Setting the date on a Honeywell RTH7400 Thermostat

My Honewell RTH7400 somehow time-travelled a day into the future, and it turns out you have to “hack” it to fix the date on a hidden diagnostic menu. Full credit to Daniel from for the solution. RTH7400

  1. Select System
  2. Press and Hold Fan
  3. Should see 0120 with setting 20 blinking
  4. Press next to 0130, this is the year
  5. Press next to 0140, this is the month
  6. Press next to 0150, this is the day
  7. Press Done.

I’ve also grabbed the PDF instruction manual for the RTH7000-series in case you find it handy!

35mm Slide Archiving Project

I’m in the process of wrapping up a bunch of ongoing projects to free up some time this spring.

When my grandparents passed away I inherited my family’s box of old slides. For more than 20 years now I’ve been working on a way to scan them – but scanners 10-15 years ago weren’t very good, slide scanners were really precise but slow (there were about 2000 slides!) and the various photo apparatus and projection capture systems were all clunky or costly, especially transferring slides to film negatives, which cost a fortune to get developed.

Along came digital, and for a while it was “close but not quite good enough” resolution. Last year I bought a new Canon DSLR (the T5i) with an insane sensor on it, and finally, after years of trying to find an effective way to digitize all of the slides, the tech allowed me to put together a super simple workflow.


I built a light table using a piece of fogged white acrylic and a fluorescent tube (daylight and incandescent balanced so there’s no colour cast) and laid the slides down on it. I have a loupe so I could quickly cull the boring ones and the ones that weren’t in focus (like nearly half! We forget how hard getting sharp photos was before multi-sensor autofocus!).

Then I’d shoot them with my macro lens – snap, snap, snap. A little cropping and colour correcting script in Photoshop finished the job, and voila – high-res digital scans of my family’s slide collection. I did the entire batch in a weekend.


That’s me in the pink hat, chillin’ in a castle in 1978. (My Great Aunt? Dad, Mom, Grandmother pushing me, and Grandfather)

A few observations from the process:

  • The photos people find most interesting are the ones with people in them. My grand-dad was a shutterbug who snapped a lot of birds and airplanes and stuff but 40 years later the ones people are excited to see are the ones with their kids and visitors from overseas and funky fashions. It sped things up to prioritize the photos based on subject.
  • I was warned explicitly as a kid to never touch the slide surfaces, but I have to assume some finger-touching must have occurred. 40 years on there’s no sign of fingerprint corrosion on any of the photos, I think the slides are physically pretty robust. Chemically though – everything is transitioning into purplish hues, and I had to do some extensive colour-correction wizardry to keep the greens and yellows vibrant.
  • The slides were very disorganized when I started – but I found a fast trick for sorting them. Slides would have been processed 24 at a time (usually 1 roll per family event) at different film development shops based on location, so when I separated Blacks from Kodak from Fujimatic just based on the logos on the slide borders, I inadvertently sorted them chronologically. Kodak England slides were unilingual, while the Canadian ones were bilingual – little characteristics that helped me group everything up without having to determine which island a palm tree species might be from. 🙂