Al­tair Star­wave 70 EDQ-R quad apo imag­ing re­frac­tor


Sky at Night Magazine - - CONTENTS - WORDS: GARY PALMER

As­tropho­tog­ra­phers have an ever-grow­ing wish­list of new kit as tech­nol­ogy keeps ad­vanc­ing. The new Star­wave 70 EDQ-R quad apo imag­ing re­frac­tor is an­other tele­scope to add to that list.

The 70 EDQ-R has a 350mm, f/5 fo­cal length and is aimed at wide-field imag­ing. With the right cam­era at­tached it can fit some very large ob­jects into its field of view. A quadru­plet de­sign of tele­scope is noth­ing new but some very care­ful at­ten­tion to de­tail has made this tele­scope a lot more user friendly.

Quadru­plet tele­scopes are made up of four lenses. The front three are for colour cor­rec­tion while a fourth lens at the back flat­tens the field of view. The flat­tener be­ing built in makes for a more sta­ble imag­ing setup rather than hav­ing to in­sert a sep­a­rate flat­tener in at the fo­cuser end. The aim is to achieve round stars right into the far cor­ners of your im­ages and good colour cor­rec­tion across the en­tire im­age.

Where the quad dif­fers from a nor­mal re­frac­tor is that the rear end ter­mi­nates in an M42 thread so that you can at­tach a cam­era di­rectly to it, or, in the case of a DSLR, by us­ing a T-adap­tor. With all tele­scopes, tem­per­a­ture changes can make a big dif­fer­ence to im­ages. In a cold en­vi­ron­ment it is rec­om­mended that you heat the tube slightly. This will help with the dif­fer­ence in glass and tube tem­per­a­ture and it can eas­ily be achieved with a dew strap around the tube on a moder­ate set­ting.

Sur­pris­ingly light

Once we’d un­packed the 70 EDQ-R, the first thing we no­ticed about the tele­scope is how light it is: with a Canon EOS 70D DSLR cam­era at­tached it weighed just 2.1kg. This re­ally does make it a grab-and-go tele­scope for even the small­est of mounts. Even with a smaller aper­ture, the change in CMOS cam­eras over the last few years means im­ages of all sorts of ob­jects are achiev­able with this tele­scope. That makes it an ideal travel scope

and a good op­tion to take with you on longer trips in­stead of a set of cam­era lenses.

Build qual­ity in gen­eral is very good, and it comes with quite a lot as stan­dard. The tube is made from light­weight al­loy with ex­tend­ing dew shield and it comes with a good set of ad­justable tube rings on a dove­tail bar. A qual­ity rack and pin­ion fo­cuser with nice, smooth move­ment adds to the qual­ity feel. The only thing we did find that let it down was a loose lens cap that kept fall­ing off.

While the 70 EDQ-R is pri­mar­ily a tele­scope for astropho­tog­ra­phy it can be used with an eye­piece by adding a 40mm ex­ten­sion to the back thread. For be­gin­ners this may make it easier to align find­er­scopes and mounts when first set­ting up.

The first tar­get we im­aged was the An­dromeda Galaxy us­ing a fin­der-guider con­fig­u­ra­tion on a portable track­ing mount set on a tri­pod. The cam­era was a Canon DSLR setup us­ing the ba­sic EOS cap­ture on the com­puter. We took 20 three­minute im­ages which cap­tured lots of de­tail in the dust lanes with round stars and vi­brant colours. For such a short amount of imag­ing time we were happy with the end re­sult. The same process was re­peated on a sub­se­quent night with the Pleiades as our tar­get, again re­veal­ing plenty of struc­tural de­tail.

Chang­ing to CMOS cam­eras was sim­ple and with M42-threaded ex­ten­sion rings on the cam­era it was easy to fo­cus on the screen. When you’re us­ing a mono cam­era, there’s am­ple space to at­tach a small fil­ter wheel in the imag­ing train if you need it. Im­ages of the Moon with a Hyper­cam 183C showed a lot of de­tail for the aper­ture.

The 70 EDQ-R is a very good ad­di­tion to any­one’s imag­ing setup and makes it very easy to cap­ture good im­ages with the min­i­mal amount of ef­fort.

M31, the An­dromeda Galaxy, im­aged with a Canon EOS 70D DLSR us­ing 20x80 sec­onds ex­po­sures

M45, the Pleiades, im­aged with a Canon EOS 70D DSLR cam­era us­ing 20x180 sec­ond ex­po­sures

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