The Sonia Close-up kit is a set of close-up diopter lenses that allow your camera / lens to focus closer than it can normally. They work by screwing onto the front filter thread of your camera's lens. The kit includes a range of strengths - +1, +2, +4, and +10. The greater the strength, the closer you can focus. The filters can be stacked too.
I bought this kit quite a few years ago, but was disappointed with the quality and hardly used it. Recently I decided to sell off quite a bit of my old photography gear I no longer use, so I thought I'd give these another look before I got rid of them.
The Sonia close-up lenses are available quite cheaply on eBay. I believe they use a single piece of glass, whereas the more expensive (decent) filters use achromatic doublet designs. Given that the Canon 500D close-up filter is around £140 in 77mm size, whereas the Sonia kit is about £20 for a kit of 4 filters in 77mm size, it's to be expected that the Sonia lenses will not be as good quality.
Like all other close-up diopter filters, the Sonia filters have the following benefits:
- Work with any lens that has filter threads (including cameras that have a fixed lens, unlike extension tubes)
- No light loss (unlike extension tubes)
- The longer the focal length of the lens used, the greater the magnification they will give
The filters are quite large, the strongest filter (+10) has a depth of 23mm. Being that my set is a 77mm filter size, they are all just over 77mm in diameter. They come boxed with a fold out filter wallet used for carrying them.
Example images taken using the Sonia close-up filters
I took some photos using the Sonia close-up filters and my Canon 450D with 18-55mm IS kit lens, and my Fuji X-A1 with 16-50mm kit lens.
Image quality with the lower strength diopters is surprisingly good, especially around the centre of the image. On the other hand, if you stack all four filters together you get a mostly sharp centre with blurred edges and large CA.
Diopter magnification / image quality comparison
With the Fuji 16-50mm lens I did some tests with the lens set to 50mm and minimum focus distance to give an example of the sort of magnification you can achieve with these lenses. With a longer focal length lens you achieve even greater magnification.
Note that although the close-up lenses don't reduce the amount of light that gets through to the image sensor, the reduction of working distance can cause a reduction in light. This can clearly be seen in the image with all lenses stacked together - the working distance was so small that the camera and close-up lenses themselves blocked quite a bit of light from reaching the ruler.
With all the lenses stacked, it adds quite a bit of weight on the end of the lens. I don't think the cheap plastic kit lenses that you get with most consumer level cameras are really designed to be able to carry so much weight.
The low diopter filters included in the kit are reasonably good, but don't provide much of a boost in magnification. The higher diopter filters provide a good boost in magnification but are pretty awful in terms of image quality.
I guess if you wanted a soft focus close-up lens this Sonia close-up kit might be okay. ACR can clean up some of the CA automatically, but it doesn't remove it completely. In my opinion you're much better to spend a lot more money on a single good quality achromatic close-up filter than wasting your money on this kit.