u/bryan112

Their reasoning is so vague. Ive only posted about film photography and food

"Dear Little Red Book user, thank you for your patience. We fully understand your current concerns. After verification, your account currently faces a security risk, and there is no other solution at this time. Please refer to the actual usage situation on the platform. We suggest you review the "Community Agreement" to confirm whether your daily usage habits comply with the platform's requirements…"

I just know that one of my post has been getting a bit of traction and then I looked at the notification and I'm banned.

Hello everyone, I just want to share a little something I'm working on. This is a sidequest for a film camera I’m designing.

Since enlarger lenses don't have a focusing mechanism, I had to make an adapter with one built in. I know there are already third-party helicoid kits available, but I felt like doing a challenge, so here I am (plus they're expensive).

I went with a basic push-pull system because I didnt know how helicoids work when I initially made this adapter last week. It was just an outer barrel, an inner barrel, and a cap to keep it all together.

It was quite shaky because of how I designed it. The inner barrel sagged due to the clearances, so I spent my Friday night designing a proper helicoid adapter for the lens. I'm actually printing this updated design right now as I'm writing this.

I’ve added some sample snapshots below from the Version 1 test. The lens is a Rodenstock El-Omegar 50mm f3.5.

Are yalls wallets ready for this?

Hey everyone,

I’m taking a quick segue from an optical bench tool I was prototyping recently. I’ve been trying to find the flange focal distances for some vintage enlarger lenses because I want to use them for a 3D-printed TLR camera I’m designing.

I wanted to share some progress on the focusing side of things. Since enlarger lenses don't have their own focusing rings, I had to make an adapter. I’m currently using a digital camera to do the trial and error so I don't waste money, with the far future goal of eventually moving these over to the film camera bodies I have (Nikon F, C/Y, and M39 mounts).

I "frankensteined" this together in SolidWorks using my last few remaining braincells. I didn't want to spend hours modeling mounts from scratch, so I grabbed a Fuji X-mount from one model and an M39 thread from another and just merged them onto my own design. I went with a basic push-pull system because helicoids are still a bit of a mystery to me! It’s just an outer barrel on the camera, an inner barrel for the lens, and a cap to keep it all from flying off.

This setup is actually helping me figure out the minimum focusing distance. I’ve never actually used these lenses for enlarging, so I was surprised by how tiny the focus throw is. From my testing outside, it only takes a very minimal shift of the barrel to change from ~3 feet to infinity.

Since this is just a prototype, everything is printed in PLA. It's quite shakey right now because the inner barrel sags down a bit due to the way I designed the clearances. The focusing is actually quite fast because the throw is so small, but it requires me to physically hold the lens in place when I shoot since it doesn't stay put on its own. I'll be moving to PETG for the final iterations to get it more durable and hopefully smoother, but I'll likely need a proper helicoid in the future to really kill that wobble and keep the focus locked.

I've also found out that this approach isn't a "one size fits all" design. The measurements I found only apply to the specific lens I used, which is a Rodenstock El-Omegar 50mm f3.5. I also have a Rodenstock Rodagon 50mm f2.8, and that one hits infinity at a completely different distance.

Initially, I was thinking of using a bellows system for focusing on the TLR camera I’m designing. However, based on what I’ve learned from this project, I’ll be switching to how most TLRs focus; a "box in a box" setup dunno what it's called. It’s basically a push-pull mechanism, which makes sense since the focus throw on these lenses is so minimal anyway.

I’ve added some sample photos below. Even with the DIY setup, the glass is impressively sharp!

EDIT:
To answer that one guy. IT'S CHEAAAP. IT'S FUUUN. ENLARGER LENSES ARE STUPIDLY SHARP.

​Here's a barebones tool I am working on for finding flange distance of lenses. I'm making one for my TLR camera project.

​It's basically a bracket on a tripod where I'm going to attach a focusing screen holder and a lens holder.

​The holders are a work in progress as I'm still trying to grasp SolidWorks. The green cube thing in the second pic is my first milestone, really, as I have not dealt with 3D modeling threads before.

​Anyway, back to the tool, this is just a rough "preview" you could say. When the holders are done, I'll lock focus and measure the distance with a caliper. There's probably a more elegant way of doing this, but it works!

Happy to hear advice and suggestions!

Edit: I have been informed in discord that im basically making an optical bench. The more you know lol