f1.2 vs. f1.4

[Brian]

Hi, I've been looking for a good 50mm or 85mm portrait lens and have noticed
the huge cost difference between the f1.2 and f1.4. Is there that much
difference?

[Randall Ainsworth]

> Hi, I've been looking for a good 50mm or 85mm portrait lens and have noticed

> the huge cost difference between the f1.2 and f1.4. Is there that much
> difference?

No.

[Jan Philips]

On Fri, 05 Sep 2003 23:35:52 GMT, "Brian" <schoolcbSPAM@earthlink.net>
wrote:

>Hi, I've been looking for a good 50mm or 85mm portrait lens and have noticed
>the huge cost difference between the f1.2 and f1.4. Is there that much
>difference?

It is half a stop. Usually that would make a difference only in
situations with pretty low light. I would recommend the 1.4 unless
you shoot in very low light.

[David]

is it 1/2 a stop? don't know for sure, but questioning.

my guess is that the money difference is not just paying for the faster
f-stop. probably better construction/glass. also, does the 1.2 have macro
features?

David

"Jan Philips" <judmccr@bellsouth.net> wrote in message
news:4ojilvcemdj6l5i9vld2qmn08bfbm36md1@4ax.com...

> On Fri, 05 Sep 2003 23:35:52 GMT, "Brian" <schoolcbSPAM@earthlink.net>
> wrote:
>

> >Hi, I've been looking for a good 50mm or 85mm portrait lens and have

noticed

> >the huge cost difference between the f1.2 and f1.4. Is there that much
> >difference?

>
> It is half a stop. Usually that would make a difference only in
> situations with pretty low light. I would recommend the 1.4 unless
> you shoot in very low light.
>

[Jan Philips]

On Sat, 6 Sep 2003 08:51:54 -0400, "David"
<dkbowmanspamisreallyannoying@cox.net> wrote:

>is it 1/2 a stop? don't know for sure, but questioning.

Yes, approximately. f/1.414 is a full stop slower than f/1 and
f/1.189 is half stop slower than f/1 and half stop faster than
f/1.414.

[Kev]

Depends on your application. For when I shoot sports indoors yes
there is a difference as I am wide open at times to be able to capture
the action. FOr portraits no the 1.4 is fine. Heack a F4 is fine as
you are using strobes anyway.

Kev


On Fri, 05 Sep 2003 23:35:52 GMT, "Brian" <schoolcbSPAM@earthlink.net>
wrote:

>Hi, I've been looking for a good 50mm or 85mm portrait lens and have noticed
>the huge cost difference between the f1.2 and f1.4. Is there that much
>difference?
>

[Randall Ainsworth]

> Depends on your application. For when I shoot sports indoors yes

> there is a difference as I am wide open at times to be able to capture
> the action. FOr portraits no the 1.4 is fine. Heack a F4 is fine as
> you are using strobes anyway.

You're not going to see an appreciable difference in low light
situations. It's not even half a stop.

[Slingblade]

On Fri, 05 Sep 2003 23:35:52 GMT, "Brian" <schoolcbSPAM@earthlink.net>
wrote:

>Hi, I've been looking for a good 50mm or 85mm portrait lens and have noticed
>the huge cost difference between the f1.2 and f1.4. Is there that much
>difference?

Assumming you're talking about 35mm cameras here...

50mm really isn't a "portrait lens". It's just the "standard" lense.
85mm is a great focal length for portraits...and most brands offer
their 85mm in f1.2 and f1.8. For the average person, I'd say the f1.8
would be more than sufficient. Unless you are doing this for a living
and are making good money, I doubt you'd want to spend the extra money
for the faster lens. Yes, it'd be great to have that little bit
larger aperture in some situations, but there's a good chance you'd
never use it fully open.

[Jan Philips]

On Sat, 06 Sep 2003 11:12:17 -0700, Randall Ainsworth
<rag@nospam.techline.com> wrote:

> You're not going to see an appreciable difference in low light
>situations. It's not even half a stop.

Comparing exactly f/1.2 to exactly f/1.4; f/1.2 is 0.4478 stop faster,
but in practice the 1.2 and 1.4 are rounded off. Half stop faster
than f/1.4 is called f/1.2.

[Frank]

Comparing exactly f/1.2 to exactly f/1.4; f/1.2 is 0.4478 stop faster,
but in practice the 1.2 and 1.4 are rounded off. Half stop faster
than f/1.4 is called f/1.2.[/QUOTE]

I believe it is 1/3 stop.
The stop can be aslo defined as the area of opened aperture, and the area is propotion (to the power of 2) to the diameter of a circle. 1.4 ^2 /1.2 ^ 2 = 1.36 .
so, it is about 1/3 stop.