In the last 2 weeks, we've been hearing about multi-element achromatic diopters being fitted onto various cameras for macro work. This usually requires a flat port which can accomodate the additional lens. Also with the various cameras now having different filter size attachments from 30mm-82mm and the various housing's limitation with port dimensions, it's a bit of a mine field to find the right diopter with the right dimensions for your housing.
Thus I decided to start a list of possible multi-element diopters for various filter sizes to fit various cameras.
**Note** I have not tested many of them so I cannot be vouch for the image quality of some of these lenses.
I'll concentrate on the 3 sensor cameras and their bigger filter sizes. Some of the links have the dimensions of the diopters for housing compatibiity:
62-77mm
Canon 500D +2 (good quality and thin)
Century Optics AD-7220/7235 +2 and +3.5 (+5.5 stacked) (very good quality but thick)
Nikon Close Up Lens 5T(+1.5) and 6T(+2.9) (good and thin/Discontinued)
Olympus MCON-35 (discontinued but still available) +2
Raynox DCR-5320 +3 and +2 (+5 stacked) (Good quality/a bit of CA)
Marumi Digital High Grade Diopter +3 and +5
Marumi comes in 52,55,58,62,67,72,77 mm sizes. It is also the OEM producer for Nikon.
The Canon 500D comes in 52,58,72,77mm sizes. Here is a comparison test between the Canon 500D and Nikon 6T
If you use a diopter which is larger in filter size, a step up ring is needed but you also use the center of the lens which is usually sharper, but resolution limited.
For 82mm, you can either use a 77mm diopter with stepdown ring (vignetting will occur at partial to full wide) or the 86mm diopter with a stepup ring.
For the smaller cameras, this little lens by Zoerk is reputed to be very good quality.
If using a step ring, the added thickness of the step ring should be considered when measuring for port compatibility.
For more information on shooting macro, check the reports by Nick Hope and Mark Thorpe.
Remember shooting macro requires the best depth of field possible, but with video cameras, the bigger the f-stop number, the more diffraction and resolution loss there is. So you must find that balance where the lens on the camera is optimized for the diopter attached.
So please let us know which diopter you use and what housing and port you fit it in so we can help others find the optimal setup for their rigs.