How do I work out what zoom a lens has?

Energize · 20 Jul 2011 at 17:38

This information seems almost top secret in that I can't find any websites discussing it.

How do I work out what zoom a lens has on a digital camera? The camera I am using now is a fuji s8000fd with an 18x zoom lens for example, how do I work out what magnification the standard 14-42mm lens on the Olympus EPL-1 can provide?

Dunks · 20 Jul 2011 at 17:46

Optical zoom = maximum focal length / minimum focal length, from a 30 second google.

Thus, 3x.

Raikiri · 20 Jul 2011 at 18:19

Energize said:
This information seems almost top secret in that I can't find any websites discussing it.

How do I work out what zoom a lens has on a digital camera? The camera I am using now is a fuji s8000fd with an 18x zoom lens for example, how do I work out what magnification the standard 14-42mm lens on the Olympus EPL-1 can provide?

By looking at the number

42mm is three times more than 14, so it has a 3x zoom. A 50-150 would still have a 3x zoom.

The equivilent field of view is 28-84mm because of the 2x multiplier.

Energize · 20 Jul 2011 at 18:50

Thanks.

Out of interest why are such small zoom lenses so large in size compared to a 1500x microscope lens?

Raikiri · 20 Jul 2011 at 19:23

Combination of factors, I suppose.

Camera sensors are, for the most part much larger than your pupils which act as the sensors when looking through the microscope.

Also don't microscopes use fixed lenses (one magnification for each lens then you just turn it to another lens for more/less) which are much less complicated than zooms and they have built in lighting, so don't need to let in as much light.

And magnification isn't the same as zoom, the Canon MP-e 65 will do 5x magnification and it's tiny compared to say a Sigma 300-800 which would only do about 0.15x mag.

Energize · 20 Jul 2011 at 21:33

Yeah I was confusing the two, microscopes have a few rotating fixed lenses and a 10-20x zoom one.

Energize · 23 Jul 2011 at 05:02

Do you know if there are any smaller lenses available for the EPL-1, a fixed focus one perhaps? Would be nice to have something more compact just for leisure stuff.

Raikiri · 23 Jul 2011 at 05:10

Olympus do a 17mm f2.8 pancake lens, Panasonic also do a 20mm f1.7 pancake. Both of these are tiny.

They're fixed focal length btw, not fixed focus.

Energize · 23 Jul 2011 at 06:24

Sorry yes, wouldn't be much good otherwise I guess.

Energize · 23 Jul 2011 at 06:31

Just had a look and it is nearly as expensive as the camera! Why does such a simple lens cost so much?

Dunks · 23 Jul 2011 at 11:57

Energize said:
Just had a look and it is nearly as expensive as the camera! Why does such a simple lens cost so much?

Because they're actually not that simple a lens?

Calabi · 23 Jul 2011 at 12:49

Funny I've got the same camera and have been wondering this. I've noticed you get kind of a distortion if you zoom to far in or out.

Energize · 23 Jul 2011 at 18:09

Dunks said:
Because they're actually not that simple a lens?

But in comparison to the zoom lens it comes with? The camera is only 280 with the 14-42mm lens.