90mm f/2.2 Petzval lens

prusaprinters

<p>A 3D printable Petzval style lens with mount options for Canon EF and Nikon F cameras. Uses a 42mm diameter 145mm focal length achromat for the front lens and a 31.7mm diameter 175mm focal length achromat for the rear. Together they are roughly 90mm and f/2.2.</p><p>The lens produces soft images with razor-thin depth of field and (in my opinion) fantastic bokeh. Field curvature causes sharpness to fall off away from the center of the image that, while less than ideal for landscape photos, creates a natural framing for portrait-type photos.</p><p>&nbsp;</p><p>I have instructions for assembly as well as a walkthrough of how I designed this lens along with more test shots on my <a href="https://www.jacksonbohm.com/read/designing-and-3d-printing-a-multi-element-portrait-lens">my website</a>.</p><p>&nbsp;</p><p>Thank you for your interest.</p><p>&nbsp;</p><p>&nbsp;</p><p><i>Edit: Added .STEP file for those who may want to play around with the design. As a heads up, the design is kinda messy (sorry) so good luck if you do want to make changes.</i></p><p>&nbsp;</p><p><i>Edit 2: To make the lens more usable I have modified my copy with a collapsible front lens hood (with threads to attach filters) and a 30mm filter ring to the focus carriage to add interchangeable apertures. Aperture disc files have been added. To calculate the f-stop of an aperture disc multiply the area of the rear lens element by ~2.5 then divide that number by the total area of the opening in your aperture disc. Apertures do not need to be circular and will impart their shape onto the bokeh of the image. I have included a couple of my more "creative" apertures as examples (the star works very nicely, the fighter jet not so much…)&nbsp;</i></p><p><i>These are the parts I added:</i></p><p><a href="https://www.bhphotovideo.com/c/product/1388613-REG/sensei_lhr2_t55_55mm_3_in_1_rubber_lens.html"><i>https://www.bhphotovideo.com/c/product/1388613-REG/sensei_lhr2_t55_55mm_3_in_1_rubber_lens.html</i></a><i> use step-up/down rings to whatever size filters you use. I can say that UV and IR performance with the lens seems acceptable, will add example shots at some point.</i></p><p><a href="https://www.bhphotovideo.com/c/product/171194-REG/Tiffen_30UVP_30mm_UV_Protector.html"><i>https://www.bhphotovideo.com/c/product/171194-REG/Tiffen_30UVP_30mm_UV_Protector.html</i></a><i> Unthread the retaining ring and remove the glass (careful, the edges of mine were quite sharp).&nbsp;</i></p><p><i>I attached the parts with 5 min epoxy. The lens hood slots between the front flange and retaining ring quite nicely, and I simply ran a bead of epoxy around the outside to avoid getting epoxy near the glass. For the rear filter ring I smeared a layer of vaseline on the rear lens element (avoiding getting any on the plastic) and applied a bead of epoxy around the outside of the ring to fix it to the focus carriage with the female threads facing out. The vaseline is easy to remove with a few cotton swabs soaked in alcohol.</i></p>