..those tiny screws that hold cameras and lenses together?

[Neil Grant]

..I have a need to make a very thin extension ring for a Mamiya 645 - thinner than the thinnest commercially available. It needs only to be about 3-4mm thick to usefully shorten the min focus distance of the 45mm lens. Of course I want to do this for minimum cost. I'm thinking it may be possible to screw a spare lens mount to the back of the existing mount on the 45mm - using the existing screw holes as long as these lined up accurately enough and if I could source much longer screws so that they would pass through both mounts and into the lens body itself. Any idea where I would get such screws from? Of course auto aperture would be lost - but that's not important.

 

[shutterfinger]

http://metricscrews.us/

 

[John Koehrer]

Also some hardware(ACE) and hobby shops the deal with RC cars/planes or small scale trains can help out.

 

[wiltw]

why not simply find yourself an 80mm lens for the 645?

 

[Neil Grant]

...i already have an 80mm, but i want to use the 45mm for framing/perspective reasons. That the image quality 'close-up' may not be all that good could be useful 'visually'.
Thanks guys for all the other suggestions.

 

[MattKing]

...i already have an 80mm, but i want to use the 45mm for framing/perspective reasons. That the image quality 'close-up' may not be all that good could be useful 'visually'.
Thanks guys for all the other suggestions.

If image quality is less important, I would look for so called "close-up filters (essentially diopters).
Although finding one in 77mm filter size might be challenging.
Correction - not difficult at all!
https://www.bhphotovideo.com/bnh/co...sZXxoCt_8QAvD_BwE&is=REG&pcur=CAD&sku=1278186

 

[John Earley]

https://www.microfasteners.com