N noob117 Senior Member Oct 16, 2006 1,314 0 36 west Jun 24, 2007 #1 i tried to use a +3 diopter hoya close-up filter on a sigma 70-300 APO but the thing is, it cannot focus or have sharp focus on the object... :dunno: :dunno: espercially on the tele-end. or is there something wrong with my lens?
i tried to use a +3 diopter hoya close-up filter on a sigma 70-300 APO but the thing is, it cannot focus or have sharp focus on the object... :dunno: :dunno: espercially on the tele-end. or is there something wrong with my lens?
D DeSwitch Senior Member Oct 28, 2005 3,202 0 36 57 1.45N 103.83E www.flickr.com Jun 24, 2007 #2 You should know that with the closeup filter you will no longer be able to focus at infinity. yr focusing distances had beed changed (reduced)
You should know that with the closeup filter you will no longer be able to focus at infinity. yr focusing distances had beed changed (reduced)
E ExplorerZ Senior Member Jan 9, 2006 7,880 1 38 West Jun 24, 2007 #3 This is cause by the fact that Hoya Closeup doesn't offer good IQ and Sigma 70-300 is soft at 300mm...
This is cause by the fact that Hoya Closeup doesn't offer good IQ and Sigma 70-300 is soft at 300mm...
N noob117 Senior Member Oct 16, 2006 1,314 0 36 west Jun 24, 2007 #4 but strange thing is it works sharp on my 18-55mm kit lens?
W wong1979 New Member Aug 16, 2005 543 0 0 Jun 24, 2007 #6 Did u focus at around 33 cm? Need to use 1000mm / (diopter) formula to get it right. In your case, 1000/3 = 333mm or 33.3 cm.
Did u focus at around 33 cm? Need to use 1000mm / (diopter) formula to get it right. In your case, 1000/3 = 333mm or 33.3 cm.
A Artosoft Senior Member Aug 31, 2005 3,710 0 0 Tanjong Katong Jun 25, 2007 #7 wong1979 said: Did u focus at around 33 cm? Need to use 1000mm / (diopter) formula to get it right. In your case, 1000/3 = 333mm or 33.3 cm. Click to expand... Additional info: That's 33.3mm is when the lens' distance set at infinity. No matter of focal length of the lens. Regards, Arto.
wong1979 said: Did u focus at around 33 cm? Need to use 1000mm / (diopter) formula to get it right. In your case, 1000/3 = 333mm or 33.3 cm. Click to expand... Additional info: That's 33.3mm is when the lens' distance set at infinity. No matter of focal length of the lens. Regards, Arto.
