Toymaster Posted June 9, 2014 Share Posted June 9, 2014 Hope this does not sound too silly but I've been investigating lighter weight refractors < 7Kg OTAs to put on my SW EQ3 Pro Mount as a grab and go for when there is a break in the cloads and no time to set-up the 300P. I started looking at MAKs and SCs that have long focal lengths and are slow tubes. Then compact Newts and now refractors with the shorter focal length and faster speeds (approx F5) to be a good all round compromise for Plannets and Brighter DSOs. Currently I'm using my Celestron 114EQ Newt OTA, which has a focal length of 1000mm and is F8.8. It is Bird - Jones Newt that is shortened by using a compound barlow type lens at the bottom of the draw tube. Works surprisingly well with my Celestron X-Cell EPs but I want better!! I might even experiment with imaging later Any ideas? Ta. Ade Link to comment Share on other sites More sharing options...
Werisit Posted June 9, 2014 Share Posted June 9, 2014 Hello Adrian. I love my little Sky-Watcher ST 102 mounted on an old Alt Az. (AZ3 I think) No counter weights or bits sticking out to squeeze through the door. There is a 120 version. My 102 does suffer from a fair bit of colour fringing so I use a Baader fringe killer filter. The yellow cast this creates doesn't bother me. The "semi apo" filter affects colour less but loses more light (not such a problem with a 120 aperture). I do put the SW 120 ED on the Alt Az sometimes but it's on the limit and not as easy to cart about and at 900mm fl doesn't give such wide field views. The bare OTA weighs about 6Kg. The 120 ED has very sharp and false colour free optics as you would hope for around 5 times the price of the ST 120. Link to comment Share on other sites More sharing options...
Toymaster Posted June 10, 2014 Author Share Posted June 10, 2014 Ok so I've been looking at Bresser Messier AR-102/600 but what few reviews there are are not brilliant. Optical quality in particular CA, which appears to be more of a problem on lower focal length low end refractors. Then my attention was drawn to the Skywatcher Startravel 120T - The jury is still out on that one but looking good value for the bucks! Now I'm moving back towards Celestron Schmidt-Cassegrain OTAs such as the C6 and C5 (Spotting scope but wider field) It all started out looking at the SW 127 Mak................. Not sure where it will end but there may be not one simple solution for a lightweight Planetary and brighter DSO scope! Considerations = Light capture to EP, contrast, optical imperfections, wide field - all to do with diameter, focal Length and quality of optics. SCs appear to have less optical imperfections but have a high slower focal ratios (narrower field of view) and better contrast for plannets but not as good for wide field DSO hunting..... What about a SC with a reducer to bring the Focal Rateo down? Makes my 300P Dob a no brainer. Ade Link to comment Share on other sites More sharing options...
Brantuk Posted June 10, 2014 Share Posted June 10, 2014 A reducer on a big Sct is a good tool for imaging dso's, and not bad for observing them either - though some say it's not the best tool for that - but there have been some very nice pics done. Link to comment Share on other sites More sharing options...
Toymaster Posted June 23, 2014 Author Share Posted June 23, 2014 Ah well after much consideration I didn't buy a refractor as I changed my spec to wide field use and DSOs and an occasional plannet. The scope had to be light enough for the mount and one that I could carry outside quickly and one that would collect a fair amout of light. Also may experiment with a lower end to mid EP camera. So I selected the biggest diameter the EQ3 Pro would take and a fastish tube speed. You ask why an EQ3 and not an NEQ5 - It came up as a reboxed item at a price I could not pass by and it is lightish with the alloy legs. Result: Skywatcher Explorer 150PDS with a 750mm focal length giving f5. It also has a 2" dual speed Crayford Focuser. Still like the idea of a refractor and / or a largish Mak or Schmidt Cassegrain or even a Ritchey Chretien Astrograph or .... or............... So far I have used Newtonians and they work for me right now and so that is where I have ended up THIS TIME Therfore rightly or wrongly Grab and Go became Grab and Go Out into the garden or take to bits and put it into the car for a trip to the Dark site. Have I fallen out with the 300P DOB - No way - The sights you see are stunning with that diameter. Downside - Weight / time to take out and setup for a break in the clouds. GoTo and tracking while good is nowhere as precise as the EQ3 Pro. So six months into the hobby and that is where I'm at. Now to use the kit and learn more about the sky. Ade Link to comment Share on other sites More sharing options...
Guest Posted July 5, 2014 Share Posted July 5, 2014 If money was no object, I'd look at an 80mm APO or ED refractor. As it is I have an ST80 (achromat). I can use it for lunar photography when my back is too bad to carry my larger telescope but have used it to take most of my deep sky images (all so far undriven): http://s197.photobucket.com/user/PhillipPugh/library/Deep%20Sky%20Objects?sort=3&start=0&page=1 Link to comment Share on other sites More sharing options...
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