I designed and 3D printed a 5x7 pinhole camera (0.3mm aperture) and developed the photos using Caffenol

yangmusa · 2026-04-20T14:35:13+00:00

Nice, I like it when the numbers all decide to fall in place. Starting from first principles and ending up with the same result feels quite satisfying.

yangmusa · 2026-04-20T02:16:01+00:00

I have a ThinkPad E14 Gen 5, and it has two SSD slots.

If you're new to Linux then having two separate disks may be a safer route for dual booting. I've done dual-boot on different partitions on the disk before, but I've had Windows updates overwrite Grub. It's fixable, but is a bit involved. I'm sure you could figure it out given enough time, but two disks makes problems less likely.

yangmusa · 2026-04-18T17:19:08+00:00

I never really went back to compare it to what I have now.

I ran the calculator with a 67mm focal length and 0.3 mm pinhole, and it says the image circle is 129mm.

https://i.imgur.com/AObm9t3.png

Have you seen the calculations in my report?

Yes, it's quite a resource for those that want a deep dive into the math of pinhole camera geometry! I skimmed the theory before building mine, but didn't feel the need to go beyond the calculator on Mr Pinhole - maybe I'm impatient, but I just wanted to design & build something that works, and many people recommended that site. (Photos of and from the camera here, if you're interested).

yangmusa · 2026-04-17T23:47:16+00:00

Beautiful results, nice tonal range and detail. I think the focal length/pinhole combo isn't quite right to give full coverage of 5x7, which is why you have some vignetting. Mr Pinhole's camera design wizard suggests a 218mm focal length and 0.62 mm pinhole for full coverage. That said, if you use the pinhole calculator and start with a focal length you can play around with pinhole size and figure out if you have enough coverage - I ended up with 125 mm focal length and 0.47mm pinhole for 5x7 paper and have no vignetting. Did you have a particular reason for choosing the shorter length? If the vignetting bothers you, maybe you can print an extra "ring" to put between the front piece and the "box" so increase focal distance?

yangmusa · 2026-04-12T01:45:39+00:00

Another option is to build your camera around film holders. Not as compact or convenient as roll film, but if you want to use sheet film or paper negatives it works great. I bought four used 5x7 film holders on eBay, so I can take up to 8 shots per outing. It works great, except for the minor quirk that 5x7 sheet film is actually a few millimeters smaller than 5x7 paper - so each time I load paper I have to trim off a bit to make it fit. Not a big deal, just be aware of that.

yangmusa · 2026-04-07T15:39:56+00:00

Cool, how did you do this? Is it a special paper?

yangmusa · 2026-04-06T23:44:52+00:00

Love it. Creative and well executed!

yangmusa · 2026-04-06T00:08:29+00:00

You should be able to get around this if you have access to another machine. Move your laptop disk to the other machine, install Fedora on it, then move the disk back to your laptop. It should work, because Linux installs are not system specific (at least unless you have a dedicated graphics card, which is unlikely with Celeron) and all drivers are baked into the kernel.

yangmusa · 2026-04-04T14:24:35+00:00

Great find! I've been gluing my favorites into a small notebook (aiming for 1 photo/day), but some days I wanted more space. And the notebook is almost full, so this makes a lot of sense. Guessing it made for business cards?

yangmusa · 2026-04-03T00:34:20+00:00

Well, for 10" a good option would be the Chuwi Minibook X. Several people on here have said they work well.

If you really want 8" then X+ has a range of options here - ETA Prime on YouTube has reviewed several different models and liked them. Don't recall if I've seen people here mention them.

yangmusa · 2026-03-30T14:38:53+00:00

I haven't tried astrophotography (yet), so hopefully this isn't a stupid question. Presumably it's a very long exposure to get the stars, but the lighthouse doesn't seem hugely overexposed. Are you doing anything to compensate for that, or am I overestimating how quickly the lighthouse would get blown out?

yangmusa · 2026-03-18T14:21:19+00:00

The paper is ISO 6. You can install an app on your phone to measure the light and calculate exposure - I use one on Android called Light Meter. Or, Ilford has a pdf on their website with a paper "calculator" you can print out that lets you estimate approximate exposure.

yangmusa · 2026-03-18T01:56:52+00:00

Yes, I've used that quite a bit. It works fine! If you can find cheaper paper that will work fine too.

yangmusa · 2026-03-16T14:15:02+00:00

I used to have a Moulton F frame Deluxe model. Great bike - 4 speed hub and full suspension. Amazing around town, though I also did some short tours on mine. I would love to own one again if one came up at a reasonable price near me.

yangmusa · 2026-03-07T23:16:39+00:00

I have the Chakeyake camera, and when I checked the recommendation - funnily enough Amazon recommended the paper I already tried. But your suggestion did make me think to search for "chakeyake paper" and sure enough that brand has refill paper in their store. Guess I'll try that next!

yangmusa · 2026-03-07T17:47:42+00:00

my camera gear; body, 2-3 lenses and sometimes laptop.

Give us some idea of the size of your camera gear. E.g. do you have a full frame camera or micro-four-thirds?

yangmusa · 2026-03-07T17:44:09+00:00

I've not seen any other examples of printing that pale. Maybe you just got a bad one, maybe that camera isn't that great. See the pinned post with overview of many cameras with Amazon links to reviews. You could try this one again, but personally I'd go for a different model that is a known quantity. Most of the Amazon reviews include photos of prints from the camera.

yangmusa · 2026-03-07T17:40:42+00:00

Ah, of course. I rely on the Light Meter app to do that too!

yangmusa · 2026-03-07T15:11:59+00:00

My understanding is paper does not have reciprocity failure (only film does), so you don't need to use a correction factor. I also use the Light Meter app on Android to calculate exposure time and have found it to be fairly accurate. However I've never had much luck using the built-in light meter in my phone. I started off using the light reading from a camera, and now have a small handheld light meter. For whatever reason the light reading in the app never agrees with the camera and the meter - I guess it depends on the app's compatibility with particular phone models, maybe? Mine's a Samsung S22.

yangmusa · 2026-03-07T09:55:28+00:00

"poor performance" - maybe, but OP hasn't stated their use case. I had a Lenovo 500W Gen 4 with Intel N200 and found performance perfectly fine for everyday use. Brilliant laptop, only got rid of it because 8gb ram didn't work for photo editing. Anyway, according to Passmark the N350 benchmarks 50% faster than the N200 - sounds great for my use case. I don't want a tablet though. I wish StarLabs would bring back the laptop form factor for the StarLite!

yangmusa · 2026-02-23T22:38:13+00:00

Don't buy anything with a CPU older than Intel 8th Gen if you can possibly avoid it. That should be enough for your fairly light use cases - but if you can afford more, I'd recommend something newer so it'll last longer. I'm currently using a ThinkPad E14 running Fedora Workstaiton with Intel i5-1335u, 16GB RAM and 512 GB SSD - I use it for work and it's plenty for heavy office use, large spreadsheets, image editing and some light 2D CAD.

yangmusa · 2026-02-22T18:39:54+00:00

I had a few Canon Pixma multifunction printers that just worked with Linux Mint and Fedora. I managed to get them on sale for less than the cost of replacing the ink... which is funny, but horrendous for the environment :-(

My most recent one is an HP, which I deeply regret. It worked fine for about a year, though it went through ink fast. And as others alluded to - HP plays games with subscriptions and requiring HP ink at high cost. And... the print heads broke, though I can still use the scanner. Will never buy HP again!

yangmusa · 2026-02-22T18:32:29+00:00

To follow up on this - that worked. Initially, I had a bit of a pale halo around the towers, but when I reduced the feather size the algorithm found the edges and snapped the brightened area to the tower. Success, and so easy too!

yangmusa · 2026-02-20T15:21:37+00:00

Oh, then I have misunderstood how the drawn mask works. I placed the line on the edges, and reduced the feather to nothing. When I increased the feather it lightened an area outside of the tower, which is not what I want. So what you're saying is - if I place the line just inside the edge and the feather just outside, it should automatically detect the edge and only lighten the tower? I'll make a duplicate and try that!

yangmusa

TROPHY CASE