# how to calculate the number of times a zoom is?

Status
Not open for further replies.

#### Paul_Yeo

##### Senior Member
how to many the zoom in mm to the "x" one?

eg, what is 12x zoom equivalent to? 12x = 300mm??

actually, how to calculate one?

#### Belle&Sebastain

##### Senior Member
take the most tele end of the zoom divide by the the widest end.

55-200mm = 200/55 = 3.63 zoom

35-350mm = 350/35 = 10 zoom

28-135mm = 135/28 = 4.8 zoom

#### mpenza

##### Senior Member
Paul_Yeo said:
how to many the zoom in mm to the "x" one?

eg, what is 12x zoom equivalent to? 12x = 300mm??

actually, how to calculate one?
depends on the widest angle. there's no fixed value for cameras.

it's different for binoculars where the base is 50mm.

#### blurblock

##### Senior Member
Paul_Yeo said:
how to many the zoom in mm to the "x" one?

eg, what is 12x zoom equivalent to? 12x = 300mm??

actually, how to calculate one?
Use your longest end and divide by the widest end .... for example .... 28 - 300 = 300 / 28 = 10.7 = 11x

#### Paul_Yeo

##### Senior Member
OK got it! thanks

so my lens is
24-120 => 120/24 = 5x zoom
70-300mm => 300/70 = 4.2X zoom

#### espn

##### Deregistered
Paul_Yeo said:
OK got it! thanks

so my lens is
24-120 => 120/24 = 5x zoom
70-300mm => 300/70 = 4.2X zoom
Yeah, but pretty useless to calculate in zoom factor.

Your 70-300 is longer reach than your 24-120VR and yet it's only 4.2x vs 5x.

#### evq

##### Senior Member
majere2sg said:
I have a couple of 1x zoom.. :cry:
Hahaha.... :bsmilie:
But u should be the richest. :think:

#### dkw

##### New Member
Paul_Yeo said:
OK got it! thanks

so my lens is
24-120 => 120/24 = 5x zoom
70-300mm => 300/70 = 4.2X zoom
As ESPN says, for SLR lenses, is a pretty useless measure. More relevant to talk about focal lengths.

#### Paul_Yeo

##### Senior Member
so, it is more for compact camera huh.

i asked bcos i saw one Panasonic camera got 12x zoom.... that;s why me asked what's the "mm" equvialent loh. ;p

#### majere2sg

##### Senior Member
Paul_Yeo said:
so, it is more for compact camera huh.

i asked bcos i saw one Panasonic camera got 12x zoom.... that;s why me asked what's the "mm" equvialent loh. ;p
if you meant the panasonic fz20, its a 36-432mm lens (35mm equiv) lens. It is actually only 6-72mm but can achieved 36-432mm (35mm equiv) due to the 6x cropping from a smaller sensor size.

Status
Not open for further replies.