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Message: <blockquote data-quote="Paul Corfield" data-source="post: 1241311" data-attributes="member: 19132">The scope is the same Skywatcher Evostar Pro 80ED. They were taken with just the 2" GSO 2X ED barlow. The scope is 600mm and with the barlow lens cell screwed into the 2" nosepiece of the T-Ring the 2X barlow gives a little more magnification than my 2X teleconverter. So that would be just slightly more than 1200mm before the crop factor. Range for all the photos was 15m and that was measured. All these shots have been cropped just to show the detail captured on the bird. Camera was Canon 450D and all photos taken in RAW.Wings - the way I arrive at the magnification is to take a photo of the same target using the scope at prime focus which in my case is at 600mm. Then I take another photo with the combination of barlow/teleconverters. In Photoshop I scale up the 600mm photo and overlay it onto the other one. I apply some transparency to the top layer and see how well they match up. It takes a few goes to get the scale just right but once a perfect match is made I make a note of the percentage needed to get that match. If I needed to increase the 600mm photo by say 530% then that converts to 600mm X 5.3 = 3180mmPaul.</blockquote>