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Message: <blockquote data-quote="Paul Corfield" data-source="post: 1793350" data-attributes="member: 19132">You are getting 2.18X so it's almost 2.2X but not quite.The way I do it is I open both images in Photoshop. Then I change the size of the small image making sure it's set to a percentage increase. I had to increase it 218% in size to get a perfect match. Once the small image is enlarged I drag it on top of the larger image and set the transparency of the top image to about 55% so I can see the one below and the one on top at the same time. I move it around and see if it matches. If it doesn't match then I undo all the previous steps in the history palette and try a different increase in size.  It's a proven method and I've tried it with both 1.4X and 2X teleconverters. For example a photo taken at 600mm needs an increase of 140% to match an image taken with a 1.4X TC and when you try it in Photoshop it works exactly. It's the same with a 2X TC. Paul.</blockquote>