# how do u calculate the 35mm and zoom range?

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#### lunas

##### Senior Member
Hi,

I am confuse with how to calculate the mm with the number of times zoom?

And what is the indication for the mm? Is it millimeter?

Thanks

#### night86mare

##### Deregistered
I quote from this website (http://www.digicamhelp.com/learn/glossary/35mm-equivalent.php)

Most people are familiar with focal lengths of 35mm camera lenses. Digital camera manufacturers describe focal lengths in terms of the lens length on a 35mm camera that will produce a similar area of view.

Focal length on one 35mm camera is the same for all others because the size of the film each uses is the same. Digital cameras, however, have different focal lengths because the size of their image sensors vary from one camera to another. Expressing focal lengths in terms of 35mm equivalent makes it easier for individuals to understand so they can compare digital camera lenses.
Is this what you're looking for?

Basically if your starting mm is say, 35 mm, then 10 x zoom = 350 mm, etc

#### zoossh

##### Senior Member
zoom range = minimum to maximum focal range of lens, e.g. 20-120mm

no. of times of zoom = max/min focal length of lens , e.g. 120/20mm = 6x

35mm film = 1.0x conversion factor
depending on individual brand's conversion factor,
1.5x conversion factor in nikon DSLR will make a 20-120mm becomes 30-180mm

#### lunas

##### Senior Member
Thanks guys, so how do I translate this understanding into photo taking?

Seems like it is not really important as I have been taking pictures without the concern of the mm thingy.

Still blur..:dunno:

#### night86mare

##### Deregistered
nothing to do with photo taking
=D

it's just a translation to fit all cameras on a common measurement scale, if you get what i mean

why they use 35mm scale is because film cams were traditionally 35mm i think, correct me if i'm wrong

of course large values, ie. 200, 300 would indicate telephoto and small values = wide.. which would affect perspective and results, i'm sure you've seen how with your h5..

e.g. in 2 diff photos, even though same subject in same location and setting roughly same size, wide will capture more of the surroundings compared to telephoto

#### Maltese

##### New Member
zooms are a series of focal lengths. And focal lengths are usually an idea of the angle of degree in terms of wideness that u can capture. For eg. a fisheye will give u 180 degree. The bigger the focal lenght, the smaller the degree is.

Zooms are just a series of prime lenses' focal length combined together. Eg. Canon has a 35-350. i.e its has a 10x power. But that doesn't mean that if u have a 10 times zoom, your subject will be 10 times bigger.

Is that what u are asking?

I think what u actually want to know is at what focal length is best for taking specific photos is it?

#### CYRN

##### Senior Member
To keep to your question directly.

If you are using a P&S.. look at the exif data, it should give your the value of zoom in mm for the pic.

Dun worry about mm thingy just yet... unless you already into DOF/Bokeh/compression..etc. Juz concentrate on getting nice pics from your cam first... the rest are just theories.

#### zoossh

##### Senior Member
the focal length of your camera will affect mainly the framing of your subject in relation to your standing position/distance from the subject.

the practical point is just to note how far are you from the subject, and the size and type of subject in proportion to the framing, e.g. a portrait of the top from the chest up till a little space above the head in a vertical take taken from 2m away at the same eye level. this is a situation you may come across and a framing you may desire. and there is often similar focal lengths that will be required to take this situation at your desired framing.

people need to know the focal lengths becos it may be outside the capability of their camera/lens to shoot certain situations at their desired framing, and hence to know what upgrades can provide, e.g. shooting with 500mm focal length with new tele lens at birds from a distance.

in order to compare with a standardize method covering different sensor sizes, all is calculated in comparison with the traditional film as 35mm equivalence.

#### Yatlapball

##### Senior Member
Zoom to me means range. But range not as in maximum distance. 11x zoom does not equal to images appearing closer than a 5x zoom.

Even a 1200mm tele prime is considered 1x zoom So go figure...

#### lunas

##### Senior Member
Hey Guys,

Another question, refer to the picture, the information on the focal length is 9.8 mm.

What does this 9.8mm represent?

#### lunas

##### Senior Member
BTW, this picture of mine is taken by H5, and I find that there is some color problem. Like purple fringe and the image isn't sharp as I have used the smallest f8 aperture. ISO is 80

So if I get a DSLR will the image of this picture be better?

#### night86mare

##### Deregistered
BTW, this picture of mine is taken by H5, and I find that there is some color problem. Like purple fringe and the image isn't sharp as I have used the smallest f8 aperture. ISO is 80

So if I get a DSLR will the image of this picture be better?
if you get a good lens, i suppose so =D
sony h series does have the problem of purple fringing, i remember
of course dslr will also allow for more room for expansion as well
but consider carefully before you take the dive! (i refuse to, right now, for various reasons)

#### lunas

##### Senior Member
if you get a good lens, i suppose so =D
sony h series does have the problem of purple fringing, i remember
of course dslr will also allow for more room for expansion as well
but consider carefully before you take the dive! (i refuse to, right now, for various reasons)