DIY Lens "Rehousing"

[JamieW]

Hey REDUsers,

I'm sure a lot of you are in the same boat as I am right now - stuck quarantining with uncertainty surrounding future work and the if/when life will return to normal. In my current boredom, I was thinking about the possibility of "rehousing" a set of Canon FD lenses I have.

The idea would be to model a sleeve designed to fit over the existing lens in CAD, and then 3d print prototypes to beef them up (95OD fronts, geared focus ring, maybe geared iris). If all works well, I would like to send the CAD models to a CNC machine to get them made in aluminum or other metal for a more solid/polished look.

I'm fairly certain that Cinematics CT.pro lenses you see on ebay (Sigma 18-35 "rehoused") do something similar to this.

Has anyone ever done this before? Any results? Or any suggestions for people who do proper rehousing at a good price?

Thanks in advance.

 

[Bastian Meier]

I had similar ideas, but with an actual rehouse. I do service Leica-R Lenses, and so I came up with the idea to actually start designing my own housing for them. But I guess till you have found out a way how to do a good rehousing it won't be any cheaper than getting a rehousing from someone Like GL Optics.

 

[Cole Sprague]

I did something similar to an Angenieux 12-120 to be able to use a matte box since it has a rotating and telescoping front. It worked with the 3d printed version, but it was rather unrefined as there were extremely difficult to print overhangs involved.

I’m not sure the real benefit of doing a full sleeve on those lenses that a set of focus and iris gears can’t accomplish while being easier to design and significantly lighter. 3D printed gears work perfectly well, I use mine everyday on a number of different lenses.

As for the 95mm OD front, there’s plenty of readily available threaded versions on the market, or you could design a version that uses the lens hood mounting tabs to lock on. That’s what I do with my Sigma Art zooms to bring them up to 114mm.

 

[Kenny Mosher]

I highly recommend GL Optics for rehousing. Super smooth focus, solid build and totally pro.

 

[Nick Gardner]

If you just want to make sleeves, then that should work, but you beter have a pretty nice 3d printer to get any kind of resolution that isn't going to look lousy and feel crunchy on the gears. You would probably be better off just buying gears for them, and maybe printing fronts to play nice with your matte box.

Nick

 

[TonyScopino_]

Anything ever follow this? Currently building my FD set, and want to either cine-mod or Rehouse entirely. Rehousing would be the most ideal, but ultimately 5k a lens just doesn't seem to tempting lol.

 

[Zack Birlew]

I simply hope it gets easier to rehouse still lenses as there is a lot of great glass out there but shoddy construction or dead mounts keep them out of consideration for most. In my lens cleaning and repair adventures, it's easy to imagine how many of these lenses, even the junky off-brand ones like Albinar, could be rehoused in much easier to work with cinema casings to really put in some nice images. However, cost is the biggest issue as you're bound to go through several revisions even if you had all the exact measurements of the lenses you're rehousing.

There's also the fact that a lot of lenses have dorky designs that would be hard to adapt, zoom lenses being the most difficult. I have a cheap find and now junk Nikon 24-120mm 3.5 AF that had a stuck filter that proved to be too difficult to remove and I ended up snapping something plastic on the inside of it that jammed the zoom, this was early on before I had learned about a rubber strap wrench. I eventually took it apart in case I could fix it but it just didn't turn out as definitely broken bits fell out and I have a now fully manual push/pull zoom that I made focal length markings by Sharpie pen when compared to a second mint copy. It technically works, all the glass is perfect, but it just needs the busted bits replaced and a new AF cable and connector if I wanted it to autofocus again, it's workable but just clunky. However, having seen it work in its current state, it could make a killer cinema zoom. What messes up that idea is that there isn't an easy way to adapt it in cinematic terms as the front element is the only part that moves and it telescopes to zoom so that makes placing the zoom and focus rings difficult without a full redesign and that cine design may end up not being all that much better than Nikon's anyway so there would be no point.

Another example is my Minolta 58mm 1.2 that I recently completely disassembled as I was tired of taking it apart to dab the oily blades. The lens is rather straightforward really and, once you figure it out, is a rather simple design but the way it's assembled can be quite confusing if you're not paying attention and being a lens that doesn't have a proper guide online, I did end up putting a couple days into reassembling it. It turned out that the helicoid assembly doesn't really require making markings and you only have to put the lens back together in the proper order with lubrication in the right places and, naturally, I didn't realize that I had put one part in place at the wrong step so while it looked right, infinity focus was impossible. Eventually, I got it back together and setting infinity focus was easy and you just slide the focus ring back on and screw it down in final position. Still, I've been wrestling with the final step of infinity focus screws which keeps slipping despite replacing the screws and I realized that I must have put too much lubrication or lubricated the wrong part so I'll eventually have to take it apart again after taking a much needed break from it. The lesson here is that a lens like this may make beautiful images but seeing the precise mechanical aspect of it, you would have to redesign the helicoid assembly, factor in the optical distance between front and rear glass element capsules, which is quite close, and, if you couldn't use the aperture as it is, you would have to redesign the aperture assembly to fit into it. Also, I have accidentally chipped my front glass element during a cleaning (thankfully far on the edge away from the imaging area) as the second element can easily fall out and clink against it so, for preservation's sake, you may also have to redesign the optical capsules themselves to prevent that.

So, for many cases like this, you're having to essentially remake the lens you're wanting to rehouse and all the design work and careful measurements required will be too much for many when they could simply get gears and simply open the mounts to take out the aperture balls for click-less apertures. Thankfully, from conversations I've had at NAB last year and a few emails since, there are some folks looking to get into the rehousing game and for less than the current competition for Canon FD and others but it's going to take some time and especially after the current global situation.

 

[Jacek Zakowicz]

Still lenses have inheritant flaws such as image shift the no sleeve is going to fix. The mechanical precision required to keep glass elements from lateral movement is what makes the cine lenses labor intensive and expensive. There is no silver bullet, just tedious mechanical labor. Trust me, I've been looking for the ultimate solution for over 30 years and keep coming back to the same conclusion....

 

[paul engstrom]

Hello,

We have a set listed for sale that seems to be pretty much exactly what the posters (and readers?) of this thread are looking for. Its a pretty unique set and for the right type of shooter I think it will be an awesome fit. Here it is if you are interested:http://www.reduser.net/forum/showth...D-PL-mount-Set-For-Sale&p=1909416#post1909416

I echo Jacek's thought re: the type of reliability rental houses and working camera crews are looking for. They typically want more on the inside of the lens than what most of the rehousing companies and DIY types are delivering. Case in point: we're having to rehouse some of our lens sets that have already been rehoused in a manner that just isn't solid enough inside for our clients' needs...

BUT -- I'm trying hard to distinguish between the higher expectation that some Redusers would have and the more modest -- but certainly still valid -- goals that other Redusers have. Using the previously mentioned set as an example, $18k for 6 modestly rehoused lenses (glass included) compared to $30k for rehousings + $10k in glass (about $40k all in) is a pretty significant difference.

For an owner-operator that will handle their equipment gently (use low torque motors or hand focusing, etc.) that extra $20k+ can be used for a lot of additional production value -- or a decent used car.

I've seen similar relatively unique sets for Panchros and that sort of thing that would be a really smart move for this type of Reduser. And of course -- RED Pro Primes. Such awesome good glass for such a little price. Those have decent mechanics... What a deal. Seriously.

In my personal case I began with a smart Canon EF mount made by Erik Widding at Birger Engineering that let me use Viewfactor's sick little focus knob to wirelessly control Canon EF lenses. It worked great. Jacek came out with a similarly awesome product a year or two later if I recall correctly. I shot short films, stock footage and promotional films with that setup. For higher level jobs I rented more robust cinema specific lenses (that really are more robust, high tolerance and reliable than most of the [but not all] rehousing and DIY options out there). These 'lesser' tools were key to the start and growth of my career.

I remain thankful for Jacek's efforts to create economical pathways to quality film work. He also hits to a high bar. He knows what the working crews require.

In a similar vein we just got some great results on a project with the Sony autofocus lenses on an A7S iii. I'm looking forward to RED's autofocus developments with electric RF lenses and improved integrations with RT motion and Cmotion FIZ units... I think these will be used by lots of filmmakers (!)

And we also recently shot with Leica's M.08 lenses -- which are just sleeved. They don't really like matte boxes and FIZ units are hard on them. BUT... weight matters and they are tiny and lightweight. Just plan on servicing them a lot.

All that to say -- it is pretty enjoyable to appreciate the different needs of different artists at different points in their careers. The higher costs for higher quality housings and lenses are not always vanity costs. And some users really can do wonderful work with far 'less' robustness and reliability...