Four Thirds Format?

Posted January 29th, 2008 by Sly

Beginning Digital Photography

The Evolt 510 that I have been using uses a 4/3 format (has a 4/3 format image sensor) while I have read that the majority of other cameras similar in specs are 1.5x crop.

Can someone explain what that means in english? ;-)

Sly

Not me. We had a similar

On January 29th, 2008 Shawn says:

Not me. We had a similar question in our Orleans Camera Class this past weekend and one of the store techs tried explaining it - he failed to do it in English though. :)
--
Shawn King
Host/Executive Producer
Your Mac Life
http://www.yourmaclifeshow.com

Those numbers only matter

On January 29th, 2008 G_Ramsey says:

Those numbers only matter if you are trying to use lens's made for a film SLR on a DSLR or perhaps the other way around. It represents the difference between the size (measured diagonally) of the sensor in a digital camera and the size of a 35 mm frame. Wikipedia has a decent explanation under "crop factor". See if that helps. In short, I don't think you need to lose sleep over it if your using all "digital" equipment.

Glenn Ramsey
Juneau, AK

This is a issue that can be

On February 18th, 2008 Fermat says:

This is a issue that can be confusing. On your camera there are a number of facts and figures that all have the value 4/3, 4:3 or Four Thirds, this makes it even more confusing.
Also this is something that is much easier to explain with a pen and paper.
looking at the specs
On your camera the Sensor size 17.3 mm (H) x 13.0 mm (V) so using the Pythagorean theorem the diagonal distance is 21.6 mm this is the important number. A negative of 35mm film is 24mm x 36mm diagonal 43mm. The Crop Factor is how much smaller your camera's sensor is than a piece of film. 43/21.6= 2 so your crop factor is 2x. A bigger crop factor means a smaller sensor.

So what does a Crop Factor mean to a normal person?
A smaller senor means you use a short lens to take the "same photo". Sly pretend that the two of us are standing next to each other you have your Evolt 510 (crop factor 2x) and I have a film camera (crop factor 1x) and we both want to take photos that have the same things it them, eg the building at the extreme right and the big tree on the extreme left. I will need a lens that is twice (2x) as long as you. eg if I use a 50mm lens you would use a 25mm lens.

One disadvantage of a crop factor of 2x rather than a full frame (crop factor 1x) is that it limits you in shooting photos with a small depth of field, where only a small amount of the photo is in focus. see this photo of Leo Laporte's

I know it is confusing, ask any more questions you want?