the RACI finder makes star hopping to faint objects much easier than relying on the 2.5º max field of view available through the telescope eyepiece. A 6×30 finder is pictured but the central position of the finder base means that there is little change in the balance of the scope so a 50mm finder works just as well.
The addition of a cabinet pull for use as a carry handle makes one-handed handling of the scope a breeze. The most obvious areas of improvement are during setup and take down but the handle can also be used to aim the scope from the back when sighting through the RDF or even viewing through the eyepiece.
Taking the OneSky on the Road
Most travelscopes wouldn’t be complete without a bag to carry them around. The bag I use with the OneSky is a Vivitar RGC-12 camcorder soft sided carry case. It fits the collapsed scope without having to remove the RDF and has room in the main compartment for the RACI finder, eyepieces, collimation tool, etc. My planisphere and Pocket Sky Atlas fit in there too. The bag’s outside pockets carry my flashlight, DwarfStar guide handle, and other handy things.
Original content copyright 2015 by David Philips. All Rights Reserved. This post may contain links to affiliate sites; sales through affiliate links may benefit this site.