| Joined: | Mon Apr 2nd, 2012 |
| Location: | South Lakeland, UK |
| Posts: | 4066 |
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Firstly the 105mm UV Nikkor has a good transmission of UV.
Normal coated and uncoated lens elements block UV by a high percentage. That means long exposures to get the acceptable UV Images. Long exposure introduce their own issues.
Secondly focus shift. The 105mm UV Nikkor is corrected for focus shift.
If you take a UV image with a normal glass lens, coated or not, you will find that whatever you focused on won't be sharp, the actual point of focus will be behind the predetermined focus point. In my experience with the Nikkor Micro 55mm f2.8 at about 500mm range there is a back focus of about 22mm, so the trick I use is to focus on the subject, then slide the camera back about 22mm on an adjustable rail, which results in sharper images.
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Robert.