Zachariah Posted December 29, 2011 Share Posted December 29, 2011 I purchased a Skywatcher evostar 90 recently and have just tonight managed to get a clear view of the moon.However, I am disappointed with the image I get. With the 25mm there is plenty of detail but too small an image, using the supplied barlow I get a bigger image but no matter how much I try I cannot get a crisp image.I know its cold and its blumming windy but I did expect better.I looked at Jupiter and I can see two faint brown bands, but its not a crisp image. Am I asking too much from this scope? Could it be conditions?I also own a Tal 1 and Jupiter looks sharper with it. Unfortunatly I wasnt able to line up and see the moon with he Tal.Help! Link to comment Share on other sites More sharing options...
nicnac Posted December 29, 2011 Share Posted December 29, 2011 you left the telescope to cool some before you used it yes?note -: those TALs are great arnt they Link to comment Share on other sites More sharing options...
Capricorn Posted December 29, 2011 Share Posted December 29, 2011 The eyepieces and barlow supplied are not great, especially the barlow.At 900mm Fl the 25mm will give 36x which will show Jupiter but as you say small. Should have made out a few moon, depends on how many were visible and a couple of bands across Jupiter. But all small.Sounds like the supplied barlow is best forgotten, most are poor, some OK some really bad.Means it is time to spend money on additional bits. Sorry.One eyepiece that tends to get good comments are the BST Explorers (Skys the Limit).If magnification is wanted the consider the 8mm first, it will give 112x. That should be good for Jupiter and later Saturn. Saturn is smaller and further away so again will be small, hopefully however clear.After that perhaps the 12mm or 15mm for medium power.BST's come in 5mm, 8mm, 12mm, 15mm, 18mm and 25mm. You already have a 25mm EP. The 5mm will give 180x and I guess this is too much for the scope, I would advise against this. The scope is an achro and will show some CA, pushing the magnification will make this more pronounced. Link to comment Share on other sites More sharing options...
nightfisher Posted December 29, 2011 Share Posted December 29, 2011 i have an 80mm f900 vixen scope that i use for grab an go, this gives very good views of the moon and jupiter, you should get similar or better views with the 90mm.....ditch the barlow and try a half decent eyepiece, around 10-12mm ep should do it Link to comment Share on other sites More sharing options...
Zachariah Posted December 29, 2011 Author Share Posted December 29, 2011 Yep I love my Tal. I leave the base unit outside with a plastic bag over it of course. The tube is in my shed so no issues with temp. So easy to set up just grab the tube and fix in on base and away you go.Back to the Skywatcher, to be fair the tube is kept indoors so no it wasnt at temp i.e blumming cold.The supplied barlow looks good, multi coated.The eyepieces supplied are 25mm (good) and 10mm (hmm) maybe I should get a good 15mm? The tal eypieces arent multi coated, the 25mm looks like the bottom of a bottle! But it peforms very well. So should I get a 15mm plossl or stick to the Tal? Link to comment Share on other sites More sharing options...
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