Manual Focus Hack for the Logitech C270 Webcam including demo

 

Impetuous guy that I am, I've done the hack.

This Logictech C270 in 720p is now a manual focus webcam.

Here's the how to:

I've figured some things out about this particular webcam.

It's angle of view is 60 degrees.

So that makes the focal length 30mm equivalent.

The lens is plastic and mounted in a small helicoid that screws in quite nice into a barrel mounted on the sensor.

 

 

 

I couldn't find any mention of the aperture but a quick search result suggested that most webcams have an f-stop of 2.0 - 2.8.

In my video, I guessed that the fixed focus point must be 3 feet.

But I'm not so sure.

I inputted the numbers into an online depth of field calculator and got these results:

Subject distance  - 3 ft

Near limit  - 2.85 ft

Far limit  - 3.17 ft

Total  - 0.32 ft

In front of subject  - 0.15 ft (47%)

Behind subject  - 0.17 ft (53%)

Hyperfocal distance - 55 ft

Circle of confusion  - 0.019 mm

 

The depth of field is only 4 inches! Which is not usable.

My guess is the ACTUAL aperture must be f11 and the ISO of the sensor is cranked up.

We could do a DOF test to deduce the actual aperture....hmmm.

I did consider drilling out the aperture to make it wider but the lense goes right up to the aperture. I would have to remove the lens from the helicoid sleeve and it's really glued in there!

Not the most exciting hack, but if you have a terrarium or some other set of macro needs and can't always spend $100 CA on webcams with focus, this fix is an option.

Have a great day.