tag:blogger.com,1999:blog-1195286216399793210.post7924108491776158771..comments2023-11-02T02:15:43.367-07:00Comments on penmachinedad: Some examples of using a lens adapterUnknownnoreply@blogger.comBlogger5125tag:blogger.com,1999:blog-1195286216399793210.post-78774310253537615162009-01-25T16:41:00.000-08:002009-01-25T16:41:00.000-08:00You're right, there is no relevant EXIF info regar...You're right, there is no relevant EXIF info regarding the B and L image, but the Sigma image report contains it.Karlhttps://www.blogger.com/profile/03934765614715564629noreply@blogger.comtag:blogger.com,1999:blog-1195286216399793210.post-45289621338553600302009-01-25T15:42:00.000-08:002009-01-25T15:42:00.000-08:00Could you email me the original files for the Sigm...Could you email me the original files for the Sigma at "200 mm" and the B&L 200 mm flower basket shots? I'd be interested to look at how the camera reports the lens EXIF data for the two lenses, but that has been stripped out of the smaller images you posted here.<BR/><BR/>I tried a similar experiment with my old Quantaray/Sigma full-frame zoom <A HREF="http://flickr.com/photos/penmachine/3227090284/" REL="nofollow">at 135 mm</A> (well, 123 mm or so; I just eyeballed it on the lens barrel) and my crop-frame Nikkor zoom <A HREF="http://flickr.com/photos/penmachine/3227087890/in/photostream/" REL="nofollow">at 135 mm</A>.<BR/><BR/>The field of view is pretty much identical (more than I would have thought, given the 12 mm difference in my quick zoom setting), and both report their real focal lengths to the camera.<BR/><BR/>Interestingly, there's a field in the full-frame Quantaray zoom's <A HREF="http://flickr.com/photos/penmachine/3227090284/meta/in/photostream" REL="nofollow">EXIF data</A> that says:<BR/><BR/>"Focal Length In 35mm Format: 183 mm"<BR/><BR/>and in the <A HREF="http://flickr.com/photos/penmachine/3227087890/meta" REL="nofollow">crop-frame Nikkor's</A>:<BR/><BR/>"Focal Length In35mm Format: 202 mm"<BR/><BR/>Both of which are also correct using the Nikon D50's 1.5x crop factor. I'd be interested to see what your Sigma reports to your Canon. I doubt the B&L will report anything. :)Derekhttps://www.blogger.com/profile/06305726604191188040noreply@blogger.comtag:blogger.com,1999:blog-1195286216399793210.post-77196640933325112832009-01-24T10:33:00.000-08:002009-01-24T10:33:00.000-08:00Further to the "lens labeling": I've posted a pict...Further to the "lens labeling": I've posted a picture of the two lenses at http://www.flickr.com/photos/mimiandpapa<BR/><BR/>DadKarlhttps://www.blogger.com/profile/03934765614715564629noreply@blogger.comtag:blogger.com,1999:blog-1195286216399793210.post-80459085670802414632009-01-24T10:08:00.000-08:002009-01-24T10:08:00.000-08:00The Sigma lens is labelled 18-200mm zoom and is us...The Sigma lens is labelled 18-200mm zoom and is used at the maximum "extension" of 200mm. The 200mm B and L lens is also labelled 200mm (fixed). If the B and L iamge (which has just about 1.5 times the width of the Sigma image) had been taken with a full-frame camera (which has 1.5 times the width of a crop frame), then the two pictures would have looked identical. Assuming that the B and L lens is labelled with its actual focal length, this implies to me that the Sigma lens is labelled with its "full-frame equivalent" focal length. <BR/><BR/>DadKarlhttps://www.blogger.com/profile/03934765614715564629noreply@blogger.comtag:blogger.com,1999:blog-1195286216399793210.post-39300598426939609292009-01-23T22:10:00.000-08:002009-01-23T22:10:00.000-08:00I'm a bit confused about two of your images --...I'm a bit confused about two of your images -- the Sigma zoom set at 200 mm, and the 200 mm B&L lens. Usually, all SLR lenses are labeled with their actual focal lengths (e.g. 200 mm), regardless of the crop factor of the sensor it's intended for.<BR/><BR/>So I would think that the angle of view for the Sigma zoom at 200 mm and the B&L lens at 200 mm would be the same. Is the Sigma lens labeled with its real focal length or its "full-frame equivalent" focal length; in other words, was it really set at 125 mm, with the B&L _really_ at 200 mm? If not, why are the angles of view different?Derekhttps://www.blogger.com/profile/06305726604191188040noreply@blogger.com