The lens is available by now! I got hold of the lens to do measurements and design a filter holder. There are already quite a lot of requests, so I’m building a series of holders for this lens too.
The first samples are available and the filter holder may be ordered via the contact form!
I built a new protoype of the filter holder. Now, I’m happy with the prototype, so the holder is already in production. The current design has reached production quality.
I couldn’t resist building a prototype for 100mm filters. It works, although with a few restrictions. Placing the holder exactly on the lens takes some training. Slightly wrong placement leads to vignetting. Since the lens is software-corrected, the RAW image covers a wider field than the resulting JPEG. There is no vignetting in the JPEG but there will be visible vignetting in the uncorrected RAW, depending on focus distance.
The advantage of using 100mm filters rather than 130mm filters is worth accepting vignetting in uncorrected images. Filter availability and pricing of 100mm filter systems versus 130mm filters are more than convincing.
There’s good news for those, wanting to use more than one filter. Although the design is extremely tight, I managed to add an additional rail for a second filter! Actually, it’s half a rail, stabilizing the filter along the sides, when attached to the first filter by two rubber bands. A thin gap between the filters will prevent scratching.