Go Back   Steve's Digicams Forums >

LinkBack Thread Tools Search this Thread
Old Oct 7, 2004, 7:00 AM   #1
Junior Member
tomdude's Avatar
Join Date: Sep 2004
Posts: 20

First of all, thanks to all of you who have answered my previous questions! I'm REALLY REALLY new at this! My Optio S40 is taking really dark flash pictures, especially at dusk and inside lower lights. It's worse when we use the crappy 3x zoom. I'm finding out 3x is really a bad excuse for the word zoom! Any way to correct this before I throw the camera (or myself) in the trash?
tomdude is offline   Reply With Quote
Sponsored Links
Old Oct 7, 2004, 10:59 AM   #2
JimC's Avatar
Join Date: Jun 2003
Location: Savannah, GA (USA)
Posts: 22,378

The lens on yourPentax is rated at f/2.6-4.8.

This is actually a fraction better than the lens on many subcompact models (typically they are around f/2.8-4.9)

This is the way lensesare rated (maximum aperture at wide angle, and maximum aperture at full zoom). A larger aperture (respresented by a smaller f/stop number) allows more light to reach the sensor through the lens.

The aperture scale (in one stop increments) goes F/1.4, F/2.0, F/2.8, F/4.0, F/5.6, F/8.0, F/11, F/16, F/22... With each one stop move to a smaller aperture (represented by larger f/stop numbers), you will need shutter speeds twice as long for proper exposure (or twice as much light for the same shutter speeds).

The lens on your model is more than twice as bright at it's wide angle setting, versus it's full zoom setting. This is typical for subcompact cameras.

As a result, the flash range is lower using zoom, too. The flash on your model is rated at 11.5ft(3.5m), dropping down as more zoom is used to6.6ft (2m)at full zoom.

This is an Auto ISO rating (so, the camera is probably increasing ISO speed to get this much range). Each time you double the ISO speed, the flash range increases by 1.4x. But, increasing ISO speed also increases noise levels (this is amplifying the signal from the camera's sensor, which also amplifies noise).

Unfortunately, you can't expect to get great flash range from a small camera with a tiny lens and flash.

If you don't want to get underexposed photos, you'll need to stay within the rated flash range (and the same applies to any other camera you are using the flash with).

As far as your dusk photos, unless you are taking photos of someone very close to the camera, flash is useless (and will give you worse performance outdoors).

What is bright to the human eye, is not to the camera's lens. For dusk photos of landscapes, etc., you'll probaby want to force the flash off (so that the camera can use slower shutter speeds for proper exposure). A tripod may be needed to keep from getting motion blur from camera shake this way (depending on how low the light is). Using a tripod will also allowyou to set the ISO speed lower so that you'll get better photos with lower noise, too.

With your existing model, if you refrain from using zoom indoors, you'll get better results and increase your flash range (as in the specifications above). You may also want to consider a slave flash for it. These units are designed to fire at the same time as the camera's main flash.

JimC is offline   Reply With Quote

Thread Tools Search this Thread
Search this Thread:

Advanced Search

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are On
Pingbacks are On
Refbacks are On

All times are GMT -5. The time now is 12:14 PM.