flash and slow focus lenses

[Rob]

Archived from groups: rec.photo.digital (More info?)

I'm new to buying lenses so I need some advice. I'm considering
buying a Tamron 28-75 lens and some of its reviews say it's a tad slow
sometimes focusing in low light. I presume a flash will help the lens
focus faster, right? I presume this is because the flash eliminates
the low light condition. Are there any other reasons?

 

[roy]

Archived from groups: rec.photo.digital (More info?)

<Rob> wrote in message news:flu8h1547efaclmj7dhrrgmikf3fshvvot@4ax.com...
> I'm new to buying lenses so I need some advice. I'm considering
> buying a Tamron 28-75 lens and some of its reviews say it's a tad slow
> sometimes focusing in low light. I presume a flash will help the lens
> focus faster, right? I presume this is because the flash eliminates
> the low light condition. Are there any other reasons?


Oh No, it won't.

Electronic flash has a duration of about 1 thousandth of a sec at maximum
power, and cosiderable shorter times at below maximum power.

It will fire when the shutter is fully open, (or the electronic equivalent
of a fully open shutter), so the lens will need to have completed focus
before then, or you would get an out of focus shot.

Some of the add on Flashes have a Focus Assist Lamp, which will be more
powerful than the Cameras. That might help, but not by much.

I would not get over bothered about reviews which claim such and such a lens
is a tad slow at AF, unless of course every reviewer said it was
unacceptably slow.

What are you planning to shoot in low light with it, rapidly moving
subjects?

Roy G

 

[Rob]

Archived from groups: rec.photo.digital (More info?)

On Wed, 31 Aug 2005 00:45:44 GMT, "Roy"
<royphoty@iona-guesthouse.co.uk> wrote:

><Rob> wrote in message news:flu8h1547efaclmj7dhrrgmikf3fshvvot@4ax.com...
>> I'm new to buying lenses so I need some advice. I'm considering
>> buying a Tamron 28-75 lens and some of its reviews say it's a tad slow
>> sometimes focusing in low light. I presume a flash will help the lens
>> focus faster, right? I presume this is because the flash eliminates
>> the low light condition. Are there any other reasons?
>
>
>Oh No, it won't.
>
>Electronic flash has a duration of about 1 thousandth of a sec at maximum
>power, and cosiderable shorter times at below maximum power.
>
>It will fire when the shutter is fully open, (or the electronic equivalent
>of a fully open shutter), so the lens will need to have completed focus
>before then, or you would get an out of focus shot.
>
>Some of the add on Flashes have a Focus Assist Lamp, which will be more
>powerful than the Cameras. That might help, but not by much.
>
>I would not get over bothered about reviews which claim such and such a lens
>is a tad slow at AF, unless of course every reviewer said it was
>unacceptably slow.
>
>What are you planning to shoot in low light with it, rapidly moving
>subjects?
>
>Roy G
>

No, just family groups at night in a dim or adequately lit living
room. I don't think they will move much because they'd be posing for
the group shot.

 

[Ryan]

Archived from groups: rec.photo.digital (More info?)

Rob wrote:
>
> I'm new to buying lenses so I need some advice. I'm considering
> buying a Tamron 28-75 lens and some of its reviews say it's a tad slow
> sometimes focusing in low light. I presume a flash will help the lens
> focus faster, right? I presume this is because the flash eliminates
> the low light condition. Are there any other reasons?


I have the F-mount version of this lens. While most of my photos occur
before dusk, I've used it at night also. I've not noticed trouble with
it focussing. I did recently shoot a wedding reception which was
indoors and for a large portion of it the lights were off except around
the edges. My outboard flash illuminates AF assist with a red lamp that
isn't too distracting and I nailed around 200 photographs of dancing
people this way. The focus in this circumstance was the same as what I
am accustomed to during the day.

 

[Guest]

Archived from groups: rec.photo.digital (More info?)

In article <431644BD.245B1746@yahoo.com>, Ryan
<quakeserver149@yahoo.com> wrote:

> I have the F-mount version of this lens. While most of my photos occur
> before dusk, I've used it at night also. I've not noticed trouble with
> it focussing. I did recently shoot a wedding reception which was
> indoors and for a large portion of it the lights were off except around
> the edges. My outboard flash illuminates AF assist with a red lamp that
> isn't too distracting and I nailed around 200 photographs of dancing
> people this way. The focus in this circumstance was the same as what I
> am accustomed to during the day.

200 shots of just people dancing? Jeez...be discriminating.