995 filter thread

[Rhys]

I looked at the slide copying adaptor for my Nikon 995. They want a ludicrous sum of money for what is essentially a piece of white perspex and some crudely manufactured tubing with filter thread on the end.

Does anybody know the pitch and diameter of the thread on the 995? Having access to a lathe, I could find an appropriately sized piece of aluminium tubing, turn a thread and spray it black then fit some white perspex on the end - all for next to nothing.

[dwig]

I wouldn't refer to the machining on the Nikon ES-E28 "poor". Its actually rather well made and, in addition to allowing rotation, allows for shifting the original in two directions, not just one as with simplier duplicatiors. My only complaint with mine is that the diffuser is not diffuse enough causing uneven lighting, a hotspot, when I use anything other than the large surface of a lightbox for illumination. Not a problem at home as I have a good color correct lightbox handy but will be if I take the copier along on trips to visit family to archive their old family images. The diffuser end is threaded for 52mm filters and I plan on experimenting with mounting an additional diffuser swapped for the glass in a cheap UV filter.

That said, the filter thread on the CP950/990/995 is 28mm diameter. I believe the pitch is 0.5mm. Sounds like a lot of work to machine the threads when you can get a step-up ring from B&H Photo for about $7 and use that for a starting point. Also, when you machine the tube, either make it rather overly large in diameter, as Nikon did, or machine a series of V grooves on the inside to function as small baffles. Simply painting it black rarely reduces the internal reflections enough, even when the special paints made for the purpose are used.

BTW, the ES-E28 places the film surface about 38mm from the front of the filter mounting ring on the camera's lens. This seems to work well with the optical system in this series of cameras.