SLR Magic Rangefinder HACK using donor glass

[Timotheus]

(repost from the Anamorphic Shooters group on FB, but I thought it would be interesting for here as well ☺️)

- SLR Magic Rangefinder hack -

I was getting a bit tired of the blue blobbin' and bleeding flares of the SLR Magic Rangefinder. With the modified Century Optics wide-angle adapters being used for single focus rehousings (by POOLi™) I started thinking of using similar glass as replacement into the otherwise fine Rangefinder helicoid. One 0.82x wide-angle adapter seemed very close in dimensions: the Fujinon WCV-82SC, also sold as RCV-82SC, and also sold under the JVC brand. Note the 82mm front thread, which is the same as the RF.

Found one cheap, disassembled it and sure enough, the two elements are very close in size to those found in the RF.

• Rear element was easily replaced because it fits just fine, using the retainer ring on the back of the RF. But be very sure to put it in the right direction, very important!
• Front element was a bit more tricky as it is somewhat thinner than the RF front element, ending up 'too deep' in the helicoid. Now it focused way past infinity and not close. So I used some step rings to lay the front element on and bring it more forward.
• I then used the original retainer ring from the WA adapter to fix the front element in the helicoid. Tadaa...a new single focus in an old housing.

Pro's:
- wider shots possible
- no more blue bleeding flares
- close focus is a bit better also, I measured around 90cm, compared to listed MFD of the Rangefinder of 110cm.

Cons:
- somewhat more distortion at the edges and more CA
- less sharp than RF in corners, but when using 2x anamorphics this is somewhat mitigated as the sharp center gets stretched out.
- requires some fiddling with step rings behind the front element as spacer to calibrate focus range.

Cheers, Tim

P.S. You can find some (boring) test shots in the Facebook post.

[CfFilmmaker]

That's a gutsy disassembly! You said they were almost the same size, how did you make up the difference?

[Timotheus]

23 hours ago, CfFilmmaker said:

That's a gutsy disassembly! You said they were almost the same size, how did you make up the difference?

It's actually relatively easy as there are only two elements that are each fixed with one retainer ring.

The rear element can be swapped out, and the Rangefinder's back retainer ring can be re-used.

On the front, the element of the Fujinon is a tad smaller and thinner. However, when using the Fujinon's original front retainer ring it grips perfectly, as that also has a 82mm outer thread, and it has a 'rim' that fits snugly over the element's edge.

Only aspect that needs some tinkering is finding adequate spacers to lay the front element on. Otherwise it ends up to 'deep' in the housing. I used step rings, which work just fine.

[Grimor]

31 minutes ago, Timotheus said:

Only aspect that needs some tinkering is finding adequate spacers to lay the front element on. Otherwise it ends up to 'deep' in the housing. I used step rings, which work just fine.

Will be really easy to desing a custom 3D printed spacer.

[CfFilmmaker]

I would be really curious to see what the image would look like if you removed the coating from that front element. I found this video and it's made me reconsider some lenses with blue flares (I'm partial to the golden ones). It looks like it changes them a substantial amount. Maybe getting rid of it could solve some of the blue haze issue.