I have a Nikon D3100. I have a 58mm solar lens I am trying to attach to the camera. What step up ring adapter would I need? A 52mm to 58mm? Also would like to be able to attach to a Nikon ED AF-S Nikkor 70-300mm 1:4.5-5.6 G VR Nikon SWM VR ED IF 67. Any help would be greatly appreciated.
What step up ring adapter would I need?
Look at the front of the lens on your camera. There should be a mark like this: ⌀ Next to that, you'll find a measurement in millimeters, for example:
⌀ 52mm That indicates the diameter of the filter threads on your lens. If that diameter doesn't match the filter you want to use, like your solar filter, then you'll need an adapter ring with male threads that match your lens's filter diameter and female threads that match the filter you want to use.
It looks like your AF-S Nikkor 70-300mm 1:4.5-5.6 G VR has a 58mm filter diameter, so if your solar filter is also 58mm, then you don't need any adapter ring at all -- just line up the threads and gently screw the filter onto the front of the lens. If you're not sure how to do that, get a knowledgeable friend to show you.