Rotating Matte Box

prusaprinters

<figure class="media"><oembed url="https://youtu.be/Ry6vtkOcxK4"></oembed></figure><p><br>There are tons of matte boxes on the market, and it seems that every month a new design is released for the prosumer segment. But none of them satisfies me for my small cinema rig, so I decided to design one myself. This was my wish list for the perfect matte box:</p><ul><li>Small and light, in line with small mirrorless camera rigs.</li><li>Be able to stack smaller and cheaper circular threaded filters.</li><li>Quick lens change without a lot of screwing, unmounting, disassembling, etc.</li><li>Hold a set of circular filters in place, ND, polarizer, mist filter, etc.</li><li>Installed variable ND in a fixed position for everyday use.</li><li>Hold a 100mm graduated ND and easily rotate the angle of the filter.</li><li>Printable on the Prusa Mini.</li></ul><h4><br>Quick Rotate-Away Mounting System</h4><p><br>Get your matte box and filter set out of the way just with one movement! No more fiddling in small spaces for changing the lens or changing or cleaning the filters. No more “can you please hold the matte box while I change the lens” or putting the matte box and valuable filters on the floor just for accessing your camera mount.</p><p>&nbsp;</p><h4>Rotating Square Filter Holder</h4><p><br>This unique design permits inserting a 100mm x 150mm graduated filter at the front of the filter stage and rotate it as desired. This allows to directly darken a specific zone of the frame and at the same time maximizing the dynamic range of your sensor, something you cannot do in post. I've had a hard time finding a matte box with a rotatable rectangular filter holder. The only solution for me until now was a cumbersome 100mm square filter holder designed for photography, defeating one of the main purpose of the matte box, to quick change lenses without unscrewing and screwing filters every time.</p><p>&nbsp;</p><h4>Use of small, light and affordable circular filters.</h4><p><br>Not everyone can afford to shoot with big, heavy and expensive PL primes and spending a fortune on 4 x 5.65 filters. None of my vintage soviet lenses need so much filter glass. This design allows me to use cheaper and smaller 77mm circular threaded filters I already own and easily cover all my smaller primes.</p><p>&nbsp;</p><h4>Fast</h4><p>Quick connection to any small lens with a 82mm step-up adapter.</p><p><br><strong>Limitations:</strong></p><p>You can set the drag of the rail system printing the rail system with less tolerance, and you can screw more and press the TPU 100mm filter holder harder, but there is a limitation of the sturdiness of the whole rig. I wouldn't put this matte box on a crash cam or a car rig driving at 100km/h. This matte box is not designed for extreme wind or movements.</p><p>Since the matte box is supported on the rails and not directly on the lens, you should always be careful with lenses that extend while zooming or focusing. It would be possible to design a "lens donut" if needed, but I'm already very happy with the current design.</p><p>&nbsp;</p><h4>Print Instructions</h4><p>I printed the rod support, the core of the matte box, the mini hood, and the fastener with the beautiful and sturdy Prusament PC-Carbon Fiber with a 0.6 nozzle. I guess it could be printed with PETG too, but for me nothing beats the look and the sturdiness of Prusaments PC-Carbon Fiber.</p><p>The 100mm Filter Holder should be printed in TPU or other flexible filament to avoid scratching your 100mm filter! I used Flexfill TPU 98A from Fillamentum for this part, and it holds the filter very well.<br>For printing this part without supports, I previously printed a 100mm x 120mm x 1.8mm box in PLA and carefully placed it in place of the filter while on a printing pause. After the piece was cooled down, I just helped the PLA to separate itself from the top layer with a cutter, so it easily slips away. If you don't want to mess with a PLA support, you could probably print this part in two separate objects.</p><p>I provide you the Fusion 360 file, so you can customize and change the model according to your rail system. I strongly recommend you to accurately measure your rod separation and test the amount of clearance for the rod support. I printed the rod support with an inner diameter, so it fists tight but enough loose for moving the matte box with one hand or in case if a lens extends while focusing . Furthermore, I sanded the inner seams of the support for a perfect fit. Please don't breathe PC carbon fiber dust and sand it underwater for your own health.</p><p>You should also accurately measure the distance from the top of the rails to the centre of the lens. This is crucial for adapting the design to your camera and rail system.</p><p>Every meaningful value for customization is set as a parameter on the fusion file.</p><p>&nbsp;</p><h4>Build Instructions</h4><p>- Sand the inner seams of the rail system away for a perfect fit.<br>- Place two M3 threaded inserts on the rail support and four M3 short threaded inserts on the fastener.<br>- Carefully fasten your variable ND in place with 6 M3x5 grub screws, taking care not to overtighten it and screwing little for little on opposing screws. The grub crews should only fasten the fixed part of the variable ND and you should be able to freely rotate the filter after installed.<br>- With the variable ND already installed, insert the fastener first and then mount the rest of the parts.<br>- Secure the rail support with the matte box core with two M3x10 screws.<br>- With four M3x12 screws, fasten the hood and front filter holder in place.</p><p>For the variable ND stage, I used a<i><strong> B+W XS-Pro ND-Vario 1-5 MRC nano 77mm</strong></i>. In case you want to install another ND, I strongly suggest rebuilding the parts using the provided fusion file and modifying the vnd_diameter variable.</p><p>&nbsp;</p>