lxforrest
Newbie
It’s been three months since I last wrote a blog. These past three months have been tough for me—quitting my job, dealing with an emergency family issue, researching suitable camera sensors, lenses, and SoC chips (with very little technical background), and asking my coder friends for help to make a long-hibernated Raspberry Pi take photos.
Finally, today I’ve kind of built my first screen-free digital camera from scratch. I’m not sure if it has the largest viewfinder for a screen-free digital camera, but it’s definitely the ugliest.
In my imagination:
Agfa Optima Sensor, got a large VF (1 inch X 0.85 inch)
My very first prototype:
Let's call it Rewindpix V -1 (Negative 1)
For the hardware:
Mission accomplished!
Outdoor photo testing will be soon and without the IR-cut filter, the image color could be very ugly, but will see.
The next step will be to apply the photo to some Lightroom presets to check if the output has a 'film-like' quality, while waiting for the film filter app to be completed.
Some updates for the Rewindpix camera hardware selection:
Sensor:
Except for Flashback, which uses a 3-4MP sensor, Camp Snap (including its brothers/sisters on AliExpress) and Paper Shoot all use 8-12MP CMOS sensors with sizes ranging from 1/3" to 1/4". I'm not sure if they use Sony IMX sensors, but the common issue is the very poor dynamic range, with blown-out highlights and pitch-black shadows.
For resolution, I do believe 8-12MP is enough for daily snapshots and social media sharing (this type of point-and-shoot camera should never compete in pixel peeping or hair-counting competitions). Most importantly, with an affordable price tag, it’s impossible to find a lens with high enough resolution to feed more than 8MP pixels into the sensor—any lens with >180 lp/mm would be incredibly expensive.
For dynamic range, however, I’ve found that some Sony IMX sensors with sizes around 1/2.3" to 1/2.8" offer better dynamic range. These are primarily used in security and surveillance cameras for improved performance in bright daylight or low-light/night vision situations. It will be interesting to test one out with a F1.4-F1.8 M12 lens
Lens:
All three mainstream cameras (Flashback, Camp Snap, and Paper Shoot) seem to be using plasticky micro lens modules. However, I may have been wrong about Paper Shoot, as based on the released specs, its lens module is sourced from Largan Precision, a well-regarded lens company in Taiwan and the paper shoot does produce the best image quality of all three. In my opinion, given the estimated BOM cost, none of the lenses are high-resolution enough to fully feed 8-12MP pixels to their sensors.
My solution to improve image quality is an 8MP M12 6mm lens paired with a 1/2.3" to 1/2.8" sensor in the 8-12MP range and a larger pixel size (1.45um - 1.55um). This combination is almost equivalent to a 40mm focal length (35mm equivalence), similar to the Ricoh GRIIIx and the Agfa Optima. This allows me to use its large viewfinder directly, making it easier for OEMs to build the molding without the need for complex future optical development. A retro point and shoot cheap version of Ricoh GRIIIx with a large viewfinder and good dynamic range. How cool will that be?
SoC:
After tearing down multiple screen-free digital cameras (including some '4K' digital cameras from Amazon), I found that the biggest issue with their in-camera 'film filter' effect is that the SoCs used have low capability to process color emulation. Without accurate white balance for photos shot in various conditions, it's nearly impossible to apply a universal filter and expect consistent, film-like results. Therefore, I am in the process of selecting a better SoC, but it needs to be affordable. It might be one of those used in true 4K dash cams, offering acceptable white balance consistency, faster processing speed, and possibly WDR support for improved dynamic range output.
I will be on China trip soon to talk to some ODMs to see if any of my ideas is feasible for a product.
Finally, today I’ve kind of built my first screen-free digital camera from scratch. I’m not sure if it has the largest viewfinder for a screen-free digital camera, but it’s definitely the ugliest.
In my imagination:
Agfa Optima Sensor, got a large VF (1 inch X 0.85 inch)
My very first prototype:
Let's call it Rewindpix V -1 (Negative 1)
For the hardware:
- Raspberry Pi 4 (Donated from one of my coder friend. It hibernated for 2 years in the drawer)
- M12 lens with 5MP resolution and 6mm focal length
- IMX519 Sensor (16MP, 1/2.6")
- Shutter cable
- Large viewfinder (salvaged from a broken Agfa optima)
- Some cardboard from Amazon box
Mission accomplished!
Outdoor photo testing will be soon and without the IR-cut filter, the image color could be very ugly, but will see.
The next step will be to apply the photo to some Lightroom presets to check if the output has a 'film-like' quality, while waiting for the film filter app to be completed.
Some updates for the Rewindpix camera hardware selection:
Sensor:
Except for Flashback, which uses a 3-4MP sensor, Camp Snap (including its brothers/sisters on AliExpress) and Paper Shoot all use 8-12MP CMOS sensors with sizes ranging from 1/3" to 1/4". I'm not sure if they use Sony IMX sensors, but the common issue is the very poor dynamic range, with blown-out highlights and pitch-black shadows.
For resolution, I do believe 8-12MP is enough for daily snapshots and social media sharing (this type of point-and-shoot camera should never compete in pixel peeping or hair-counting competitions). Most importantly, with an affordable price tag, it’s impossible to find a lens with high enough resolution to feed more than 8MP pixels into the sensor—any lens with >180 lp/mm would be incredibly expensive.
For dynamic range, however, I’ve found that some Sony IMX sensors with sizes around 1/2.3" to 1/2.8" offer better dynamic range. These are primarily used in security and surveillance cameras for improved performance in bright daylight or low-light/night vision situations. It will be interesting to test one out with a F1.4-F1.8 M12 lens
Lens:
All three mainstream cameras (Flashback, Camp Snap, and Paper Shoot) seem to be using plasticky micro lens modules. However, I may have been wrong about Paper Shoot, as based on the released specs, its lens module is sourced from Largan Precision, a well-regarded lens company in Taiwan and the paper shoot does produce the best image quality of all three. In my opinion, given the estimated BOM cost, none of the lenses are high-resolution enough to fully feed 8-12MP pixels to their sensors.
My solution to improve image quality is an 8MP M12 6mm lens paired with a 1/2.3" to 1/2.8" sensor in the 8-12MP range and a larger pixel size (1.45um - 1.55um). This combination is almost equivalent to a 40mm focal length (35mm equivalence), similar to the Ricoh GRIIIx and the Agfa Optima. This allows me to use its large viewfinder directly, making it easier for OEMs to build the molding without the need for complex future optical development. A retro point and shoot cheap version of Ricoh GRIIIx with a large viewfinder and good dynamic range. How cool will that be?
SoC:
After tearing down multiple screen-free digital cameras (including some '4K' digital cameras from Amazon), I found that the biggest issue with their in-camera 'film filter' effect is that the SoCs used have low capability to process color emulation. Without accurate white balance for photos shot in various conditions, it's nearly impossible to apply a universal filter and expect consistent, film-like results. Therefore, I am in the process of selecting a better SoC, but it needs to be affordable. It might be one of those used in true 4K dash cams, offering acceptable white balance consistency, faster processing speed, and possibly WDR support for improved dynamic range output.
I will be on China trip soon to talk to some ODMs to see if any of my ideas is feasible for a product.
