A DIY 177mm f/8 Cooke triplet for 4x5 from off-the shelf lenses that YOU can build

[Steven Tribe]

Also ordered a thread turning tool..........

Now this is getting interesting!!

Link, please?

[Nodda Duma]

Just look up "thread turning tool" on ebay (without the quotes). It's a lathe tool.

[Jody_S]

Just look up "thread turning tool" on ebay (without the quotes). It's a lathe tool.

Next you'll be converting that thing to CNC so you can start production...

[Nodda Duma]

Lenses arrived from Thorlabs, along with the snack pack they always include.

[Nodda Duma]

I'll edge blacken the lenses.

[Nodda Duma]

I just dry fit the lenses to see what it'd (tack bonded in place with NOA 61). Imaged a light bulb 15 ft away onto my notebook and it forms a nice sharp image. Iphone picture compression doesn't quite do it justice.

[Nodda Duma]

Not satisfied with that, I made a camera obscura of sorts out of a soda box (which my wife drinks, ripping the boxes open like a grizzly bear) to measure focal length and view image from more distant objects.

[Nodda Duma]

Close-up of the focused image.

[Tim Meisburger]

Looking good! It will be really interesting to see a portrait, when you have it complete.

[Nodda Duma]

Thanks.

Flange focal length (distance from the outside mounting flange to image plane) measures ~ 165mm. Reversed, focal length measures 200. Very rough measurements of course. Maybe I'll have a 2-step zoom

Next I'll either pull the optics to machine the slot for the waterhouse stops, or make a lensboard to mount it to my camera. Slow and steady, or go for broke? Decisions, decisions...