# Len size???

Status
Not open for further replies.

#### club_de_oldman

##### New Member
Hello everyboby

I am new in photography and getting confuse over len size, like 35-250mm or something like 55-450mm...and so on, can anyone explain what does this figure mean??? :dunno:

Appreciate anyone can help :sweatsm:

#### Witness

##### Senior Member
35 , 50 ,200 etc refer to the focal lengths of ya lens.... sometime like a 2x 3x 12x digital zoom like tt....

450mm should be ard 12x zoom if i am not mistaken....

for SLRs there are zooms and primes (fixed focal lengths)....

explain ya question?

##### New Member
The longer the focal length, the further you can focus.
For 35-250mm zoom, it means you have (250/35) times zoom.

#### club_de_oldman

##### New Member
hey guys thanks for the help it does enlighten me right now I am using FZ10 with 12x zoom I have check the manue and Witness you are right 12 x = 450mm :thumbsup:

So I guess until I reach SLR than I need those lens :sweat:

Thanks again guys cheers

#### Xaler

##### New Member
The longer the focal length, the further you can focus.
For 35-250mm zoom, it means you have (250/35) times zoom.
Check out this link for a visual example.

#### showtime

##### New Member
The longer the focal length, the further you can focus.
this is false... all lenses can focus a distance of infinity...

#### espn

##### Deregistered
Witness said:
35 , 50 ,200 etc refer to the focal lengths of ya lens.... sometime like a 2x 3x 12x digital zoom like tt....

450mm should be ard 12x zoom if i am not mistaken....

for SLRs there are zooms and primes (fixed focal lengths)....

explain ya question?

The zoom factor is dependent on the wide and tele end values. You cannot assume 450mm = 12x zoom.

If the wide end is 45mm the zoom factor will be 10X. If the wide end is 100mm, then the zoom factor will be 4.5X.

In short, zoom factor is useless, the actual range is more useful in gauging if the camera / len is suitable for your usage.

#### blurblock

##### Senior Member
club_de_oldman said:
hey guys thanks for the help it does enlighten me right now I am using FZ10 with 12x zoom I have check the manue and Witness you are right 12 x = 450mm

So I guess until I reach SLR than I need those lens :sweat:

Thanks again guys cheers
Not excatly true ...... if your wide end starts at 10mm then 12x Zoom = 120mm only ... Exactly how high is 12x depends on the wide side of the lens actually. It just happens your wide side starts at 38mm or 37.5mm and thus your long side is 450mm

#### mervlam

##### Senior Member
espn said:
The zoom factor is dependent on the wide and tele end values. You cannot assume 450mm = 12x zoom.

If the wide end is 45mm the zoom factor will be 10X. If the wide end is 100mm, then the zoom factor will be 4.5X.

In short, zoom factor is useless, the actual range is more useful in gauging if the camera / len is suitable for your usage.
it's image magnification, not zoom factor. :nono:

#### mervlam

##### Senior Member
Witness said:
35 , 50 ,200 etc refer to the focal lengths of ya lens.... sometime like a 2x 3x 12x digital zoom like tt....

450mm should be ard 12x zoom if i am not mistaken....

for SLRs there are zooms and primes (fixed focal lengths)....

explain ya question?
that's absolutely wrong.. what espn posted is correct. pls dont mis-inform people.

#### Witness

##### Senior Member
oh ok...sorry bout tt....

#### club_de_oldman

##### New Member
wah dam deep ....this will take me awhile to understand :embrass:

You guys are great thanks

#### Xaler

##### New Member
Agree, it does take a while to "digest" (same for me initially).

Forget about how many times zoom, it doesn't say much technical info--only marketing guys make it sound like the world depends on maximum zoom power.

Know that the shorter focal lengths (e.g. 15mm) are wide-angles, you can see a lot--good for landscape. Of course all the objects look smaller. The longer focal lenghts (e.g. 300mm) are telephotos, you don't see much of the surrounding left and right, but you can see far--good for shooting birds. The objects are "larger" too.

So for your camera, it goes from 35-450? Means you can ZOOM from 35 (wide) to 450 (telephoto). The lenses that gives best quality have fixed focal lengths (i.e. cannot zoom; or 1x zoom!).

#### club_de_oldman

##### New Member
Thanks man,

So, the first digi (35mm) is for the angle and next digi (300mm) is for the length, like zoom distance.....

Hope I am right ! :sweat:

#### Xaler

##### New Member
club_de_oldman said:
Thanks man,

So, the first digi (35mm) is for the angle and next digi (300mm) is for the length, like zoom distance.....

Hope I am right ! :sweat:
Just refer to this link. This is assuming you're standing on the same spot but with different focal lengths. *click* on the different focal lengths and see the difference it makes (Note: I've no affiliation to Canon whatsoever, I just find it a very good interactive example).

#### singscott

##### New Member
Ayo people can miss inform and complicate thing man. When we put 24-70mm mean it is a zoom lens that you can zoom from 24mm (the widest focus length) to 70mm (the longest focus length). Focus length is not equal to zoom factor :bsmilie:

#### Ah_Seng

##### New Member
Why am I seeing stars now???

Ok....let's say I have a Sigma 28-300mm (f3.5-f6.3) lens, and there's another Sigma 70-200mm (f2.8) in the market as well, does it make sense to buy that 70-200mm lens, if I don't need that f2.8?

Or if I buy, it would be becos of that f2.8 for shallower depth of field?

Seeing more stars now...... :bigeyes: :dunno: :bigeyes:

#### Witness

##### Senior Member
2.8 will make the lens faster.....i.e with the bigger aperature u can achieve higher shutter speeds....

if u dun need the 2,8 then i kind of dun make sense lo.... having a big max aperature gives the flexibility in using the lens...

#### Xaler

##### New Member
eagles_creek said:
Why am I seeing stars now???

Ok....let's say I have a Sigma 28-300mm (f3.5-f6.3) lens, and there's another Sigma 70-200mm (f2.8) in the market as well, does it make sense to buy that 70-200mm lens, if I don't need that f2.8?

Or if I buy, it would be becos of that f2.8 for shallower depth of field?

Seeing more stars now...... :bigeyes: :dunno: :bigeyes:
No, it wouldn't make sense to get the 70-200mm f2.8 if you don't need it ;p
f2.8 gives a shallower depth of field and it's also a fast lens as Witness mentioned. Either way, you'll find that a wide aperture does come in handy.

The 28-300mm is a good general lens but you might want to think of upgrading in the future. I have a Tamron 28-200mm f3.8-5.6, it's adequate, but not great.

Status
Not open for further replies.