Fault finding

Printed Circuit Boards

New PCBs are in

New PCBs have arrived, these represent a significant upgrade to the previous alpha version. Circuit errors have been corrected and most importantly the light meter has been integrated into the board. Normally the components on these circuit boards would be placed by robots, as we are at the prototype stage still we are hand soldering all the components. This means working with tweezers under a magnifying glass and double checking everything before applying power to the circuit. It can be pretty easy to fry a board if you don’t do things in a methodical manner, so we are taking our time to get things right.

Once the key components are on board we can power up and run a few tests. Then the main chip, the “brain” of the TYCH can be programmed and full board functionality tested out. We’ve got 10 to build up into Beta units plus a few extras to allow us to continue development whilst people are testing the cameras for us.


Light leaks

Light leaks and focus woes

It’s fair to say I wasn’t expecting the first few rolls of film to be perfect. I was very pleased to be getting recognisable images from the 1st working camera. Turns out there are a few issues to resolve. The focus is out of whack for all but the pinhole lens, pinholes have this lovely habit of always being in focus (albeit a slightly dreamy focus). For the meniscus polycarbonate lens things are clearly a little bit off. Images from my 1st 2 films taken with this lens have all been a little out of focus. I have a plan for fixing this issue, essentially it boils down to getting the lens positioned at exactly the right distance from the film. Solving that problem was going to need a special bit of kit, more on that later.

The other problem was a nice selection pf light leaks. My 1st black and white film was taken on an overcast day and I didn’t really notice anything unusual. Once I ran a colour film through the camera however the problem was a bit more obvious. If you are ever trying to track down light leaks there are a few things to bear in mind;

  • Red light leaks on colour negative typically come from the back of the camera as the light is filtered through the film base.
  • White light leaks are most likely from the lens side of the camera.
  • Any leaks that span the whole film from top to bottom are very likely due to rear door light leaks.

Turns out I had all of the above! Under strong sunlight the camera had more holes than a broken sieve.
The process for tracking them down involves close examination of your negatives, a good torch and some black tape. I am working on a redesign of the rear door labyrinth light seals (I had cut a few corners on the 1st design) which is now looking good. Also I spotted a rather large hole in the shutter mechanism which only shows up in strong light at certain angles! I’ve got a solution in the works for this as well so the next films should start to show the true potential of the TYCH.