Follow Focus + Matte Box

[Matthew B Clark]

Wow, apologies for the terrible spelling.

[Matthew B Clark]

I mean, I know it sounds dumb, but I'm freaking out about lens height. Because everyone with these gizmos shoots with little baby sized DLSRs and Blackmagic cameras and such. So they aren't really "designed" for an old Russian 16mm camera with a fat zoom lens on it, ya know? Anyway.

 

Is this workable? Sticking these 16" rods into this other complete baseplate system?

 

Baseplate/system overall: http://www.amazon.com/Fotasy-BPR-Making-System-Release/dp/B005HTMYTO/ref=sr_1_2?s=electronics&ie=UTF8&qid=1417286065&sr=1-2&keywords=fotasy+rail

 

16" rods to stick in there: http://www.amazon.com/Fotasy-Rod_40cm-16-Inch-Mattebox-Cleaning/dp/B00DUK1K3I/ref=sr_1_4?s=electronics&ie=UTF8&qid=1417286065&sr=1-4&keywords=fotasy+rail

 

Good to go? Sorry for being mentaly challenged on the subject.

[Gregg MacPherson]

Hey,

I don't know if that that rod base system is giving you anything usefull. This whole piece of kit is designed to do other things. The sliding plate isn't usefull there and I don't like the design of that.

 

Easiest way will be to see what other K-3 people have done.

 

Thinking from scratch. The rods need to be 85mm below the optical center of the lens and they need to be centered on that axis horizontally. Is the K-3's 3/8" mounting thread centered on the lens axis? That may help if you do adapt something semi ready to go.

 

If you sit the camera on a flat surface and measure from surface to the optical centre, you will see how the rod base needs to be configured. The camera or the rod clamp will need to be packed up.

 

There are simple little rod clamp blocks cheap on eBay that you could screw to a 10mm aluminum plate. Thread your own holes in that plate so you have correct position with the optical center. If you don't have access to a workshop then there may be something on eBay you could adapt.

 

I'm away today, I'll read what happened tonight. Have fun. Eat candy after this job's done.

[Matthew B Clark]

Gregg! I got to the last line with a cookie in my mouth! I'm already feeling the guilt. But, thank you for the tips here.

 

I measured it up...

 

The mounting thread is exactly 1 inch off axis. Here is a photo of the bottom of a K3 to help show it exactly in practice:

 

 

Lens axis to base measures 3 inches (76mm) roughly. I'm sure there's a mm or two give on that. But that's pretty accurate. I measured from the grooved center of the aperture ring down to the base on a flat surface.

 

 

And from mounting thread to end of the zoom lens (fully extended) is just under 8 inches.

 

So for my shopping list, I guess I need:

• 16" rods
• Baseplate that slides the mount side to side at least 1"

Any recommended brands of stuff like this? Especially on the cheap.

[Matthew B Clark]

Wonderng if the Zacuto Universal Baseplate can be slid side to side up to a full 1" while staying stable...

[Gregg MacPherson]

I haven't seen the Zacuto one you're refering to.

 

I would go with something simple and cheap and maybe redrill a couple of holes to reposition the rod clamp. Saw some simple and cheap ones on eBay.

http://www.ebay.com/itm/Rod-Clamp-Tripod-Mount-Cheese-Plate-fr-15mm-Rod-Support-Follow-Focus-DSLR-Rig-V3-/360619459229?pt=LH_DefaultDomain_0&hash=item53f698429d#ht_2376wt_943

 

http://www.ebay.com/itm/Tripod-Mount-accessory-Cheese-Base-Plate-Rod-Clamp-fr-15mm-Rod-Support-DSLR-Rig/170867959814?_trksid=p2047675.c100010.m2109&_trkparms=aid%3D555012%26algo%3DPW.MBE%26ao%3D1%26asc%3D27890%26meid%3D4d6a8bbe1a644353bded416aa723771d%26pid%3D100010%26prg%3D11452%26rk%3D11%26rkt%3D24%26sd%3D281028224347#ht_1878wt_943

[Matthew B Clark]

That looks tempting, except I don't have the slightest idea what to use to connect that to my camera threads (except maybe a random screw!)

 

The Zacuto I was referring to was this:

 

http://www.bhphotovideo.com/bnh/controller/home?O=&sku=587442&gclid=CJrQtYHrosICFUmCMgodHiUAzA&Q=&is=REG&A=details

 

One of the photos shows it sliding over to accomodate weirdo cameras like mine. If there's a cheaper way, I'm all ears. But I think that one on eBay is just inviting me to flub the job with my driling skills.

Edited November 30, 2014 by Matthew B Clark

[Gregg MacPherson]

That Zacuto looks complicated and expensive, relative to what you need. But I did a drawing and the K-3 is trickey when trying to adapt cheap available parts. The rod clamp cant just screw to the top of the plate without using a thick packer for the camera. So i looked at a solution where the rod clamp is screwed to the front of the plate. Sent the drawings to you as PDF. May be better solutions. Any ?

 

Ping me back with an address and I will send drawings

Gregg MacPherson <viz(at)xtra.co.nz>

Edited November 30, 2014 by Gregg MacPherson

[Gregg MacPherson]

I'll try attaching here as PDF.

 

rod base for K-3 top and rear view.pdfrod base for K-3 side view.pdf

Edited November 30, 2014 by Gregg MacPherson

[Matthew B Clark]

Gregg, thank you so much for providing those drawings to me, and really to all. That's really generous of you to step up and get into it to that degree, so thank you!

[Gregg MacPherson]

Hey, no prob's. That rod clamp is a best approximation from pics on the web, so not super accurate on height, but good enough to see the problem.

 

With the solution I gave you may have problems setting up with some sliding plates that you may use with big lenses. The rod clamp protrudes below, so may be in the way. Nicer to have everything level on the base. So maybe it is better to flip the clamp 180 so its base is flush with the base of the plate, then add a packer under the camera to get the height right.

 

If you learn how to drill and tap holes or befriend a machinist or hoby workshop guy you can make the part you need. And basic cheeze plates, a piece of aluminum plate with lots of holes and threaded holes so you can improvise camera mount setups.

 

Too much fun (so nerdy).

[Matthew B Clark]

Na, it's not nerdy. It is a big help! PS, do you think if I do the super16 lens re-centering ring conversion later on (it shifts the lens axis over 1.17mm) it will cause any issues down the road? That's one thing I'm also trying to account for now rather than later if it happens. If that small lens shift is not going to cause any issues with a matte box (in real life practice anyway), then I would leave it be and get the normal mount made. If it's sounding like a red flag let me know and I'll probably just account for that while getting this made. Sorry for all the questions. But if there's one thing I've learned it's to swallow your pride and actually ask. No matter how silly it sounds to whoever. Because if you don't know, then I mean, you don't know. And I kind of want to know....right?! Haha! Alright.

[Gregg MacPherson]

Re the MB after re-centering for S16.
There's normally some flexibility from the light seal. All the cheap boxes seem to like these neoprene donuts. Good MBs (and one or two of the cheap ones) have a round rubber bellows. In the center of that is a stepped fitting sized to the lens, which also has some wiggle room.

 

Aligning lens, plate, rod clamp.
Your machinist will know how to do this. If stuck I can send some ideas. Here are some tips.
Fit your zoom and find the center of the lens cap. If that rotates with focus, the center should stay the same height off the table.

Make the base plate parallel to the camera right hand side and the front of the plate a perfect 90deg. You might screw something onto the right hand edge of the plate to maintain the camera parallel.
On a flat table, assemble everything with packers to get the heights right and the lens cetered.
.
I don't think you need sideways adjustment to allow standard 16 vs S16, but it may help if the engineering isn't accurate enough. You could mill slots rather than drilled holes in the rod clamp.

 

Position of camera fore and aft, mounting holes.
(during the mock up assembly, or after the rod clamp is screwed on)
Slide the camera foreward as far as you can while keeping good finger access to switch etc. You need a mounting hole for that position.

 

Refinements to the drawings I attached.
I would use three screws to fix the rod clamp.
I forgot to draw the threaded holes for the tripod/sliding plate. A line of those would probably be about 17mm to the left of the camera mounting holes. You won't need all those mounting holes.
The right hand thumb screw will bump into the plate, just remove a little material so it can rotate.
The plate dimensions are an estimate. You could elongate it and trim some off the right side. Make that side flush with the camera, then you could screw a strip of aluminum on to maintain parallel.

 

Did you find a friendly machinist? By the time you are 50 you will probably laugh that you didn't just make this yourself.

Edited December 1, 2014 by Gregg MacPherson