BETO74 0 #1 July 20, 2013 This post is specifically related to the sigma lens used on Canon cameras with cropped format. The question: is there a noticeable difference between a picture taken at the same distance of the subject with the different lenses? 15mm, 8mm and 4mm looking at the specification of each lens, seems that the picture will come out some what the same, given that a cropped format camera is used and the focal values of each camera are some what similar. I had the 15mm sigma mounted on a Canon Rebel Ti and loved it for all purpose skydiving shots does anyone have tried taken pictures with 8mm and 4mm alike what are the differences? They have the same angle of view and similar focusing distances and apertures I assume the pictures will be not much difference from each other. 15mm specifications Focal Length: 15 mm Aperture: Maximum: f/2.8 Minimum: f/22 Format Compatibility: 35mm Film / Full-Frame Digital Sensor Canon (APS-C) Angle of View: 180° Minimum Focus Distance: 5.9" (14.99 cm) Magnification: 0.26x 8mm specifications Focal Length: 8 mm Aperture: Maximum: f/3.5 Minimum: f/22 Format Compatibility: 35mm Film / Full-Frame Digital Sensor Canon (APS-C) Angle of View: 180° Minimum Focus Distance: 5.3" (13.46 cm) Magnification: 0.21x 4mm specifications Focal Length: 4 mm Aperture: Maximum: f/22 Format Compatibility: 35mm Film / Full-Frame Digital Sensor Canon (APS-C) Angle of View: 180° Minimum Focus Distance: 5.3" (13.46 cm) Magnification: 0.21xhttp://web.mac.com/ac057a/iWeb/AC057A/H0M3.html Quote Share this post Link to post Share on other sites
DSE 5 #2 July 20, 2013 They'll still be quite different from each other. The glass separation alone, plus aberration from lens to lens will be different. Blades are different. This doesn't mean one will be "better" than the other, but the aesthetics of the image will be different. I suppose it depends on your definition of "somewhat" in "somewhat the same." Quote Share this post Link to post Share on other sites
guscabana 0 #3 July 22, 2013 The 15mm is a normal fisheye, which gives you 180 degrees angle diagonally, in a 3x2 format. The 8mm is a circular fisheye which gives you a 180 degrees angle horizontally and vertically, means a round image in the center of the 3x2 frame. Both gives you this resuts in a full frame sensor camera. In a cropped sensor camera, the 4,5mm gives you the 8mm (in a FF) results and the 15mm will give you something like a 21 mm lens. Check this chart... Hope its help. Quote Share this post Link to post Share on other sites
BETO74 0 #4 July 25, 2013 Thanks for the explanation and the tablehttp://web.mac.com/ac057a/iWeb/AC057A/H0M3.html Quote Share this post Link to post Share on other sites
