I now have enough experience to write a review.
- Inexpensive. $140 on Amazon. A “real” Nikon lens can run into the thousands.
- Works. It does what it says. It will bring things into close focus. Including things you don’t want to get too close to.
- Small, light and maneuverable A conventional telephoto lens is much longer and heavier.
- Close focus You can focus on surprisingly close objects. This makes it great for taking pictures of things that don’t appreciate humans getting up close and personal.
- Weakly coupled to the camera. Everything is manual, including exposure.
- No autofocus. This limits its use in rapidly changing situations. Following a moving bird for example.
- Paper-thin focus. Be prepared to take several photos to get the focus right
- Infinity is not set at infinity on the lens. Don’t assume the stars are in focus.
- The 2x extender leads to barrel distortions.
I generally use it with a fast shutter exposure (1/4000 s) to avoid blur and then control the exposure with the camera’s “film speed” setting. In bright light that’s about 2000ASA. In dim light, you may have to play around.
It’s also critical to make sure that the T-mount is firmly screwed into the lens. If it comes loose you won’t be able to focus.
This picture shows what I mean by paper thin focus:
Note that I’ve focused on one wing of the butterfly and the other wing is completely out of focus.
In summary, you get what you pay for. It works. There are several things that could be better, but you have to fork over the cash. I wouldn’t use it for rapidly changing things like sports or moving creatures. But if you have the time to focus and remember to take several shots, it’s a great little lens.